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Life Could Have Evolved 15 Million Years After the Big Bang, Says Cosmologist

Posted by Unknown on from the star-trek-explained dept.

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."

3 of 312 comments (clear)

  1. This is frightening by JoshuaZ · · Score: 5, Interesting

    This is pretty scary. One of the major unsolved problems right now is the Fermi problem- why we don't see any signs of civilizations other than our own, not just no radio transmissions but no Dyson spheres (and yes, we've looked http://home.fnal.gov/~carrigan/infrared_astronomy/Fermilab_search.htm, stellar uplifting, ringworlds or the like. Whatever is blocking this is the so-called Great Filter https://en.wikipedia.org/wiki/Great_Filter. Now, some of the Filter could be in our past. It may be tough for life to arise or for multicellular life to arise, etc. However, the more disturbing possibility is that it exists in our future: maybe civilizations before they can spread out manage to wipe themselves out with their technologies, such as through nuclear war, bad nanotech, engineered bioweapons, resource depletion, environmental damage, or something we haven't even thought about before.

    Over the last few years, more and more evidence has suggested that a lot of the obvious filtration events in the past aren't serious filters. For example, we've found that planets are common. This is not only an example of more such evidence, but it suggests that if life got started it would have had billions years more to evolve, meaning that evolutionarily based filters will be substantially less effective. Worse, it undermines one of the easier ways to try and get around a filter, to suggest that the conditions for complex life didn't arise until recently. There are serious problems with that idea already (especially the fact that life on Earth spent hundreds of millions of years in near stasis), and this makes those problems even more severe. If this checks out, it will be strong evidence that a substantial portion of the filter is in the future. If so, it is likely that the Filter is something that is going to happen to us within the next few hundred years, since it gets harder to wipe out a civilization once they spread beyond their initial planet, and most obvious things that would do so are also more noticeable.

    1. Re:This is frightening by wvmarle · · Score: 5, Interesting

      We can probably ignore the sun's background radiation: if an alien civilisation is advanced enough to see our planet next to the sun in visible light (reflection from the sun's rays) they can probably focus enough to pick up our radio signals (the sun's radio frequency waves will not be deflected by the Earth much if at all). The fact that there are radio signals coming from our planet should be the giveaway. No other planet in our solar system is producing such signals. And that's of course assuming this alien entity is using radio waves themselves for communication, and as such thinks it's a good idea to look for radio waves as a sign of the presence of intelligent life.

      Same for this SETI, I don't think we'll ever be able to understand alien signals beyond the mere fact that they are out there.

  2. Well known filter is currently active by Anonymous Coward · · Score: 5, Interesting

    The following is nothing new, but few people want to face up to what it really means for us. The 6th Mass Extinction is well under way, and it has nothing to do with cuddly pandas and (less cuddly) tigers and rhinos disappearing. It's the microscopic life such as oceanic biota, nearly all of it unseen by most people, that's disappearing at a devastating pace like nothing that's ever happened before on this planet.

    We can live without the top-end mammals that make the extinction news on the TV. We can't live without the microbiota. We are not independent of them, they keep the biosphere running and our crops producing, and without the biosphere we are no more.

    The collapse of biodiversity is, on geological scales, vertically downwards, and at some point it simply hits the zero axis. It could happen even more suddenly if a tipping point is reached, because species are inter-dependent. The current decline is not the normal sort of gradually falling curve as seen in the past 5 extinctions. On the biodiversity graph, this event is an abrupt termination of all life. You can't argue with the biodiversity curve.

    We don't really need more Great Filter theories. This one is not a theory, it's measured, and it's quite enough all by itself.