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Maybe There's No Life in Space Because We're Too Early
Long-time Slashdot reader sehlat shares "a highly accessible summary" of a new theory about why we haven't yet find life on other planets -- that "we're not latecomers, but very, very early." From Lab News:
The universe is 13.8 billion years old, with Earth forming less than five billion years ago. One school of thought among scientists is that there is life billions of years older than us in space. But this recent study in the Journal of Cosmology and Astroparticle Physics argues otherwise... "We find that the chance of life grows much higher in the distant future..."
Stars larger than approximately three times the Sun's mass will perish before life has a chance to evolve... The smallest stars weigh less than a tenth as much as the sun and will glow for 10 trillion years, meaning life has lot of time to begin on those planets orbiting them in the 'habitable zone'. The probability of life increases over time so the chance of life is many times higher in the distant future than now.
The paper ultimately concludes that life "is most likely to exist near 0.1 solar-mass stars ten trillion years from now."
Stars larger than approximately three times the Sun's mass will perish before life has a chance to evolve... The smallest stars weigh less than a tenth as much as the sun and will glow for 10 trillion years, meaning life has lot of time to begin on those planets orbiting them in the 'habitable zone'. The probability of life increases over time so the chance of life is many times higher in the distant future than now.
The paper ultimately concludes that life "is most likely to exist near 0.1 solar-mass stars ten trillion years from now."
Thousands of lightyears, sometimes even more, so we see thousands of years in the past
The Universe has been around for 13.8 billion years. A few thousand years one way or the other is insignificant. TFA isn't talking about us being a millennium ahead of other civilizations, it is about us being billions of years too early.
So similar to Star Trek, we just might get to know the club when we qualify for it (FTL Communication or Travel).....
Even on Star Trek, there are many civilizations that decline to join "the club". Star Trek is silly anyway, because it is unlikely that so many civilizations would reach nearly the exact same degree of development at exactly the same time. Also, as we learn more and more about physics, we get more and more confirmation that FTL communication/travel is fundamentally impossible. It is highly unlikely that interstellar travel will ever be like taking the train to work.
3) Complex life does survive, but for some reason doesn't communicate or colonize other worlds (a "Prime Directive", or perhaps they "sublime" in the Ian Banks/Culture sense)
Or because no one has found a way around that pesky speed-of-light barrier, and the vast distances simply make inter-species communication, let alone travel, utterly impractical. This has always seemed, at least to me, the least romantic but most pragmatic answer to the question of why we don't meet aliens, or even hear from them.
Irony: Agile development has too much intertia to be abandoned now.
I am afraid that I have never been persuaded by "civilisation will destroy itself" arguments, because (a) they have a poor definition of "destroy" and (b) options for further evolution don't seem to be well considered.
Expanding briefly if I may: Most cataclysmic events postulated don't seem cataclysmic enough. Suppose for example there was a huge nuclear war. Might that and the ensuing nuclear winter push humanity back to the dark ages? Well, very possibly it might, but we know from practical experience that getting from the dark ages to now takes about 1500 years or so, probably rather less if you have the smoking remains of the previous civilisation to get clues from. So, we get another go at being an advanced civilisation and presumably can repeat this depressing episode over and over again (see Azimov's excellent 1941 short story Nightfall).
For these cataclysmic events to actually make mankind extinct the population has to be reduced below a practical reproductive minimum (which clearly depends at least in part on how spread out the survivors are). We could imagine perhaps some sort of synthetic plague to which no-one is immune and which survives in the environment to such an extent that even small highly isolated populations are eventually infected. It sounds a bit unlikely to me, but again we know from experience that given a few million years our ape cousins will evolve to replace us. Of course, all primates could also be vulnerable to the disease, in which case we just have to wait even longer for an evolutionary replacement.
Conclusion: Short of managing to destroy all multicellular life forms, planets which evolve advanced life will have advanced civilisations from then on with possible gaps.
I think the first few seasons of Babylon 5 is a better analogy. In fact, the first few seasons of Babylon 5 is basically about the struggle between the older races and the younger races. It's possible that we are one of the "old ones" but an early stage. It's also possible that we are one of the younger races but, to the "old ones" we are nearly indistinguishable from ants (G'Kar gives a nice speech about this).
On a more serious note, anyone who has sat and given some thought to what the TFS talks about has probably realized that we could be one of the earliest sentient races. The universe didn't start with the ingredients of life. It was brewed in stars and then spread by the exploding of stars and the re-coalescence of that material. That shortens the possible time frame for sentient life but, you also need a fairly quiescent part of the galaxy to give sentient life enough time to form. So, really, it's impractical for sentient life to arise until *all* nearby giant stars have gone supernova. Then you have the time it takes for new solar systems to form and stabilize, basic life to come into existence, mass extinctions, the possibility that lifeforms unsuitable for sentience will dominate a planet, etc, etc.
It really takes an extraordinary amount of luck, over an extraordinary amount of time, for sentient life to form. And, as we've seen in the last century, it also takes a lot of luck for a technological society to not destroy itself.