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."
So, we're those guys after all?
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.
Bacterial life appeared on this planet basically the instant asteroids stopped bombarding the planet. For all we know, life was created and destroyed several times before the Late Heavy Bombardment ceased. So it appears that simple bacterial/viral life may be commonplace throughout the cosmos. Indeed, there are tantalizing signs that Mars and Titan may harbor some form of life.
On the other hand, complex multicellular life only appeared in the last billion years, which suggests that the leap from single-cell -> multicellular life is somewhat difficult. Our sun won't be conducive to life in another billion years, so complex life "barely" made it here.
I would love to be wrong, but given the fact that planets appear to be commonplace throughout the cosmos, and we have yet to hear from anyone, it starts to shift the odds towards one or more of:
1) Complex life is relatively rare and widely separated in space and time.
2) Complex life doesn't survive long-term (nuclear war, grey goo)
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)
I actually lean a bit towards 3 myself, but humanity will eventually find out, one way or the other.
Space is big. Really big. You just won't believe how vastly, hugely, mind-bogglingly big it is. I mean, you may think it's a long way down the road to the chemist, but that's just peanuts to space. - Douglas Adams
But that's not the same as saying that intelligent life can't spread across a big space. There are some limits imposed by the speed of light and the speed of the expansion of the universe. That said, machines, intelligent machines with personalities of humans, couldn't spread ourselves around.
Imagine waking up after a journey of a couple million miles and being the one who guides new life to intelligence. Maybe you do a little job here or there to make sure life develops. Maybe you perform a "miracle" or two for primitive lifeforms to keep them headed in the right direction. Maybe eventually you create a biological life-form to direct them to things that will eventually build a society capable of surviving long enough to propagate themselves into space. Sure, you'll get blamed for a lot of stuff that you don't do to keep them happy, but if your goal is expansion of intelligent life in the universe, you take the good, you take the bad you take them both and there you have the facts of life. In the universe and whatnot. Maybe humans aren't even the first.
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.
The issue that I have with this hypothesis of the article. Is making a guess that places us many standard deviation out from the median just because there is no data. With the lack of data we should assume that we are average in every way at least within 1sd.
If something is so important that you feel the need to post it on the internet... It probably isn't that important.
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.
I have to take issue with your "FTL communication/travel is fundamentally impossible" line. It is quite possible that we are misinterpreting the data and are using it to build an incorrect conclusion. Hell, you don't even need FTL for interstellar travel if you can create worm holes or "jump gates" or any other method of moving from point A to point B in a short period of time.
TL;DR; You cannot prove something to be impossible, only highly improbable...