I think that PhilC is making reference to a certain 'E.T.' made famous in a movie similarly named.

stewer: Yes, I agree completely.  While finding extraterrestrials is nobel and worthwhile in some ways, wouldn't it be better to find ways to keep this boat (human civilization) from sinking before looking for distant boats on the horizon which couldn't be of much service anyway (possibly sinking as well)?  Not only do we need to fight diseases but to realize our heritage (lit. descent) and come to grips with it so that we can forge a better society and civilization more so devoid of the atrocities perpetuated by governments, institutions, groups, and individuals.  What can I say, I daydream alot. :)

mwafarmer: My point about photons from stars exactly.  Stars emit radiation at 360d (enumerable numbers of photons per second).  The further away a 'receptor' is the smaller the area of the emitter that is encountered.  When you start talking thousands and millions of light years, you are talking an area so small as to make encounters with these photons rare.  Luckily, photons are being emitted quite regularly from stars and do stream in.  But for some distant galaxies, we're talking a photon a second at best.  To build a blurry image of an object, you need several thousands of photons.  This is why telescopes train on a point in the sky and absorb light for hours or over days or months even!  To really get a signal from a far off ET would require that the ET was transmitting at 360d for a long time - and happen to have those signals start encountering Earth at about this time in our history for us to even receive them.

Worse than that is occlusion.  EM can't propagate through solid bodies (easily except at very high energies) - and can be diffused by gaseous or plasmatic bodies.  What makes up most of the Milky Way - big voluminous clouds of gas and plasma.  It doesn't look like that much when looking at the night sky - but you can see the band faintly on a clear night out of terrestrial light occlusion.  It'll be hard enough to get that incalculably small sliver of energy from an ET signal but add on the impediments it must cross in its path from there to here and you might be lucky once in a million times (i.e.: million ETs).  See my previous post for my estimates of ETs out there.

C makes it easy to shoot yourself in the foot. C++ makes it harder, but when you do, you blow your whole leg off.

 -- Bjarne Stroustrup

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