Well-Actually War Trall Actaeon Posted January 22, 2014 Share Posted January 22, 2014 Heat death? Big bounce? Vacuum metastability event? Discuss. Not up to speed? Read, then discuss. (Personally, I take a certain amount of comfort in the multiverse theory, but would still prefer something cyclical.) Quote Link to comment Share on other sites More sharing options...
Hatchling Cockatrice Randomizer Posted January 22, 2014 Share Posted January 22, 2014 I'm not going to be around to find out. Entropy will probably have it slowly die out as it cools off. Quote Link to comment Share on other sites More sharing options...
Hatchling Cockatrice Alorael at Large Posted January 22, 2014 Share Posted January 22, 2014 Zeno's paradox implies that as the end of the universe approaches planck time will asymptotically lengthen and we'll never actually get there. —Alorael, who has horribly bastardized multiple branches of human thought just for you! springacres, Goldengirl and A less presumptuous name. 3 Quote Link to comment Share on other sites More sharing options...
Magnificent Ornk Student of Trinity Posted January 22, 2014 Share Posted January 22, 2014 I think the scenario that seems most likely now is that all the galaxies end up far away from each other, as cosmic expansion increases, and each galaxy dies its lonely heat death in isolation. The universe is currently just into its third generation of stars; I don't know how many cycles of star formation and death the average galaxy can support, but in principle the resources are finite. The curve of nuclear binding energy bottoms out at iron. Once enough primordial hydrogen and helium has been fused up into iron, the fuel mixture may just get too lean for further star formation. There are lots of uncertainties in all of this, however. We know too little about really long term physics to be sure about anything. Quote Link to comment Share on other sites More sharing options...
Unflappable Drayk adc. Posted January 22, 2014 Share Posted January 22, 2014 The universe (99% correct prediction by me) will stay the same in less than 1 Earth hour. ----- -Nightwatcher Quote Link to comment Share on other sites More sharing options...
Magnificent Ornk Student of Trinity Posted January 22, 2014 Share Posted January 22, 2014 I've already drunk one coffee in that time. So the universe has already changed. Sorry. Goldengirl 1 Quote Link to comment Share on other sites More sharing options...
Hatchling Cockatrice Randomizer Posted January 22, 2014 Share Posted January 22, 2014 I've already drunk one coffee in that time. So the universe has already changed. Sorry. There you go again, trying to create localized order out of chaos. Quote Link to comment Share on other sites More sharing options...
Unflappable Drayk adc. Posted January 22, 2014 Share Posted January 22, 2014 I didn't know that the 1% was that resilient... . . . . . I've turned really spammy, I guess I should stop posting by now... ----- -Nightwatcher Quote Link to comment Share on other sites More sharing options...
Garrulous Glaahk Questionably Legal Posted January 22, 2014 Share Posted January 22, 2014 I've turned really spammy, I guess I should stop posting by now... ----- -Nightwatcher Spam where no man has spammed before! . . .which would not be here. The universe will end when the amout of spam slowly building up in the dark reaches of the internet reaches critical mass and collapses in on itself, forming a black hole that destroys reality as we know it. Student of Trinity and springacres 2 Quote Link to comment Share on other sites More sharing options...
Easygoing Eyebeast Jerakeen Posted January 23, 2014 Share Posted January 23, 2014 I like the Eternally Expanding Self-Reproducing Chaotic Inflationary Universe (PDF). Don't really understand it, but I like it. Quote Link to comment Share on other sites More sharing options...
Garrulous Glaahk Vexivero Posted January 27, 2014 Share Posted January 27, 2014 When I took Astronomy a few years back, the theory that connected with me was that because the universe is expanding at such a rapid rate eventually everything will spread out so thin nothing will have any energy. So everything in the universe will eventually just freeze. I'm not a science guy or anything, so with my limited knowledge on anything about the world that makes the most sense to me. —Vexivero, who is a casual fan of astronomy. He wonders what will happen to humankind in the centuries to come, and how many mysteries will be unraveled during that time. Alas, this is also saddening as well, as he will probably never know most of the answers. Quote Link to comment Share on other sites More sharing options...
Well-Actually War Trall Cairo Jim Posted January 27, 2014 Share Posted January 27, 2014 What gets me about that theory is, although the universe is expanding, why should matter be expanding as well? Quote Link to comment Share on other sites More sharing options...
Hatchling Cockatrice Lilith Posted January 27, 2014 Share Posted January 27, 2014 What gets me about that theory is, although the universe is expanding, why should matter be expanding as well? You're thinking of the "big rip" hypothesis. Basically, the idea is it's not just that the universe is expanding in the sense that things are moving apart from each other, but that space itself is expanding, causing the distances between things to get bigger. Normally this happens on a short enough timescale that everyday objects are easily held together by more familiar physical forces, but it's possible that the rate of expansion is increasing over time, which would mean that eventually the expansion becomes too rapid for any attractive forces to hold against it. Quote Link to comment Share on other sites More sharing options...
Magnificent Ornk Student of Trinity Posted January 27, 2014 Share Posted January 27, 2014 That's correct, except that short time scales aren't really the issue. It's that the forces that tend to stretch space need a lot of elbow room to have much effect. As in, millions of light-years of elbow room. The expansion effects are good at expanding the enormous voids between galaxies, but they're easily outweighed by even the tenuous gravity between stars that are many light-years apart. Against electrostatic forces holding matter together, they're really negligible. You could imagine scaling up the cosmological constant to the point where this would no longer be true, but I think you'd have to increase it by something like forty powers of ten. I don't know any serious theories in which the cosmological constant increases in future. Accelerating expansion normally happens (in theories) just because the big voids get steadily bigger, so the constant cosmological constant makes them expand ever faster. This would leave galaxies pretty much intact, let alone stars and planets and people. It would just make intergalactic travel more expensive. If we let in hypothetical scenarios for which there's no evidence but that can't be ruled out, though, then in principle the whole universe could still be in a false vacuum, like the one considered as the initial state in models for so-called cosmic inflation. Inflation is a hypothetical early period in the universe, very shortly after the Big Bang, in which the cosmological constant was in effect very much larger than it seems to be now, so that space expanded very quickly. Then we settled into the true vacuum (if it is the true vacuum, and not just a longer-lived false one) and the cosmological constant dropped to near zero. If we haven't yet hit the true vacuum, then in principle there could be a second stage of inflation starting any time. It could be a doozy, ripping even atoms apart; a kill switch on the universe, waiting to fall. As from the power of sacred lays The spheres began to move, And sung the great Creator's praise To all the blest above: So, when the last and dreadful hour This crumbling pageant shall devour, The trumpet shall be heard on high, The dead shall live, the living die, And Music shall untune the sky. Quote Link to comment Share on other sites More sharing options...
Hatchling Cockatrice Lilith Posted January 27, 2014 Share Posted January 27, 2014 I've never heard of that scenario. It's pretty far-fetched. The forces that tend to stretch space need a lot of elbow room, as it were, to have much effect. They're good at expanding the enormous voids between galaxies, but they're easily outweighed by even the tenuous gravity between stars that are many light-years apart. Against electrostatic forces holding matter together, they're really negligible. It's something one sees in pop-sci stuff from time to time; there's a Wikipedia article on it. Obviously I don't have much idea of how plausible it is, but yeah, the idea does seem to be that it's premised on an increasing cosmological constant. Quote Link to comment Share on other sites More sharing options...
Magnificent Ornk Aran Posted January 27, 2014 Share Posted January 27, 2014 If we haven't yet hit the true vacuum, then in principle there could be a second stage of inflation starting any time. It could be a doozy, ripping even atoms apart; a kill switch on the universe, waiting to fall. If I read it right, the bubble would expand at light speed, and we wouldn't even see it coming. It could already be happening. It could be reaching the edge of the solar system right now ! Quote Link to comment Share on other sites More sharing options...
Magnificent Ornk Student of Trinity Posted January 27, 2014 Share Posted January 27, 2014 Or it could start in your breakfast cereal bowl one morning. Careful with that spoon. Quote Link to comment Share on other sites More sharing options...
Well-Actually War Trall Khoth Posted January 31, 2014 Share Posted January 31, 2014 Greg Egan wrote a novel (Schild's Ladder) where that happens (although it happens at half the speed of light so there can be a story). It's pretty cool. Quote Link to comment Share on other sites More sharing options...
Easygoing Eyebeast *i Posted January 31, 2014 Share Posted January 31, 2014 In principle, the universe in an inflationary scenario could expand faster than the speed of light. As it is believed to have done in the very early universe. But wait? Doesn't this violate special relativity? No. Those rules only apply to information (light and matter) not space itself. Quote Link to comment Share on other sites More sharing options...
Unflappable Drayk Edgwyn Posted January 31, 2014 Share Posted January 31, 2014 The worm that is swallowing it's tail will choke and die and the universe will end. But there will be a restaurant there at the end. Questionably Legal 1 Quote Link to comment Share on other sites More sharing options...
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