[Anonymouse]

Originally Posted by Earl of Bronze

Well. If the human race is the only (alleged) intelligent life in our galaxy, never mind the universe as a whole. Then it's a terrible waste of space....

Someone's been watching Contact again - and why not, it was a good movie, reasonably faithful to Carl's excellent novel.

It makes sense for the MoD to close down the department, if for no other reason than that if we are getting visitors, there's nothing we can do about it because the ability to come here at all across light-years directly implies considerably more advanced technology than ours and, indirectly, weapons capability we can't possibly defend against. Note that I'm not touching the conspiracy theories; as Terry Pratchett pointed out, given their track record in terms of keeping terrestrial secrets, it seems unlikely they could conceal extra-terrestrial ones (though I must admit I think Project Blue Book was a smokescreen). It's possible there is something going on. But I've no real idea as to what.


My opinion? While I don't think they're necessarily coming here, I'm pretty sure they exist, on the grounds of the Theory of Mediocrity if nothing else.

To explain: we're pretty sure, from observational evidence, that the laws of the Universe are the same irrespective of where you are in the Universe (except in a black hole, but if you're in one of those you have a whole other set of problems rather more pressing than the issue of intelligent life...). Thus if, for example, you mix 2 volumes of hydrogen with 1 volume of oxygen and provide a spark, you'll get 1 volume of water, and this is true whether you're on Earth, a planet in the Andromeda galaxy (2.2 million light-years away and, I gather, getting closer) or anywhere else you happen to name. From this it seems likely that stars of similar age and spectral class (approx. 5.5 billion years, G2) will have similar planetary systems, because the laws of physics that dictate the formation of such systems are the same. Bear in mind, too, that ours is a very common type of star; there are millions in our galaxy alone.

From this, it seems likely there are other planets similar to Earth, i.e. life-bearing. Surely, therefore, at least some must have life similar to ours. True, we were lucky to have Jupiter (which acts as a cosmic vacuum cleaner and thus prevents the inner planets from being bombarded by space debris to such an extent that they'd either be smashed to bits or never get a chance to form in the first place) and the Moon (which stabilises the Earth's natural tendency to wobble on its axis and thus allows the formation of a reasonably stable climate), but still.

Why haven't we detected them? Several possible reasons (other than, duh, they don't exist to be detected):

1) They're not as advanced as us and therefore don't have radios and the like, thus no detectable transmissions.

2) They are as advanced as us, if not more so, but they're either too distant for us to have detected their transmissions yet or they're too distant for their transmissions to reach us at all (stellar dust, nebulae etc. interfering and scattering the radio waves, plus the good ol' inverse square law).

3) They're more advanced than us, and thus have already passed through the radio-transmission stage. They have developed tight-beam transmissions and technologies such as cable, and thus there are no transmissions for us to detect - we developed radio telescopes too late to pick them up. It's happening here; in a century or so this planet will likely be radio-silent, except for the occasional natural burst. So maybe other civilisations have already reached that stage.

4) They're secretive, for whatever reason, and don't want to be detected.

5) Any combination of the above, and/or all of them, and/or others we can't even guess at.

It is the height of hubris and arrogance - though ironically all too human - to assume that it's just us. I suspect that the reason people don't want to believe otherwise is that if we're not unique then we're no longer special, privileged, whatever.

My own feeling is that if they're right, the Universe is a far lonelier place than it should be, and that thought is one of the few things that scares me to the bone.

Why would they come here? Oh, no no no no no, I'm not touching that one either.