Ken Olum - Will the Universe Ever End?

can we all worry about our end but some of us are are strange enough to worry about the end of the whole universe what does that mean how many different ways can the universe end I'm sure there are many ways in which the universe could end um the simplest way the way that's going to happen if there's nothing going on that we don't know about is that everything will get very dark and cold uh eventually all the stars will use up their fuel and burn out eventually all the black holes will evaporate the protons will Decay nothing with any structure will be left there won't be any possibility for life anymore because there won't be any energy any free energy for people to live on and there will still be space and there'll still be random radiation right there'll still be random radiation but it will be very very cold radiation and as as long as there's not something new dynamically going on in the universe it will continue expanding faster and faster forever and things will quickly become very cold so yes there will be a bath of radiation but the colder the bath of radiation becomes the less it can be used for anything uh and so there won't be really any chance for anything interesting to happen so it it'll there'll be a universe but there'll be nothing interesting in it that's right okay that's one kind of end so another possibility is that the universe will really come to an end in some way a sharp end for examp that sounds scary end well it's very unlikely to happen soon nevertheless if you're concerned about things that happen in billions of years um one way that the Universe might come to an end is that what we think of as the vacuum empty space might not be the lowest energy state it might be possible for it to Decay into something else some different kind of stuff which would be very unlike what we have um after that decay the universe would then collapse and in any case once the universe in which we live had decayed into something else the laws of physics would be completely different so suddenly um we would not be here anymore this usual way that this might happen is through the nucleation of a bubble so if you imagine that somewhere out in space somehow a little bubble forms of uh something which is different and has a lower energy this bubble might expand it would expand at essentially the speed of light when this bubble passed over us we would cease to exist so there's and eventually that would just go through the whole univers the universe would be covered by bubbles like this nothing would be left except this other whatever it was that was left behind yeah now is there a finite possibility of such a bubble occurring if there is then at some point it has to happen well there are two pieces to the question question of the finite possibility of a bubble occurring uh one is does the Right theory of cosmology the right fundamental Theory of physics really allow the vacuum to Decay into something else the answer to that is nobody knows sure if it did allow it then it would come with some finite probability therefore eventually this would happen so the universe would not go on forever um becoming darker and darker and colder and colder except that if the universe is expanding exponentially as it appears to be now we don't know if that exponential expansion will go on forever if the universe is expanding exponentially the growth in the volume due to the expansion could be bigger forever than the loss of the volume due to the formation of the bubble of something else so the bubble of the nucleating bubble that destroying everything will never catch up to the ones that are cre right so there'll be Bubbles and Bubbles and Bubbles and in the space between the bubbles everything will keep expanding inside the bubble probably collapses but in in between the bubbles everything expands and so maybe half the universe is taken up by these growing bubbles but the half which is left expands by 10 times so there's more space now than there was before so the universe could go on that way even though any given point you would expect eventually to be swallowed up by a bubble and come to an end the total amount of leftover space which is still just expanding and getting colder would still grow forever yeah so that would be the comfort as we instantly disappeared we would know that uh infinite numbers of new areas were being formed in some of those who knows what happened I'm not so sure what should be comfortable about the universe which is becoming increasingly empty and nothing is going on of more interest to me at least is the possibility that new universes like ours could form as bubbles so in addition to a bubble of something we call it terminal meaning everything in there comes to an end there could also be new bubbles bubbles with universes like ours which would form it random in places and then this wouldn't allow us to continue on forever but inside that bubble it would grow it would become a whole new infinite Universe of its own and that Universe would be full of people and everything else that can happen in a universe because it would be infinitely big so people like us would come into existence again now there's uh an argument that says that with multiple universes all this uh exponential growth of universes and some of them will have life because even if life is very rare and some of those you'll have intelligence as it grows and this is infinite then you have all these civilizations so they would say that those civilizations might be able to simulate a universe and you can go from then to say therefore if it's happening infinite maybe there's an infinite number of simulated universes and maybe it's more likely that we're a simulation yes then what there is an argument that we could be simulated people inside some giant computer run by some other kind of people it could be People Like Us it could be people utterly unlike us we don't have any access to what the people running the simulation might be so of course another way for a universe to end is that they decided to simulate this universe for a certain period of time and then the program was stopped run out of money and they ran out of money they ran out of Computer Resources you know I do simulations myself and I run them when I think they're interesting and I run them when I have the resources to run them and then I turn them off and I run different simulations so we could all be simulated the simulation could be very good so that we wouldn't know that we were simulated and then the universe could come to an end merely because uh the simulators decided that was enough simul of our universe and they'd go on to something else would there be any possibility of the entirety of the universe we're using it in in Loosely but not just the one we're SE seated in but the entire Multiverse all the universes coming to an end is that even possible well the general idea of the way that multiverses work all possible things are happening so collapsing universes that do come to an end or being produced and expanding universes that don't come to an end or being produced but uh of course the whole thing could be in ass simulation so if the real theory of the universe is the usual Multiverse Theory nucleation of different kinds of universes some grow some collapse there will always be growing ones but if the correct underlying theory of this is something more complicated than that uh for example the universe is being simulated then of course the entire whole thing could be simulated the entire Multiverse could be simulated and after a while it's the end well yeah but in that case you have something else doing the simulation and so that exist right so of course we know nothing about what kind of intelligent entity it would be that's built these big computers that do the simulation there could also be all kinds of things we don't know and we never can know for certain if the laws of physics that we have our understanding of the universe is the final understanding there could be more to it the universe could require some sort of stuff to exist and after a while the stuff could run out out or there could be laws of physics that we don't know anything about now that come into play only after a long period of time so yes all pieces of the universe could come to an end because of things we don't know about and there really will never be a certain answer to that you'll never come to the point that you can say uh I know for certain now I know everything there is about the universe there could always be another layer another thing that you don't know that comes into play eventually so the question uh will the universe ever come to an end I don't could ever be really definitively answered

Channel: Closer To Truth

Views: 27,392

Keywords: closer to truth, robert lawrence kuhn, Ken Olum, cosmos, cosmology, science

Id: kxRaZm5rcaw

Length: 8min 33sec (513 seconds)

Published: Tue Feb 06 2024