8 ms·
This reminds me of "The Habitable Epoch of the Early Universe" https://arxiv.org/abs/1312.0613 https://arxiv.org/abs/1312.0613 where it is pointed out that for
by evanb 8y ago
This reminds me of "The Habitable Epoch of the Early Universe" https://arxiv.org/abs/1312.0613 https://arxiv.org/abs/1312.0613 where it is pointed out that for some time during cosmological evolution, the universe would have been quite comfortable and rocky planets (if any existed) could have had liquid water, with no need to be in a Goldilocks zone---the whole universe was Goldilocks!
- emilfihlman 8y agoWhoa. Now this is super interesting!
- vatys 8y agoBack then everything would have also been so much closer together. The universe could have been like one great bustling city. Perhaps, from that perspective, we are already in some long-tail end-of-days time. Planets and stars and galaxies are so far apart as to make travel difficult or impossible.
- api 8y agoA science fiction story set in this time would be truly epic and beautiful.
- vatys 8y agoTruly. But a story which inevitably must end with expansion, cooling, and a new need to huddle around stars.
- mikeash 8y agoOur story inevitably ends with the Earth roasting and then freezing as the Sun ages. There’s still lots of good stuff to tell in the meantime.
- evanb 8y agoThe Integral Trees (Larry Niven, 1984) is about a society living in a ring of gas around a neutron star. Not quite the same, but a similar interesting astrophysical idea.
- Zuider 8y agoSpace 1999 was a little like that. The premise was that the moon was blasted out of the Solar system into interstellar space. Somehow, the doughty denizens of Moonbase Alpha managed to encounter a new planet with intelligent life in nearly every episode. That would have required the stars to be pretty close.
- phs318u 8y agoThanks for the reminder. I was completely OBSESSED with that show as a kid.
- zzedd 8y agoI seem to remember an episode in Stephen Baxter's "Evolution" where two dinosaurs discuss the idea of technical progress but were stymied by a catastrophic event.
- christudor 8y agoTau Zero by Poul Anderson is an interesting little novel that touches on some of this stuff.
- edem 8y agoWe're kinda in the mid-game. We can still see __a lot__ of galaxies and can still reach them. The universe will keep expanding forever and at some point, the cosmic event horizon will shrink to the size of our galaxy. There is still a wide variety of stars including supergiants which can seed the galaxy with heavy elements when they go supernova. There will be a time when only Red Dwarves will survive, and after trillions of years the universe will enter a dark age when there are no stars with visible light left.
- 01100011 8y agoDo we really know that the expansive forces will continue forever? Is it possible we're living in milk spilled on the floor of some higher dimensional reality and at some point the "surface tension" will override the expansive forces?
- edem 8y agoThis depends on the cosmological constant (dark energy). There are 3 scenarios: The big rip, the big crunch and equilibrium. In the big rip scenario, dark energy will overpower all other forces and at some point space itself will expand so fast that the cosmic event horizon will be smaller than the smallest particle which means that nothing will be able to reach anything (even particles). In the big crunch scenario expansion will stop at some point and it will reverse and in the end the whole universe will be concentrated in a point (just like before the big bang). Equilibrium means that the expansion stops but does not reverse. What do you mean by "surface tension"?
- deleted 8y ago[deleted]
- edflsafoiewq 8y agoWhat is z in that paper?
- evanb 8y agoFirst words of the abstract: > In the redshift range 100<(1+z)<137, ... z is the letter often used for redshift, https://en.wikipedia.org/wiki/Redshift https://en.wikipedia.org/wiki/Redshift, a stand-in for cosmological time that's easy to extract experimentally (as compared to an actual time). (1+z) is essentially the ratio by which the universe is bigger today than it was when the physics being observed happened.