Originally posted by ferneyhoughgeliebte
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Ever felt insignificant?
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amateur51
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heliocentric
Returning to the "insignificance" angle, there are different ways of looking at it. There's the one with which the thread began which draws attention to our insignificance relative to the size and duration of the universe. Then there's the one hinted at by Bryn earlier on which draws attention to the existence in this universe of intelligence, and in particular the ability of one very small part of the universe to contemplate and to attempt to understand the whole... looking out at the myriad galaxies it's still unclear whether this has happened anywhere else, and it certainly doesn't seem to have happened elsewhere in our immediate vicinity in this galaxy (our presence would be now theoretically detectable within a sphere of radius somewhat over 100 light years (in the time since the first radio broadcast) and expanding at the speed of light, and no such broadcasts have yet been picked up from elsewhere), unless in forms we're unable to recognise, so the evolution of intelligence is maybe not that common; also, it has existed on this planet for the merest blink of an eye compared with the age of the universe, so there is also perhaps something special about this moment in its history. In other words this place and time and this intelligent species might be by no means insignificant.
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amateur51
Originally posted by Simon View PostOK, thank you for your rational response. I'll put my side of the theory, if at all possible, tomorrow. I'm due out at 9.30 this evening.
Did you know that they've name a cheese after Simon?
Or was it the other way round?
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heliocentric
Originally posted by Dave2002 View PostThere are probably fewer than 1000 sun like stars within 100 light years. One estimate is 586.
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Originally posted by heliocentric View PostRight. But there seems to be no reason why an extraterrestrial civilisation should be anywhere close to ours in age, so the majority of them would either be a lot younger than ours or a lot older, and in the latter case their radio signals would have travelled a lot further, if at any point in their development they used electromagnetic waves for communication. As Enrico Fermi was the first to point out, the fact that we don't see any evidence of intelligent life outside the solar system seems to be in need of an explanation.
1. Assume (almost certainly incorrectly) that the difficulty of detecting distant signals can be disregarded.
2. Consider a radius of 1 million light years. This is feasible regarding time frames.
We have not yet discovered any other intelligent life within 100 light years. Assume there could be at least one, but the probability of finding one group of intelligent beings is 1/(100 million). Within a radius of 1 million light years, all other things being equal (which I've already written is not the case) then the probability finding one can be shown to be around 0.6.
If the probability of finding life within 100 light years (when? soon? within what time period?) is as large as 1/(1 million), then it becomes almost certain that life will be found within a 1 million light year radius - though a limiting factor could be the resource limitations at our end, as the detection problem would be at least 10^8 times harder.
Could be that Fermi might be right, though much more rigorous analysis needs to be done. Presumably others have already had a go, and come up with much more meaningful values than here.
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always thought that it might be prudent not to look for other life forms in the galaxies .... they might quite fancy eating us ..... quite happy to preserve any significance we might have uninterruptedAccording to the best estimates of astronomers there are at least one hundred billion galaxies in the observable universe.
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Originally posted by aka Calum Da Jazbo View Postalways thought that it might be prudent not to look for other life forms in the galaxies .... they might quite fancy eating us ..... quite happy to preserve any significance we might have uninterrupted
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Resurrection Man
Originally posted by Dave2002 View Post.....
We have not yet discovered any other intelligent life within 100 light years. .....
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heliocentric
Originally posted by Resurrection Man View PostBut that isn't definite proof that they are not there. It is quite conceivable that if their civilisation was much older and more technologically advanced than ours that they could 'hide' their presence from our, to them, technically primitive equipment.
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Originally posted by Resurrection Man View PostUmmm.. the majority of your posts ?Last edited by Flosshilde; 03-10-12, 07:53.
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amateur51
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