Life Could Have Evolved 15 Million Years After the Big Bang, Says Cosmologist 312
KentuckyFC writes "Goldilocks zones are regions around stars that are 'just right' for liquid water and for the chemistry of life as we know it. Now one cosmologist points out that the universe must have been through a Goldilocks epoch, a period in which warm, watery conditions could have existed on almost any planet in the entire cosmos. The key phenomenon here is the cosmic background radiation, the afterglow of the Big Bang which was blazing hot when it first formed. But as the universe expanded, the wavelength of this radiation increased, lowering its energy. Today, it is an icy 3 Kelvin. But somewhere along the way, it must have been between 273 and 300 Kelvin, just right to keep water in liquid form. According to the new calculations, this Goldilocks epoch would have occurred when the universe was about 15 million years old and would have lasted for several million years. And since the first stars had a lifespan of only 3 million years or so, that allows plenty of time for the heavy elements to have formed which are necessary for planet formation and the chemistry of life. Indeed, if live did evolve a this time, it would have predated life on Earth by about 10 billion years."
Re:Anthropic Principle (Score:5, Informative)
With no offense to an AC on Slashdot, and acknowledging that I also do not agree with Loeb's conclusions in this paper (even describing some of it as "calculations" is stretching the word somewhat), I can confirm that Loeb is an extremely capable cosmologist who has contributed far more to science than I ever have (and, I would guess, than you ever have either - though obviously I might be wrong on that one) and than most people ever have. He's one of the people I'd say would understand the anthropic principle.
I'm not sure what he was intending to accomplish here, but in general his output is of the highest quality.
Re:So Space Whales? (Score:5, Informative)
Re:All I know (Score:5, Informative)
Evolution doesn't have an inevitable "upward" direction. Today's microbes are every bit as "evolved" as we are from Earth's first inhabitants. So far, humans are no more than an evolutionary blip --- perhaps one that briefly flourishes, then vanishes away with nary a trace. Given billions of more years, evolution may simply produce a differently-colored cockroach, rather than a transcendent race of super-beings.
Re:This is frightening (Score:5, Informative)
, it's just not possible to build the kind of things you'd see at stellar distances.
I'm curious why you think that given that for example a small Class A stellar engine https://en.wikipedia.org/wiki/Stellar_engine [wikipedia.org] appears to be buildable with what we know about materials science. And this isn't the only example of such. The requirements are purely on the amount of resources that need to go in, not physical limitations. Yes, some specific suggestions would require materials that look impossible. For example, an inflexible single piece ringworld is likely to be impossible (the tensile strength among other requirements make it implausible). But many megascale structures aren't in that category.
But let me guess, you believe the aliens use magical particles like tachyons and gravitons to communicate and we're just too stupid to figure it out but when we do we'll be invited to the galactic fraternity, right?
No. Absolutely not. First note that tachyons and gravitons aren't "magical" there's a massive difference between theoretical particles consistent with the laws of physics. It is likely that tachyons do not exist, since they'd either allow causality violations (unlikely) or they'd not allow communication. Similarly, thinking that one could use something like gravitons to communicate is just silly since they'd be incredibly weak. I don't have any belief in some galactic fraternity, but your attempt to pigeon hole rather than read what people write is interesting. Concerns about the Great Filter arise specifically from there being no evidence of anything remotely like that. If there were any reason to think that was at all likely, we could breath a lot easier.
For the record I think that there is life everywhere in the universe because the laws of physics will be the same.
So, we're in complete agreement here. But the problem is what this leads to: it means that out of the civilizations, none of them are trying anything on a large scale, not even the few more ambitious ones. This suggests that once life gets sufficiently advanced, it gets wiped out somehow. The Great Filter is a serious problem: Nick Bostrom and his colleagues at the Future of Humanity Institute for example have given this a lot of thought. See for example http://www.nickbostrom.com/extraterrestrial.pdf [nickbostrom.com]. And this is very much the sort of problem where if it exists, pretending it doesn't won't make it go away.
Re:Too little time... (Score:2, Informative)
Don't be silly. At that point in time there were no planets at all -- hydrogen was about the only thing in the universe, until stars started burning hot and fast to put heavier elements into the universe.
This article is pointless conjecture. Conditions for life as we know it could not have possibly existed, due to a lack of pressure, gravity and a planet to live on, materials required to put anything together, etc. The only thing that this shows is that it was warm enough for life, while utterly disregarding the rest; it's like saying that you have an oven that's heated up to 350 degrees, so there should be a cake in there, without putting any of the ingredients into the oven. Including a pan for the cake.
Re:Millions of years of life-supporting conditions (Score:4, Informative)
Panspermia is the concept of taking one in a trillion odds of a shot hitting the target and firing that shot a trillion times. I'm not particularly advocating for it, but it has at least some basis in plausibility.
We know that rocks from others planets can and do get shot out by meteor impacts on a routine basis as some have landed on Earth. We know that these impacts shoot out large quantities of rocks at a time into space at random directions. We also know that gravitational currents [popsci.com] can help objects naturally move between planets.
We also know that bacteria can survive being left in outer space for years [bbc.co.uk] at a time. We know that the interior of a meteorite does not particularly heat [naturalsciences.org] up upon re-entry into the Earth's atmosphere. We know that bacteria are found inside of rocks inside the Earth when we look for them.
Now I'm not going to get into life (bacteria etc) evolving and everything that goes with it. I'm certainly not saying that Panspermia has any evidence of having ever occurred. I'm simply saying that the idea of Panspermia has at least some plausibility as a delivery mechanism for bacteria like life that had already evolved on it's own.
Re:Millions of years of life-supporting conditions (Score:5, Informative)