tag:blogger.com,1999:blog-23099071469973722022024-03-05T17:17:30.276+00:00BillysuggerAnything that comes to mind...Billysuggerhttp://www.blogger.com/profile/10673508741175504300noreply@blogger.comBlogger37125tag:blogger.com,1999:blog-2309907146997372202.post-89200067360344260592015-10-14T02:59:00.000+01:002015-10-14T02:59:58.782+01:00Interstellar Radio Propagation<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhercaS2B5soM-89-XciZk0L5I5GC3sL1jXWS5N9nAYKxDMBQb_F89DUjq5SviYwxuE6SVTHDSBrkhWQEqoInk7sx9MgTlPDjPJV_DALvnURmfzvGz2NTUQDmK5iQyRJVilm41Qr2RxzVB9/s1600/Proxima+Centauri.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><span style="font-family: Arial, Helvetica, sans-serif; font-size: x-small;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhercaS2B5soM-89-XciZk0L5I5GC3sL1jXWS5N9nAYKxDMBQb_F89DUjq5SviYwxuE6SVTHDSBrkhWQEqoInk7sx9MgTlPDjPJV_DALvnURmfzvGz2NTUQDmK5iQyRJVilm41Qr2RxzVB9/s1600/Proxima+Centauri.jpg" /></span></a></div>
<div style="text-align: center;">
<span style="font-family: Arial, Helvetica, sans-serif; font-size: x-small;"><span style="font-family: "Arial","sans-serif"; mso-bidi-font-size: 11.0pt;"><span style="font-size: xx-small;">Proxima Centauri: The Closest Star. <o:p></o:p></span></span><br />
<span style="font-size: xx-small;"><span style="font-family: Times New Roman;">
</span><span style="font-family: "Arial","sans-serif"; mso-bidi-font-size: 11.0pt;">Credit & Copyright:<span style="mso-spacerun: yes;"> </span>David Malin, UK Schmidt Telescope, DSS, AAO<o:p></o:p></span></span><br />
<span style="font-family: Times New Roman; font-size: xx-small;">
</span></span></div>
<span style="font-family: Arial; font-size: x-small;"><span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;"></span><br />
<span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;">It's a staple of Science Fiction, and an
unquestioned fact of our modern age, that aliens could be listening to our
radio and watching our TV broadcasts, as our signals race across the galaxy at
the speed of light.<span style="mso-spacerun: yes;"> </span>They could be
studying our weaknesses, preparing their attack!<span style="mso-spacerun: yes;"> </span>But really, is that possible?</span><br />
<div class="MsoNoSpacing" style="margin: 0cm 0cm 0pt;">
<span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;"></span> </div>
<div class="MsoNoSpacing" style="margin: 0cm 0cm 0pt;">
<span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;"></span><span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;">I have long been fascinated by the
possibility of finding life beyond our solar system, or of aliens finding
us.<span style="mso-spacerun: yes;"> </span>But rather than wishful thinking,
scaremongering or falling for alien abduction tales, I'm far more interested in
the realistic prospects of such a discovery.<span style="mso-spacerun: yes;">
</span>So when Prof. Brian Cox threw down the gauntlet for listeners to BBC
Radio 4's <a href="http://www.bbc.co.uk/programmes/b00snr0w" target="_blank">The Infinite Monkey Cage</a> to carry out a fundamental but accessible
calculation to illustrate the real likelihood of one form of contact, I was
fascinated.</span></div>
<div class="MsoNoSpacing" style="margin: 0cm 0cm 0pt;">
<span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;"></span> </div>
<div class="MsoNoSpacing" style="margin: 0cm 0cm 0pt;">
<span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;"></span><span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;">Episode 5 of Series 12 was broadcast on 3
August 2015, and I heard it several weeks later via the show's podcast
feed.<span style="mso-spacerun: yes;"> </span>The previous week's episode
focussed on extra-terrestrial life and alien contact, but <a href="http://www.bbc.co.uk/programmes/b063zx1g" target="_blank">Episode 5</a>
concentrated on speed, including land speed record attempts as well as the
fundamental barrier in physics that is the speed of light.</span></div>
<div class="MsoNoSpacing" style="margin: 0cm 0cm 0pt;">
<span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;"></span> </div>
<div class="MsoNoSpacing" style="margin: 0cm 0cm 0pt;">
<span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;"></span><span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;">If you want to download and listen to the
episode yourself, at 38m 38s, presenter Robin Ince asks about radio signals
leaking into space and Professor Danielle George, of University of Manchester,
describes broadcast transmissions degrading in power with the inverse square
law. Then Robin asks Brian Cox to calculate how far away through space their
own radio broadcast would be detectable. Prof. Cox ad lib ponders the problem and then
defines the listeners' challenge, which I summarise here:</span></div>
<div class="MsoNoSpacing" style="margin: 0cm 0cm 0pt;">
<span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;"></span><span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;"></span><blockquote class="tr_bq">
<em>"Suppose a 200kW transmitter broadcasts for 1 second
at 198kHz, find the distance at which there remains one photon per square
metre."</em></blockquote>
<br /></div>
</span><span style="font-family: Arial; font-size: x-small;"><div class="MsoNoSpacing" style="margin: 0cm 0cm 0pt;">
<span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;">Now, we can argue the merits of this
threshold, whether one photon per second per square metre is easy or unduly
difficult for advanced aliens to detect, (and I shall return to this
question).<span style="mso-spacerun: yes;"> </span>But for now, let's solve the
problem.</span></div>
<span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;"></span><br />
<span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;"></span><span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;">First, we need to know how many photons of
radio energy are transmitted in one second.<span style="mso-spacerun: yes;">
</span>Then we need to find the distance at which all these photons are spread
out to one per square metre.</span><br />
<div class="MsoNoSpacing" style="margin: 0cm 0cm 0pt;">
<span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;"></span> </div>
<div class="MsoNoSpacing" style="margin: 0cm 0cm 0pt;">
<span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;"></span><span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;">So let's do it...<span style="mso-spacerun: yes;"> </span>First, let's define some parameters and
constants:<o:p></o:p></span></div>
<span style="font-family: Times New Roman; font-size: small;">
</span><br />
<span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;"><div class="MsoNoSpacing" style="margin: 0cm 0cm 0pt;">
<span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;">Transmitted power,<span style="mso-tab-count: 1;"> </span>P = 200kW<o:p></o:p></span></div>
<div class="MsoNoSpacing" style="margin: 0cm 0cm 0pt;">
<span style="font-family: Times New Roman; font-size: small;">
</span><span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;">Frequency,<span style="mso-tab-count: 2;"> </span>f
= 198kHz<o:p></o:p></span></div>
<div class="MsoNoSpacing" style="margin: 0cm 0cm 0pt;">
<span style="font-family: Times New Roman; font-size: small;">
</span><span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;">Planck's constant,<span style="mso-tab-count: 1;"> </span>h = 6.6x10<sup>-34</sup>Js</span></div>
<div class="MsoNoSpacing" style="margin: 0cm 0cm 0pt;">
<span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;"></span> </div>
<div class="MsoNoSpacing" style="margin: 0cm 0cm 0pt;">
<span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;"></span><span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;">As Prof. Cox helpfully reminded us, the
energy of a photon is given by its frequency multiplied by Planck's constant,
so</span></div>
<div class="MsoNoSpacing" style="margin: 0cm 0cm 0pt;">
<span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;"></span> </div>
<div class="MsoNoSpacing" style="margin: 0cm 0cm 0pt;">
<span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;"></span><span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;">Photon energy,<span style="mso-tab-count: 2;"> </span>E = hf</span></div>
</span><div class="MsoNoSpacing" style="margin: 0cm 0cm 0pt;">
<span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;"></span> </div>
<div class="MsoNoSpacing" style="margin: 0cm 0cm 0pt;">
<span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;">So each photon at 198kHz carries 198x10<sup>3</sup>
x 6.6x10<sup>-34</sup> = 1.3x10<sup>-28</sup>J of energy.</span></div>
<div class="MsoNoSpacing" style="margin: 0cm 0cm 0pt;">
<span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;"></span> </div>
<div class="MsoNoSpacing" style="margin: 0cm 0cm 0pt;">
<span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;"></span><span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;">And since a power of 200kW delivers precisely
200kJ of energy per second, in one second the transmitter delivers 200kJ of
energy.</span></div>
<div class="MsoNoSpacing" style="margin: 0cm 0cm 0pt;">
<span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;"></span> </div>
<div class="MsoNoSpacing" style="margin: 0cm 0cm 0pt;">
<span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;"></span><span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;">So we divide the energy transmitted by the
energy per photon to find the number of photons transmitted.</span></div>
<div class="MsoNoSpacing" style="margin: 0cm 0cm 0pt;">
<span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;"></span> </div>
<div class="MsoNoSpacing" style="margin: 0cm 0cm 0pt;">
<span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;"></span><span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;">Number of photons, N = 200x10<sup>3</sup> / 1.3x10<sup>-28</sup>
= 1.25x10<sup>33</sup> photons.</span></div>
<div class="MsoNoSpacing" style="margin: 0cm 0cm 0pt;">
<span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;"></span> </div>
<div class="MsoNoSpacing" style="margin: 0cm 0cm 0pt;">
<span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;"></span><span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;">That's an awful lot of photons!<span style="mso-spacerun: yes;"> </span>So now we need to spread these photons out
over a sphere to the point where there's one square metre of area on the sphere
for each photon.</span></div>
<div class="MsoNoSpacing" style="margin: 0cm 0cm 0pt;">
<span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;"></span> </div>
<div class="MsoNoSpacing" style="margin: 0cm 0cm 0pt;">
<span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;">T</span><span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;">he area of a sphere, A = 4πr<sup>2</sup> m<sup>2</sup>,
where r is the radius of the sphere.</span></div>
<div class="MsoNoSpacing" style="margin: 0cm 0cm 0pt;">
<span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;"></span> </div>
<div class="MsoNoSpacing" style="margin: 0cm 0cm 0pt;">
<span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;">S</span><span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;">o, a sphere with an area of 1.25x10<sup>33</sup>
is given by the equation 1.25x10<sup>33</sup> = 4πr<sup>2</sup>.</span></div>
<div class="MsoNoSpacing" style="margin: 0cm 0cm 0pt;">
<span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;"></span> </div>
<div class="MsoNoSpacing" style="margin: 0cm 0cm 0pt;">
<span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;"></span><span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;">Rearranging this to find r gives, r = √( 1.25x10<sup>33</sup>
/ 4π ) = 1.0x10<sup>16</sup> metres.</span></div>
<div class="MsoNoSpacing" style="margin: 0cm 0cm 0pt;">
<span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;"></span> </div>
<div class="MsoNoSpacing" style="margin: 0cm 0cm 0pt;">
<span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;"></span><span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;">That's an unfeasibly large distance by human
standards, but on the astronomical distance scale, it's almost exactly one
light year!</span></div>
<div class="MsoNoSpacing" style="margin: 0cm 0cm 0pt;">
<span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;"></span> </div>
<div class="MsoNoSpacing" style="margin: 0cm 0cm 0pt;">
<span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;"></span><span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;">So once the Radio 4 long wave signal
broadcasting The Infinite Monkey Cage gets to a light year from Earth, it will
comprise only one photon per square metre, per second.<span style="mso-spacerun: yes;"> </span>And by Brian Cox's criterion, it will have
degraded to the point of undetectability.</span></div>
<div class="MsoNoSpacing" style="margin: 0cm 0cm 0pt;">
<span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;"></span> </div>
<div class="MsoNoSpacing" style="margin: 0cm 0cm 0pt;">
<span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;"></span><span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;">Now bear in mind that the nearest extra-solar
star, pictured above, is Proxima Centauri which is 4.2 light years away.<span style="mso-spacerun: yes;"> </span>And if that was conducive to intelligent
life, which it is not, our signal would not make it a quarter of the way there.<span style="mso-spacerun: yes;"> </span>So by this criterion, which is not unreasonable
at all, we are to all intents and purposes radio silent to any alien life out
there, as far as commercial broadcast transmissions are concerned.</span></div>
<div class="MsoNoSpacing" style="margin: 0cm 0cm 0pt;">
<span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;"></span> </div>
<div align="center" class="MsoNoSpacing" style="margin: 0cm 0cm 0pt;">
<span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;">=====</span></div>
<div class="MsoNoSpacing" style="margin: 0cm 0cm 0pt;">
<span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;"></span> </div>
<div class="MsoNoSpacing" style="margin: 0cm 0cm 0pt;">
<span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;"></span><span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;">So now, how reasonable is this as a
limit?<span style="mso-spacerun: yes;"> </span>Can we find an argument which
breaks this?</span></div>
<div class="MsoNoSpacing" style="margin: 0cm 0cm 0pt;">
<span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;"></span> </div>
<div class="MsoNoSpacing" style="margin: 0cm 0cm 0pt;">
<span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;"></span><i style="mso-bidi-font-style: normal;"><span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;">One
photon per square metre per second seems like an arbitrary limit, why can't
advanced aliens detect those?</span></i><span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;"> Well, as advanced
as aliens might be, there has to be a signal to receive.<span style="mso-spacerun: yes;"> </span>The bandwidth of an audio signal is a few
kHz, which means that you'd need <i style="mso-bidi-font-style: normal;">at least</i>
5,000 samples per second to reconstruct the transmitted signal.<span style="mso-spacerun: yes;"> </span>And that's not a technological limit, which advanced
civilizations could surpass, it's a fundamental information limit.<span style="mso-spacerun: yes;"> </span>Worse still, one photon carries no amplitude
information, so unless the reconstruction is to be distorted beyond use, they
would need to detect many photons per sample. <span style="mso-spacerun: yes;"> </span>A good signal would use several hundred
amplitude levels, but you could get away with perhaps 20 or so.<span style="mso-spacerun: yes;"> </span>So now, to reconstruct a useful signal, you'd need 100,000
photons per second.<span style="mso-spacerun: yes;"> </span>At just one light
year, that would require a receiving antenna with an area of 100,000m<sup>2</sup>,
or a <i style="mso-bidi-font-style: normal;">perfect</i> dish with a diameter of 350
metres (1,200 feet).</span></div>
<div class="MsoNoSpacing" style="margin: 0cm 0cm 0pt;">
<span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;"></span> </div>
<div class="MsoNoSpacing" style="margin: 0cm 0cm 0pt;">
<span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;"></span><i style="mso-bidi-font-style: normal;"><span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;">But
aliens have limitless capabilities, because... well, aliens! So they could
build a 350 metre dish.</span></i><span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;"><span style="mso-spacerun: yes;">
</span>Well, perhaps.<span style="mso-spacerun: yes;"> </span>But now consider
that signal power drops with the square of distance, and dish area increases with
the square of diameter.<span style="mso-spacerun: yes;"> </span>So double the
distance, double the dish diameter.<span style="mso-spacerun: yes;">
</span>There are plenty of stars nearby, but to find one which can possibly be
inhabited by life which could evolve to sufficient intelligence, we need to
look tens of light years away. Say fifty light years.<span style="mso-spacerun: yes;"> </span>So now they need a dish fifty times bigger,
that's 18km (11 miles) across.<span style="mso-spacerun: yes;"> </span>And to
search their neighbourhood to a fifty light year radius, they'd need to steer
that, and keep it adequately parabolic too.<span style="mso-spacerun: yes;">
</span>Consider too that fifty light years is on the extreme edge of optimism
for reasonable numbers to plug into the Drake Equation, and the probability of
another technologically advanced lifeform existing within 50 light years from
us is not zero, but it must be very, very low.</span></div>
<div class="MsoNoSpacing" style="margin: 0cm 0cm 0pt;">
<span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;"></span> </div>
<div class="MsoNoSpacing" style="margin: 0cm 0cm 0pt;">
<span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;"></span><i style="mso-bidi-font-style: normal;"><span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;">So
what about higher powered transmitters?</span></i><span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;"><span style="mso-spacerun: yes;"> </span>The 200kW BBC Radio 4 long wave transmitter is
fairly typical for its waveband.<span style="mso-spacerun: yes;"> </span>The
Europe 1 transmitter in Germany is about the most powerful long wave
transmitter on the planet, pushing out 2000kW at 183kHz.<span style="mso-spacerun: yes;"> </span>That'll increase range by about three times,
to 3 light years.<span style="mso-spacerun: yes;"> </span>In terms of astronomy,
that half an order of magnitude<span style="mso-spacerun: yes;"> </span>and makes
little difference to the feasibility of being heard.<span style="mso-spacerun: yes;"> </span>It increases Brian Cox's limit from a light
year to three, still well short of Proxima Centauri.</span></div>
<div class="MsoNoSpacing" style="margin: 0cm 0cm 0pt;">
<span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;"></span> </div>
<div class="MsoNoSpacing" style="margin: 0cm 0cm 0pt;">
<span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;"></span><i style="mso-bidi-font-style: normal;"><span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;">How
about other wavebands?</span></i><span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;"><span style="mso-spacerun: yes;">
</span>Our atmosphere only allows through certain wavebands.<span style="mso-spacerun: yes;"> </span>Long wave will get through, short wave will
not.<span style="mso-spacerun: yes;"> </span>Above that, VHF radio and UHF TV
transmissions can get through, but as frequency increases, so does the energy
in each photon.<span style="mso-spacerun: yes;"> </span>So at higher
frequencies, the number of photons for the same power is proportionately less,
and so the range to receive sufficient photons to reconstruct the transmitted
signal reduces too.<span style="mso-spacerun: yes;"> </span>The upshot is, signals
at frequencies above long wave will be undetectable closer rather than farther
out.</span></div>
<div class="MsoNoSpacing" style="margin: 0cm 0cm 0pt;">
<span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;"></span> </div>
<div class="MsoNoSpacing" style="margin: 0cm 0cm 0pt;">
<span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;"></span><i style="mso-bidi-font-style: normal;"><span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;">You've
only considered omni-directional signals, how about directed beams?</span></i><span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;"><span style="mso-spacerun: yes;"> </span>Well, yeah.<span style="mso-spacerun: yes;">
</span>If you're talking SETI listening to the equivalent of Arecibo, then
that's a different question entirely.<span style="mso-spacerun: yes;">
</span>What I'm talking about is our routine commercial broadcast
transmissions.<span style="mso-spacerun: yes;"> </span>Many of those are
vaguely directed, particularly the higher frequency transmissions.<span style="mso-spacerun: yes;"> </span>And those already suffer from worse propagation
issues than long wave.<span style="mso-spacerun: yes;"> </span>But it's true
that a directed transmission is more powerful than an omni-directional one,
(one which transmits equal power in all directions).<span style="mso-spacerun: yes;"> </span>And although the power density increases in the transmitted direction, the area of
sky covered reduces, reducing the likelihood of any receiver within range
detecting the signal.<span style="mso-spacerun: yes;"> </span>So directed
broadcast transmissions don't help us.</span></div>
<div class="MsoNoSpacing" style="margin: 0cm 0cm 0pt;">
<span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;"></span> </div>
<div align="center" class="MsoNoSpacing" style="margin: 0cm 0cm 0pt;">
<span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;">=====</span></div>
<div class="MsoNoSpacing" style="margin: 0cm 0cm 0pt;">
<span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;"></span> </div>
<div class="MsoNoSpacing" style="margin: 0cm 0cm 0pt;">
<span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;"></span><span style="font-family: "Arial","sans-serif"; font-size: 10pt; mso-bidi-font-size: 11.0pt;">Finally, let me be clear: I'm not saying that
it's <i style="mso-bidi-font-style: normal;">impossible</i> for our transmissions
to be detected by alien civilisations, if they exist.<span style="mso-spacerun: yes;"> </span>But what I am saying is that the above is a
reasoned argument supported by calculation that it's very, very
improbable that there could be any within receiving range.<span style="mso-spacerun: yes;"> </span>It's just not as easy as
E.T. sitting on a planet orbiting, say, Tau Ceti with his transistor radio,
listening to <em>Hancock's Half Hour</em> or <em>I Love Lucy</em>.<span style="mso-spacerun: yes;"> </span>If we're going to make contact with
technological civilisations, we'll need a highly funded, planned and directed
effort.<span style="mso-spacerun: yes;"> </span>Trusting on radio broadcasts leaking into
space isn't going to cut it.<o:p></o:p></span></div>
<span style="font-family: Times New Roman; font-size: small;">
</span></span><br />
Billysuggerhttp://www.blogger.com/profile/10673508741175504300noreply@blogger.com1tag:blogger.com,1999:blog-2309907146997372202.post-33042135668952418782015-02-23T15:14:00.000+00:002015-02-23T15:14:32.764+00:00The etymology of DonutWhen my young daughter said or did something worthy of the name, I would call her a <i>silly sausage</i>, as an innocuous, playful tease. So when my son became old enough, (he was born in 2000), I used the same phrase. But he objected to it, not wanting to be called a <i>sausage</i>. Not wanting to upset him, I tried to think of another fun, food related play-name. We all like donuts, so I picked that and he seemed to prefer it. If he spilled his drink, or teased his sister, or made a joke, I'd call him a <i>donut</i>.<br />
<br />
He and I even came up with a silly song together:<br />
<br />
<div style="text-align: center;">
You're a donut, you're a donut,</div>
<div style="text-align: center;">
you'd be doing quite well if you had a brain cell,</div>
<div style="text-align: center;">
you're a donut, you're a donut...</div>
<br />
I'd never heard the term used in that context before, but it was picked up by other family members. We travelled the UK, from the south coast of England to Scotland, through cities and theme parks, and never thought once of the influence we may be having on our language as we may have been overheard.<br />
<br />
A few years ago I heard Al Murray use the expression on TV, and wondered where he heard it. Then last week, I heard it on Eastenders too. I mentioned it to my son, who looked up the origin. He found a couple of sources, not before the early 2000s, one in Scotland and one in southern England.<br />
<br />
So I'm wondering, did I coin the term <i>donut</i>, as a playful name for a silly person?Billysuggerhttp://www.blogger.com/profile/10673508741175504300noreply@blogger.com0tag:blogger.com,1999:blog-2309907146997372202.post-75875818446693349432014-09-28T02:24:00.002+01:002015-10-14T03:03:30.514+01:00Hiccups - and their cure<i>This post is a re-publication of an article I posted on my website many years ago. I have used the cure below successfully many times on many people. I am yet to find a case of hiccups this will not cure.</i><br />
<br />
<b>Health Warning</b> - I am no medical expert, please consult one if you need assistance. If you have good cause to enlighten me, please comment below. I will gladly
consider warranted corrections.
<br />
<i><br />
</i><br />
<div class="header">
<b>Hiccups</b></div>
There is quite a mystery about hiccups. Medical knowledge seems to be rather
limited about their causes, and cures. So it is not surprising that many home
remedies remain popular, even if they blatantly don't work.
<br />
<br />
Have you ever been shocked out of your hiccups? If so, please comment below.<br />
<br />
<div class="header">
<b>Conventional wisdom on hiccups</b></div>
According to the NHS, hiccups "don't seem to have a useful purpose". This can be
translated as "we haven't a clue what they're for".
<br />
<br />
According to the Phylogenetic hypothesis, hiccups are an evolutionary remnant of
earlier amphibian respiration. That's only 250 million years out of date then.
<br />
<br />
<div class="header">
<b>Short term verses persistent hiccups</b></div>
As far as I know we all get short term hiccups. These are sometimes humorous,
sometimes irritating. This page deals with short term hiccups.
<br />
<br />
However there is a rare but more sinister version which is not humorous at all.
Persistent hiccups are those which continue for longer than 48 hours and these
usually result from an underlying medical cause. They can be positively
debilitating and can prevent the sufferer from working, sleeping, eating and
performing many ordinary functions of life. If you have hiccups which last for
longer than 48 hours, please seek medical advice without further delay.
<br />
<br />
<div class="header">
<b>My Hypothesis</b></div>
Mammals appear to be unique among vertebrates in that we can breath while we feed. This is essential for infants suckling, and has the nutritional advantage that we can take time to chew our food. Reptiles and birds can do neither of these, and must swallow chunks of food whole, which means that their food takes longer to digest. However, breathing while we feed does not come without added complexity.<br />
<br />
Hiccups seem to be associated with the phasing of swallowing and breathing in
mammals. Swallowing is a complex process which involves four different
neurological mechanisms which must be correctly coordinated to enable a bolus
to pass from the mouth to the oesophagus without entering the trachea. If we
fail to close the trachea we risk aspirating part of the bolus into the trachea
which we know as "going down the wrong way" and produces a powerful cough reflex
to clear the airway. In extreme cases, a piece of food can block the trachea
which causes choking.
<br />
<br />
Normally we unconsciously time our swallow to occur at the moment when we have
fully inhaled, and momentarily hold our breath while the epiglottis closes our
airway and the bolus passes cleanly into the oesophagus. This allows us to
remain fully oxygenated during swallowing, and prevents us from aspirating
which may happen if we inhaled as we swallowed. It also ensures we have a
lungful of air in case we get it wrong and need a good strong cough.
<br />
<br />
My hypothesis is that failing to synchronise swallowing with inhaled
breath-holding risks causing spasms, which present as hiccups, and that re-synchronising swallowing with inhaled
breath-holding can cure hiccups.
<br />
<br />
<div class="header">
<b>Supporting Evidence</b></div>
Many causes of hiccups are given in the usual references. A great many of
them are associated with mis-phasing our swallowing and breathing. Let's examine
some of the commonly cited causes of hiccups. All of these involve a disruption
in the ordered synchronisation to our swallowing and breathing. It is important
to remember that we swallow not only when we eat or drink, but regularly swallow
saliva unconsciously<i>.</i><br />
<br />
<table border="0" cellpadding="10" style="text-align: top;"><tbody>
<tr><td width="50%"><u>Commonly Cited Cause</u></td>
<td width="50%"><u>My Explanation</u></td>
</tr>
<tr>
<td>Eating or drinking quickly</td>
<td>If we eat too quickly we swallow too soon rather than at peak
inhalation.</td>
</tr>
<tr>
<td>Alcohol</td>
<td>Alcohol produces a general loss of coordination which is required to
synchronise swallowing with breathing.</td>
</tr>
<tr>
<td>Sudden excitement or shock</td>
<td>Excitement or shock can cause an involuntary inhalation which can
interrupt our synchronisation.</td>
</tr>
<tr>
<td>A sudden change in temperature</td>
<td>This can cause a shock induced inhalation.</td>
</tr>
<tr>
<td>Spicy food</td>
<td>Surprising food taste or temperature can also cause a shock induced
inhalation.</td>
</tr>
<tr>
<td>Carbonated (fizzy) drinks</td>
<td>Fizzy drinks commonly cause regurgitated air (burping) which interrupts
both swallowing and breathing functions.</td>
</tr>
<tr>
<td>Swallowing air</td>
<td>Swallowing air also causes regurgitation (burping).</td>
</tr>
<tr>
<td>Smoking</td>
<td>Smokers often exhale while drawing smoke into their mouth. Tobacco smoke
promotes salivation and if the smoker swallows immediately prior to inhaling
the smoke then the swallow will occur during full exhalation. This is exactly
opposite to our normal synchronisation.</td>
</tr>
</tbody></table>
The other major piece of supporting evidence is the success of the cure as described
below which aims to resynchronise swallowing and breathing functions.<br />
<br />
<br />
None of the above qualifies as scientific evidence. The first is is hypothetical narrative; the second is anecdote. I would be most interested in supporting any proposed scientific evaluation of my cure.<br />
<br />
<br />
<div class="header">
<b>Billy's Hiccup Cure</b></div>
Billy's cure simply involves relaxing and resynchronising breathing and
swallowing. It's a simple step-by-step process which I've found to work with many people, particularly children.
<br />
<ol>
<li>Sit somewhere quiet and calm.
</li>
<li>Breath in SLOWLY until your chest is full.
</li>
<li>Breath out SLOWLY until your chest is empty.
</li>
<li>Breath in SLOWLY until your chest is full and hold your breath.
</li>
<li>Swallow three times.
</li>
<li>Breath out SLOWLY until your chest is empty.
</li>
<li>Gently breath again normally.
</li>
<li>If you still hiccup, repeat the process once more.
</li>
</ol>
<br />
Does this work for you? If so then pass it on. If it doesn't,
then do please let me know by commenting, telling me what happened
and what worked in the end.
Billysuggerhttp://www.blogger.com/profile/10673508741175504300noreply@blogger.com0tag:blogger.com,1999:blog-2309907146997372202.post-78259304224593676552014-08-28T23:23:00.001+01:002014-08-28T23:25:39.609+01:00The face of a Murderer<div class="separator" style="clear: both; text-align: center;">
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgpCNTiLKmQ1qIf1LkpO8fGBhtwbGWGJUNYL8Yd0JxakdXqRDSqjsbSLNOQVkiiZIE-MUaTtLFjWHpAcpzgNh-s3Y0tR5XME6bMN6VfrloELvM1WgsUC_2ePO9Rv6QczBO7latJ_I0AQCLe/s1600/Murderer.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgpCNTiLKmQ1qIf1LkpO8fGBhtwbGWGJUNYL8Yd0JxakdXqRDSqjsbSLNOQVkiiZIE-MUaTtLFjWHpAcpzgNh-s3Y0tR5XME6bMN6VfrloELvM1WgsUC_2ePO9Rv6QczBO7latJ_I0AQCLe/s1600/Murderer.jpg" height="223" width="320" /></a></div>
<br />
Actor Brendan O'Carrol is most famous for playing his alter ego, Mrs Brown. But his most recent screen time has been on an episode of the BBC's family history programme, Who Do You Think You Are?<br />
<br />
Brendan, who hails from Dublin, always knew that his grandfather had been murdered in 1920, and that his family always believed that he had been killed by the British military. I'm not going to spoil the show and give details, and those details are not necessary to the point of my post. So I'll leave it to Brendan and the BBC to tell his story in full. It's well worth seeing if you can catch it.<br />
<br />
I have no connections to Ireland, no known Irish blood, no allegiance to Catholicism or Protestantism. But I grew up in England in the 1970s, knowing that Irish nationalists were planting bombs in my country to kill me and my fellows. The risk to me, living in rural England, was remote, but it forged an allegiance to the British side of the conflict, if for no other reason than pure self-interest.<br />
<br />
In my adult years, as a student of human nature, I am cautious of simplistic fallacies such as "our side is always honourable", and was fully accepting when the truth about the 1972 Bloody Sunday massacre finally came out, and David Cameron apologised on behalf of the nation. But still, no prosecutions have been successfully brought. And no closure process has been entered into, like the Truth and Reconciliation process which followed the end of Apartheid in South Africa.<br />
<br />
Brendan achieved far more than he hoped for in tracing his grandfather's murderers: not only did he establish a motive and method, but he even identified the man who pulled the trigger - his cold face stares from the photo above. The motive was not noble, indeed it was not worth a man's life. And it is revealed that the killer lived a full life following his many crimes, and died having never faced justice. This is not the closure I would want in Brendan's position. He has no formal justice; no apology from a representative of our nation, which sent a cold, ruthless murderer to kill of our behalf. As much as I'd like just to put my arm around Brendan and express my sorrow and regret for the loss of a grandfather in his life who was taken on behalf of my forebears, I can't do that. But in bringing this story to light, in telling us all what happened in those dark days of 1920 in Dublin, when so much violence and hatred was rife, he brings dignity and a different kind of justice to his family - the justice of truth being told, that we may know what has been done on our behalf, and hold to account our leaders for their actions now and in future.Billysuggerhttp://www.blogger.com/profile/10673508741175504300noreply@blogger.com0tag:blogger.com,1999:blog-2309907146997372202.post-12587168872015093772014-07-22T02:23:00.000+01:002015-10-14T03:02:30.406+01:00On the Nature of Mathematics<div class="separator" style="clear: both; text-align: center;">
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjH_K0mRMYwa14ZPqL7y5OuPBZuEBuUXUtaEeIyYqtUze9tXHrz8IcwkLkyo6YwCC8fq2rhJ7zmvLNLCr4RC4EUyZDhmVzLsPW_9SpA5Sb0egguKtOKyoQhyFJfzBCvT6IlKMBpO06tO7YK/s1600/London+Underground.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjH_K0mRMYwa14ZPqL7y5OuPBZuEBuUXUtaEeIyYqtUze9tXHrz8IcwkLkyo6YwCC8fq2rhJ7zmvLNLCr4RC4EUyZDhmVzLsPW_9SpA5Sb0egguKtOKyoQhyFJfzBCvT6IlKMBpO06tO7YK/s1600/London+Underground.jpg" /></a></div>
<br />
<span style="font-family: Arial, Helvetica, sans-serif;">Hands up, I'm way outside my sphere of expertise here: I'm no mathematician, physicist or epistemologist. I know enough to be dangerous, but not enough to make any ground-breaking contributions. So why read any further? Well, I have something to say on this which has been worming around in my mind for years, sometimes peeping into my consciousness for a fleeting moment, before vanishing back to obscurity. But it's now well enough formed to describe as a starting point, if not with any degree of eloquence. And even if I haven't made any breakthrough, let me perhaps lay a cobble along a road which may be interesting to walk. Please be patient...</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"></span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">I have long thought about the nature of mathematics in relation to physics. The two disciplines are closely linked, particularly at the limits of today's advanced cosmology and particle physics. Many physicists and mathematicians have marvelled at the predictive power of mathematics, at the way that theories can be synthesized mathematically into structures which suggest discoveries to be made experimentally, if only to realise some perceived 'beauty' by completing an elegant mathematical structure. When lo and behold the discovery is made, theorists marvel at mathematics and its pre-eminence among the intellectual disciplines.</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"></span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">Some go further still: Roger Penrose holds mathematics to be the reality of nature, and if that wasn't enough, that mathematical concepts have a metaphysical existence in the universe independent of mathematicians, as if Pythagoras's Theorem was floating in the ether for the Greeks to discover and document.</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"></span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">I have long held mathematics to be a human construct which represents the world around us, and not some disembodied mystical entity. I have found every other metaphysical construct to evaporate under the harsh light of critical examination, and I have no patience to entertain disembodied equations emerging from the Big Bang! But I see a problem: my view of mathematics as a construct just doesn't fit with the predictive power mathematics has proved to wield. The discovery of the Higgs boson was a triumph of the predictive power of mathematics, and one which has not sufficiently been heralded in my view. So there must be something more to mathematics than just a toolbag of strategies for solving practical problems.</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"></span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">There is something transcendent about mathematics. If you know what a materialistic skeptic I am, you'll appreciate the enormity of that statement. Solving equations, as I do from time to time as an engineer, feels like refining truth - cancelling terms feels like spooning off the dross from the ever more pure and precious metal sought. The formal proofs of theorems are eternal - once proven they are never broken, and reveal their truth for eternity. There is some kind of magic in mathematics, but I just can't follow Penrose down his metaphysical road. That way lies madness!</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"></span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">I also have bags of humbug for the ancient Greek philosophers. Hemlock wasn't Socrates's only herbal vice: just what was he on when he came up with the Allegory of the Cave? So I'm more than slightly embarrassed that my resolution to the problem of mathematics has certain similarities to his shadows on a cave wall.</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"></span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">While listening to back issue podcasts of The Infinite Monkey Cage a few days ago, with Brian Cox perhaps stating as final that mathematics is truth, while Robin Ince teases him on multiple levels simultaneously, which you only realise are much more clever than at first appears some time later, a thought popped into my consciousness, and decided to hang around.</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"></span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">The thought was: "there is a structure of underlying truth to the universe which we hairless apes are not adapted to comprehend, but parts of which are projected onto our limited consciousness, and the shadows formed are what we call mathematics".</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"></span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">Sitting there, like a mischevous imp at the corner of my mind, that thought cast off other thoughts. I thought of the schematic map of the London Underground. When laid out geographically, the tube network is fiendishly complex. But the schematic representation just shows what we need to know to plan a route from A to B, and where to change lines. It's a functional representation of London, but it's not actually London. So if the underlying truth is like London, but we only have parts of a schematic tube map, there are limited things we can know about London, (er, I mean truth). We know schematically that the Jubilee line crosses the Circle line twice, and if we know that in real London it crosses at one point, (we have solid experimental evidence for one physical law), then we can infer from the rules of topology that it must cross somewhere else (and make a prediction to test experimentally), even if we've never been to Baker St.</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"></span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">There are truths which are so obvious to us that they seem pointless to express: like the number 2 is half of 4, and sits neatly between 1 and 3. Perhaps if we were not adapted to life as apes, but as supreme logicians, Pythagoras's Theorem would be similarly trivial, and unworthy of a name. So perhaps there is no need for a disembodied metaphysical law of right triangles in the universe, right triangles just are the way they are. And it's not obvious to us because we don't have the right kind of minds to appreciate it, and have to construct formal proofs instead. These proofs seem so magical and powerful to us, that some of us think they have a special existence, but that's just an illusion born of our limited perception. And perhaps the behaviour of waves and particles, and spacetime, and the unity of forces, are all logically deducible, if only we could perceive the logic so clearly.</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"></span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">So we build pieces of a reality map through our reasoning and by our observations, and call these pieces laws and theorems. But these laws and theorems are our constructs, our inventions to account for the way the universe is, to steer our ape minds to conform for a moment to the truth of reality, while the universe just goes on being what it is without any need for such trivia.</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"></span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">On this view then, mathematics really is the projection of reality onto human consciousness. And as the contours of our consciousness change, so do the mathematical strategies we use. When I learned basic number theory as a child, I used abacuses to count-on and perform basic addition. My children were taught the number line, which is a different concept. So their mathematics will be different to mine, not because truth is different for us, but because their consciousness of number is different from mine.</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"></span><br />
<span style="font-family: Arial, Helvetica, sans-serif;">What can this idea tell us we didn't know before? Well it does suggest that there may be limitations to what we can discover. In terms of the analogy, there may be areas of our consciousness which our cerebral topography keeps in mathematical shadow, corresponding to universal truths we can never comprehend. But who knows, if we can find where these conceptual gaps lie, perhaps mankind's perseverance at solving problems will find routes around these gaps, allowing us to solve theoretical and practical problems regardless. Quantum theory could be one of those gaps - we just do not have minds equipped to understand the world on such small scales, but we have mathematical strategies which allow us to skirt the edge of our blind spot and solve quantum mechanical problems anyway. We've done rather well for ourselves, don't you think?</span>Billysuggerhttp://www.blogger.com/profile/10673508741175504300noreply@blogger.com0tag:blogger.com,1999:blog-2309907146997372202.post-27044650258771426642014-07-10T00:28:00.000+01:002014-07-10T00:28:55.595+01:00Fiat justitia ruat caelum<div class="separator" style="clear: both; text-align: center;">
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjY8fnKR0DzVEuBk-mb6iVsYGVcYCOOtuC1UUOmmycVIQ6keZKSCxLMuKliUWbEXNelv1b94RBn2JXT_As6F6FHr2qGLXk3SWB6IKVPccHrPYkgz3QaDnIKR7MZIW5mtq5KiYEhxcaPHw1d/s1600/EBS.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjY8fnKR0DzVEuBk-mb6iVsYGVcYCOOtuC1UUOmmycVIQ6keZKSCxLMuKliUWbEXNelv1b94RBn2JXT_As6F6FHr2qGLXk3SWB6IKVPccHrPYkgz3QaDnIKR7MZIW5mtq5KiYEhxcaPHw1d/s1600/EBS.jpg" height="320" width="274" /></a></div>
<br />
Dame Elizabeth Butler-Sloss is under fire for having taken the chair to inquire into allegations of historic establishment cover up of child abuse, when her brother stands accused of being party to such cover up. There is indeed a <i>prima facie</i> conflict of interest here, and I've been thinking this one over all day, (off and on, among other things). Now I think I have reached a personal conclusion.<br />
<br />
What needs inquiring into, (among other important things, but this one’s pretty central), is this: we had people in positions of authority and responsibility who are alleged to have been conflicted when they became aware of allegations of wrongdoing, but failed to pursue those allegations because that may have disadvantaged them in some way. Perhaps politically, perhaps in their career aspirations, perhaps because it threatened to bring into disrepute a social group to which they belonged. We've accepted these people into positions of authority and responsibility with the unspoken bargain that they should in return exercise such powers responsibly, for the benefit of wider society and not for personal protection or advancement. And we've been let down: by cash for questions; by the MPs expenses scandal; by the failure to hold Jimmy Savile to account; by disgraceful cover ups over Hillsborough; by the phone hacking scandal.<br />
<br />
It seems to me that there will be no one in the establishment with the authority to inquire into this matter, who is not tainted in some way by association. And despite the appearance of conflicted interests, that is not what we need. What is needed is someone who has the integrity to rigorously inquire into these allegations <i>despite </i>it being potentially damaging to the good name of a close family member, and not someone whose potential embarrassment remains concealed.<br />
<br />
All commentators who seem well enough informed to judge her describe Dame EBS as possessing impeccable integrity and unparalleled qualifications to chair this inquiry. And continuing to chair the inquiry would give her the opportunity to set an example to those pillars of the establishment and inquire into this matter as rigorously as they all perhaps should have done all those years ago, and damn the consequences.<br />
<br />
I think she should proceed, and show them what integrity looks like, because it's a lesson many in the establishment need to learn.<br />
<br />
<a href="http://www.bbc.co.uk/news/uk-28211253" rel="nofollow" target="_blank">Profile: Dame Elizabeth Butler-Sloss</a><br />
<a href="http://en.wikipedia.org/wiki/Fiat_justitia_ruat_caelum" rel="nofollow" target="_blank">Fiat justitia ruat caelum</a>Billysuggerhttp://www.blogger.com/profile/10673508741175504300noreply@blogger.com0tag:blogger.com,1999:blog-2309907146997372202.post-24933188900962519382014-07-01T18:02:00.001+01:002014-07-01T18:02:17.960+01:00LogMeIn - Can that let anyone in?<div class="separator" style="clear: both; text-align: center;">
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgDc_XrxmDDBIRaXjVPnAISe2r4X6MI5S83s9Y7jCu_LZ1bSI8sslvZ3qCIfrpQBI1mFG72z_O_bo1Gfkwj5mTf-TTPcMIJGEWr4FeD-eZpycYhwFCTm0M92x0tImOAZ2bqrYHuX9-t1JkP/s1600/Logmein_Logo.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgDc_XrxmDDBIRaXjVPnAISe2r4X6MI5S83s9Y7jCu_LZ1bSI8sslvZ3qCIfrpQBI1mFG72z_O_bo1Gfkwj5mTf-TTPcMIJGEWr4FeD-eZpycYhwFCTm0M92x0tImOAZ2bqrYHuX9-t1JkP/s1600/Logmein_Logo.png" /></a></div>
<br />
<br />
Until recently, I used a service called LogMeIn, which allows me to access other computers I've set up with specific accounts. I used it primarily to enable me to provide technical support to family members. It's an incredibly useful service, and until recently a limited service was available completely free of charge. Recently the free option was withdrawn so I stopped using it.<br />
<br />
I used it twice for business purposes, one time setting up a specific email address so that a client could access a remote computer I had set up to configure a specific piece of equipment installed on another continent.<br />
<br />
Then I began to receive spam email which had been sent to the login email address I used for business that one time. I knew that the email address had not been published. I knew that only I had access to the server receiving emails to the address used. I knew that I had not used it for any other purpose, and that there was no benefit to it being used by anyone else, since only I could receive emails sent to it. The email address used for spam HAD to have been released by LogMeIn. So I emailed LogMeIn and explained, but I just received a generic denial, and left it at that.<br />
<br />
Today I received an invoice for $826, purporting to be from LogMeIn, sent not to the exclusive login account previously sent spam, but to my business email address. The attached invoice contained no data, so I was fairly sure it was a phishing attempt to defraud me. Sure enough, one look at the LogMeIn Facebook page reveals other victims complaining of the same scam. I forwarded the information to LogMeIn, along with my rationale for believing that it was attempted fraud.<br />
<br />
Now I think about it, my alarm bells are ringing loudly. LogMeIn has allowed my private data to fall into the hands of criminals, witness the exclusive login email address now used for spam. That's irritating. Now their customers are being targeted with attempted fraud. That's alarming. But how bad could this be?<br />
<br />
I used LogMeIn to gain authorised access to computers, with the knowledge and trust of the owners of those computers. But the means to do that, in the form of login credentials to the computers involved, is entrusted to LogMeIn. And I now know that information entrusted to LogMeIn has fallen into the hands of criminals. So how safe are the computers I have used with LogMeIn? If someone with malicious or fraudulent intent can gain unauthorised access to those computers, they may have access to all sorts of information which could be harmful, such as login details to banking services, financial accounts, employee personnel records, medical details, intellectual property, state secrets,... the list is endless.<br />
<br />
I have removed LogMeIn from all my computers, and family computers. But this remains a concern. If LogMeIn cannot secure client data, and they hold the keys to millions of computers worldwide, is it wise to entrust LogMeIn with those keys? Think about it... it gets frightening if you do!<br /><br />LogMeIn also provides services marketed as RemotelyAnywhere, join.me, Xively, Cubby and BoldChat.Billysuggerhttp://www.blogger.com/profile/10673508741175504300noreply@blogger.com0tag:blogger.com,1999:blog-2309907146997372202.post-71223617234511361162014-05-08T14:58:00.000+01:002014-05-08T14:58:07.841+01:00Halal or Not Halal? That is the Question.<div class=" _186j" data-offset-key="0.0.0" data-reactid=".14.1:4.0.$right.0.0.0.0.1.0.0.1.0.$0=10=10" style="background-color: white; color: #141823; direction: ltr; font-family: 'helvetica neue', helvetica, arial, 'lucida grande', sans-serif; font-size: 12px; line-height: 16px; position: relative; white-space: pre-wrap;">
Today's news is full of stories that Halal meat is being sold in the UK without being labelled as such. Now let's get this clear: according to the BBC, 90% of UK Halal meat is from animals which have been pre-stunned, so they conform to legal requirements without the religious exemption. So what's the issue?</div>
<div class=" _186j" data-offset-key="0.0.0" data-reactid=".14.1:4.0.$right.0.0.0.0.1.0.0.1.0.$0=10=10" style="background-color: white; color: #141823; direction: ltr; font-family: 'helvetica neue', helvetica, arial, 'lucida grande', sans-serif; font-size: 12px; line-height: 16px; position: relative; white-space: pre-wrap;">
During the Foot & Mouth crisis, having seen videos of a man running around a field with a bolt gun after a sheep, I decided to look into legal slaughter practices, (he should have been imprisoned in my opinion), and in doing so I also looked into Halal practices.</div>
<div class=" _186j" data-offset-key="4.0.0" data-reactid=".14.1:4.0.$right.0.0.0.0.1.0.0.1.0.$4=10=10" style="background-color: white; color: #141823; direction: ltr; font-family: 'helvetica neue', helvetica, arial, 'lucida grande', sans-serif; font-size: 12px; line-height: 16px; position: relative; white-space: pre-wrap;">
<span class="" data-offset-key="4.0.0" data-reactid=".14.1:4.0.$right.0.0.0.0.1.0.0.1.0.$4=10=10.$4=10=10">The biggest issue for me, way bigger than whether someone speaks magic spells over my food, is that correctly carried out, to the spirit and letter of the law, legal slaughter in the UK is as humane as it's reasonably practical to be. And in my view it's far preferable to death from predation or disease in the wild.</span></div>
<div class=" _186j" data-offset-key="6.0.0" data-reactid=".14.1:4.0.$right.0.0.0.0.1.0.0.1.0.$6=10=10" style="background-color: white; color: #141823; direction: ltr; font-family: 'helvetica neue', helvetica, arial, 'lucida grande', sans-serif; font-size: 12px; line-height: 16px; position: relative; white-space: pre-wrap;">
<span class="" data-offset-key="6.0.0" data-reactid=".14.1:4.0.$right.0.0.0.0.1.0.0.1.0.$6=10=10.$6=10=10">The problem I have is that human nature does not pre-dispose us to treat other humans, let alone other animals, with the dignity, respect and humanity required when there is so much potential for suffering. So we need far greater safeguards against the darker side of our nature in the slaughtering process. I have some in mind, which include routine oversight by independent observers, but the cost would be unacceptable to many people who just want a cheap meal to feed their families.</span></div>
<div class=" _186j" data-offset-key="8.0.0" data-reactid=".14.1:4.0.$right.0.0.0.0.1.0.0.1.0.$8=10=10" style="background-color: white; color: #141823; direction: ltr; font-family: 'helvetica neue', helvetica, arial, 'lucida grande', sans-serif; font-size: 12px; line-height: 16px; position: relative; white-space: pre-wrap;">
<span class="" data-offset-key="8.0.0" data-reactid=".14.1:4.0.$right.0.0.0.0.1.0.0.1.0.$8=10=10.$8=10=10">There are three main requirements for the practice of Halal slaughter: ritual cleanliness; hygienic cleanliness; and minimising the suffering of the animal being slaughtered. Whatever you think of Islam today, these requirements clearly underlie Halal practices and they are entirely consistent with the best ethical practice in humane animal slaughter.</span></div>
<div class=" _186j" data-offset-key="10.0.0" data-reactid=".14.1:4.0.$right.0.0.0.0.1.0.0.1.0.$10=10=10" style="background-color: white; color: #141823; direction: ltr; font-family: 'helvetica neue', helvetica, arial, 'lucida grande', sans-serif; font-size: 12px; line-height: 16px; position: relative; white-space: pre-wrap;">
<span class="" data-offset-key="10.0.0" data-reactid=".14.1:4.0.$right.0.0.0.0.1.0.0.1.0.$10=10=10.$10=10=10">Considering the time when these requirements were established, there was not the knowledge of disease causes we have today, and the distinction between ritual and hygienic cleanliness was entirely blurred. Speaking magic spells over the animal was just as important as ensuring that the animal did not have a communicable disease. The strict requirements of the blade, and the manner in which it is used, are clearly intended to minimise pain and bring about unconsciousness as quickly as possible, both requirements for humane slaughter.</span></div>
<div class=" _186j" data-offset-key="12.0.0" data-reactid=".14.1:4.0.$right.0.0.0.0.1.0.0.1.0.$12=10=10" style="background-color: white; color: #141823; direction: ltr; font-family: 'helvetica neue', helvetica, arial, 'lucida grande', sans-serif; font-size: 12px; line-height: 16px; position: relative; white-space: pre-wrap;">
<span class="" data-offset-key="12.0.0" data-reactid=".14.1:4.0.$right.0.0.0.0.1.0.0.1.0.$12=10=10.$12=10=10">The prohibition on pre-stunning prevents botched attempts which could cause unimaginably greater suffering than a clean Halal kill. And given the state of knowledge over a thousand years ago, when these requirements were founded, I cannot in all conscience condemn it. And having read the scientific literature examining both sides, I find it hard even to insist on pre-stunning, but on balance I do support it.</span></div>
<div class=" _186j" data-offset-key="14.0.0" data-reactid=".14.1:4.0.$right.0.0.0.0.1.0.0.1.0.$14=10=10" style="background-color: white; color: #141823; direction: ltr; font-family: 'helvetica neue', helvetica, arial, 'lucida grande', sans-serif; font-size: 12px; line-height: 16px; position: relative; white-space: pre-wrap;">
<span class="" data-offset-key="14.0.0" data-reactid=".14.1:4.0.$right.0.0.0.0.1.0.0.1.0.$14=10=10.$14=10=10">So, the Halal requirements for cleanliness and the humane treatment of animals are precisely the same as those which underlie our legal requirements today. If Halal practices could be refined in the light of new scientific evidence, then I have no doubt that they would allow carefully prescribed pre-stunning, and place less emphasis on magic spells. Halal practices were introduced for precisely the same reasons we want humane slaughter today, and dogmatically holding to the letter of scripture, while denying improvements in the light of new knowledge, which support its spirit and clear purpose, can be neither just nor holy.</span></div>
<div class=" _186j" data-offset-key="16.0.0" data-reactid=".14.1:4.0.$right.0.0.0.0.1.0.0.1.0.$16=10=10" style="background-color: white; color: #141823; direction: ltr; font-family: 'helvetica neue', helvetica, arial, 'lucida grande', sans-serif; font-size: 12px; line-height: 16px; position: relative; white-space: pre-wrap;">
<span class="" data-offset-key="16.0.0" data-reactid=".14.1:4.0.$right.0.0.0.0.1.0.0.1.0.$16=10=10.$16=10=10">According to the BBC, 90% of UK Halal meat is from animals which have been pre-stunned, so they conform to legal requirements. There is no legal prohibition on magic spells, since we all know they do nothing so cannot possibly do us harm. Therefore, I would be perfectly content to buy and eat Halal meat from animals treated according to secular law, including careful pre-stunning, with or without the magic spells and added Halal requirements, and whether labelled as such or not.</span></div>
<div class=" _186j" data-offset-key="18.0.0" data-reactid=".14.1:4.0.$right.0.0.0.0.1.0.0.1.0.$18=10=10" style="background-color: white; color: #141823; direction: ltr; font-family: 'helvetica neue', helvetica, arial, 'lucida grande', sans-serif; font-size: 12px; line-height: 16px; position: relative; white-space: pre-wrap;">
<span class="" data-offset-key="18.0.0" data-reactid=".14.1:4.0.$right.0.0.0.0.1.0.0.1.0.$18=10=10.$18=10=10">The final issue troubles me as a secular Humanist: compare two circumstances.</span></div>
<div class=" _186j" data-offset-key="18.0.0" data-reactid=".14.1:4.0.$right.0.0.0.0.1.0.0.1.0.$18=10=10" style="background-color: white; color: #141823; direction: ltr; font-family: 'helvetica neue', helvetica, arial, 'lucida grande', sans-serif; font-size: 12px; line-height: 16px; position: relative; white-space: pre-wrap;">
<span class="" data-offset-key="18.0.0" data-reactid=".14.1:4.0.$right.0.0.0.0.1.0.0.1.0.$18=10=10.$18=10=10">1) The legal, ritual slaughter of animals by a devoutly religious person, who believes he is being watched over by an invisible master who requires the animal to be treated with respect.</span></div>
<div class=" _186j" data-offset-key="18.0.0" data-reactid=".14.1:4.0.$right.0.0.0.0.1.0.0.1.0.$18=10=10" style="background-color: white; color: #141823; direction: ltr; font-family: 'helvetica neue', helvetica, arial, 'lucida grande', sans-serif; font-size: 12px; line-height: 16px; position: relative; white-space: pre-wrap;">
<span class="" data-offset-key="18.0.0" data-reactid=".14.1:4.0.$right.0.0.0.0.1.0.0.1.0.$18=10=10.$18=10=10">2) The slaughter by the hand of the kind of person I can imagine applying for and doing the job of slaughterman in a secular abattoir, without independent oversight.</span></div>
<div class=" _186j" data-offset-key="18.0.0" data-reactid=".14.1:4.0.$right.0.0.0.0.1.0.0.1.0.$18=10=10" style="background-color: white; color: #141823; direction: ltr; font-family: 'helvetica neue', helvetica, arial, 'lucida grande', sans-serif; font-size: 12px; line-height: 16px; position: relative; white-space: pre-wrap;">
<span class="" data-offset-key="18.0.0" data-reactid=".14.1:4.0.$right.0.0.0.0.1.0.0.1.0.$18=10=10.$18=10=10">In the light of this comparison, and knowledge of the requirements for Halal slaughter and secular slaughter, I do have a hard time condemning Halal practice.</span></div>
<div class=" _186j" data-offset-key="20.0.0" data-reactid=".14.1:4.0.$right.0.0.0.0.1.0.0.1.0.$20=10=10" style="background-color: white; color: #141823; direction: ltr; font-family: 'helvetica neue', helvetica, arial, 'lucida grande', sans-serif; font-size: 12px; line-height: 16px; position: relative; white-space: pre-wrap;">
<span class="" data-offset-key="20.0.0" data-reactid=".14.1:4.0.$right.0.0.0.0.1.0.0.1.0.$20=10=10.$20=10=10">This is an emotive subject, but I do have one request. Before condemning my heresy, please do read up on the details and argue from a position of knowledge of the subject. Then please feel free to weigh in.</span></div>
Billysuggerhttp://www.blogger.com/profile/10673508741175504300noreply@blogger.com0tag:blogger.com,1999:blog-2309907146997372202.post-8607320511879008202014-05-03T21:39:00.000+01:002015-10-14T03:04:57.538+01:00Billysugger Simples: How to measure temperature with a Thermistor<div class="MsoNormal">
<span style="font-family: Arial, Helvetica, sans-serif;"><b>Introduction</b></span></div>
<div class="MsoNormal">
<br /></div>
<div class="MsoNormal">
<span style="font-family: Arial, Helvetica, sans-serif;">Often we have a requirement to measure the temperature of
the board, the environment or some process.
Here’s a quick and easy guide to simple temperature measurement using a
simple, cheap thermistor.</span></div>
<div class="MsoNormal">
<br /></div>
<div class="MsoNormal">
<span style="font-family: Arial, Helvetica, sans-serif;">There are numerous silicon devices on the market which seem
to simplify temperature measurement, but it’s difficult to beat a good quality
NTC thermistor. I’ve used them to measure
the temperature of things as diverse as engine manifolds to LEDs, and in medical applications have
measured patient internal temperatures to accuracies far better than 0.1°C.</span></div>
<div class="MsoNormal">
<br /></div>
<div class="MsoNormal">
<span style="font-family: Arial, Helvetica, sans-serif;"><b>Selecting the Thermistor</b></span></div>
<div class="MsoNormal">
<br /></div>
<div class="MsoNormal">
<span style="font-family: Arial, Helvetica, sans-serif;">There are two types of thermistor, defined by whether their
resistance increases or decreases as temperature rises. Temperature is best measured using NTC
(negative temperature coefficient) thermistors, whose resistance decreases as
temperature rises.</span></div>
<div class="MsoNormal">
<br /></div>
<div class="MsoNormal">
<span style="font-family: Arial, Helvetica, sans-serif;">There are two parameters of importance in defining the
characteristic: A reference resistance and the Beta value. The reference resistance is usually specified
as the resistance at a temperature of 25°C.
The most common types have a 10k resistance at 25°C. The Beta value specifies how the resistance
varies as temperature deviates from the reference temperature. The most common types have values in the
region of 4000 and have units of Kelvin.</span></div>
<div class="MsoNormal">
<br /></div>
<div class="MsoNormal">
<span style="font-family: Arial, Helvetica, sans-serif;">For this example, we will use a Vishay NTCLE100E3103JB0,
(Farnell/Newark part 1187031, Digikey part BC2301-ND). This is a cheap and simple leaded part with a
2.54mm (0.1”) lead spacing, has a 10k resistance at 25°C and a Beta value
B=3977K.</span></div>
<div class="MsoNormal">
<br /></div>
<div class="separator" style="clear: both; text-align: center;">
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhONc5NRm3-F4urU7Y2g_5HCifD8z6-WY9VIUSCJD5j0JG22S5mnwWc6HsFC-gZOh2VDWQRxank-fzy-ImipER2HksRO1NeVZdbcF_TOjv8g3dkHoUiuEJGYJOIJpU6JMR0t2MVp1jZiqQ7/s1600/thermistor.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhONc5NRm3-F4urU7Y2g_5HCifD8z6-WY9VIUSCJD5j0JG22S5mnwWc6HsFC-gZOh2VDWQRxank-fzy-ImipER2HksRO1NeVZdbcF_TOjv8g3dkHoUiuEJGYJOIJpU6JMR0t2MVp1jZiqQ7/s1600/thermistor.png" /></a></div>
<div class="MsoNormal">
<br /></div>
<div class="MsoNormal">
<br /></div>
<div class="MsoNormal">
<span style="font-family: Arial, Helvetica, sans-serif;">There are many, many types of NTC thermistor, some with
different case styles including surface mount parts, different reference
resistances for nominal temperature ranges other than room temperature, and
different tolerances for accuracy. This
one is good for general purpose air temperature measurement.</span></div>
<div class="MsoNormal">
<br /></div>
<div class="MsoNormal">
<span style="font-family: Arial, Helvetica, sans-serif;"><b>The Measurement Circuit</b></span></div>
<div class="MsoNormal">
<br /></div>
<div class="MsoNormal">
<span style="font-family: Arial, Helvetica, sans-serif;">The thermistor is connected to the ADC 0V and in series with
a reference resistor, forming a potential divider from the ADC reference. A filter capacitor across the thermistor will
reduce any thermal noise, or other pickup.</span></div>
<div class="MsoNormal">
<br /></div>
<div class="separator" style="clear: both; text-align: center;">
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh9EfN9OGCdyhJZ6swG45cxPUYIt9fQVIGSJmvFISy6Ef1JrDuXv3jH9epUPHyDgFjWJl5Knf1L2g2AR-TyU0bQahC-tDxUKzxxNeL-KOv1CzBO_SQNP8Pc1_DdyWMo4no7yv8C5l5LtdTe/s1600/NTC.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="284" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh9EfN9OGCdyhJZ6swG45cxPUYIt9fQVIGSJmvFISy6Ef1JrDuXv3jH9epUPHyDgFjWJl5Knf1L2g2AR-TyU0bQahC-tDxUKzxxNeL-KOv1CzBO_SQNP8Pc1_DdyWMo4no7yv8C5l5LtdTe/s1600/NTC.png" width="320" /></a></div>
<div class="MsoNormal">
<br /></div>
<div class="MsoNormal">
<br /></div>
<div class="MsoNormal">
<span style="font-family: Arial, Helvetica, sans-serif;">Now, we can easily calculate the ADC value at 25°C. And we’ll see that as the temperature
increases, the thermistor resistance decreases and the voltage measured at the
ADC falls.</span></div>
<div class="MsoNormal">
<br /></div>
<div class="MsoNormal">
<span style="font-family: Arial, Helvetica, sans-serif;"><b>Calculating Temperature</b></span></div>
<div class="MsoNormal">
<br /></div>
<div class="MsoNormal">
<span style="font-family: Arial, Helvetica, sans-serif;">We could approximate the thermistor response as a linear
function, but beyond a very small range around 25°C, the errors would quickly
become unacceptable. A better
approximation is made by using the Beta-curve function:</span></div>
<div class="MsoNormal">
<br /></div>
<div class="MsoNormal">
<div style="text-align: center;">
<span style="font-family: Arial, Helvetica, sans-serif;">R = exp[(Beta/Tk) + LN(A)]</span></div>
</div>
<div class="MsoNormal">
<br /></div>
<div class="MsoNormal">
<span style="font-family: Arial, Helvetica, sans-serif;">Where Tk is the thermistor temperature in Kelvin, not
degrees centigrade, and LN(A) is a constant value for the thermistor. (Kelvin
is an absolute temperature scale, where Tk = Tc + 273.15).</span></div>
<div class="MsoNormal">
<br /></div>
<div class="MsoNormal">
<span style="font-family: Arial, Helvetica, sans-serif;">Solving the above equation for temperature gives</span></div>
<div class="MsoNormal">
<br /></div>
<div class="MsoNormal">
<div style="text-align: center;">
<span style="font-family: Arial, Helvetica, sans-serif;">Tk = Beta/(LN(R)-LN(A))</span></div>
</div>
<div class="MsoNormal">
<br /></div>
<div class="MsoNormal">
<span style="font-family: Arial, Helvetica, sans-serif;">Or</span></div>
<div class="MsoNormal">
<br /></div>
<div class="MsoNormal">
<div style="text-align: center;">
<span style="font-family: Arial, Helvetica, sans-serif;">Tc = Beta/(LN(R)-LN(A)) – 273.15</span></div>
</div>
<div class="MsoNormal">
<br /></div>
<div class="MsoNormal">
<span style="font-family: Arial, Helvetica, sans-serif;">Where</span></div>
<div class="MsoNormal">
<br /></div>
<div class="MsoNormal">
<div style="text-align: center;">
<span style="font-family: Arial, Helvetica, sans-serif;">LN(A) = LN(R25)-(Beta/298.15)</span></div>
</div>
<div class="MsoNormal">
<br /></div>
<div class="MsoNormal">
<span style="font-family: Arial, Helvetica, sans-serif;">But now we need to know the thermistor resistance R. The ADC value depends of the resistance R as
follows:</span></div>
<div class="MsoNormal">
<br /></div>
<div class="MsoNormal">
<div style="text-align: center;">
<span style="font-family: Arial, Helvetica, sans-serif;">ADC = ADC_TOP * R / (R + Rref)</span></div>
</div>
<div class="MsoNormal">
<br /></div>
<div class="MsoNormal">
<span style="font-family: Arial, Helvetica, sans-serif;">Where ADC_TOP is the highest value given by the ADC, (e.g.
4095 for a 12-bit ADC), and Rref is the reference resistor value.</span></div>
<div class="MsoNormal">
<br /></div>
<div class="MsoNormal">
<span style="font-family: Arial, Helvetica, sans-serif;">Solving for R gives</span></div>
<div class="MsoNormal">
<br /></div>
<div class="MsoNormal">
<div style="text-align: center;">
<span style="font-family: Arial, Helvetica, sans-serif;">R = Rref * ADC / ((ADC_ TOP * Kadc) – ADC)</span></div>
</div>
<div class="MsoNormal">
<br /></div>
<div class="MsoNormal">
<span style="font-family: Arial, Helvetica, sans-serif;"><b>Implementing in C-code</b></span></div>
<div class="MsoNormal">
<br /></div>
<div class="MsoNormal">
<span style="font-family: Arial, Helvetica, sans-serif;">The following is representative of code which calculates
temperature measured using the above method.
The detailed code will need to be adapted depending on your processor, your
board and your thermistor.</span></div>
<blockquote class="tr_bq">
<span style="font-family: Courier New, Courier, monospace;">// Include math library for calculations</span><br />
<span style="font-family: Courier New, Courier, monospace;">#include <math.h> </span><br />
<span style="font-family: Courier New, Courier, monospace;"><br /></span>
<span style="font-family: Courier New, Courier, monospace;">// Define ADC parameters</span><br />
<span style="font-family: Courier New, Courier, monospace;">#define ADC_TOP 1023 </span><br />
<span style="font-family: Courier New, Courier, monospace;"><br /></span>
<span style="font-family: Courier New, Courier, monospace;">// Define thermistor parameters</span><br />
<span style="font-family: Courier New, Courier, monospace;">#define R_NTC 10000</span><br />
<span style="font-family: Courier New, Courier, monospace;">#define BETA 3977</span><br />
<span style="font-family: Courier New, Courier, monospace;">#define LNA (-4.12858298874828)</span><br />
<span style="font-family: Courier New, Courier, monospace;"><br /></span>
<span style="font-family: Courier New, Courier, monospace;">// Define Reference Resistor</span><br />
<span style="font-family: Courier New, Courier, monospace;">#define R_REF 15000 </span><br />
<span style="font-family: Courier New, Courier, monospace;"><br /></span>
<span style="font-family: Courier New, Courier, monospace;">float read_temperature(void)</span><br />
<span style="font-family: Courier New, Courier, monospace;">{</span><br />
<span style="font-family: Courier New, Courier, monospace;"> float x = 0; </span><br />
<span style="font-family: Courier New, Courier, monospace;"><br /></span>
<span style="font-family: Courier New, Courier, monospace;"> // Calculate thermistor resistance from ADC</span><br />
<span style="font-family: Courier New, Courier, monospace;"> x = (R_REF * adc[0]) / (ADC_TOP – adc[0]; </span><br />
<span style="font-family: Courier New, Courier, monospace;"><br /></span>
<span style="font-family: Courier New, Courier, monospace;"> // Calculate Kelvin temperature from resistance</span><br />
<span style="font-family: Courier New, Courier, monospace;"> x = BETA / (log(x) - LNA); </span><br />
<span style="font-family: Courier New, Courier, monospace;"><br /></span>
<span style="font-family: Courier New, Courier, monospace;"> // Convert temperature to Celsius</span><br />
<span style="font-family: Courier New, Courier, monospace;"> x = x – 273.15; </span><br />
<span style="font-family: Courier New, Courier, monospace;"><br /></span>
<span style="font-family: Courier New, Courier, monospace;"> // Return result</span><br />
<span style="font-family: Courier New, Courier, monospace;"> return(x);</span><br />
<span style="font-family: Courier New, Courier, monospace;">}</span></blockquote>
<div class="MsoNormal" style="line-height: 115%; margin-bottom: 10pt;">
<o:p><span style="font-family: Arial, Helvetica, sans-serif;"> </span></o:p><span style="font-family: Arial, Helvetica, sans-serif;">And
if you want to play around with different thermistor parameters, I’ve prepared an <a href="http://www.billysugger.com/files/Billysugger%20Simples%20-%20Thermistor%20Temperature%20Measurement.xls" rel="nofollow" target="_blank">Excel file</a> with all the calculations included.</span></div>
Billysuggerhttp://www.blogger.com/profile/10673508741175504300noreply@blogger.com4tag:blogger.com,1999:blog-2309907146997372202.post-21914039265241043552013-09-13T20:20:00.000+01:002013-09-13T20:20:23.163+01:00Why I oppose gambling - A humanist perspectiveI don't like gambling. Many people don't like gambling, some for religious reasons. But I'm a humanist, so I have no religious reasons. So why do I oppose it?<br />
<br />
We all live under the illusion that what we see is real, and what we think is true. These illusions are so compelling that many people refuse to believe that our awareness is an illusion, but neuroscience and the study of the paranormal prove that the images in our minds are not accurate pictures of the real world.<br />
<br />
Some of the differences between human perception and reality are classified under the title 'cognitive biases'. These include the perception that 'I' am more important to the world around me than is justified. Another key human bias is that we have a tendency to overestimate the chance of good things happening to us, and underestimate the chance of bad things happening, <em>even in the face of compelling evidence to the contrary</em>.<br />
<br />
Because we are alive, we are descended from ancestors who won through tough times and out-competed their peers in the struggle for survival and reproduction. And we inherited the traits which helped make that difference, for example the tendency to persevere in the face of adversity, and not the abilities accurately to assess probabilities of success versus failure. Indeed, we are spectacularly maladapted for mathematics, which is why so many of us find it hard. We have to defeat our in-built biases and become disciplined in following rules of logic which are as unnatural as they are successful.<br />
<br />
Just how bad we are at intuitive math, particularly when it comes to assessing risk and probability, is shown by the following BBC video. When I first saw this kind of demonstration I was utterly convinced that the probability of winning remained 50:50, (you'll see what I mean when you watch it). Even Professor of Mathematics Marcus du Sautoy was convinced. He worked it out mathematically, I modelled the game in Excel, (independently of course, I don't move in such noble circles), and the correct answer really is 1 in 3 if you keep to your original guess.<br />
<br />
<a href="http://www.bbc.co.uk/news/magazine-24045598" target="_blank">BBC News Magazine - Monty Hall problem: The probability puzzle that makes your head melt</a><br />
<br />
So what has this to do with gambling? Well we're programmed to assess risk and probability incorrectly. We inherently overestimate our chance of winning compared to losing. If Alan had been tempted to bet on the game, Marcus could've cleaned him out. Alan is inherently no worse at this than you, me or anyone else. And when we use intuition and common sense about gambling, we make decisiona as rational as a child playing on a railway track.<br />
<br />
The only gambling I entertain is the English Grand National, (an annual horse race over jumps, on which many people make a token bet). But I take the role of family bookmaker and stakes each person can afford to lose. I've come away on top every year except one. Even when my wife got third place this year, I paid out less in winnings than I made in stakes on her other bets. And that's how gambling works - it's <em>always</em> rigged against the punter, it's just that we're all programmed to ignore that fact.<br />
<br />
This makes gambling as much a vice as addiction to narcotics. And the bookmaker is the pusher. Both vices involve bypassing reasoned choice. Both involve someone making money by exploiting other people whose decision making is compromised. Both ruin lives. And in my opinion, both should be outlawed.<br />
Billysuggerhttp://www.blogger.com/profile/10673508741175504300noreply@blogger.com0tag:blogger.com,1999:blog-2309907146997372202.post-2219924915304396052013-07-14T14:51:00.001+01:002013-07-14T14:51:05.061+01:00Winchester Science Festival 2013While planning my visit to the Winchester Science Festival next weekend, I was looking for a programme laid out as a timetable, so my family and I could mark sessions of interest then plan what we were going to see when. I couldn't find one, so I decided to compile one. My OCD compelled me to make a reasonable job of it, so I now have a printable PDF which can be printed on one double-sided page per day, (one side per morning or afternoon).<br />
<br />
If you're thinking of going, feel free to download it here: <a href="http://bit.ly/12y4Gja" target="_blank">WinSciFest2013.pdf</a><br />
<br />
Otherwise, for a quick summary, see the table below (without photos and session descriptions).<br />
<br />
<table border="1" cellpadding="0" cellspacing="0" class="MsoTableGrid" style="border-collapse: collapse; border: none; mso-border-alt: solid windowtext .5pt; mso-padding-alt: 2.85pt 2.85pt 2.85pt 2.85pt; mso-table-layout-alt: fixed; mso-yfti-tbllook: 1184; width: 542px;">
<thead>
<tr style="height: 34.95pt; mso-yfti-firstrow: yes; mso-yfti-irow: 0; page-break-inside: avoid;">
<td colspan="2" nowrap="" style="border: solid windowtext 1.0pt; height: 34.95pt; mso-border-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 194.25pt;" valign="top" width="259">
<div align="center" class="MsoNormal" style="text-align: center;">
<b><span style="color: #365f91; font-family: "Candara","sans-serif"; font-size: 12.0pt; mso-bidi-font-family: Arial; mso-bidi-font-size: 10.0pt; mso-themecolor: accent1; mso-themeshade: 191;">SATURDAY
MORNING<o:p></o:p></span></b></div>
<div align="center" class="MsoNormal" style="text-align: center;">
<b><span style="color: #00b0f0; font-family: "Candara","sans-serif"; font-size: 12.0pt; mso-bidi-font-family: Arial; mso-bidi-font-size: 10.0pt;">Performance Hall</span></b><span style="font-family: Candara, sans-serif; font-size: 12pt;"><o:p></o:p></span></div>
</td>
<td nowrap="" style="border-right: solid windowtext 1.0pt; border: none; height: 34.95pt; mso-border-left-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-right-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 14.15pt;" width="19"></td>
<td colspan="2" nowrap="" style="border-left: none; border: solid windowtext 1.0pt; height: 34.95pt; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 7.0cm;" valign="top" width="265">
<div align="center" class="MsoNormal" style="text-align: center;">
<b><span style="color: #365f91; font-family: "Candara","sans-serif"; font-size: 12.0pt; mso-bidi-font-family: Arial; mso-bidi-font-size: 10.0pt; mso-themecolor: accent1; mso-themeshade: 191;">SATURDAY
MORNING<o:p></o:p></span></b></div>
<div align="center" class="MsoNormal" style="text-align: center;">
<b><span style="color: #fabf8f; font-family: "Candara","sans-serif"; font-size: 12.0pt; mso-bidi-font-family: Arial; mso-bidi-font-size: 10.0pt; mso-themecolor: accent6; mso-themetint: 153;">Learning Room</span></b><span style="font-family: Candara, sans-serif; font-size: 12pt;"><o:p></o:p></span></div>
</td>
</tr>
<tr style="height: 94.5pt; mso-yfti-irow: 1; page-break-inside: avoid;">
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<div align="center" class="MsoNormal" style="text-align: center;">
<b><span style="font-family: "Candara","sans-serif"; mso-bidi-font-family: Arial; mso-bidi-font-size: 10.0pt;">Sat 10:00<o:p></o:p></span></b></div>
</td>
<td style="border-bottom: solid windowtext 1.0pt; border-left: none; border-right: solid windowtext 1.0pt; border-top: none; height: 94.5pt; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 156.35pt;" width="208">
<div class="MsoNormal">
<b><span style="font-family: Candara, sans-serif;">DR HELEN CZERSKI</span></b><span style="font-family: Candara, sans-serif;"><o:p></o:p></span></div>
<div class="MsoNormal">
<i><span style="font-family: Candara, sans-serif;">A WORLD OF SCIENCE TOYS<o:p></o:p></span></i></div>
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<br /></div>
<div class="MsoNormal">
<span style="font-family: Candara, sans-serif;"><v:shapetype coordsize="21600,21600" filled="f" id="_x0000_t75" o:preferrelative="t" o:spt="75" path="m@4@5l@4@11@9@11@9@5xe" stroked="f">
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</v:f></v:f></v:f></v:f></v:f></v:f></v:f></v:f></v:f></v:f></v:f></v:f></v:formulas>
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<b><span style="font-family: "Candara","sans-serif"; mso-bidi-font-family: Arial; mso-bidi-font-size: 10.0pt;">Sat 10:00<o:p></o:p></span></b></div>
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<div class="MsoNormal">
<b><span style="font-family: Candara, sans-serif;">DR JEN GUPTA</span></b><span style="font-family: Candara, sans-serif;"><o:p></o:p></span></div>
<div class="MsoNormal">
<i><span style="font-family: Candara, sans-serif;">STARGAZING TBC<o:p></o:p></span></i></div>
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<br /></div>
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</v:imagedata></v:shape></span><span style="font-family: Candara, sans-serif;"><o:p></o:p></span></div>
</td>
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<b><span style="font-family: "Candara","sans-serif"; mso-bidi-font-family: Arial; mso-bidi-font-size: 10.0pt;">Sat 11:00<o:p></o:p></span></b></div>
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<div class="MsoNormal">
<b><span style="font-family: Candara, sans-serif;">DR ADAM RUTHERFORD</span></b><span style="font-family: Candara, sans-serif;"> <o:p></o:p></span></div>
<div class="MsoNormal">
<i><span style="font-family: Candara, sans-serif;">CREATION: THE ORIGIN AND<o:p></o:p></span></i></div>
<div class="MsoNormal">
<i><span style="font-family: Candara, sans-serif;">THE FUTURE OF LIFE<o:p></o:p></span></i></div>
<div class="MsoNormal">
<br /></div>
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<span style="font-family: Candara, sans-serif;"><v:shape id="Picture_x0020_34" o:spid="_x0000_i1055" style="height: 86.25pt; mso-wrap-style: square; visibility: visible; width: 86.25pt;" type="#_x0000_t75">
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</td>
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<b><span style="font-family: "Candara","sans-serif"; mso-bidi-font-family: Arial; mso-bidi-font-size: 10.0pt;">Sat 11:00<o:p></o:p></span></b></div>
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<div class="MsoNormal">
<b><span style="font-family: Candara, sans-serif;">DR SIMON WATT</span></b><span style="font-family: Candara, sans-serif;"><o:p></o:p></span></div>
<div class="MsoNormal">
<i><span style="font-family: Candara, sans-serif;">SPERM WARFARE<o:p></o:p></span></i></div>
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<br /></div>
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<b><span style="font-family: "Candara","sans-serif"; mso-bidi-font-family: Arial; mso-bidi-font-size: 10.0pt;">Sat 12:00<o:p></o:p></span></b></div>
</td>
<td style="border-bottom: solid windowtext 1.0pt; border-left: none; border-right: solid windowtext 1.0pt; border-top: none; height: 94.5pt; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 156.35pt;" width="208">
<div class="MsoNormal">
<b><span style="font-family: Candara, sans-serif;">PROF DEBRA SKENE</span></b><span style="font-family: Candara, sans-serif;"><o:p></o:p></span></div>
<div class="MsoNormal">
<i><span style="font-family: Candara, sans-serif;">HOW YOUR BODY TELLS THE TIME<o:p></o:p></span></i></div>
<div class="MsoNormal">
<br /></div>
<div class="MsoNormal">
<span style="font-family: Candara, sans-serif;"><v:shape id="Picture_x0020_32" o:spid="_x0000_i1053" style="height: 86.25pt; mso-wrap-style: square; visibility: visible; width: 86.25pt;" type="#_x0000_t75">
<v:imagedata o:title="" src="file:///C:\DOCUME~1\Mark\LOCALS~1\Temp\msohtmlclip1\01\clip_image005.jpg">
</v:imagedata></v:shape></span><span style="font-family: Candara, sans-serif;"><o:p></o:p></span></div>
</td>
<td nowrap="" style="border-right: solid windowtext 1.0pt; border: none; height: 94.5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-right-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 14.15pt;" width="19"></td>
<td nowrap="" style="border-bottom: solid windowtext 1.0pt; border-left: none; border-right: solid windowtext 1.0pt; border-top: none; height: 94.5pt; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 35.45pt;" valign="top" width="47">
<div align="center" class="MsoNormal" style="text-align: center;">
<b><span style="font-family: "Candara","sans-serif"; mso-bidi-font-family: Arial; mso-bidi-font-size: 10.0pt;">Sat 12:00<o:p></o:p></span></b></div>
</td>
<td style="border-bottom: solid windowtext 1.0pt; border-left: none; border-right: solid windowtext 1.0pt; border-top: none; height: 94.5pt; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 163.0pt;" width="217">
<div class="MsoNormal">
<b><span style="font-family: Candara, sans-serif;">PROF BOB NICHOL</span></b><span style="font-family: Candara, sans-serif;"><o:p></o:p></span></div>
<div class="MsoNormal">
<i><span style="font-family: Candara, sans-serif;">SETI: THE SEARCH FOR<o:p></o:p></span></i></div>
<div class="MsoNormal">
<i><span style="font-family: Candara, sans-serif;">EXTRATERRESTRIAL LIFE<o:p></o:p></span></i></div>
<div class="MsoNormal">
<br /></div>
<div class="MsoNormal">
<span style="font-family: Candara, sans-serif;"><v:shape id="Picture_x0020_7" o:spid="_x0000_i1052" style="height: 86.25pt; mso-wrap-style: square; visibility: visible; width: 81.75pt;" type="#_x0000_t75">
<v:imagedata o:title="" src="file:///C:\DOCUME~1\Mark\LOCALS~1\Temp\msohtmlclip1\01\clip_image006.jpg">
</v:imagedata></v:shape></span><span style="font-family: Candara, sans-serif;"><o:p></o:p></span></div>
</td>
</tr>
<tr style="height: 13.75pt; mso-yfti-irow: 4; page-break-inside: avoid;">
<td nowrap="" style="border-bottom: solid windowtext 1.0pt; border: none; height: 13.75pt; mso-border-bottom-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 37.9pt;" valign="top" width="51"></td>
<td style="border-bottom: solid windowtext 1.0pt; border: none; height: 13.75pt; mso-border-bottom-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 156.35pt;" width="208"></td>
<td nowrap="" style="border: none; height: 13.75pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 14.15pt;" width="19"></td>
<td nowrap="" style="border-bottom: solid windowtext 1.0pt; border: none; height: 13.75pt; mso-border-bottom-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 35.45pt;" valign="top" width="47"></td>
<td style="border-bottom: solid windowtext 1.0pt; border: none; height: 13.75pt; mso-border-bottom-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 163.0pt;" width="217"></td>
</tr>
<tr style="height: 29.75pt; mso-yfti-irow: 5; page-break-inside: avoid;">
<td colspan="2" nowrap="" style="border-top: none; border: solid windowtext 1.0pt; height: 29.75pt; mso-border-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 194.25pt;" valign="top" width="259">
<div align="center" class="MsoNormal" style="text-align: center;">
<b><span style="color: #365f91; font-family: "Candara","sans-serif"; font-size: 12.0pt; mso-bidi-font-family: Arial; mso-bidi-font-size: 10.0pt; mso-themecolor: accent1; mso-themeshade: 191;">SATURDAY
AFTERNOON<o:p></o:p></span></b></div>
<div align="center" class="MsoNormal" style="text-align: center;">
<b><span style="color: #00b0f0; font-family: "Candara","sans-serif"; font-size: 12.0pt; mso-bidi-font-family: Arial; mso-bidi-font-size: 10.0pt;">Performance Hall</span></b><span style="font-family: Candara, sans-serif; font-size: 12pt;"><o:p></o:p></span></div>
</td>
<td nowrap="" style="border-right: solid windowtext 1.0pt; border: none; height: 29.75pt; mso-border-left-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-right-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 14.15pt;" width="19"></td>
<td colspan="2" nowrap="" style="border-bottom: solid windowtext 1.0pt; border-left: none; border-right: solid windowtext 1.0pt; border-top: none; height: 29.75pt; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 7.0cm;" valign="top" width="265">
<div align="center" class="MsoNormal" style="text-align: center;">
<b><span style="color: #365f91; font-family: "Candara","sans-serif"; font-size: 12.0pt; mso-bidi-font-family: Arial; mso-bidi-font-size: 10.0pt; mso-themecolor: accent1; mso-themeshade: 191;">SATURDAY
AFTERNOON<o:p></o:p></span></b></div>
<div align="center" class="MsoNormal" style="text-align: center;">
<b><span style="color: #fabf8f; font-family: "Candara","sans-serif"; font-size: 12.0pt; mso-bidi-font-family: Arial; mso-bidi-font-size: 10.0pt; mso-themecolor: accent6; mso-themetint: 153;">Learning Room</span></b><span style="font-family: Candara, sans-serif; font-size: 12pt;"><o:p></o:p></span></div>
</td>
</tr>
<tr style="height: 94.5pt; mso-yfti-irow: 6; page-break-inside: avoid;">
<td nowrap="" style="border-top: none; border: solid windowtext 1.0pt; height: 94.5pt; mso-border-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 37.9pt;" valign="top" width="51">
<div align="center" class="MsoNormal" style="text-align: center;">
<b><span style="font-family: "Candara","sans-serif"; mso-bidi-font-family: Arial; mso-bidi-font-size: 10.0pt;">Sat 14:00<o:p></o:p></span></b></div>
</td>
<td style="border-bottom: solid windowtext 1.0pt; border-left: none; border-right: solid windowtext 1.0pt; border-top: none; height: 94.5pt; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 156.35pt;" width="208">
<div class="MsoNormal">
<b><span style="font-family: Candara, sans-serif;">PROF MARK MIODOWNIK</span></b><span style="font-family: Candara, sans-serif;"><o:p></o:p></span></div>
<div class="MsoNormal">
<i><span style="font-family: Candara, sans-serif;">STUFF MATTERS<o:p></o:p></span></i></div>
<div class="MsoNormal">
<br /></div>
<div class="MsoNormal">
<span style="font-family: Candara, sans-serif;"><v:shape id="Picture_x0020_31" o:spid="_x0000_i1051" style="height: 86.25pt; mso-wrap-style: square; visibility: visible; width: 86.25pt;" type="#_x0000_t75">
<v:imagedata o:title="" src="file:///C:\DOCUME~1\Mark\LOCALS~1\Temp\msohtmlclip1\01\clip_image007.jpg">
</v:imagedata></v:shape></span><span style="font-family: Candara, sans-serif;"><o:p></o:p></span></div>
</td>
<td nowrap="" style="border-right: solid windowtext 1.0pt; border: none; height: 94.5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-right-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 14.15pt;" width="19"></td>
<td nowrap="" style="border-bottom: solid windowtext 1.0pt; border-left: none; border-right: solid windowtext 1.0pt; border-top: none; height: 94.5pt; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 35.45pt;" valign="top" width="47">
<div align="center" class="MsoNormal" style="text-align: center;">
<b><span style="font-family: "Candara","sans-serif"; mso-bidi-font-family: Arial; mso-bidi-font-size: 10.0pt;">Sat 14:00<o:p></o:p></span></b></div>
</td>
<td style="border-left: none; border: solid windowtext 1.0pt; height: 94.5pt; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 163.0pt;" width="217">
<div class="MsoNormal">
<b><span style="font-family: Candara, sans-serif;">ALAN LAWRIE</span></b><span style="font-family: Candara, sans-serif;"><o:p></o:p></span></div>
<div class="MsoNormal">
<i><span style="font-family: Candara, sans-serif;">SECRETS OF THE SATURN V<o:p></o:p></span></i></div>
<div class="MsoNormal">
<br /></div>
<div class="MsoNormal">
<span style="font-family: Candara, sans-serif;"><v:shape id="Picture_x0020_6" o:spid="_x0000_i1050" style="height: 86.25pt; mso-wrap-style: square; visibility: visible; width: 81.75pt;" type="#_x0000_t75">
<v:imagedata o:title="" src="file:///C:\DOCUME~1\Mark\LOCALS~1\Temp\msohtmlclip1\01\clip_image008.jpg">
</v:imagedata></v:shape></span><span style="font-family: Candara, sans-serif;"><o:p></o:p></span></div>
</td>
</tr>
<tr style="height: 94.5pt; mso-yfti-irow: 7; page-break-inside: avoid;">
<td nowrap="" style="border-top: none; border: solid windowtext 1.0pt; height: 94.5pt; mso-border-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 37.9pt;" valign="top" width="51">
<div align="center" class="MsoNormal" style="text-align: center;">
<b><span style="font-family: "Candara","sans-serif"; mso-bidi-font-family: Arial; mso-bidi-font-size: 10.0pt;">Sat 15:00<o:p></o:p></span></b></div>
</td>
<td style="border-bottom: solid windowtext 1.0pt; border-left: none; border-right: solid windowtext 1.0pt; border-top: none; height: 94.5pt; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 156.35pt;" width="208">
<div class="MsoNormal">
<b><span style="font-family: Candara, sans-serif;">ROBERT LLEWELLYN</span></b><span style="font-family: Candara, sans-serif;"><o:p></o:p></span></div>
<div class="MsoNormal">
<i><span style="font-family: Candara, sans-serif;">ELECTRIC CARS ARE RUBBISH,<o:p></o:p></span></i></div>
<div class="MsoNormal">
<i><span style="font-family: Candara, sans-serif;">AREN'T THEY?<o:p></o:p></span></i></div>
<div class="MsoNormal">
<br /></div>
<div class="MsoNormal">
<span style="font-family: Candara, sans-serif;"><v:shape id="Picture_x0020_15" o:spid="_x0000_i1049" style="height: 86.25pt; mso-wrap-style: square; visibility: visible; width: 87.75pt;" type="#_x0000_t75">
<v:imagedata o:title="" src="file:///C:\DOCUME~1\Mark\LOCALS~1\Temp\msohtmlclip1\01\clip_image009.jpg">
</v:imagedata></v:shape></span><span style="font-family: Candara, sans-serif;"><o:p></o:p></span></div>
</td>
<td nowrap="" style="border-right: solid windowtext 1.0pt; border: none; height: 94.5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-right-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 14.15pt;" width="19"></td>
<td nowrap="" style="border-bottom: solid windowtext 1.0pt; border-left: none; border-right: solid windowtext 1.0pt; border-top: none; height: 94.5pt; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 35.45pt;" valign="top" width="47">
<div align="center" class="MsoNormal" style="text-align: center;">
<b><span style="font-family: "Candara","sans-serif"; mso-bidi-font-family: Arial; mso-bidi-font-size: 10.0pt;">Sat 15:00<o:p></o:p></span></b></div>
</td>
<td style="border-bottom: solid windowtext 1.0pt; border-left: none; border-right: solid windowtext 1.0pt; border-top: none; height: 94.5pt; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 163.0pt;" width="217">
<div class="MsoNormal">
<b><span style="font-family: Candara, sans-serif;">BEN LITTLEFIELD</span></b><span style="font-family: Candara, sans-serif;"><o:p></o:p></span></div>
<div class="MsoNormal">
<i><span style="font-family: Candara, sans-serif;">STRONGER, GREENER, FASTER<o:p></o:p></span></i></div>
<div class="MsoNormal">
<br /></div>
<div class="MsoNormal">
<span style="font-family: Candara, sans-serif;"><v:shape id="Picture_x0020_30" o:spid="_x0000_i1048" style="height: 86.25pt; mso-wrap-style: square; visibility: visible; width: 81.75pt;" type="#_x0000_t75">
<v:imagedata o:title="" src="file:///C:\DOCUME~1\Mark\LOCALS~1\Temp\msohtmlclip1\01\clip_image010.jpg">
</v:imagedata></v:shape></span><span style="font-family: Candara, sans-serif;"><o:p></o:p></span></div>
</td>
</tr>
<tr style="height: 185.6pt; mso-yfti-irow: 8; page-break-inside: avoid;">
<td nowrap="" style="border-top: none; border: solid windowtext 1.0pt; height: 185.6pt; mso-border-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 37.9pt;" valign="top" width="51">
<div align="center" class="MsoNormal" style="text-align: center;">
<b><span style="font-family: "Candara","sans-serif"; mso-bidi-font-family: Arial; mso-bidi-font-size: 10.0pt;">Sat 16:00<o:p></o:p></span></b></div>
</td>
<td style="border-bottom: solid windowtext 1.0pt; border-left: none; border-right: solid windowtext 1.0pt; border-top: none; height: 185.6pt; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 156.35pt;" width="208">
<div class="MsoNormal">
<b><span style="font-family: Candara, sans-serif;">PROFESSOR BRUCE HOOD</span></b><span style="font-family: Candara, sans-serif;"><o:p></o:p></span></div>
<div class="MsoNormal">
<i><span style="font-family: Candara, sans-serif;">THE SELF ILLUSION<o:p></o:p></span></i></div>
<div class="MsoNormal">
<br /></div>
<div class="MsoNormal">
<span style="font-family: Candara, sans-serif;"><v:shape id="Picture_x0020_23" o:spid="_x0000_i1047" style="height: 85.5pt; mso-wrap-style: square; visibility: visible; width: 86.25pt;" type="#_x0000_t75">
<v:imagedata o:title="" src="file:///C:\DOCUME~1\Mark\LOCALS~1\Temp\msohtmlclip1\01\clip_image011.jpg">
</v:imagedata></v:shape></span><span style="font-family: Candara, sans-serif;"><o:p></o:p></span></div>
</td>
<td nowrap="" style="border-right: solid windowtext 1.0pt; border: none; height: 185.6pt; mso-border-left-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-right-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 14.15pt;" width="19"></td>
<td nowrap="" style="border-bottom: solid windowtext 1.0pt; border-left: none; border-right: solid windowtext 1.0pt; border-top: none; height: 185.6pt; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 35.45pt;" valign="top" width="47">
<div align="center" class="MsoNormal" style="text-align: center;">
<b><span style="font-family: "Candara","sans-serif"; mso-bidi-font-family: Arial; mso-bidi-font-size: 10.0pt;">Sat 16:00<o:p></o:p></span></b></div>
</td>
<td style="border-bottom: solid windowtext 1.0pt; border-left: none; border-right: solid windowtext 1.0pt; border-top: none; height: 185.6pt; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 163.0pt;" width="217">
<div class="MsoNormal">
<b><span style="font-family: Candara, sans-serif;">DR ED WAUGH</span></b><span style="font-family: Candara, sans-serif;"><o:p></o:p></span></div>
<div class="MsoNormal">
<i><span style="font-family: Candara, sans-serif;">DRILLING IN ANTARCTICA:<o:p></o:p></span></i></div>
<div class="MsoNormal">
<i><span style="font-family: Candara, sans-serif;">THE LAKE ELLSWORTH PROJECT<o:p></o:p></span></i></div>
<div class="MsoNormal">
<br /></div>
<div class="MsoNormal">
<span style="font-family: Candara, sans-serif;"><v:shape id="Picture_x0020_5" o:spid="_x0000_i1046" style="height: 85.5pt; mso-wrap-style: square; visibility: visible; width: 81.75pt;" type="#_x0000_t75">
<v:imagedata o:title="" src="file:///C:\DOCUME~1\Mark\LOCALS~1\Temp\msohtmlclip1\01\clip_image012.jpg">
</v:imagedata></v:shape></span><span style="font-family: Candara, sans-serif;"><o:p></o:p></span></div>
</td>
</tr>
<tr style="height: 94.5pt; mso-yfti-irow: 9; page-break-inside: avoid;">
<td nowrap="" style="border-top: none; border: solid windowtext 1.0pt; height: 94.5pt; mso-border-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 37.9pt;" valign="top" width="51">
<div align="center" class="MsoNormal" style="text-align: center;">
<b><span style="font-family: "Candara","sans-serif"; mso-bidi-font-family: Arial; mso-bidi-font-size: 10.0pt;">Sat 17:00<o:p></o:p></span></b></div>
</td>
<td style="border-bottom: solid windowtext 1.0pt; border-left: none; border-right: solid windowtext 1.0pt; border-top: none; height: 94.5pt; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 156.35pt;" width="208">
<div class="MsoNormal">
<b><span style="font-family: Candara, sans-serif;">MAGGIE PHILBIN</span></b><span style="font-family: Candara, sans-serif;"><o:p></o:p></span></div>
<div class="MsoNormal">
<i><span style="font-family: Candara, sans-serif;">TEENTECH<o:p></o:p></span></i></div>
<div class="MsoNormal">
<br /></div>
<div class="MsoNormal">
<span style="font-family: Candara, sans-serif;"><v:shape id="Picture_x0020_4" o:spid="_x0000_i1045" style="height: 85.5pt; mso-wrap-style: square; visibility: visible; width: 86.25pt;" type="#_x0000_t75">
<v:imagedata o:title="" src="file:///C:\DOCUME~1\Mark\LOCALS~1\Temp\msohtmlclip1\01\clip_image013.jpg">
</v:imagedata></v:shape></span><span style="font-family: Candara, sans-serif;"><o:p></o:p></span></div>
</td>
<td nowrap="" style="border: none; height: 94.5pt; mso-border-left-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 14.15pt;" width="19"></td>
<td nowrap="" style="border: none; height: 94.5pt; mso-border-top-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 35.45pt;" valign="top" width="47"></td>
<td style="border: none; height: 94.5pt; mso-border-top-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 163.0pt;" width="217"></td>
</tr>
<tr style="height: 10.15pt; mso-yfti-irow: 10; page-break-inside: avoid;">
<td nowrap="" style="border-bottom: solid windowtext 1.0pt; border: none; height: 10.15pt; mso-border-bottom-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 37.9pt;" valign="top" width="51"></td>
<td style="border-bottom: solid windowtext 1.0pt; border: none; height: 10.15pt; mso-border-bottom-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 156.35pt;" width="208"></td>
<td nowrap="" style="border: none; height: 10.15pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 14.15pt;" width="19"></td>
<td nowrap="" style="border-bottom: solid windowtext 1.0pt; border: none; height: 10.15pt; mso-border-bottom-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 35.45pt;" valign="top" width="47"></td>
<td style="border-bottom: solid windowtext 1.0pt; border: none; height: 10.15pt; mso-border-bottom-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 163.0pt;" width="217"></td>
</tr>
<tr style="height: 29.75pt; mso-yfti-irow: 11; page-break-inside: avoid;">
<td colspan="2" nowrap="" style="border-top: none; border: solid windowtext 1.0pt; height: 29.75pt; mso-border-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 194.25pt;" valign="top" width="259">
<div align="center" class="MsoNormal" style="text-align: center;">
<b><span style="color: #365f91; font-family: "Candara","sans-serif"; font-size: 12.0pt; mso-bidi-font-family: Arial; mso-bidi-font-size: 10.0pt; mso-themecolor: accent1; mso-themeshade: 191;">SUNDAY
MORNING<o:p></o:p></span></b></div>
<div align="center" class="MsoNormal" style="text-align: center;">
<b><span style="color: #00b0f0; font-family: "Candara","sans-serif"; font-size: 12.0pt; mso-bidi-font-family: Arial; mso-bidi-font-size: 10.0pt;">Performance Hall</span></b><span style="font-family: Candara, sans-serif; font-size: 12pt;"><o:p></o:p></span></div>
</td>
<td nowrap="" style="border-right: solid windowtext 1.0pt; border: none; height: 29.75pt; mso-border-left-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-right-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 14.15pt;" width="19"></td>
<td colspan="2" nowrap="" style="border-bottom: solid windowtext 1.0pt; border-left: none; border-right: solid windowtext 1.0pt; border-top: none; height: 29.75pt; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 7.0cm;" valign="top" width="265">
<div align="center" class="MsoNormal" style="text-align: center;">
<b><span style="color: #365f91; font-family: "Candara","sans-serif"; font-size: 12.0pt; mso-bidi-font-family: Arial; mso-bidi-font-size: 10.0pt; mso-themecolor: accent1; mso-themeshade: 191;">SUNDAY
MORNING<o:p></o:p></span></b></div>
<div align="center" class="MsoNormal" style="text-align: center;">
<b><span style="color: #fabf8f; font-family: "Candara","sans-serif"; font-size: 12.0pt; mso-bidi-font-family: Arial; mso-bidi-font-size: 10.0pt; mso-themecolor: accent6; mso-themetint: 153;">Learning Room</span></b><span style="font-family: Candara, sans-serif; font-size: 12pt;"><o:p></o:p></span></div>
</td>
</tr>
<tr style="height: 94.5pt; mso-yfti-irow: 12; page-break-inside: avoid;">
<td nowrap="" style="border-top: none; border: solid windowtext 1.0pt; height: 94.5pt; mso-border-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 37.9pt;" valign="top" width="51">
<div align="center" class="MsoNormal" style="text-align: center;">
<b><span style="font-family: "Candara","sans-serif"; mso-bidi-font-family: Arial; mso-bidi-font-size: 10.0pt;">Sun 10:00<o:p></o:p></span></b></div>
</td>
<td style="border-bottom: solid windowtext 1.0pt; border-left: none; border-right: solid windowtext 1.0pt; border-top: none; height: 94.5pt; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 156.35pt;" width="208">
<div class="MsoNormal">
<b><span style="font-family: Candara, sans-serif;">DR TOM CRICK</span></b><span style="font-family: Candara, sans-serif;"><o:p></o:p></span></div>
<div class="MsoNormal">
<i><span style="font-family: Candara, sans-serif;">COMPUTING: THE SCIENCE OF<o:p></o:p></span></i></div>
<div class="MsoNormal">
<i><span style="font-family: Candara, sans-serif;">NEARLY EVERYTHING<o:p></o:p></span></i></div>
<div class="MsoNormal">
<br /></div>
<div class="MsoNormal">
<span style="font-family: Candara, sans-serif;"><v:shape id="Picture_x0020_10" o:spid="_x0000_i1044" style="height: 85.5pt; mso-wrap-style: square; visibility: visible; width: 85.5pt;" type="#_x0000_t75">
<v:imagedata o:title="" src="file:///C:\DOCUME~1\Mark\LOCALS~1\Temp\msohtmlclip1\01\clip_image014.jpg">
</v:imagedata></v:shape></span><span style="font-family: Candara, sans-serif;"><o:p></o:p></span></div>
</td>
<td nowrap="" style="border: none; height: 94.5pt; mso-border-left-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 14.15pt;" width="19"></td>
<td nowrap="" style="border: none; height: 94.5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 35.45pt;" valign="top" width="47"></td>
<td style="border: none; height: 94.5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 163.0pt;" width="217"></td>
</tr>
<tr style="height: 94.5pt; mso-yfti-irow: 13; page-break-inside: avoid;">
<td nowrap="" style="border-top: none; border: solid windowtext 1.0pt; height: 94.5pt; mso-border-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 37.9pt;" valign="top" width="51">
<div align="center" class="MsoNormal" style="text-align: center;">
<b><span style="font-family: "Candara","sans-serif"; mso-bidi-font-family: Arial; mso-bidi-font-size: 10.0pt;">Sun 11:00<o:p></o:p></span></b></div>
</td>
<td style="border-bottom: solid windowtext 1.0pt; border-left: none; border-right: solid windowtext 1.0pt; border-top: none; height: 94.5pt; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 156.35pt;" width="208">
<div class="MsoNormal">
<b><span style="font-family: Candara, sans-serif;">DR DEAN BURNETT</span></b><span style="font-family: Candara, sans-serif;"><o:p></o:p></span></div>
<div class="MsoNormal">
<i><span style="font-family: Candara, sans-serif;">BRAINS, I AM IN YOU!<o:p></o:p></span></i></div>
<div class="MsoNormal">
<br /></div>
<div class="MsoNormal">
<span style="font-family: Candara, sans-serif;"><v:shape id="Picture_x0020_22" o:spid="_x0000_i1043" style="height: 86.25pt; mso-wrap-style: square; visibility: visible; width: 86.25pt;" type="#_x0000_t75">
<v:imagedata o:title="" src="file:///C:\DOCUME~1\Mark\LOCALS~1\Temp\msohtmlclip1\01\clip_image015.jpg">
</v:imagedata></v:shape></span><span style="font-family: Candara, sans-serif;"><o:p></o:p></span></div>
</td>
<td nowrap="" style="border: none; height: 94.5pt; mso-border-left-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 14.15pt;" width="19"></td>
<td nowrap="" style="border: none; height: 94.5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 35.45pt;" valign="top" width="47"></td>
<td style="border: none; height: 94.5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 163.0pt;" width="217"></td>
</tr>
<tr style="height: 94.5pt; mso-yfti-irow: 14; page-break-inside: avoid;">
<td nowrap="" style="border-top: none; border: solid windowtext 1.0pt; height: 94.5pt; mso-border-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 37.9pt;" valign="top" width="51">
<div align="center" class="MsoNormal" style="text-align: center;">
<b><span style="font-family: "Candara","sans-serif"; mso-bidi-font-family: Arial; mso-bidi-font-size: 10.0pt;">Sun 12:00<o:p></o:p></span></b></div>
</td>
<td style="border-bottom: solid windowtext 1.0pt; border-left: none; border-right: solid windowtext 1.0pt; border-top: none; height: 94.5pt; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 156.35pt;" width="208">
<div class="MsoNormal">
<b><span style="font-family: Candara, sans-serif;">DR LISA MCNEILL</span></b><span style="font-family: Candara, sans-serif;"><o:p></o:p></span></div>
<div class="MsoNormal">
<i><span style="font-family: Candara, sans-serif;">NO MARGIN FOR ERROR<o:p></o:p></span></i></div>
<div class="MsoNormal">
<br /></div>
<div class="MsoNormal">
<span style="font-family: Candara, sans-serif;"><v:shape id="Picture_x0020_14" o:spid="_x0000_i1042" style="height: 86.25pt; mso-wrap-style: square; visibility: visible; width: 86.25pt;" type="#_x0000_t75">
<v:imagedata o:title="" src="file:///C:\DOCUME~1\Mark\LOCALS~1\Temp\msohtmlclip1\01\clip_image016.jpg">
</v:imagedata></v:shape></span><span style="font-family: Candara, sans-serif;"><o:p></o:p></span></div>
</td>
<td nowrap="" style="border: none; height: 94.5pt; mso-border-left-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 14.15pt;" width="19"></td>
<td nowrap="" style="border: none; height: 94.5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 35.45pt;" width="47"></td>
<td style="border: none; height: 94.5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 163.0pt;" valign="top" width="217"></td>
</tr>
<tr style="height: 18.05pt; mso-yfti-irow: 15; page-break-inside: avoid;">
<td nowrap="" style="border-bottom: solid windowtext 1.0pt; border: none; height: 18.05pt; mso-border-bottom-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 37.9pt;" valign="top" width="51"></td>
<td style="border-bottom: solid windowtext 1.0pt; border: none; height: 18.05pt; mso-border-bottom-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 156.35pt;" width="208"></td>
<td nowrap="" style="border: none; height: 18.05pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 14.15pt;" width="19"></td>
<td nowrap="" style="border-bottom: solid windowtext 1.0pt; border: none; height: 18.05pt; mso-border-bottom-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 35.45pt;" width="47"></td>
<td style="border-bottom: solid windowtext 1.0pt; border: none; height: 18.05pt; mso-border-bottom-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 163.0pt;" valign="top" width="217"></td>
</tr>
<tr style="height: 29.75pt; mso-yfti-irow: 16; page-break-inside: avoid;">
<td colspan="2" nowrap="" style="border-top: none; border: solid windowtext 1.0pt; height: 29.75pt; mso-border-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 194.25pt;" valign="top" width="259">
<div align="center" class="MsoNormal" style="text-align: center;">
<b><span style="color: #365f91; font-family: "Candara","sans-serif"; font-size: 12.0pt; mso-bidi-font-family: Arial; mso-bidi-font-size: 10.0pt; mso-themecolor: accent1; mso-themeshade: 191;">SUNDAY AFTERNOON<o:p></o:p></span></b></div>
<div align="center" class="MsoNormal" style="text-align: center;">
<b><span style="color: #00b0f0; font-family: "Candara","sans-serif"; font-size: 12.0pt; mso-bidi-font-family: Arial; mso-bidi-font-size: 10.0pt;">Performance Hall</span></b><span style="font-family: Candara, sans-serif; font-size: 12pt;"><o:p></o:p></span></div>
</td>
<td nowrap="" style="border-right: solid windowtext 1.0pt; border: none; height: 29.75pt; mso-border-left-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-right-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 14.15pt;" width="19"></td>
<td colspan="2" nowrap="" style="border-bottom: solid windowtext 1.0pt; border-left: none; border-right: solid windowtext 1.0pt; border-top: none; height: 29.75pt; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 7.0cm;" valign="top" width="265">
<div align="center" class="MsoNormal" style="text-align: center;">
<b><span style="color: #365f91; font-family: "Candara","sans-serif"; font-size: 12.0pt; mso-bidi-font-family: Arial; mso-bidi-font-size: 10.0pt; mso-themecolor: accent1; mso-themeshade: 191;">SUNDAY AFTERNOON<o:p></o:p></span></b></div>
<div align="center" class="MsoNormal" style="text-align: center;">
<b><span style="color: #fabf8f; font-family: "Candara","sans-serif"; font-size: 12.0pt; mso-bidi-font-family: Arial; mso-bidi-font-size: 10.0pt; mso-themecolor: accent6; mso-themetint: 153;">Learning Room</span></b><span style="font-family: Candara, sans-serif; font-size: 12pt;"><o:p></o:p></span></div>
</td>
</tr>
<tr style="height: 94.5pt; mso-yfti-irow: 17; page-break-inside: avoid;">
<td nowrap="" style="border-top: none; border: solid windowtext 1.0pt; height: 94.5pt; mso-border-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 37.9pt;" valign="top" width="51">
<div align="center" class="MsoNormal" style="text-align: center;">
<b><span style="font-family: "Candara","sans-serif"; mso-bidi-font-family: Arial; mso-bidi-font-size: 10.0pt;">Sun 14:00<o:p></o:p></span></b></div>
</td>
<td style="border-bottom: solid windowtext 1.0pt; border-left: none; border-right: solid windowtext 1.0pt; border-top: none; height: 94.5pt; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 156.35pt;" width="208">
<div class="MsoNormal">
<b><span style="font-family: Candara, sans-serif;">PROF COLM MULCAHY</span></b><span style="font-family: Candara, sans-serif;"> <o:p></o:p></span></div>
<div class="MsoNormal">
<i><span style="font-family: Candara, sans-serif;">MATHEMAGIC WITH<o:p></o:p></span></i></div>
<div class="MsoNormal">
<i><span style="font-family: Candara, sans-serif;">A DECK OF CARDS<o:p></o:p></span></i></div>
<div class="MsoNormal">
<br /></div>
<div class="MsoNormal">
<span style="font-family: Candara, sans-serif;"><v:shape alt="Colm Mulcahy" id="_x0000_i1041" style="height: 84.75pt; mso-wrap-style: square; visibility: visible; width: 80.25pt;" type="#_x0000_t75">
<v:imagedata o:title="Colm Mulcahy" src="file:///C:\DOCUME~1\Mark\LOCALS~1\Temp\msohtmlclip1\01\clip_image017.jpg">
</v:imagedata></v:shape></span><span style="font-family: Candara, sans-serif;"><o:p></o:p></span></div>
</td>
<td nowrap="" style="border-right: solid windowtext 1.0pt; border: none; height: 94.5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-right-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 14.15pt;" width="19"></td>
<td nowrap="" style="border-bottom: solid windowtext 1.0pt; border-left: none; border-right: solid windowtext 1.0pt; border-top: none; height: 94.5pt; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 35.45pt;" valign="top" width="47">
<div align="center" class="MsoNormal" style="text-align: center;">
<b><span style="font-family: "Candara","sans-serif"; mso-bidi-font-family: Arial; mso-bidi-font-size: 10.0pt;">Sun 14:00<o:p></o:p></span></b></div>
</td>
<td style="border-left: none; border: solid windowtext 1.0pt; height: 94.5pt; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 163.0pt;" width="217">
<div class="MsoNormal">
<b><span style="font-family: Candara, sans-serif;">MEGAN WHEWELL</span></b><span style="font-family: Candara, sans-serif;"><o:p></o:p></span></div>
<div class="MsoNormal">
<i><span style="font-family: Candara, sans-serif;">HOW DO WE KNOW<o:p></o:p></span></i></div>
<div class="MsoNormal">
<i><span style="font-family: Candara, sans-serif;">WE LANDED ON THE MOON<o:p></o:p></span></i></div>
<div class="MsoNormal">
<br /></div>
<div class="MsoNormal">
<span style="font-family: Candara, sans-serif;"><v:shape id="_x0000_i1040" style="height: 86.25pt; mso-wrap-style: square; visibility: visible; width: 81.75pt;" type="#_x0000_t75">
<v:imagedata o:title="" src="file:///C:\DOCUME~1\Mark\LOCALS~1\Temp\msohtmlclip1\01\clip_image018.jpg">
</v:imagedata></v:shape></span><span style="font-family: Candara, sans-serif;"><o:p></o:p></span></div>
</td>
</tr>
<tr style="height: 94.5pt; mso-yfti-irow: 18; page-break-inside: avoid;">
<td nowrap="" style="border-top: none; border: solid windowtext 1.0pt; height: 94.5pt; mso-border-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 37.9pt;" valign="top" width="51">
<div align="center" class="MsoNormal" style="text-align: center;">
<b><span style="font-family: "Candara","sans-serif"; mso-bidi-font-family: Arial; mso-bidi-font-size: 10.0pt;">Sun 15:00<o:p></o:p></span></b></div>
</td>
<td style="border-bottom: solid windowtext 1.0pt; border-left: none; border-right: solid windowtext 1.0pt; border-top: none; height: 94.5pt; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 156.35pt;" width="208">
<div class="MsoNormal">
<b><span style="font-family: Candara, sans-serif;">PROF DOROTHY BISHOP</span></b><span style="font-family: Candara, sans-serif;"><o:p></o:p></span></div>
<div class="MsoNormal">
<i><span style="font-family: Candara, sans-serif;">THE REF, IMPACT FACTORS,<o:p></o:p></span></i></div>
<div class="MsoNormal">
<i><span style="font-family: Candara, sans-serif;">AND OTHER DAMAGING TRENDS: THOUGHTS
FROM<o:p></o:p></span></i></div>
<div class="MsoNormal">
<i><span style="font-family: Candara, sans-serif;">A GRUMPY OLD SCIENTIST<o:p></o:p></span></i></div>
<div class="MsoNormal">
<br /></div>
<div class="MsoNormal">
<span style="font-family: Candara, sans-serif;"><v:shape alt="Dorothy Bishop" id="_x0000_i1039" style="height: 84.75pt; mso-wrap-style: square; visibility: visible; width: 80.25pt;" type="#_x0000_t75">
<v:imagedata o:title="Dorothy Bishop" src="file:///C:\DOCUME~1\Mark\LOCALS~1\Temp\msohtmlclip1\01\clip_image019.jpg">
</v:imagedata></v:shape></span><span style="font-family: Candara, sans-serif;"><o:p></o:p></span></div>
</td>
<td nowrap="" style="border-right: solid windowtext 1.0pt; border: none; height: 94.5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-right-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 14.15pt;" width="19"></td>
<td nowrap="" style="border-bottom: solid windowtext 1.0pt; border-left: none; border-right: solid windowtext 1.0pt; border-top: none; height: 94.5pt; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 35.45pt;" valign="top" width="47">
<div align="center" class="MsoNormal" style="text-align: center;">
<b><span style="font-family: "Candara","sans-serif"; mso-bidi-font-family: Arial; mso-bidi-font-size: 10.0pt;">Sun 15:00<o:p></o:p></span></b></div>
</td>
<td style="border-bottom: solid windowtext 1.0pt; border-left: none; border-right: solid windowtext 1.0pt; border-top: none; height: 94.5pt; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 163.0pt;" width="217">
<div class="MsoNormal">
<b><span style="font-family: Candara, sans-serif;">DR MATTHEW WRIGHT</span></b><span style="font-family: Candara, sans-serif;"><o:p></o:p></span></div>
<div class="MsoNormal">
<i><span style="font-family: Candara, sans-serif;">HOW SCIENCE SHAPED MUSIC<o:p></o:p></span></i></div>
<div class="MsoNormal">
<br /></div>
<div class="MsoNormal">
<span style="font-family: Candara, sans-serif;"><v:shape id="Picture_x0020_2" o:spid="_x0000_i1038" style="height: 86.25pt; mso-wrap-style: square; visibility: visible; width: 81.75pt;" type="#_x0000_t75">
<v:imagedata o:title="" src="file:///C:\DOCUME~1\Mark\LOCALS~1\Temp\msohtmlclip1\01\clip_image020.jpg">
</v:imagedata></v:shape></span><span style="font-family: Candara, sans-serif;"><o:p></o:p></span></div>
</td>
</tr>
<tr style="height: 94.5pt; mso-yfti-irow: 19; page-break-inside: avoid;">
<td nowrap="" style="border-top: none; border: solid windowtext 1.0pt; height: 94.5pt; mso-border-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 37.9pt;" valign="top" width="51">
<div align="center" class="MsoNormal" style="text-align: center;">
<b><span style="font-family: "Candara","sans-serif"; mso-bidi-font-family: Arial; mso-bidi-font-size: 10.0pt;">Sun 16:00<o:p></o:p></span></b></div>
</td>
<td style="border-bottom: solid windowtext 1.0pt; border-left: none; border-right: solid windowtext 1.0pt; border-top: none; height: 94.5pt; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 156.35pt;" width="208">
<div class="MsoNormal">
<b><span style="font-family: Candara, sans-serif;">DR SIMON WATT</span></b><span style="font-family: Candara, sans-serif;"><o:p></o:p></span></div>
<div class="MsoNormal">
<i><span style="font-family: Candara, sans-serif;">WHY WE DIE...,<o:p></o:p></span></i></div>
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<br /></div>
<div class="MsoNormal">
<span style="font-family: Candara, sans-serif;"><v:shape id="Picture_x0020_33" o:spid="_x0000_i1037" style="height: 86.25pt; mso-wrap-style: square; visibility: visible; width: 86.25pt;" type="#_x0000_t75">
<v:imagedata o:title="" src="file:///C:\DOCUME~1\Mark\LOCALS~1\Temp\msohtmlclip1\01\clip_image004.jpg">
</v:imagedata></v:shape></span><span style="font-family: Candara, sans-serif;"><o:p></o:p></span></div>
</td>
<td nowrap="" style="border: none; height: 94.5pt; mso-border-left-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 14.15pt;" width="19"></td>
<td nowrap="" style="border: none; height: 94.5pt; mso-border-top-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 35.45pt;" valign="top" width="47"></td>
<td style="border: none; height: 94.5pt; mso-border-top-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 163.0pt;" width="217"></td>
</tr>
<tr style="height: 94.5pt; mso-yfti-irow: 20; page-break-inside: avoid;">
<td nowrap="" style="border-top: none; border: solid windowtext 1.0pt; height: 94.5pt; mso-border-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 37.9pt;" valign="top" width="51">
<div align="center" class="MsoNormal" style="text-align: center;">
<b><span style="font-family: "Candara","sans-serif"; mso-bidi-font-family: Arial; mso-bidi-font-size: 10.0pt;">Sun 17:00<o:p></o:p></span></b></div>
</td>
<td style="border-bottom: solid windowtext 1.0pt; border-left: none; border-right: solid windowtext 1.0pt; border-top: none; height: 94.5pt; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 156.35pt;" width="208">
<div class="MsoNormal">
<b><span style="font-family: Candara, sans-serif;">PROF JON BUTTERWORTH</span></b><span style="font-family: Candara, sans-serif;"><o:p></o:p></span></div>
<div class="MsoNormal">
<i><span style="font-family: Candara, sans-serif;">ATLAS SHRUGGED; <o:p></o:p></span></i></div>
<div class="MsoNormal">
<i><span style="font-family: Candara, sans-serif;">OUR NEW BOSON<o:p></o:p></span></i></div>
<div class="MsoNormal">
<br /></div>
<div class="MsoNormal">
<span style="font-family: Candara, sans-serif;"><v:shape id="Picture_x0020_17" o:spid="_x0000_i1036" style="height: 85.5pt; mso-wrap-style: square; visibility: visible; width: 74.25pt;" type="#_x0000_t75">
<v:imagedata o:title="" src="file:///C:\DOCUME~1\Mark\LOCALS~1\Temp\msohtmlclip1\01\clip_image021.jpg">
</v:imagedata></v:shape></span><span style="font-family: Candara, sans-serif;"><o:p></o:p></span></div>
</td>
<td nowrap="" style="border: none; height: 94.5pt; mso-border-left-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 14.15pt;" width="19"></td>
<td nowrap="" style="border: none; height: 94.5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 35.45pt;" valign="top" width="47"></td>
<td style="border: none; height: 94.5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 163.0pt;" width="217"></td>
</tr>
<tr style="height: 18.85pt; mso-yfti-irow: 21; page-break-inside: avoid;">
<td nowrap="" style="border-bottom: solid windowtext 1.0pt; border: none; height: 18.85pt; mso-border-bottom-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 37.9pt;" valign="top" width="51"></td>
<td style="border-bottom: solid windowtext 1.0pt; border: none; height: 18.85pt; mso-border-bottom-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 156.35pt;" width="208"></td>
<td nowrap="" style="border: none; height: 18.85pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 14.15pt;" width="19"></td>
<td nowrap="" style="border-bottom: solid windowtext 1.0pt; border: none; height: 18.85pt; mso-border-bottom-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 35.45pt;" valign="top" width="47"></td>
<td style="border-bottom: solid windowtext 1.0pt; border: none; height: 18.85pt; mso-border-bottom-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 163.0pt;" width="217"></td>
</tr>
<tr style="height: 29.75pt; mso-yfti-irow: 22; page-break-inside: avoid;">
<td colspan="2" nowrap="" style="border-top: none; border: solid windowtext 1.0pt; height: 29.75pt; mso-border-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 194.25pt;" valign="top" width="259">
<div align="center" class="MsoNormal" style="text-align: center;">
<b><span style="color: #365f91; font-family: "Candara","sans-serif"; font-size: 12.0pt; mso-bidi-font-family: Arial; mso-bidi-font-size: 10.0pt; mso-themecolor: accent1; mso-themeshade: 191;">MONDAY
MORNING<o:p></o:p></span></b></div>
<div align="center" class="MsoNormal" style="text-align: center;">
<b><span style="color: #00b0f0; font-family: "Candara","sans-serif"; font-size: 12.0pt; mso-bidi-font-family: Arial; mso-bidi-font-size: 10.0pt;">Performance Hall</span></b><span style="font-family: Candara, sans-serif; font-size: 12pt;"><o:p></o:p></span></div>
</td>
<td nowrap="" style="border-right: solid windowtext 1.0pt; border: none; height: 29.75pt; mso-border-left-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-right-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 14.15pt;" width="19"></td>
<td colspan="2" nowrap="" style="border-bottom: solid windowtext 1.0pt; border-left: none; border-right: solid windowtext 1.0pt; border-top: none; height: 29.75pt; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 7.0cm;" valign="top" width="265">
<div align="center" class="MsoNormal" style="text-align: center;">
<b><span style="color: #365f91; font-family: "Candara","sans-serif"; font-size: 12.0pt; mso-bidi-font-family: Arial; mso-bidi-font-size: 10.0pt; mso-themecolor: accent1; mso-themeshade: 191;">MONDAY
MORNING<o:p></o:p></span></b></div>
<div align="center" class="MsoNormal" style="text-align: center;">
<b><span style="color: #fabf8f; font-family: "Candara","sans-serif"; font-size: 12.0pt; mso-bidi-font-family: Arial; mso-bidi-font-size: 10.0pt; mso-themecolor: accent6; mso-themetint: 153;">Learning Room</span></b><span style="font-family: Candara, sans-serif; font-size: 12pt;"><o:p></o:p></span></div>
</td>
</tr>
<tr style="height: 94.5pt; mso-yfti-irow: 23; page-break-inside: avoid;">
<td nowrap="" style="border-top: none; border: solid windowtext 1.0pt; height: 94.5pt; mso-border-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 37.9pt;" valign="top" width="51">
<div align="center" class="MsoNormal" style="text-align: center;">
<b><span style="font-family: "Candara","sans-serif"; mso-bidi-font-family: Arial; mso-bidi-font-size: 10.0pt;">Mon 10:00<o:p></o:p></span></b></div>
</td>
<td style="border-bottom: solid windowtext 1.0pt; border-left: none; border-right: solid windowtext 1.0pt; border-top: none; height: 94.5pt; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 156.35pt;" width="208">
<div class="MsoNormal">
<b><span style="font-family: Candara, sans-serif;">DR KAREN MASTERS</span></b><span style="font-family: Candara, sans-serif;"><o:p></o:p></span></div>
<div class="MsoNormal">
<i><span style="font-family: Candara, sans-serif;">A RAINBOW VIEW OF<o:p></o:p></span></i></div>
<div class="MsoNormal">
<i><span style="font-family: Candara, sans-serif;">THE ANDROMEDA GALAXY<o:p></o:p></span></i></div>
<div class="MsoNormal">
<br /></div>
<div class="MsoNormal">
<span style="font-family: Candara, sans-serif;"><v:shape id="Picture_x0020_1" o:spid="_x0000_i1035" style="height: 85.5pt; mso-wrap-style: square; visibility: visible; width: 84.75pt;" type="#_x0000_t75">
<v:imagedata o:title="" src="file:///C:\DOCUME~1\Mark\LOCALS~1\Temp\msohtmlclip1\01\clip_image022.jpg">
</v:imagedata></v:shape></span><span style="font-family: Candara, sans-serif;"><o:p></o:p></span></div>
</td>
<td nowrap="" style="border-right: solid windowtext 1.0pt; border: none; height: 94.5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-right-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 14.15pt;" width="19"></td>
<td nowrap="" style="border-bottom: solid windowtext 1.0pt; border-left: none; border-right: solid windowtext 1.0pt; border-top: none; height: 94.5pt; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 35.45pt;" valign="top" width="47">
<div align="center" class="MsoNormal" style="text-align: center;">
<b><span style="font-family: "Candara","sans-serif"; mso-bidi-font-family: Arial; mso-bidi-font-size: 10.0pt;">Mon 10:00<o:p></o:p></span></b></div>
</td>
<td style="border-left: none; border: solid windowtext 1.0pt; height: 94.5pt; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 163.0pt;" width="217">
<div class="MsoNormal">
<b><span style="font-family: Candara, sans-serif;">NICOLE SLAVIN</span></b><span style="font-family: Candara, sans-serif;"><o:p></o:p></span></div>
<div class="MsoNormal">
<i><span style="font-family: Candara, sans-serif;">FUN WITH BRAINS AND BEYOND<o:p></o:p></span></i></div>
<div class="MsoNormal">
<i><span style="font-family: Candara, sans-serif;">(FOR AGES 7+)<o:p></o:p></span></i></div>
<div class="MsoNormal">
<br /></div>
<div class="MsoNormal">
<span style="font-family: Candara, sans-serif;"><v:shape id="Picture_x0020_21" o:spid="_x0000_i1034" style="height: 85.5pt; mso-wrap-style: square; visibility: visible; width: 86.25pt;" type="#_x0000_t75">
<v:imagedata o:title="" src="file:///C:\DOCUME~1\Mark\LOCALS~1\Temp\msohtmlclip1\01\clip_image023.jpg">
</v:imagedata></v:shape></span><span style="font-family: Candara, sans-serif;"><o:p></o:p></span></div>
</td>
</tr>
<tr style="height: 94.5pt; mso-yfti-irow: 24; page-break-inside: avoid;">
<td nowrap="" style="border-top: none; border: solid windowtext 1.0pt; height: 94.5pt; mso-border-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 37.9pt;" valign="top" width="51">
<div align="center" class="MsoNormal" style="text-align: center;">
<b><span style="font-family: "Candara","sans-serif"; mso-bidi-font-family: Arial; mso-bidi-font-size: 10.0pt;">Mon 11:00<o:p></o:p></span></b></div>
</td>
<td style="border-bottom: solid windowtext 1.0pt; border-left: none; border-right: solid windowtext 1.0pt; border-top: none; height: 94.5pt; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 156.35pt;" width="208">
<div class="MsoNormal">
<b><span style="font-family: Candara, sans-serif;">DR HEATHER WILLIAMS</span></b><span style="font-family: Candara, sans-serif;"><o:p></o:p></span></div>
<div class="MsoNormal">
<i><span style="font-family: Candara, sans-serif;">PHYSICS GETS TO<o:p></o:p></span></i></div>
<div class="MsoNormal">
<i><span style="font-family: Candara, sans-serif;">THE HEART OF THE MATTER<o:p></o:p></span></i></div>
<div class="MsoNormal">
<br /></div>
<div class="MsoNormal">
<span style="font-family: Candara, sans-serif;"><v:shape id="Picture_x0020_16" o:spid="_x0000_i1033" style="height: 85.5pt; mso-wrap-style: square; visibility: visible; width: 86.25pt;" type="#_x0000_t75">
<v:imagedata o:title="" src="file:///C:\DOCUME~1\Mark\LOCALS~1\Temp\msohtmlclip1\01\clip_image024.jpg">
</v:imagedata></v:shape></span><span style="font-family: Candara, sans-serif;"><o:p></o:p></span></div>
</td>
<td nowrap="" style="border-right: solid windowtext 1.0pt; border: none; height: 94.5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-right-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 14.15pt;" width="19"></td>
<td nowrap="" style="border-bottom: solid windowtext 1.0pt; border-left: none; border-right: solid windowtext 1.0pt; border-top: none; height: 94.5pt; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 35.45pt;" valign="top" width="47">
<div align="center" class="MsoNormal" style="text-align: center;">
<b><span style="font-family: "Candara","sans-serif"; mso-bidi-font-family: Arial; mso-bidi-font-size: 10.0pt;">Mon 11:00<o:p></o:p></span></b></div>
</td>
<td style="border-bottom: solid windowtext 1.0pt; border-left: none; border-right: solid windowtext 1.0pt; border-top: none; height: 94.5pt; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 163.0pt;" width="217">
<div class="MsoNormal">
<b><span style="font-family: Candara, sans-serif;">DAVID GREEN</span></b><span style="font-family: Candara, sans-serif;"><o:p></o:p></span></div>
<div class="MsoNormal">
<i><span style="font-family: Candara, sans-serif;">ECOISLAND; THE HARDWARE AND SOFTWARE
FIX FOR PLANET EARTH<o:p></o:p></span></i></div>
<div class="MsoNormal">
<br /></div>
<div class="MsoNormal">
<span style="font-family: Candara, sans-serif;"><v:shape id="Picture_x0020_12" o:spid="_x0000_i1032" style="height: 85.5pt; mso-wrap-style: square; visibility: visible; width: 80.25pt;" type="#_x0000_t75">
<v:imagedata o:title="" src="file:///C:\DOCUME~1\Mark\LOCALS~1\Temp\msohtmlclip1\01\clip_image025.jpg">
</v:imagedata></v:shape></span><span style="font-family: Candara, sans-serif;"><o:p></o:p></span></div>
</td>
</tr>
<tr style="height: 94.5pt; mso-yfti-irow: 25; page-break-inside: avoid;">
<td nowrap="" style="border-top: none; border: solid windowtext 1.0pt; height: 94.5pt; mso-border-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 37.9pt;" valign="top" width="51">
<div align="center" class="MsoNormal" style="text-align: center;">
<b><span style="font-family: "Candara","sans-serif"; mso-bidi-font-family: Arial; mso-bidi-font-size: 10.0pt;">Mon 12:00<o:p></o:p></span></b></div>
</td>
<td style="border-bottom: solid windowtext 1.0pt; border-left: none; border-right: solid windowtext 1.0pt; border-top: none; height: 94.5pt; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 156.35pt;" width="208">
<div class="MsoNormal">
<b><span style="font-family: Candara, sans-serif;">PROF DAME WENDY HALL</span></b><span style="font-family: Candara, sans-serif;"><o:p></o:p></span></div>
<div class="MsoNormal">
<i><span style="font-family: Candara, sans-serif;">NO WOMAN, NO RASPBERRY PI<o:p></o:p></span></i></div>
<div class="MsoNormal">
<br /></div>
<div class="MsoNormal">
<span style="font-family: Candara, sans-serif;"><v:shape id="Picture_x0020_9" o:spid="_x0000_i1031" style="height: 86.25pt; mso-wrap-style: square; visibility: visible; width: 86.25pt;" type="#_x0000_t75">
<v:imagedata o:title="" src="file:///C:\DOCUME~1\Mark\LOCALS~1\Temp\msohtmlclip1\01\clip_image026.jpg">
</v:imagedata></v:shape></span><span style="font-family: Candara, sans-serif;"><o:p></o:p></span></div>
</td>
<td nowrap="" style="border: none; height: 94.5pt; mso-border-left-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 14.15pt;" width="19"></td>
<td nowrap="" style="border: none; height: 94.5pt; mso-border-top-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 35.45pt;" valign="top" width="47"></td>
<td style="border: none; height: 94.5pt; mso-border-top-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 163.0pt;" width="217"></td>
</tr>
<tr style="height: 15.65pt; mso-yfti-irow: 26; page-break-inside: avoid;">
<td nowrap="" style="border-bottom: solid windowtext 1.0pt; border: none; height: 15.65pt; mso-border-bottom-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 37.9pt;" valign="top" width="51"></td>
<td style="border-bottom: solid windowtext 1.0pt; border: none; height: 15.65pt; mso-border-bottom-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 156.35pt;" width="208"></td>
<td nowrap="" style="border: none; height: 15.65pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 14.15pt;" width="19"></td>
<td nowrap="" style="border-bottom: solid windowtext 1.0pt; border: none; height: 15.65pt; mso-border-bottom-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 35.45pt;" valign="top" width="47"></td>
<td style="border-bottom: solid windowtext 1.0pt; border: none; height: 15.65pt; mso-border-bottom-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 163.0pt;" width="217"></td>
</tr>
<tr style="height: 29.75pt; mso-yfti-irow: 27; page-break-inside: avoid;">
<td colspan="2" nowrap="" style="border-top: none; border: solid windowtext 1.0pt; height: 29.75pt; mso-border-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 194.25pt;" valign="top" width="259">
<div align="center" class="MsoNormal" style="text-align: center;">
<b><span style="color: #365f91; font-family: "Candara","sans-serif"; font-size: 12.0pt; mso-bidi-font-family: Arial; mso-bidi-font-size: 10.0pt; mso-themecolor: accent1; mso-themeshade: 191;">MONDAY AFTERNOON<o:p></o:p></span></b></div>
<div align="center" class="MsoNormal" style="text-align: center;">
<b><span style="color: #00b0f0; font-family: "Candara","sans-serif"; font-size: 12.0pt; mso-bidi-font-family: Arial; mso-bidi-font-size: 10.0pt;">Performance Hall</span></b><span style="font-family: Candara, sans-serif; font-size: 12pt;"><o:p></o:p></span></div>
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<td nowrap="" style="border-right: solid windowtext 1.0pt; border: none; height: 29.75pt; mso-border-left-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-right-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 14.15pt;" width="19"></td>
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<div align="center" class="MsoNormal" style="text-align: center;">
<b><span style="color: #365f91; font-family: "Candara","sans-serif"; font-size: 12.0pt; mso-bidi-font-family: Arial; mso-bidi-font-size: 10.0pt; mso-themecolor: accent1; mso-themeshade: 191;">MONDAY AFTERNOON<o:p></o:p></span></b></div>
<div align="center" class="MsoNormal" style="text-align: center;">
<b><span style="color: #fabf8f; font-family: "Candara","sans-serif"; font-size: 12.0pt; mso-bidi-font-family: Arial; mso-bidi-font-size: 10.0pt; mso-themecolor: accent6; mso-themetint: 153;">Learning Room</span></b><span style="font-family: Candara, sans-serif; font-size: 12pt;"><o:p></o:p></span></div>
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<div align="center" class="MsoNormal" style="text-align: center;">
<b><span style="font-family: "Candara","sans-serif"; mso-bidi-font-family: Arial; mso-bidi-font-size: 10.0pt;">Mon 14:00<o:p></o:p></span></b></div>
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<td style="border-bottom: solid windowtext 1.0pt; border-left: none; border-right: solid windowtext 1.0pt; border-top: none; height: 94.5pt; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 5.65pt 2.85pt; width: 156.35pt;" width="208">
<div class="MsoNormal">
<b><span style="font-family: Candara, sans-serif;">PROF SOPHIE SCOTT</span></b><span style="font-family: Candara, sans-serif;"><o:p></o:p></span></div>
<div class="MsoNormal">
<i><span style="font-family: Candara, sans-serif;">LAUGHTERLAB<o:p></o:p></span></i></div>
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<br /></div>
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<span style="font-family: Candara, sans-serif;"><v:shape id="Picture_x0020_20" o:spid="_x0000_i1030" style="height: 86.25pt; mso-wrap-style: square; visibility: visible; width: 81.75pt;" type="#_x0000_t75">
<v:imagedata o:title="" src="file:///C:\DOCUME~1\Mark\LOCALS~1\Temp\msohtmlclip1\01\clip_image027.jpg">
</v:imagedata></v:shape></span><span style="font-family: Candara, sans-serif;"><o:p></o:p></span></div>
</td>
<td nowrap="" style="border-right: solid windowtext 1.0pt; border: none; height: 94.5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-right-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 14.15pt;" width="19"></td>
<td nowrap="" style="border-bottom: solid windowtext 1.0pt; border-left: none; border-right: solid windowtext 1.0pt; border-top: none; height: 94.5pt; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 35.45pt;" valign="top" width="47">
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<b><span style="font-family: "Candara","sans-serif"; mso-bidi-font-family: Arial; mso-bidi-font-size: 10.0pt;">Mon 14:00<o:p></o:p></span></b></div>
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<td style="border-left: none; border: solid windowtext 1.0pt; height: 94.5pt; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 163.0pt;" width="217">
<div class="MsoNormal">
<b><span style="font-family: Candara, sans-serif;">PROF JAMES SMITH</span></b><span style="font-family: Candara, sans-serif;"><o:p></o:p></span></div>
<div class="MsoNormal">
<i><span style="font-family: Candara, sans-serif;">FROM CHERNOBYL TO FUKUSHIMA:
PREDICTING THE CONSEQUENCES OF NUCLEAR ACCIDENTS</span></i><span style="font-family: Candara, sans-serif;"> <o:p></o:p></span></div>
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<br /></div>
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<span style="font-family: Candara, sans-serif;"><v:shape id="Picture_x0020_11" o:spid="_x0000_i1029" style="height: 86.25pt; mso-wrap-style: square; visibility: visible; width: 86.25pt;" type="#_x0000_t75">
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</v:imagedata></v:shape></span><span style="font-family: Candara, sans-serif;"><o:p></o:p></span></div>
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<tr style="height: 94.5pt; mso-yfti-irow: 29; page-break-inside: avoid;">
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<b><span style="font-family: "Candara","sans-serif"; mso-bidi-font-family: Arial; mso-bidi-font-size: 10.0pt;">Mon 15:00<o:p></o:p></span></b></div>
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<td style="border-bottom: solid windowtext 1.0pt; border-left: none; border-right: solid windowtext 1.0pt; border-top: none; height: 94.5pt; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 5.65pt 2.85pt; width: 156.35pt;" width="208">
<div class="MsoNormal">
<b><span style="font-family: Candara, sans-serif;">DR FRAN SCOTT</span></b><span style="font-family: Candara, sans-serif;"><o:p></o:p></span></div>
<div class="MsoNormal">
<i><span style="font-family: Candara, sans-serif;">SCIENCE MISADVENTURES<o:p></o:p></span></i></div>
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<br /></div>
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<span style="font-family: Candara, sans-serif;"><v:shape id="Picture_x0020_27" o:spid="_x0000_i1028" style="height: 86.25pt; mso-wrap-style: square; visibility: visible; width: 81.75pt;" type="#_x0000_t75">
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</v:imagedata></v:shape></span><span style="font-family: Candara, sans-serif;"><o:p></o:p></span></div>
</td>
<td nowrap="" style="border-right: solid windowtext 1.0pt; border: none; height: 94.5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-right-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 14.15pt;" width="19"></td>
<td nowrap="" style="border-bottom: solid windowtext 1.0pt; border-left: none; border-right: solid windowtext 1.0pt; border-top: none; height: 94.5pt; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 35.45pt;" valign="top" width="47">
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<b><span style="font-family: "Candara","sans-serif"; mso-bidi-font-family: Arial; mso-bidi-font-size: 10.0pt;">Mon 15:00<o:p></o:p></span></b></div>
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<td style="border-bottom: solid windowtext 1.0pt; border-left: none; border-right: solid windowtext 1.0pt; border-top: none; height: 94.5pt; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 163.0pt;" width="217">
<div class="MsoNormal">
<b><span style="font-family: Candara, sans-serif;">DR SIMON WATT</span></b><span style="font-family: Candara, sans-serif;"><o:p></o:p></span></div>
<div class="MsoNormal">
<i><span style="font-family: Candara, sans-serif;">DR DEATH AND THE MEDI-EVIL MEDICINE
SHOW<o:p></o:p></span></i></div>
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<br /></div>
<div class="MsoNormal">
<span style="font-family: Candara, sans-serif;"><v:shape id="Picture_x0020_26" o:spid="_x0000_i1027" style="height: 86.25pt; mso-wrap-style: square; visibility: visible; width: 86.25pt;" type="#_x0000_t75">
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</v:imagedata></v:shape></span><span style="font-family: Candara, sans-serif;"><o:p></o:p></span></div>
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<tr style="height: 94.5pt; mso-yfti-irow: 30; page-break-inside: avoid;">
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<b><span style="font-family: "Candara","sans-serif"; mso-bidi-font-family: Arial; mso-bidi-font-size: 10.0pt;">Mon 16:00<o:p></o:p></span></b></div>
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<td style="border-bottom: solid windowtext 1.0pt; border-left: none; border-right: solid windowtext 1.0pt; border-top: none; height: 94.5pt; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 5.65pt 2.85pt; width: 156.35pt;" width="208">
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<b><span style="font-family: Candara, sans-serif;">GRRLSCIENTIST</span></b><span style="font-family: Candara, sans-serif;"><o:p></o:p></span></div>
<div class="MsoNormal">
<i><span style="font-family: Candara, sans-serif;">ENDANGERED SPECIES<o:p></o:p></span></i></div>
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<br /></div>
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<span style="font-family: Candara, sans-serif;"><v:shape id="Picture_x0020_25" o:spid="_x0000_i1026" style="height: 86.25pt; mso-wrap-style: square; visibility: visible; width: 86.25pt;" type="#_x0000_t75">
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</v:imagedata></v:shape></span><span style="font-family: Candara, sans-serif;"><o:p></o:p></span></div>
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<td nowrap="" style="border: none; height: 94.5pt; mso-border-left-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 14.15pt;" width="19"></td>
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<td style="border: none; height: 94.5pt; mso-border-top-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 163.0pt;" width="217"></td>
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<b><span style="font-family: "Candara","sans-serif"; mso-bidi-font-family: Arial; mso-bidi-font-size: 10.0pt;">Mon 17:00<o:p></o:p></span></b></div>
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<td style="border-bottom: solid windowtext 1.0pt; border-left: none; border-right: solid windowtext 1.0pt; border-top: none; height: 94.5pt; mso-border-alt: solid windowtext .5pt; mso-border-left-alt: solid windowtext .5pt; mso-border-top-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 5.65pt 2.85pt; width: 156.35pt;" width="208">
<div class="MsoNormal">
<b><span style="font-family: Candara, sans-serif;">DR KAREN JAMES</span></b><span style="font-family: Candara, sans-serif;"><o:p></o:p></span></div>
<div class="MsoNormal">
<i><span style="font-family: Candara, sans-serif;">DARWIN, THE BEAGLE PROJECT AND
GALAPAGOS NOW<o:p></o:p></span></i></div>
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<br /></div>
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<span style="font-family: Candara, sans-serif;"><v:shape alt="Karen James" id="Picture_x0020_3" o:spid="_x0000_i1025" style="height: 84.75pt; mso-wrap-style: square; visibility: visible; width: 84.75pt;" type="#_x0000_t75">
<v:imagedata o:title="Karen James" src="file:///C:\DOCUME~1\Mark\LOCALS~1\Temp\msohtmlclip1\01\clip_image031.jpg">
</v:imagedata></v:shape></span><span style="font-family: Candara, sans-serif;"><o:p></o:p></span></div>
</td>
<td nowrap="" style="border: none; height: 94.5pt; mso-border-left-alt: solid windowtext .5pt; padding: 2.85pt 2.85pt 2.85pt 2.85pt; width: 14.15pt;" width="19"></td>
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Billysuggerhttp://www.blogger.com/profile/10673508741175504300noreply@blogger.com0tag:blogger.com,1999:blog-2309907146997372202.post-63956508300602271292013-07-14T12:17:00.000+01:002013-09-13T20:21:40.179+01:00The Atheist's Tale<br />
<span style="color: #333333; font-family: lucida grande, tahoma, verdana, arial, sans-serif;"><span style="font-size: 11px; line-height: 14px;">Who has the burden of proof for an extraordinary claim? Those who make the claim or those who challenge the claim?</span></span><br />
<span style="color: #333333; font-family: lucida grande, tahoma, verdana, arial, sans-serif;"><span style="font-size: 11px; line-height: 14px;"><br /></span></span><span style="color: #333333; font-family: lucida grande, tahoma, verdana, arial, sans-serif;"><span style="font-size: 11px; line-height: 14px;">At first, it is quite reasonable to give benefit of the doubt to a man who makes a claim, such as "I have a unicorn in my garden". After all, we have not searched his garden and have no proof that he has no unicorn, and it seems reasonable to take the word of a man who has not been shown to lie. So reasonably, we take his word at face value and allow that he may indeed have a unicorn in his garden.</span></span><br />
<span style="color: #333333; font-family: lucida grande, tahoma, verdana, arial, sans-serif;"><span style="font-size: 11px; line-height: 14px;"><br /></span></span><span style="color: #333333; font-family: lucida grande, tahoma, verdana, arial, sans-serif;"><span style="font-size: 11px; line-height: 14px;">When we visit his home, we are interested to see the unicorn, but when asked the man says he has a big garden and the unicorn isn't around the house at the moment, but it is there nonetheless. We're disappointed, of course, but we have no reason to disbelieve him.</span></span><br />
<span style="color: #333333; font-family: lucida grande, tahoma, verdana, arial, sans-serif;"><span style="font-size: 11px; line-height: 14px;"><br /></span></span><span style="color: #333333; font-family: lucida grande, tahoma, verdana, arial, sans-serif;"><span style="font-size: 11px; line-height: 14px;">Later the man makes a moral judgement about our behaviour, such as "it is wrong to eat wheat on a Wednesday", and when asked why this is so, the man replies that his unicorn told him so. We are irritated by such judgement, and surprised that not only this man claims to have a unicorn, but that it can speak also. So we ask to see this unicorn and ask why it is wrong to eat wheat on a Wednesday. We search the garden with the man and find no unicorn, but have no proof that none exists. When challenged to produce the unicorn, the man now claims that the unicorn is invisible, and is in all parts of the garden at the same time.</span></span><br />
<span style="color: #333333; font-family: lucida grande, tahoma, verdana, arial, sans-serif;"><span style="font-size: 11px; line-height: 14px;"><br /></span></span><span style="color: #333333; font-family: lucida grande, tahoma, verdana, arial, sans-serif;"><span style="font-size: 11px; line-height: 14px;">Now the man's claim is looking extraordinary for a number of reasons:</span></span><br />
<span style="color: #333333; font-family: lucida grande, tahoma, verdana, arial, sans-serif;"><span style="font-size: 11px; line-height: 14px;">1. We have never seen a unicorn, and they are popularly believed to be fictional;</span></span><br />
<span style="color: #333333; font-family: lucida grande, tahoma, verdana, arial, sans-serif;"><span style="font-size: 11px; line-height: 14px;">2. We have never heard an animal speak, and most people accept that only humans speak;</span></span><br />
<span style="color: #333333; font-family: lucida grande, tahoma, verdana, arial, sans-serif;"><span style="font-size: 11px; line-height: 14px;">3. The man changed his story to suit his needs as we enquired further about his talking unicorn;</span></span><br />
<span style="color: #333333; font-family: lucida grande, tahoma, verdana, arial, sans-serif;"><span style="font-size: 11px; line-height: 14px;">4. We have never had experience of invisible animals, and invisibility has never been demonstrated; and</span></span><br />
<span style="color: #333333; font-family: lucida grande, tahoma, verdana, arial, sans-serif;"><span style="font-size: 11px; line-height: 14px;">5. The concept of something being everywhere at once appears contradictory.</span></span><br />
<span style="color: #333333; font-family: lucida grande, tahoma, verdana, arial, sans-serif;"><span style="font-size: 11px; line-height: 14px;"><br /></span></span><span style="color: #333333; font-family: lucida grande, tahoma, verdana, arial, sans-serif;"><span style="font-size: 11px; line-height: 14px;">So we conclude that on the balance of probability, the man's claim is bogus and put the onus on him to prove the existence of his unicorn.</span></span><br />
<span style="color: #333333; font-family: lucida grande, tahoma, verdana, arial, sans-serif;"><span style="font-size: 11px; line-height: 14px;"><br /></span></span><span style="color: #333333; font-family: lucida grande, tahoma, verdana, arial, sans-serif;"><span style="font-size: 11px; line-height: 14px;">We tell the man not to be so silly and judgemental about our wheat eating habits, and go about our business, trying to avoid aggravating someone who appears not to have a firm grasp on reality.</span></span><br />
<span style="color: #333333; font-family: lucida grande, tahoma, verdana, arial, sans-serif;"><span style="font-size: 11px; line-height: 14px;"><br /></span></span><span style="color: #333333; font-family: lucida grande, tahoma, verdana, arial, sans-serif;"><span style="font-size: 11px; line-height: 14px;">Then we find that the man is a teacher is our children's school and is telling them that his unicorn is real, that they should not eat wheat on Wednesdays and other rules about how to live their lives which he cannot substantiate, other than by claiming his invisible unicorn told him so, and the children must believe him.</span></span><br />
<span style="color: #333333; font-family: lucida grande, tahoma, verdana, arial, sans-serif;"><span style="font-size: 11px; line-height: 14px;"><br /></span></span><span style="color: #333333; font-family: lucida grande, tahoma, verdana, arial, sans-serif;"><span style="font-size: 11px; line-height: 14px;">So now we are angry that our children are being indoctrinated and ask the school to stop him. When we find that the school governors are unicorn believers too, that none of them can prove the existence of unicorns either, but fully support the indoctrination of our children, we are outraged. We speak to local politicians and media, and mount a campaign to stop this silliness. But then the government, many members of whom turn out to believe in pixies or leprechauns, equally without foundation, object that we are trying to restrict people's right to believe what they choose to believe, and criticise us for being arrogant and intolerant.</span></span><br />
<span style="color: #333333; font-family: lucida grande, tahoma, verdana, arial, sans-serif;"><span style="font-size: 11px; line-height: 14px;"><br /></span></span><span style="color: #333333; font-family: lucida grande, tahoma, verdana, arial, sans-serif;"><span style="font-size: 11px; line-height: 14px;">We hold our heads in our hands, wondering how these people can be so deluded, and how we can have our children taught math, English and science, without all this mumbo-jumbo. We realise that it is we who are in the minority, and the world deluded.</span></span><br />
<span style="color: #333333; font-family: lucida grande, tahoma, verdana, arial, sans-serif;"><span style="font-size: 11px; line-height: 14px;"><br /></span></span><span style="color: #333333; font-family: lucida grande, tahoma, verdana, arial, sans-serif;"><span style="font-size: 11px; line-height: 14px;">What should we do?</span></span><br />
<div>
<br /></div>
Billysuggerhttp://www.blogger.com/profile/10673508741175504300noreply@blogger.com0tag:blogger.com,1999:blog-2309907146997372202.post-84426904384996571662013-07-01T09:43:00.001+01:002015-10-14T03:06:33.989+01:00Does a computer use more electricity when charging USB devices?I was introduced to this fascinating <a href="http://superuser.com/questions/604383/does-a-computer-use-more-electricity-when-charging-usb-devices" target="_blank">question</a>, and its intriguing proposed answer, by <a href="https://www.facebook.com/sciencebase.fans" target="_blank">David Bradley</a>.<br />
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It was suggested that because the efficiency of a power supply increases as it is loaded to its design output power, it is possible to draw 5W of power to charge a USB device, while taking less than 5W of extra power from the wall outlet. While that sounded reasonable on the face of it, I wondered if the idea represented better use of existing power, or actually getting something for nothing. So as an electronics engineer with an interest in physics, I did some calculations to find out. Here is the response I posted:<br />
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Short Answer:</h2>
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<strong style="background-color: transparent; border: 0px currentColor; margin: 0px; padding: 0px; vertical-align: baseline;">YES; you'll <em style="background-color: transparent; border: 0px currentColor; margin: 0px; padding: 0px; vertical-align: baseline;">always</em> pay for the USB power with at least that much more power from the wall</strong>. Not only is this required by the laws of thermodynamics, it's also inherent in the way power supplies work.</div>
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Longer Answer:</h2>
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We'll take the whole system of the computer, its internal power supply, its operating circuits and the USB port circuitry to be one big, black box called the Supply. For the purposes of this illustration, the whole computer is one oversized USB charger, with two outputs: the computer operating power, which we will call <strong style="background-color: transparent; border: 0px currentColor; margin: 0px; padding: 0px; vertical-align: baseline;"><em style="background-color: transparent; border: 0px currentColor; margin: 0px; padding: 0px; vertical-align: baseline;">Pc</em></strong>, and the output USB power, which we will call <strong style="background-color: transparent; border: 0px currentColor; margin: 0px; padding: 0px; vertical-align: baseline;"><em style="background-color: transparent; border: 0px currentColor; margin: 0px; padding: 0px; vertical-align: baseline;">Pu</em></strong>.</div>
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Converting power from one form, (voltage, current, frequency), to another, and conducting power from one part of a circuit to another, are all physical processes which are less than perfect. Even in an ideal world, with superconductors and yet-to-be-invented components, the circuit can be no better than perfect. (The importance of this subtle message will turn out to be the key to this answer). If you want 1W out of a circuit, you <em style="background-color: transparent; border: 0px currentColor; margin: 0px; padding: 0px; vertical-align: baseline;">must</em> put in at least 1W, and in all practical cases a bit more than 1W. That <em style="background-color: transparent; border: 0px currentColor; margin: 0px; padding: 0px; vertical-align: baseline;">bit more</em>is the power lost in the conversion and is called <em style="background-color: transparent; border: 0px currentColor; margin: 0px; padding: 0px; vertical-align: baseline;">loss</em>. We will call the loss power <strong style="background-color: transparent; border: 0px currentColor; margin: 0px; padding: 0px; vertical-align: baseline;"><em style="background-color: transparent; border: 0px currentColor; margin: 0px; padding: 0px; vertical-align: baseline;">Pl</em></strong>, and it is directly related to the amount of power delivered by the supply. Loss is almost always evident as heat, and is why electronic circuits which carry large power levels must be ventilated.</div>
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There is some mathematical function, (an equation), which describes how the loss varies with output power. This function will involve the square of output voltage or current where power is lost in resistance, a frequency multiplied by output voltage or current where power is lost in switching. But we don't need to dwell on that, we can wrap all that irrelevant detail into one symbol, which we will call <strong style="background-color: transparent; border: 0px currentColor; margin: 0px; padding: 0px; vertical-align: baseline;"><em style="background-color: transparent; border: 0px currentColor; margin: 0px; padding: 0px; vertical-align: baseline;">f(Po)</em></strong>, where <em style="background-color: transparent; border: 0px currentColor; margin: 0px; padding: 0px; vertical-align: baseline;">Po</em> is the total output power, and is used to relate output power to loss by the equation <strong style="background-color: transparent; border: 0px currentColor; margin: 0px; padding: 0px; vertical-align: baseline;"><em style="background-color: transparent; border: 0px currentColor; margin: 0px; padding: 0px; vertical-align: baseline;">Pl = f(Pc+Pu)</em></strong>.</div>
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A power supply is a circuit which requires power to operate, even if it is delivering no output power at all. Electronics engineers call this the <em style="background-color: transparent; border: 0px currentColor; margin: 0px; padding: 0px; vertical-align: baseline;">quiescent</em> power, and we'll refer to it as <strong style="background-color: transparent; border: 0px currentColor; margin: 0px; padding: 0px; vertical-align: baseline;"><em style="background-color: transparent; border: 0px currentColor; margin: 0px; padding: 0px; vertical-align: baseline;">Pq</em></strong>. Quiescent power is constant, and is absolutely unaffected by how hard the power supply is working to deliver the output power. In this example, where the computer is performing other functions besides powering the USB charger, we include the operating power of the other computer functions in <strong style="background-color: transparent; border: 0px currentColor; margin: 0px; padding: 0px; vertical-align: baseline;"><em style="background-color: transparent; border: 0px currentColor; margin: 0px; padding: 0px; vertical-align: baseline;">Pq</em></strong>.</div>
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All this power comes from the wall outlet, and we will call the input power, <strong style="background-color: transparent; border: 0px currentColor; margin: 0px; padding: 0px; vertical-align: baseline;"><em style="background-color: transparent; border: 0px currentColor; margin: 0px; padding: 0px; vertical-align: baseline;">Pw</em></strong>, (<em style="background-color: transparent; border: 0px currentColor; margin: 0px; padding: 0px; vertical-align: baseline;">Pi</em> looks confusingly like<em style="background-color: transparent; border: 0px currentColor; margin: 0px; padding: 0px; vertical-align: baseline;">Pl</em>, so I switched to <em style="background-color: transparent; border: 0px currentColor; margin: 0px; padding: 0px; vertical-align: baseline;">Pw</em> for wall-power).</div>
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So now we are ready to put the above together and get a description of how these power contributions are related. Well firstly we know that every microwatt of power output, or loss, comes from the wall. So:</div>
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<em style="background-color: transparent; border: 0px currentColor; margin: 0px; padding: 0px; vertical-align: baseline;"><strong style="background-color: transparent; border: 0px currentColor; margin: 0px; padding: 0px; vertical-align: baseline;">Pw = Pq + Pl + Pc + Pu</strong></em></div>
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And we know that <strong style="background-color: transparent; border: 0px currentColor; margin: 0px; padding: 0px; vertical-align: baseline;"><em style="background-color: transparent; border: 0px currentColor; margin: 0px; padding: 0px; vertical-align: baseline;">Pl = f(Pc+Pu)</em></strong>, so:</div>
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<em style="background-color: transparent; border: 0px currentColor; margin: 0px; padding: 0px; vertical-align: baseline;"><strong style="background-color: transparent; border: 0px currentColor; margin: 0px; padding: 0px; vertical-align: baseline;">Pw = Pq + f(Pc+Pu) + Pc + Pu</strong></em></div>
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Now we can test the hypothesis that <strong style="background-color: transparent; border: 0px currentColor; margin: 0px; padding: 0px; vertical-align: baseline;">taking power from the USB output increases then wall power by less than the USB power</strong>. We can formalise this hypothesis, see where it leads, and see whether it predicts something absurd, (in which case the hypothesis is false), or predicts something realistic, (in which case the hypotheses remains plausible).</div>
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We can write the hypothesis first as:</div>
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<strong style="background-color: transparent; border: 0px currentColor; margin: 0px; padding: 0px; vertical-align: baseline;">(Wall power <em style="background-color: transparent; border: 0px currentColor; margin: 0px; padding: 0px; vertical-align: baseline;">with</em> USB load) - (Wall power <em style="background-color: transparent; border: 0px currentColor; margin: 0px; padding: 0px; vertical-align: baseline;">without</em> USB load) < (USB power)</strong></div>
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and mathematically as:</div>
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<em style="background-color: transparent; border: 0px currentColor; margin: 0px; padding: 0px; vertical-align: baseline;"><strong style="background-color: transparent; border: 0px currentColor; margin: 0px; padding: 0px; vertical-align: baseline;">[ Pq + f(Pc+Pu) + Pc + Pu ] - [ Pq + f(Pc) + Pc ] < Pu</strong></em></div>
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Now we can simplify this by eliminating the same terms on both sides of the minus sign and removing the brackets:</div>
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<em style="background-color: transparent; border: 0px currentColor; margin: 0px; padding: 0px; vertical-align: baseline;"><strong style="background-color: transparent; border: 0px currentColor; margin: 0px; padding: 0px; vertical-align: baseline;">f(Pc+Pu) + Pu - f(Pc) < Pu</strong></em></div>
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then by subtracting <strong style="background-color: transparent; border: 0px currentColor; margin: 0px; padding: 0px; vertical-align: baseline;"><em style="background-color: transparent; border: 0px currentColor; margin: 0px; padding: 0px; vertical-align: baseline;">Pu</em></strong> from both sides of the inequality (< sign):</div>
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<em style="background-color: transparent; border: 0px currentColor; margin: 0px; padding: 0px; vertical-align: baseline;"><strong style="background-color: transparent; border: 0px currentColor; margin: 0px; padding: 0px; vertical-align: baseline;">f(Pc+Pu) - f(Pc) < 0</strong></em></div>
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Here is our absurdity. What this result means in plain English is:</div>
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<em style="background-color: transparent; border: 0px currentColor; margin: 0px; padding: 0px; vertical-align: baseline;"><strong style="background-color: transparent; border: 0px currentColor; margin: 0px; padding: 0px; vertical-align: baseline;">The extra loss involved in taking more power from the supply is negative</strong></em></div>
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This means negative resistors, negative voltages dropped across semiconductor junctions, or power magically appearing from the cores of inductors. All of this is nonsense, fairy tales, wishful thinking of perpetual-motion machines, and is absolutely impossible.</div>
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Conclusion:</h2>
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It is not physically possibly, theoretically or otherwise, to get power out of a computer USB port, with less than the same amount of extra power coming from the wall outlet.</div>
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What did @zakinster miss?</h2>
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With the greatest respect to @zakinster, he has misunderstood the nature of efficiency. Efficiency is a<em style="background-color: transparent; border: 0px currentColor; margin: 0px; padding: 0px; vertical-align: baseline;">consequence</em> of the relationship between input power, loss and output power, and <em style="background-color: transparent; border: 0px currentColor; margin: 0px; padding: 0px; vertical-align: baseline;">not</em> a physical quantity for which input power, loss and output power are consequences.</div>
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To illustrate, let's take the case of a power supply with a maximum output power of 900W, losses given by <strong style="background-color: transparent; border: 0px currentColor; margin: 0px; padding: 0px; vertical-align: baseline;"><em style="background-color: transparent; border: 0px currentColor; margin: 0px; padding: 0px; vertical-align: baseline;">Pl = APo² + BPo</em></strong> where A = 10^-4 and B = 10^-2, and Pq = 30W. Modelling the efficiency (<strong style="background-color: transparent; border: 0px currentColor; margin: 0px; padding: 0px; vertical-align: baseline;"><em style="background-color: transparent; border: 0px currentColor; margin: 0px; padding: 0px; vertical-align: baseline;">Po/Pi</em></strong>) of such a power supply in Excel and graphing it on a scale similar to the Anand Tech curve, gives:</div>
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<img alt="enter image description here" src="http://i.stack.imgur.com/KYwlk.jpg" style="background-color: transparent; border: 0px currentColor; margin: 0px; max-width: 640px; padding: 0px; vertical-align: baseline;" /></div>
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This model has a very steep initial curve, like the <a href="http://i.stack.imgur.com/nefh7.png" rel="nofollow" target="_blank">Anand Tech supply</a>, but is modelled entirely according to the analysis above which makes free power absurd.</div>
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Let's take this model and look at the examples @zakinster gives in Case 2 and Case 3. If we change <strong style="background-color: transparent; border: 0px currentColor; margin: 0px; padding: 0px; vertical-align: baseline;"><em style="background-color: transparent; border: 0px currentColor; margin: 0px; padding: 0px; vertical-align: baseline;">Pq </em></strong>to 50W, and make the supply <em style="background-color: transparent; border: 0px currentColor; margin: 0px; padding: 0px; vertical-align: baseline;">perfect</em>, with zero loss, then we can get 80% efficiency at 200W load. But even in this perfect situation, the best we can get at 205W is 80.39% efficiency. To reach the 80.5% @zakinster suggests is a practical possibility requires a negative loss function, which is impossible. And achieving 82% efficiency is still more impossible.</div>
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For summary, please refer to <strong style="background-color: transparent; border: 0px currentColor; margin: 0px; padding: 0px; vertical-align: baseline;">Short Answer</strong> above.</div>
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Billysuggerhttp://www.blogger.com/profile/10673508741175504300noreply@blogger.com0tag:blogger.com,1999:blog-2309907146997372202.post-87924290294156056412013-03-25T01:15:00.002+00:002013-03-25T01:15:30.704+00:00BBC CensorshipRowan Atkinson made a mild and amusing sketch portraying the Arch Bishop of Canterbury which was recently broadcast as part of the BBC telethon Comic Relief. It drew around 2000 complaints, citing the subject matter, language used and the timing of the broadcast. The BBC's response was to issue a grovelling apology, withdraw its support from one of the nation's greatest comedy talents, and cut the clip from the BBC online catchup service, iPlayer.<br />
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Why not take a look and see for yourself how offensive it really is...<br />
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<iframe allowfullscreen='allowfullscreen' webkitallowfullscreen='webkitallowfullscreen' mozallowfullscreen='mozallowfullscreen' width='320' height='266' src='https://www.youtube.com/embed/eVen3LudUN0?feature=player_embedded' frameborder='0'></iframe></div>
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In reply to a call for action from this <a href="http://gspellchecker.wordpress.com/2013/03/24/is-religion-exempt-from-satire-according-to-the-bbc-clarification-and-your-action-required/" target="_blank">blogger</a>, I posted the following complaint on the BBC website.<br />
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<span style="background-color: white;">I am shocked that the BBC has chosen to remove Rowan Atkinson’s Red Nose sketch from iPlayer coverage. While the BBC received many complaints citing the subject matter, language and timing of the broadcast, there is no substance to those complaints. I challenge each of the three justifications, and the decision of the BBC:</span></div>
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<span style="background-color: white;">SUBJECT MATTER<br />BBC Comic Relief is well known for its irreverent humour, and Atkinson’s sketch is entirely in keeping with the spirit and custom of the event. If the BBC is now judging the established religion to be beyond the acceptable limits of mild mockery, then this represents a significant change which deserves open, public debate.</span></div>
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<span style="background-color: white;">LANGUAGE<br />The sketch carries two words, arse and shag, used sparingly, which according to the BBC’s own editorial guidance on language have the potential to cause mild offence, and are generally permitted without referral and for broadcast before the watershed in suitable contexts such as comedic satire.</span></div>
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<span style="background-color: white;">TIMING<br />BBC guidelines permit the use of mild language before the watershed. Furthermore, the sketch was broadcast prior to the decision to censor it from iPlayer, and removing it from iPlayer provides absolutely no remedy for the timing of the original broadcast.</span></div>
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<span style="background-color: white;">THE BBC DECISION<br />It is evident that the decision of the BBC was made to pander to a hypersensitive religious lobby, and not based on editorial content whatsoever. The decision is without sound justification and threatens democratic free speech.</span></div>
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If you disagree, and think that Rowan Atkinson's sketch was beyond the limits of acceptable humour to be broadcast, please let me know - I really am interested to know why. If instead you'd prefer to make a complaint yourself, feel free to do so <a href="http://www.bbc.co.uk/complaints/complain-online/" rel="nofollow" target="_blank">here</a>...Billysuggerhttp://www.blogger.com/profile/10673508741175504300noreply@blogger.com0tag:blogger.com,1999:blog-2309907146997372202.post-41761539842692604802012-12-17T01:14:00.002+00:002012-12-17T01:14:29.093+00:00WAKE UP AMERICA!!!!<br />
<span style="font-family: Arial, Helvetica, sans-serif;"><a href="http://llewblog.squarespace.com/journal/2012/12/15/if-not-now-when.html" target="_blank">"Last year Handguns Killed: 48 in Japan, 8 in Great Britain, 34 in Switzerland, 52 in Canada, 58 in Israel, 21 in Sweden, 10,728 in the United States." </a></span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><br /></span>
<span style="font-family: Arial, Helvetica, sans-serif;">On that basis, the 77 people killed by Anders Behring Breivik in Sweden are matched by those killed by handguns alone in the United States EVERY 63 HOURS.</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><br /></span>
<span style="font-family: Arial, Helvetica, sans-serif;">If you have a child in the US, then taking account of the population ratio, YOUR CHILD is 6,705 times more likely to be killed by a handgun than my child in the UK. It's not 10% more, or 50% more, or even 100% more,... </span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><br /></span>
<span style="font-family: Arial, Helvetica, sans-serif;">IT'S 670,400% MORE.</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><br /></span>
<span style="font-family: Arial, Helvetica, sans-serif;">WTF is going on America? If you cannot see the magnitude of this problem you have, you are seriously deluding yourselves. Wake up and smell the coffee people, it's not about "guns don't kill people..." or "a right to bear arms..." or "the government wants to control us...", it's about an epidemic of homicide in your nation which has now added these poor little children. If you understand this, and you're okay with that, then you're seriously fucked up. WAKE UP AMERICA!!!! Do something about this, and DO IT NOW!!!</span><br />
<span style="font-family: Arial, Helvetica, sans-serif;"><br /></span>
<span style="font-family: Arial, Helvetica, sans-serif;"><b>WAKE UP AMERICA!!!!</b></span><br />
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Billysuggerhttp://www.blogger.com/profile/10673508741175504300noreply@blogger.com0tag:blogger.com,1999:blog-2309907146997372202.post-69732549328194290942012-08-26T14:13:00.001+01:002012-08-26T14:46:28.162+01:00Revitalise the Reformation<span style="background-color: white; color: #333333; font-family: Verdana, sans-serif; line-height: 17px;">Today, Cardinal Keith O'Brien has his army of priests read out the following message against inclusive marriage.</span><br />
<blockquote class="tr_bq">
<span style="font-family: Verdana, sans-serif; font-size: x-small;"><span style="background-color: white; line-height: 19.78333282470703px;">A Message for </span><span style="background-color: white; line-height: 19.78333282470703px;">Marriage Sunday</span><br style="background-color: white; line-height: 19.78333282470703px; margin: 0px; outline: none; padding: 0px;" /><span style="background-color: white; line-height: 19.78333282470703px;">26 August 2012</span><br style="background-color: white; line-height: 19.78333282470703px; margin: 0px; outline: none; padding: 0px;" /><br style="background-color: white; line-height: 19.78333282470703px; margin: 0px; outline: none; padding: 0px;" /><span style="background-color: white; line-height: 19.78333282470703px;">from </span><span style="background-color: white; line-height: 19.78333282470703px;">The Bishops’ Conference of Scotland</span><br style="background-color: white; line-height: 19.78333282470703px; margin: 0px; outline: none; padding: 0px;" /><br style="background-color: white; line-height: 19.78333282470703px; margin: 0px; outline: none; padding: 0px;" /><span style="background-color: white; line-height: 19.78333282470703px;">In all things, we as Catholics look to Jesus Christ as our model and teacher. When asked about marriage He gave a profound and rich reply: “Have you not read that the Creator, from the beginning, ‘made them male and female’, and said: ‘This is why a man must leave father and mother and cling to his wife and the two become one body’.” (Matthew, 19: 4-5)</span><br style="background-color: white; line-height: 19.78333282470703px; margin: 0px; outline: none; padding: 0px;" /><span style="background-color: white; line-height: 19.78333282470703px;">In the Year of Faith, which begins this October, we wish to place a special emphasis on the role of the family founded on marriage. The family is the domestic Church, and the first place in which the faith is transmitted. For that reason it must have a primary focus in our prayerful considerations during this period of grace. </span><br style="background-color: white; line-height: 19.78333282470703px; margin: 0px; outline: none; padding: 0px;" /><span style="background-color: white; line-height: 19.78333282470703px;">We write to you having already expressed our deep disappointment that the Scottish Government has decided to redefine marriage and legislate for same-sex marriage. We take this opportunity to thank you for your past support in defense of marriage and hope you will continue to act against efforts to redefine it. We reaffirm before you all the common wisdom of humanity and the revealed faith of the Church that marriage is a unique life-long union of a man and a woman.</span><br style="background-color: white; line-height: 19.78333282470703px; margin: 0px; outline: none; padding: 0px;" /><span style="background-color: white; line-height: 19.78333282470703px;">In circumstances when the true nature of marriage is being obscured, we wish to affirm and celebrate the truth and beauty of the Sacrament of Matrimony and family life as Jesus revealed it; to do something new to support marriage and family life in the Catholic community and in the country; and to reinforce the vocation of marriage and the pastoral care of families which takes in the everyday life of the Church in dioceses and parishes across the country.</span><br style="background-color: white; line-height: 19.78333282470703px; margin: 0px; outline: none; padding: 0px;" /><span style="background-color: white; line-height: 19.78333282470703px;">For that reason, in the forthcoming Year of Faith we have decided to establish a new Commission for Marriage and the Family. This Commission will be led by a bishop and will be composed mostly of lay men and women. The Commission will be charged with engaging with those young men and women who will be future husbands and wives, fathers and mothers, and with those who already live out their vocation to marriage and parenthood in surroundings which often make it hard to sustain and develop the full Catholic family life we cherish. </span><br style="background-color: white; line-height: 19.78333282470703px; margin: 0px; outline: none; padding: 0px;" /><span style="background-color: white; line-height: 19.78333282470703px;">We wish to support too, those who are widowed, separated and divorced and all who need to feel the Church’s maternal care in the circumstances in which they find themselves. The new Commission will promote the true nature of marriage as both a human institution and a union blessed by Jesus. The Commission will be asked to develop an online presence so that prayer, reflection, formation and practical information on matters to do with marriage and family life can be quickly accessible to all. It will also work to produce materials and organise events which will support ordinary Catholic families in their daily lives. During the course of the coming year we will ask for your support for these initiatives.</span><br style="background-color: white; line-height: 19.78333282470703px; margin: 0px; outline: none; padding: 0px;" /><span style="background-color: white; line-height: 19.78333282470703px;">Our faith teaches us that marriage is a great and holy mystery. The Bishops of Scotland will continue to promote and uphold the universally accepted definition of marriage as the union solely of a man and a woman. At the same time, we wish to work positively for the strengthening of marriage within the Church and within our society.</span><br style="background-color: white; line-height: 19.78333282470703px; margin: 0px; outline: none; padding: 0px;" /><span style="background-color: white; line-height: 19.78333282470703px;">This is an important initiative for all our people, but especially our young people and children. We urge you to join us in this endeavour. Pray for your own family every day, and pray for those families whose lives are made difficult by the problems and cares which they encounter. Finally, we invite you to pray for our elected leaders, invoking the Holy Spirit on them, that they may be moved to safeguard marriage as it has always been understood, for the good of Scotland and of our society.</span>
</span></blockquote>
<span style="font-family: Verdana, sans-serif;"><span style="background-color: white; color: #333333; line-height: 17px;">This is precisely the kind of unwarranted political interference that the Reformation and Act of Supremacy in England, and similar laws in Scotland, were designed to prevent.</span><span style="background-color: white; color: #333333; line-height: 17px;"> </span></span><br />
<span style="font-family: Verdana, sans-serif;"><br style="background-color: white; color: #333333; line-height: 17px;" /><span style="background-color: white; color: #333333; line-height: 17px;">This poor excuse for a Christian describes equal marriage rights as a "grotesque subversion of a universally accepted human right". What human right is being subverted, Cardinal? None at all. As a celibate bachelor, what makes you an authority on what subverts a loving marriage?</span></span><br />
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<span style="color: #333333;"><span style="font-family: Verdana, sans-serif; line-height: 17px;"><br /></span></span></div>
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<span style="color: #333333;"><span style="font-family: Verdana, sans-serif; line-height: 17px;">The message reveals clearly the flaws in his argument on the matter. It describes the biblical account of Christ's teaching on marriage:</span></span></div>
<div>
<blockquote class="tr_bq">
<span style="font-family: Verdana, sans-serif; font-size: x-small;"><span style="background-color: white; line-height: 19.766666412353516px;">“Have you not read that the Creator, from the beginning, ‘made them male and female’, and said: ‘This is why a man must leave father and mother and cling to his wife and the two become one body’.” (Matthew, 19: 4-5)</span> </span></blockquote>
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<span style="font-family: Verdana, sans-serif;"><span style="background-color: white;"><span style="color: #333333;"><span style="line-height: 17px;">Here Christ describes an example of marriage, he does not mandate this as the </span></span><i style="color: #333333; line-height: 17px;">only</i><span style="color: #333333;"><span style="line-height: 17px;"> form of marriage. Indeed, the question he answers is about divorce, not homosexuality, </span></span></span><span style="background-color: white; line-height: 19.75px;"> </span><span style="background-color: white; font-size: x-small; line-height: 19.75px;">(Matthew, 19: 3)</span><span style="background-color: white;"><span style="color: #333333;"><span style="line-height: 17px;">. And he goes on to describe celibacy in various circumstances saying "</span></span></span><span style="color: #333333;"><span style="line-height: 17px;">He who is able to accept it, let him accept it". </span></span><span style="background-color: white; line-height: 19.75px;"> </span><span style="background-color: white; font-size: x-small; line-height: 19.75px;">(Matthew, 19: 11-12)</span><span style="color: #333333; line-height: 17px;">. Christ teaches not one dogmatic rule which all must follow, but freedom to live a sexual life according to individual needs and circumstances, within a loving and faithful framework. What could better promote a loving and faithful sexual relationship than marriage?</span></span></div>
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<span style="color: #333333; font-family: Verdana, sans-serif; line-height: 17px;"><br /></span></div>
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<span style="color: #333333; font-family: Verdana, sans-serif; line-height: 17px;">Then the bishops say,</span></div>
<blockquote class="tr_bq">
<span style="font-family: Verdana, sans-serif; font-size: x-small;"><span style="color: #333333; line-height: 17px;">"</span><span style="background-color: white; line-height: 19.766666412353516px;">The family is the domestic Church, and the first place in which the faith is transmitted. For that reason it must have a primary focus</span><span style="background-color: white; color: #333333; line-height: 17px;">".</span></span></blockquote>
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<span style="background-color: white; color: #333333; font-family: Verdana, sans-serif; line-height: 17px;">So there we have it: this is not about the good of society, or following the teachings of Christ, this is about evangelizing the Roman Catholic faith. Surely these men are calling on gay people to deny their sexuality, enter into deceitful heterosexual marriages and raise more child fodder for their church. Here we see the sordid, evil, subversive motives of the church laid bare.</span></div>
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<span style="background-color: white; color: #333333; font-family: Verdana, sans-serif; line-height: 17px;"><br /></span></div>
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<span style="background-color: white; color: #333333; font-family: Verdana, sans-serif; line-height: 17px;">But not content with subverting families and children to their own purposes, (a trait you will recall that is not new), they also hope to subvert the democratic process:</span></div>
<blockquote class="tr_bq">
<span style="background-color: white; line-height: 19.766666412353516px;"><span style="font-family: Verdana, sans-serif; font-size: x-small;">"Finally, we invite you to pray for our elected leaders, invoking the Holy Spirit on them, that they may be moved to safeguard marriage as it has always been understood...".</span></span></blockquote>
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<span style="background-color: white; color: #333333; font-family: Verdana, sans-serif; line-height: 17px;">So you want your congregation to pray for god to overrule the consciences of the democratically elected representatives of the Scottish people, and do the dirty work of a foreign papal power? This is the 21st century - I mean: <i>are you nuts</i>?</span></div>
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<span style="background-color: white; color: #333333; font-family: Verdana, sans-serif; line-height: 17px;"><br /></span></div>
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<span style="background-color: white; color: #333333; font-family: Verdana, sans-serif; line-height: 17px;">But there is humour to be found in this rotten diatribe too:</span></div>
<blockquote class="tr_bq">
<span style="background-color: white; line-height: 19.766666412353516px;"><span style="font-family: Verdana, sans-serif; font-size: x-small;">"Our faith teaches us that marriage is a great and holy mystery".</span></span></blockquote>
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<span style="background-color: white; color: #333333; font-family: Verdana, sans-serif; line-height: 17px;">Yeah mate, marriage may be a mystery to you bunch of alleged celibates. But the <i>real</i> mystery is the reason you think that anyone should listen to a bunch of sexually repressed paedophile-protectors in dresses on matters of love, sexuality, marriage and family. You guys are about as unqualified to speak authoritatively on these matters as it's possible to be.</span></div>
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<span style="background-color: white; color: #333333; font-family: Verdana, sans-serif; line-height: 17px;"><br /></span></div>
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<span style="font-family: Verdana, sans-serif;"><span style="background-color: white; color: #333333; line-height: 17px;">So p</span><span style="background-color: white; color: #333333; line-height: 17px;">erhaps this kind of papal vitriol is a sure sign you guys in Scotland are heading in the right direction. Keep up the good work!</span></span></div>
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Billysuggerhttp://www.blogger.com/profile/10673508741175504300noreply@blogger.com1tag:blogger.com,1999:blog-2309907146997372202.post-41225354809251890272012-05-03T00:19:00.002+01:002012-05-03T00:39:19.818+01:00Am I really a bigot?<br />
I have a confession to make: When I saw the story linked to below, my first reaction was delight that someone who had clearly suffered such a long and difficult identity crisis now had the chance to resolve it, and at such a stage in life when many people would not consider something so drastic.<br />
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<a href="http://www.bbc.co.uk/news/uk-england-sussex-17913771" rel="nofollow" target="_blank">BBC News - East Sussex pensioner to have sex change op</a>
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<br />
No, that's not the confession. The confession is that not long ago I know my first reaction would have been a visceral repulsion, followed by a rational re-evaluation, and shame at the contradiction.<br />
<br />
Gender identity is such a deeply ingrained part of human consciousness that it can be a real challenge to accept that which crosses intuitive gender boundaries. Reason and empathy tell me that homosexuality is perfectly valid, that gender reassignment can be positive and transforms the lives of those in need of it. But in my teens, when I met a transsexual who came to my family home, I was too confused and afraid look her in the eye. In my twenties, when meeting a colleague and her girlfriend, at a gay bar in California, I was too afraid to leave the car park and go inside. I knew it was okay, but couldn't confront the reality myself. So I was a closet, intuitive bigot, and I was ashamed of myself for that.<br />
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But in the years since, I've known many delightful people who happen not to share my bedroom tastes, and it doesn't matter a damn. For years, I've let my gut get on with what it does, and made decisions with my head. And now, finally, I find my gut has fallen into step with my reason and my instinctive reaction to this story is joy. <br />
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Like many faculties, my gut reactions evolved long ago, for reasons which no longer apply, and I can live with that, allow them to be arcane and accept that as a personal limitation. But I now know that by getting to know different kinds of people, who are different from me in all sorts of ways, I can become a better person and put aside visceral prejudices and be open to anyone.<br />
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So what does this story do to you? What's your gut reaction? What does your rational head say, and which are you going to allow to win? What do you make of my conflicted sensibilities? Are you shocked and appalled at my inner prejudice, or can you recognise the conflict? All civil comments welcome!Billysuggerhttp://www.blogger.com/profile/10673508741175504300noreply@blogger.com0tag:blogger.com,1999:blog-2309907146997372202.post-61109457061756208262011-07-26T21:44:00.001+01:002015-10-14T03:07:20.271+01:00Orbital Mechanics for Dummies - Orbital EnergyNow we're going to consider the energy in an orbit, and we'll consider two forms of energy: kinetic energy from the speed of motion around the central body; and gravitational potential energy by virtue of the forces in a gravitational field, (which we'll call gravitational energy for short).<br />
<br />
First we need to consider a reference point. Here on Earth, it is tempting to consider being at rest on the ground to be the zero orbital energy point. But that means for flight between different planets we have different references to consider and that won't do. The solution is to consider the reference point to be stationary at an infinite distance from the central body, where the gravitational field is zero. Then we can use this reference for flight between as many different bodies as we wish.<br />
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<b>Kinetic energy</b> is easy, and from high school physics I remember it is given by<br />
<br />
E<sub><span style="font-family: "Arial","sans-serif"; font-size: 10pt;">k</span></sub> = ½mV²<br />
<br />
But from our equation [1] we found that in a circular orbit,<br />
<br />
<span style="font-family: "Arial","sans-serif"; font-size: 10pt;">V<sub>C</sub></span>² = GM/r<br />
<br />
So in such an orbit,<br />
<br />
E<sub><span style="font-family: "Arial","sans-serif"; font-size: 10pt;">k</span></sub> = ½GMm/r = GMm/2r [2]<br />
<br />
This is an important equation and we'll call it [2]. Just take a moment to consider what this means: the kinetic energy of a body in circular orbit is proportional to the masses of the bodies, and inversely proportional to the distance between them. So as the mass of either body increases, so the kinetic energy increases. As the distance <i>increases</i>, so the kinetic energy <i>decreases</i>. This fits with equation [1] which told us that as distance increases, so orbital speed decreases.<br />
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Now <b>gravitational energy</b> is a little harder to understand. It is the work done by gravity to bring a body from infinite distance to a radius r from the central body. At each step along the way, the gravity from the central body applies a force of GMm/r². At each step dr along the way from infinity to r, the work done is the force GMm/r² multiplied by the distance dr. And we add all those steps together by integrating the force from infinity to r as follows:<br />
<br />
<span style="color: blue; font-size: x-small;">If calculus puts you off, feel free to take my word for it and skip to equation [3]</span> <br />
<br />
<div class="MsoNormal">
E<sub><span style="font-family: "Arial","sans-serif"; font-size: 10pt;">g</span></sub> = <span style="font-size: x-large;">∫</span><sub>∞</sub><sup>r</sup> GMm/r² dr </div>
<div class="MsoNormal">
<br /></div>
<div class="MsoNormal">
= GMm <span style="font-size: x-large;">∫</span><sub>∞</sub><sup>r</sup> 1/r² </div>
<div class="MsoNormal">
<br /></div>
<div class="MsoNormal">
= GMm [-1/r]<sub>∞</sub><sup>r</sup> </div>
<div class="MsoNormal">
<br /></div>
<div class="MsoNormal">
= -GMm [ (1/r) - (1/∞) ]<sub></sub></div>
<div class="MsoNormal">
<br /></div>
<div class="MsoNormal">
= -GMm [ (1/r) - 0 ]<sub></sub></div>
<div class="MsoNormal">
<br /></div>
<div class="MsoNormal">
E<sub><span style="font-family: "Arial","sans-serif"; font-size: 10pt;">g</span></sub> = -GMm/r [3] <span style="color: blue; font-size: x-small;"><= equation [3]</span></div>
<div class="MsoNormal">
<br /></div>
<div class="MsoNormal">
This too is an important equation and we'll call it [3]. Just take a moment to consider what this means: the gravitational energy of a body in circular orbit is proportional to the masses of the bodies, and inversely proportional to the distance between them. <i>But it has a minus sign</i>, I hear you say. Yes indeed, and that means that gravitational energy <i>increases</i> (becomes less negative) as an object is lifted away from the central body. That fits with the idea that energy is required to do work in lifting the object. It also has some convenient consequences for orbital mechanics which we'll see later on.</div>
<div class="MsoNormal">
<br /></div>
<div class="MsoNormal">
Now that was the hardest piece of maths we'll do in this series, and there is no further calculus at all! Whether you followed the integration or skipped it, please go back and make sure you understand these two energies because they lay the foundation for truly understanding orbits, and all kinds of interplanetary travel.<br />
<br />
To wrap up orbital energy, we'll add kinetic energy and gravitational energy together into a single value.<br />
<br />
E<sub><span style="font-family: "Arial","sans-serif"; font-size: 10pt;">o</span></sub> = E<sub><span style="font-family: "Arial","sans-serif"; font-size: 10pt;">k</span></sub> + E<sub><span style="font-family: "Arial","sans-serif"; font-size: 10pt;">g</span></sub><br />
<br />
= GMm/2r - GMm/r <br />
<br />
E<sub><span style="font-family: "Arial","sans-serif"; font-size: 10pt;">o</span></sub> = -GMm/2r [4]<br />
<div class="MsoNormal">
<br />
Notice that orbital energy is negative, and increases in value as radius increases. It's as though this energy represents how far the body is located down into the gravity well of the central body. And if you imagine raising this energy past zero to a positive value as representing the orbiting body climbing out of the gravity well, then this will lead nicely on to the concept of escape velocity which we'll cover next time.</div>
</div>
<div class="MsoNormal">
<br /></div>
<div class="MsoNormal">
That's enough for this post. Next time we'll consider how energy oscillates between kinetic and gravitational energies in elliptical orbits, and look at escape velocity.</div>
Billysuggerhttp://www.blogger.com/profile/10673508741175504300noreply@blogger.com8tag:blogger.com,1999:blog-2309907146997372202.post-44244170387392936012011-07-18T16:30:00.000+01:002015-10-14T03:01:27.337+01:00Orbital Mechanics for Dummies - Kepler's Third Law<!--[if gte mso 9]><xml> <o:OfficeDocumentSettings> <o:RelyOnVML/> <o:AllowPNG/> </o:OfficeDocumentSettings> </xml><![endif]--><!--[if gte mso 9]><xml> <w:WordDocument> <w:View>Normal</w:View> <w:Zoom>0</w:Zoom> <w:TrackMoves/> <w:TrackFormatting/> <w:PunctuationKerning/> <w:ValidateAgainstSchemas/> <w:SaveIfXMLInvalid>false</w:SaveIfXMLInvalid> <w:IgnoreMixedContent>false</w:IgnoreMixedContent> <w:AlwaysShowPlaceholderText>false</w:AlwaysShowPlaceholderText> <w:DoNotPromoteQF/> <w:LidThemeOther>EN-GB</w:LidThemeOther> <w:LidThemeAsian>X-NONE</w:LidThemeAsian> <w:LidThemeComplexScript>X-NONE</w:LidThemeComplexScript> <w:Compatibility> <w:BreakWrappedTables/> <w:SnapToGridInCell/> <w:WrapTextWithPunct/> <w:UseAsianBreakRules/> <w:DontGrowAutofit/> <w:SplitPgBreakAndParaMark/> <w:DontVertAlignCellWithSp/> <w:DontBreakConstrainedForcedTables/> <w:DontVertAlignInTxbx/> <w:Word11KerningPairs/> <w:CachedColBalance/> </w:Compatibility> <m:mathPr> <m:mathFont m:val="Cambria Math"/> <m:brkBin m:val="before"/> <m:brkBinSub m:val="--"/> <m:smallFrac m:val="off"/> <m:dispDef/> <m:lMargin m:val="0"/> <m:rMargin m:val="0"/> <m:defJc m:val="centerGroup"/> <m:wrapIndent m:val="1440"/> <m:intLim m:val="subSup"/> <m:naryLim m:val="undOvr"/> </m:mathPr></w:WordDocument> </xml><![endif]--><!--[if gte mso 9]><xml> <w:LatentStyles DefLockedState="false" DefUnhideWhenUsed="true"
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<div class="MsoNormal" style="mso-margin-bottom-alt: auto; mso-margin-top-alt: auto;">
<span style="font-size: 12.0pt; mso-ascii-font-family: Arial; mso-bidi-font-family: Arial; mso-fareast-font-family: "Times New Roman"; mso-fareast-language: EN-GB; mso-hansi-font-family: Arial;">This post is an aside. Here I show how to prove Kepler's third law of planetary motion from what we have done so far. Nothing which follows depends on it, and if you choose to skip this post then you will lose nothing of substance from the series on Orbital Mechanics.</span></div>
<div class="MsoNormal" style="mso-margin-bottom-alt: auto; mso-margin-top-alt: auto;">
<br /></div>
<div class="MsoNormal" style="mso-margin-bottom-alt: auto; mso-margin-top-alt: auto;">
<span style="font-size: 12.0pt; mso-ascii-font-family: Arial; mso-bidi-font-family: Arial; mso-fareast-font-family: "Times New Roman"; mso-fareast-language: EN-GB; mso-hansi-font-family: Arial;">Kepler's third law states that</span></div>
<div class="MsoNormal" style="mso-margin-bottom-alt: auto; mso-margin-top-alt: auto;">
<br /></div>
<div align="center" class="MsoNormal" style="mso-margin-bottom-alt: auto; mso-margin-top-alt: auto; text-align: center;">
<i><span style="font-size: 12.0pt; mso-ascii-font-family: Arial; mso-bidi-font-family: Arial; mso-fareast-font-family: "Times New Roman"; mso-fareast-language: EN-GB; mso-hansi-font-family: Arial;">the square of the period of a planetary orbit is proportional to the cube of its distance from the Sun</span></i><span style="font-size: 12.0pt; mso-ascii-font-family: Arial; mso-bidi-font-family: Arial; mso-fareast-font-family: "Times New Roman"; mso-fareast-language: EN-GB; mso-hansi-font-family: Arial;">. </span></div>
<div class="MsoNormal" style="mso-margin-bottom-alt: auto; mso-margin-top-alt: auto;">
<br /></div>
<div class="MsoNormal" style="mso-margin-bottom-alt: auto; mso-margin-top-alt: auto;">
<span style="font-size: 12.0pt; mso-ascii-font-family: Arial; mso-bidi-font-family: Arial; mso-fareast-font-family: "Times New Roman"; mso-fareast-language: EN-GB; mso-hansi-font-family: Arial;">In one orbit, the orbiting body travels a distance equal to the circumference of the circle with radius r. This distance is 2</span><span style="font-size: 12.0pt; mso-ascii-font-family: Arial; mso-bidi-font-family: Arial; mso-bidi-theme-font: minor-latin; mso-fareast-font-family: "Times New Roman"; mso-fareast-language: EN-GB; mso-hansi-font-family: Arial;">πr. So the time taken to travel this distance, or the period of the orbit in seconds, P, is given by</span><span style="font-size: 12.0pt; mso-ascii-font-family: Arial; mso-bidi-font-family: Arial; mso-fareast-font-family: "Times New Roman"; mso-fareast-language: EN-GB; mso-hansi-font-family: Arial;"></span></div>
<div class="MsoNormal" style="mso-margin-bottom-alt: auto; mso-margin-top-alt: auto;">
<br /></div>
<div class="MsoNormal" style="mso-margin-bottom-alt: auto; mso-margin-top-alt: auto;">
<span style="font-size: 12.0pt; mso-ascii-font-family: Arial; mso-bidi-font-family: Arial; mso-fareast-font-family: "Times New Roman"; mso-fareast-language: EN-GB; mso-hansi-font-family: Arial;">P = 2πr / </span><span style="mso-ascii-font-family: Arial; mso-bidi-font-family: Arial; mso-bidi-font-size: 10.0pt; mso-fareast-font-family: "Times New Roman"; mso-fareast-language: EN-GB; mso-hansi-font-family: Arial;">V<sub>C</sub></span><span style="font-size: 12.0pt; mso-ascii-font-family: Arial; mso-bidi-font-family: Arial; mso-fareast-font-family: "Times New Roman"; mso-fareast-language: EN-GB; mso-hansi-font-family: Arial;"></span></div>
<div class="MsoNormal" style="mso-margin-bottom-alt: auto; mso-margin-top-alt: auto;">
<br /></div>
<div class="MsoNormal" style="mso-margin-bottom-alt: auto; mso-margin-top-alt: auto;">
<span style="font-size: 12.0pt; mso-ascii-font-family: Arial; mso-bidi-font-family: Arial; mso-fareast-font-family: "Times New Roman"; mso-fareast-language: EN-GB; mso-hansi-font-family: Arial;">Taking the square of both sides gives</span></div>
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<br /></div>
<div class="MsoNormal" style="mso-margin-bottom-alt: auto; mso-margin-top-alt: auto;">
<span style="font-size: 12.0pt; mso-ascii-font-family: Arial; mso-bidi-font-family: Arial; mso-fareast-font-family: "Times New Roman"; mso-fareast-language: EN-GB; mso-hansi-font-family: Arial;">P² = 4π²r² / </span><span style="mso-ascii-font-family: Arial; mso-bidi-font-family: Arial; mso-bidi-font-size: 10.0pt; mso-fareast-font-family: "Times New Roman"; mso-fareast-language: EN-GB; mso-hansi-font-family: Arial;">V<sub>C</sub></span><span style="font-size: 12.0pt; mso-ascii-font-family: Arial; mso-bidi-font-family: Arial; mso-fareast-font-family: "Times New Roman"; mso-fareast-language: EN-GB; mso-hansi-font-family: Arial;">²</span></div>
<div class="MsoNormal" style="mso-margin-bottom-alt: auto; mso-margin-top-alt: auto;">
<br /></div>
<div class="MsoNormal" style="mso-margin-bottom-alt: auto; mso-margin-top-alt: auto;">
<span style="font-size: 12.0pt; mso-ascii-font-family: Arial; mso-bidi-font-family: Arial; mso-fareast-font-family: "Times New Roman"; mso-fareast-language: EN-GB; mso-hansi-font-family: Arial;">Now from our last post we know that</span></div>
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<br /></div>
<div class="MsoNormal" style="mso-margin-bottom-alt: auto; mso-margin-top-alt: auto;">
<span style="mso-ascii-font-family: Arial; mso-bidi-font-family: Arial; mso-bidi-font-size: 10.0pt; mso-fareast-font-family: "Times New Roman"; mso-fareast-language: EN-GB; mso-hansi-font-family: Arial;">V<sub>C</sub></span><span style="font-size: 12.0pt; mso-ascii-font-family: Arial; mso-bidi-font-family: Arial; mso-fareast-font-family: "Times New Roman"; mso-fareast-language: EN-GB; mso-hansi-font-family: Arial;">² = GM/r </span></div>
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<br /></div>
<div class="MsoNormal" style="mso-margin-bottom-alt: auto; mso-margin-top-alt: auto;">
<span style="font-size: 12.0pt; mso-ascii-font-family: Arial; mso-bidi-font-family: Arial; mso-fareast-font-family: "Times New Roman"; mso-fareast-language: EN-GB; mso-hansi-font-family: Arial;">Putting this into the equation for the period squared gives</span></div>
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<br /></div>
<div class="MsoNormal" style="mso-margin-bottom-alt: auto; mso-margin-top-alt: auto;">
<span style="font-size: 12.0pt; mso-ascii-font-family: Arial; mso-bidi-font-family: Arial; mso-fareast-font-family: "Times New Roman"; mso-fareast-language: EN-GB; mso-hansi-font-family: Arial;">P² = 4π²r² / </span><span style="mso-ascii-font-family: Arial; mso-bidi-font-family: Arial; mso-bidi-font-size: 10.0pt; mso-fareast-font-family: "Times New Roman"; mso-fareast-language: EN-GB; mso-hansi-font-family: Arial;">(</span><span style="font-size: 12.0pt; mso-ascii-font-family: Arial; mso-bidi-font-family: Arial; mso-fareast-font-family: "Times New Roman"; mso-fareast-language: EN-GB; mso-hansi-font-family: Arial;">GM/r)</span></div>
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<br /></div>
<div class="MsoNormal" style="mso-margin-bottom-alt: auto; mso-margin-top-alt: auto;">
<span style="font-size: 12.0pt; mso-ascii-font-family: Arial; mso-bidi-font-family: Arial; mso-fareast-font-family: "Times New Roman"; mso-fareast-language: EN-GB; mso-hansi-font-family: Arial;">which simplifies to</span></div>
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<br /></div>
<div class="MsoNormal" style="mso-margin-bottom-alt: auto; mso-margin-top-alt: auto;">
<span style="font-size: 12.0pt; mso-ascii-font-family: Arial; mso-bidi-font-family: Arial; mso-fareast-font-family: "Times New Roman"; mso-fareast-language: EN-GB; mso-hansi-font-family: Arial;">P² = 4π²r</span><sup><span style="mso-ascii-font-family: Arial; mso-bidi-font-family: Arial; mso-bidi-font-size: 10.0pt; mso-fareast-font-family: "Times New Roman"; mso-fareast-language: EN-GB; mso-hansi-font-family: Arial;">3</span></sup><span style="font-size: 12.0pt; mso-ascii-font-family: Arial; mso-bidi-font-family: Arial; mso-fareast-font-family: "Times New Roman"; mso-fareast-language: EN-GB; mso-hansi-font-family: Arial;"> / GM</span></div>
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<br /></div>
<div class="MsoNormal" style="mso-margin-bottom-alt: auto; mso-margin-top-alt: auto;">
<span style="font-size: 12.0pt; mso-ascii-font-family: Arial; mso-bidi-font-family: Arial; mso-fareast-font-family: "Times New Roman"; mso-fareast-language: EN-GB; mso-hansi-font-family: Arial;">Now if this equation is applied to planets orbiting the Sun, then <i>the square of period of the orbit</i>, P², is directly proportional to <i>the cube of the distance from the Sun</i>, r</span><sup><span style="mso-ascii-font-family: Arial; mso-bidi-font-family: Arial; mso-bidi-font-size: 10.0pt; mso-fareast-font-family: "Times New Roman"; mso-fareast-language: EN-GB; mso-hansi-font-family: Arial;">3</span></sup><span style="font-size: 12.0pt; mso-ascii-font-family: Arial; mso-bidi-font-family: Arial; mso-fareast-font-family: "Times New Roman"; mso-fareast-language: EN-GB; mso-hansi-font-family: Arial;">. So we have proved Kepler's third law.</span></div>
Billysuggerhttp://www.blogger.com/profile/10673508741175504300noreply@blogger.com0tag:blogger.com,1999:blog-2309907146997372202.post-73439462605265422832011-07-17T20:44:00.001+01:002015-10-14T03:13:34.015+01:00Orbital Mechanics for Dummies - Circular OrbitsLast time we looked at the kinds of basic orbits, and gave a description of how the orbiting body moves in each. Now we will dip our toe in the maths water.<br />
<br />
The first step is to define the parameters of the orbit, according to the following diagram.<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgkmMRGIknERjRWyppiFBhlOIWkN8LY44mTTD9XFqVhZ8Gtl_OfCQ8wCqmfTKAMmYKoMog3elsrgBKrBB0ayM9FvAfl3NBgDfY81ArTpuXzzDRuL18sgFQ4Ep_NrdX3jaz3SpqyLR3rSeY2/s1600/Fig_01.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgkmMRGIknERjRWyppiFBhlOIWkN8LY44mTTD9XFqVhZ8Gtl_OfCQ8wCqmfTKAMmYKoMog3elsrgBKrBB0ayM9FvAfl3NBgDfY81ArTpuXzzDRuL18sgFQ4Ep_NrdX3jaz3SpqyLR3rSeY2/s1600/Fig_01.jpg" /></a></div>
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<br />
M is the mass of the central body, in kilograms (kg).<br />
m is the mass of the orbiting body, in kilograms (kg).<br />
r is the orbital radius between the centres of the bodies, in metres (m).<br />
v is the speed at which the orbiting body moves around the central body, in metres per second (m/s).<br />
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There are a few other parameters we'll use along the way:<br />
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G is Newton's gravitational constant, and is equal to 6.67 x10<sup>-11</sup> m<sup>3</sup>/kg/s<sup>2</sup>.</div>
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<span style="font-family: "Arial","sans-serif"; font-size: 10pt;">V<sub>C</sub></span> is the speed of a body moving in a perfect circular orbit, in metres per second (m/s).</div>
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<span style="font-family: "Arial","sans-serif"; font-size: 10pt;">V<sub>E</sub></span> is the speed of a body moving just fast enough to escape from orbit, in metres per second (m/s).</div>
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A is an acceleration, expressed as a change in speed per second (m/s²).</div>
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</div>
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From the previous post we know that for a circular orbit the orbiting body moves under centripetal acceleration which is provided by the gravity field of the central body. So we need formulae for both centripetal acceleration and gravitational acceleration.</div>
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From high school physics we recall that centripetal acceleration is given by</div>
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<span style="font-family: "Arial","sans-serif"; font-size: 10pt;">A<sub>C</sub></span> = V²/r</div>
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and gravitational acceleration is given by</div>
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<span style="font-family: "Arial","sans-serif"; font-size: 10pt;">A<sub>G</sub></span> = GM/r²</div>
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Now since centripetal acceleration is provided by gravitational acceleration, <span style="font-family: "Arial","sans-serif"; font-size: 10pt;">A<sub>C</sub></span> = <span style="font-family: "Arial","sans-serif"; font-size: 10pt;">A<sub>G</sub></span> so</div>
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V²/r = GM/r²</div>
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and because we can eliminate the /r on each side, and in a circular orbit V = <span style="font-family: "Arial","sans-serif"; font-size: 10pt;">V<sub>C</sub></span></div>
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<span style="font-family: "Arial","sans-serif"; font-size: 10pt;">V<sub>C</sub></span>² = GM/r [1]</div>
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There we have it, our first equation for orbital mechanics. Wasn't so hard, was it? It's such an important equation that I've labelled it [1] so we can refer to it again. What it tells us is that the square of the orbital speed is proportional to the mass of the central body, and inversely proportional to the orbital radius. The constant of proportionality is Newton's gravitational constant.</div>
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<b>Example</b></div>
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</div>
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To try this out, let's work out how fast the International Space Station (ISS) travels around the Earth. As I remember, it's around 17,500mph. But can our equation [1] confirm that?</div>
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The mass of the Earth is 5.97 x10<sup>24</sup> kg.</div>
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The radius of the Earth is 6.37 x10<sup>6</sup> m.</div>
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The ISS orbits at 350km above the surface, so the orbital radius is 6.72 x10<sup>6</sup> m.</div>
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<span style="font-family: "Arial","sans-serif"; font-size: 10pt;">V<sub>C</sub></span>² = GM/r = 6.67 x10<sup>-11</sup> x 5.97 x10<sup>24</sup> / 6.72 x10<sup>6</sup> = 59.3 x10<sup>6</sup>.</div>
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Taking the square root gives</div>
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<span style="font-family: "Arial","sans-serif"; font-size: 10pt;">V<sub>C</sub></span> =7,700 m/s.</div>
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Since there are 1,610 metres in a mile, and 3,600 seconds in an hour,</div>
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Orbital Speed = 7,700 x 3,600 / 1,610 = <b>17,200 mph</b>.<br />
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That works for me! Next time we'll take on the giant of orbital mechanics and prove Kepler's third law. </div>
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Billysuggerhttp://www.blogger.com/profile/10673508741175504300noreply@blogger.com3tag:blogger.com,1999:blog-2309907146997372202.post-63560224142540039952011-07-16T22:13:00.003+01:002011-07-17T19:39:44.133+01:00Orbital Mechanics for Dummies - Orbital Basics<div class="MsoNormal">I’m going to deal with very simple situations, as these make both understanding and the maths easier, and most real situations can be usefully approximated by these simple cases. The central body is vastly more massive than the orbiting body, so we can consider the central body to be fixed, and just work on the orbiting body.</div><div class="MsoNormal"><br />
</div><div class="MsoNormal">The simplest orbit is perfectly circular. The orbiting body moves in a circle at just the right speed so that its centrifugal force is precisely balanced by the gravitational force between the bodies. We will call that speed <span style="font-family: "Arial","sans-serif"; font-size: 10pt;">V<sub>C</sub></span>.</div><div class="MsoNormal"><br />
</div><div class="MsoNormal">Now physics purists will tell us that centrifugal force is an illusion, so to satisfy them we’ll consider acceleration rather than force and describe the orbit as the path where centripetal acceleration is provided by the gravity of the central body. We’ll do the maths for this in the next post. For now, here’s the circular orbit as a diagram.</div><div class="MsoNormal"><br />
</div><div class="separator" style="clear: both; text-align: center;"></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgXPISeS9lBh2VMgGQUPGYMVFvNZw0ULkSsFsOD21AvnNh95vLXm2wmAvcjusCGmlum-tGV7FUCU0aFNLNQbgamQeH0c-YFPh1HMaroAcBHDb1l7oPgf_jkaidFFStA7nuFWLLTyYgIEfh3/s1600/Fig_01.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgXPISeS9lBh2VMgGQUPGYMVFvNZw0ULkSsFsOD21AvnNh95vLXm2wmAvcjusCGmlum-tGV7FUCU0aFNLNQbgamQeH0c-YFPh1HMaroAcBHDb1l7oPgf_jkaidFFStA7nuFWLLTyYgIEfh3/s1600/Fig_01.jpg" /></a></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgM2Slz3BOdy5JACoRdW-WdjY63SDIaTSRQBrzLGRsvOtOy1arRaPuh2hoJTPD4b5u89PCeWyXtx1o-SlbH4Eeql6SLbmOJMbqWgezNC4XCnGE6dWLHbAdS7fkRX6JZxaHiaofgvy8sk14W/s1600/Fig_02.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"></a></div><div class="MsoNormal"><br />
</div><div class="MsoNormal">A variation of this orbit is the elliptical orbit. If at point A the orbiting body accelerates by a small amount, (less than 41% of <span style="font-family: "Arial","sans-serif"; font-size: 10pt;">V<sub>C</sub></span>), then as it proceeds around the central body its extra speed will cause it to climb away from the circular orbit path. As it climbs against the force of gravity from the central body, the orbiting body decelerates. It reaches its furthest point at B, directly opposite A, and begins to accelerate back towards the original point A once again.</div><div class="MsoNormal"><br />
</div><div class="MsoNormal" style="text-align: center;"> <a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgM2Slz3BOdy5JACoRdW-WdjY63SDIaTSRQBrzLGRsvOtOy1arRaPuh2hoJTPD4b5u89PCeWyXtx1o-SlbH4Eeql6SLbmOJMbqWgezNC4XCnGE6dWLHbAdS7fkRX6JZxaHiaofgvy8sk14W/s1600/Fig_02.jpg" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgM2Slz3BOdy5JACoRdW-WdjY63SDIaTSRQBrzLGRsvOtOy1arRaPuh2hoJTPD4b5u89PCeWyXtx1o-SlbH4Eeql6SLbmOJMbqWgezNC4XCnGE6dWLHbAdS7fkRX6JZxaHiaofgvy8sk14W/s1600/Fig_02.jpg" /></a></div><div class="MsoNormal"></div><div class="MsoNormal"><br />
</div><div class="MsoNormal">Point A, the closest to the central body, is called periapsis. Point B, the furthest from the central body, is called apoapsis.</div><div class="MsoNormal"><br />
</div><div class="MsoNormal">When the orbiting body is at point B, it is travelling more slowly than the circular orbit speed, <span style="font-family: "Arial","sans-serif"; font-size: 10pt;">V<sub>C</sub></span>’, at that radius from the central body. Now if the orbiting body accelerates again at point B, to <span style="font-family: "Arial","sans-serif"; font-size: 10pt;">V<sub>C</sub></span>’, it will follow a new circular orbit passing through B.</div><div class="MsoNormal"><br />
</div><div class="MsoNormal" style="text-align: center;"> <a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEidWx4VuCbXJOhfauWuMzwM4N9HH6IHvlSmtGQkZqVGIASorIyJ79jmDyZzxRL_d7vYfE8ASMvUeLE2nEG_FbLlF0Ia3-SwrgQm1Es3denV9wAPltD4_8CtGBYMlBBsMAmKksqCpUSAci5H/s1600/Fig_03.jpg" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEidWx4VuCbXJOhfauWuMzwM4N9HH6IHvlSmtGQkZqVGIASorIyJ79jmDyZzxRL_d7vYfE8ASMvUeLE2nEG_FbLlF0Ia3-SwrgQm1Es3denV9wAPltD4_8CtGBYMlBBsMAmKksqCpUSAci5H/s1600/Fig_03.jpg" /></a></div><div class="MsoNormal"><br />
</div><div class="MsoNormal">This kind of manoeuvre, where an elliptical transfer orbit is used to change between orbits of different radii, is used frequently in space flight. Some satellites are put into geostationary orbits, where they orbit once in 24 hours and appear stationary over particular points on the equator as the Earth rotates. When a geostationary satellite is launched, it is inserted into a transfer orbit with apoapsis at the geostationary radius. Then a dedicated engine is fired at apoapsis to accelerate and achieve a circular geostationary orbit. A variation of this kind of transfer orbit was used by Apollo spacecraft to reach the Moon.</div><div class="MsoNormal"><br />
</div><div class="MsoNormal">Finally, if the orbiting body accelerates by 41% of <span style="font-family: "Arial","sans-serif"; font-size: 10pt;">V<sub>C</sub></span> or more, then this speed causes it to climb away as before, but this time it is travelling fast enough that the gravity field from the central body reduces more quickly than the body decelerates, and the body continues climbing indefinitely. The body has exceeded the escape velocity, <span style="font-family: "Arial","sans-serif"; font-size: 10pt;">V<sub>E</sub></span>, has escaped the gravity field and will not return.</div><div class="MsoNormal"><br />
</div><div class="MsoNormal" style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhiITtMwKVARyhTCs8FO2yIF8XPC7X6zD3bDXVC0ZTaEXey-KP2r7SLvEM6-OXLJNb7jnPXjWxBoLsBvjdHad20Def3jEqSZPNG-JeBoFdjR2vKYEEq2s-Vvn2MfgnKHnrbjz24-q9705yJ/s1600/Fig_04.jpg" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhiITtMwKVARyhTCs8FO2yIF8XPC7X6zD3bDXVC0ZTaEXey-KP2r7SLvEM6-OXLJNb7jnPXjWxBoLsBvjdHad20Def3jEqSZPNG-JeBoFdjR2vKYEEq2s-Vvn2MfgnKHnrbjz24-q9705yJ/s1600/Fig_04.jpg" /></a> </div><div class="MsoNormal"><br />
</div><div class="MsoNormal"><br />
</div><div class="MsoNormal">These are the basic principles to grasp for now. Next time we will look at some simple maths to describe these different cases.</div>Billysuggerhttp://www.blogger.com/profile/10673508741175504300noreply@blogger.com3tag:blogger.com,1999:blog-2309907146997372202.post-35599209117347724822011-07-16T12:04:00.001+01:002011-07-18T15:35:44.558+01:00Orbital Mechanics for Dummies - IntroductionI have been following the <a href="http://dawn.jpl.nasa.gov/">Dawn mission to asteroid Vesta</a> with keen interest. The mission team is relying on simulation data because for various reasons accurate measurements of the probe's position are only available occasionally. The probe is expected to achieve orbital insertion around Vesta today, but without accurate data not available until tomorrow, we can only speculate on whether orbit has been achieved.<br />
<br />
For hour-by-hour data, the team relies on <a href="http://dawn.jpl.nasa.gov/mission/live_shots.asp">the MYSTIC simulator</a>. This gives vital data including Dawn's speed in relation to Vesta, and its range to the asteroid.<br />
<br />
I'm no rocket scientist, but I do have basic skills in physics and maths, and a keen interest in space flight. A number of years ago, I worked out my own very basic system for understanding orbital mechanics, including the basic equations for simple orbits, from first principles. I used these, with the simulation data, to show that Dawn appeared to have achieved orbital insertion around Vesta earlier this morning.<br />
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I have discussed my calculations with others interested in this mission. It occurs to me that there may be other keen amateurs out there interested in understanding the basics of orbital mechanics. So it is my intention to publish a series of posts on the subject.<br />
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It won't be for everyone, by a long way. But if you have a good grasp of high school physics and maths, you should be able to follow along. My own maths ability reached its limit shortly after high school level, so I haven't included anything too demanding! It also won't satisfy real rocket scientists, who use levels of calculus way beyond me and can tell you all the fundamentals I've missed out. However, if my basic version is flawed rather than just simplistic, then I'd really like to be corrected so please do get in touch!<br />
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If you're interested, keep an eye out for my following posts which detail my <b>Orbital Mechanics for Dummies</b>...<br />
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By the way, the title is not intended to patronize. I consider myself to be a mathematical dummy, at least compared to the abilities of my peers when I was studying. My aim is to use my limited skills to understand how orbits work, and how to work out their parameters. There are plenty of more complete works on the subject, but this is intended to be an easy entry.Billysuggerhttp://www.blogger.com/profile/10673508741175504300noreply@blogger.com0tag:blogger.com,1999:blog-2309907146997372202.post-36756051821246270522011-06-26T10:43:00.001+01:002011-06-26T12:17:06.005+01:00Are humans immune from extinction?Steve Zara made <a href="http://zarbi.posterous.com/we-will-survive">interesting post</a> about a discussion PZ Meyers is having on Twitter. Steve argues that humans have developed technology which is close to bringing human evolution to a halt, that we will soon leave Earth and colonise the solar system and thereby become immune from global catastrophies.<br />
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I would like to explore a counter argument: I maintain that humans are still subject to natural selection.<br />
<br />
The greatest selection pressure of all is death of an embryo or foetus from developmental defects - such as a missing circulatory system - which make development impossible. The majority of fertilised ova do not survive to birth, and many of these don't even make it to implantation.<br />
<br />
We have made great strides in combating disease, yet we remain in a microbiological arms race. Modern medicine provides an enormous selection pressure on human pathogens which are evolving to get around it. MRSA and C-Diff are examples.<br />
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Our abilities to survive modern diets also provides selection pressure. We have evolved the ability to digest lactose into adulthood within the last 10,000 years, since we domesticated dairy animals. No other mammal species can do this.<br />
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We haven't colonised space yet, and in my opinion it will be some considerable time before off-world colonies become completely independent of humans on Earth, if ever.<br />
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We need only a pandemic which wipes out enough people that space travel is abandoned as an expensive luxury. Then we are all eggs back in the same basket, and vulnerable to global catastrophe.<br />
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Finally, the very technologies which allow us to manipulate ourselves and our environments, makes us vulnerable to the failure of those technologies. A catastrophe which disables modern communication, high-tech industry and global commerce, would leave people with complex prostheses or reliance on drugs for survival, facing imminent doom.<br />
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I know how long it takes me to be debilitated when my internet connection goes down, but if it never came back up, or I could never buy car fuel, pay with a credit card or shop for food, I'd be back in the pre-industrial age in days.<br />
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I have great confidence in human adaptability, ingenuity and ability to survive extreme conditions. But I don't think we're any more immune from extinction than the dinosaurs were.Billysuggerhttp://www.blogger.com/profile/10673508741175504300noreply@blogger.com0tag:blogger.com,1999:blog-2309907146997372202.post-60564841178233808982011-06-17T23:29:00.000+01:002011-06-17T23:29:07.824+01:00Why versus HowI've just been looking through <a href="http://www.simpleguidetohumanism.org.uk/">The Really Simple Guide to Humanism</a>, (which is an excellent introduction btw), and in particular a video on the question <a href="http://www.simpleguidetohumanism.org.uk/24.html">Without a God, or religion, why should we care about anything?</a> About 2/3 of the way through, <a href="http://en.wikipedia.org/wiki/Colin_Blakemore">Colin Blakemore</a> brings up an old point that science should address questions of <i><b>how</b></i> and leave questions of <b><i>why</i></b> to religion. Of course, in the context of humanism, this means <i>the <b>why</b> questions are suspicious back doors into religious thinking</i>. But I fundamentally disagree. And here's why.<br />
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<b><i>Why</i></b> addresses issues of greater complexity than <i><b>how</b></i> typically does, but that does not mean the question presupposes that the answer makes reference to an intelligent agent. And the biological answer to <i><b>why</b> am I here</i> is substantially different from that to <b><i>how</i></b><i> did I come to be here</i>.<br />
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<i><b>How</b> did I come to be here</i> prompts an answer which addresses the biological mechanisms around reproduction. It may include sexual dimorphism, meiosis, fertilisation, mitosis and embryology. It is a perfectly valid discussion to have, but has a narrower scope than discussions which <i><b>why</b></i> questions prompt.<br />
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<i><b>Why</b> am I here</i> prompts a biological explanation which is far more profound, and addresses fundamental questions of existence, which are not the exclusive domain of religion. For example, I may answer that you are here because your parents succeeded in making you, that their parents succeeded in making them, and that every one of your ancestors, unlike most of their competitors, succeeded in leaving offspring who also succeeded against the competition to leave offspring. I could go on to point out that some of the reasons your ancestors succeeded was because they happened to have combinations of genes which made them well adapted to successfully reproduce in the environment they lived in. Finally, we could consider that your ancestors were also successful, in part, because they passed on the genes which gave them their success, and that you are likely to possess many of those successful genes yourself.<br />
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So <i><b>why</b> am I here</i> can prompt a discussion of the fundamentals of evolution which are often beyond the scope of <i><b>how</b></i> questions. Why would any thinking person want to dismiss that?Billysuggerhttp://www.blogger.com/profile/10673508741175504300noreply@blogger.com0tag:blogger.com,1999:blog-2309907146997372202.post-81212489230794030792011-06-16T10:46:00.000+01:002011-06-16T10:46:34.723+01:00AwesomeI am beginning to hate the word 'awesome', with a passion!<br />
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How can I be so animated by a word? Well I'm not, but I resent its use, and try as I can, I can't think of a single instance where there would not be a better choice.<br />
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It has no descriptive power and seems to be used as a place holder for a superlative adjective which the speaker can't be bothered to think of. It's this capacity for the word to dumb-down the articulation of the speaker which I resent. Life and language are rich, powerful and colourful. The word 'awesome' is mid-grey, colourless, non-descriptive and above all thoughtless. It could be anything: 'blah' would do just as well. "Oh your shoes are just blah" says precisely as much as "Oh your shoes are just awesome". In either case it gives an impression of being disingenuous; of having to say something positive but having nothing positive to say, except perhaps that we have seen 91210.<br />
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Just imagine what we could say in its place to describe 'awesome' shoes. We could say something like: creative; thought provoking; imaginative; beautiful; elaborate; colourful; stylish; unique; fashionable; stunning; irreverent; sexy; outrageous; delightfully expensive;... you get the idea I'm sure. And if it's not shoes, the possibilities increase considerably.<br />
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But what if you want to describe the shoes being so singularly unique that they inspire genuine awe? Then they are truly 'awe inspiring'.<br />
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I can see no point in the word 'awesome' at all.Billysuggerhttp://www.blogger.com/profile/10673508741175504300noreply@blogger.com3