Sir Roger Penrose | Can Aeons Explain The Big Bang? | 2020 Nobel Prize winner

the common view about the beginning of the universe is that started with the Big Bang and this is certainly the view which has held for a long time but and the question raised is what happened before the Big Bang and the quiz your answer to that question is well the notion of before involves a notion of time and there wasn't any time notion before the universe was there so it's a meaningless question and that's the sort of response I would have given until recently when I say recently this is in the last decade and a half I've come to the view that there was something before the Big Bang my current view is that yes there was a big bang it's not like the old steady state theory well the universe's was more or less the same a new material was created created all the time and then expanding expanded and new material came that's not the view the view is that the universe had this phase called the Big Bang and then it's expanded and it goes on expanding and it's now indulging in this what's called the exponential expansion which is caused by what people call dark energy now it's actually the case that in 1917 two years after unsign introduced his general theory of relativity he put in a term into the equations an extra little piece which was called the cosmological constant I introduced this in order to have a universe which was static and he knew that by putting this extra term in the cosmological constant he could have a model of the universe which stayed the same all the time which is what he wanted however he realized this was a mistake because the universe was observed to be expanding and he when he clearly took that on board he rejected his cosmological constant however it turns out that he was right all along in that this term that he introduced has an effect which causes what we see now as an extra expansion that the universe is doing it's sort of expansion slow down and then it started to increase in this exponential way which is referred to well they call it exponential expansion but it's referred to as a result of maybe what they call dark energy now dark energy doesn't mean anything it's a term I think it's a bad term because the first part is called dark and that would mean it would look dark but it's invisible you look straight through it it's not really dark it's not even really energy because energy according to Einstein is equivalent to mass and mass attracts so if it's really energy in the ordinary sense it would pull universe back together but it doesn't it pushes it away so it's a strange kind of energy it's not really but it is exactly what his cosmological constant would do so the universe is doing this exponential expansion now in current cosmology there's also something else which is introduced just after the Big Bang looks just like this other exponential expansion but it occurred according to theory in the first where it's hard to say is exactly but think of a number with 32 digits a big number take the inverse the reciprocal of that very tiny number that fraction of a second that ridiculously small fraction of a second this thing called inflation is supposed to have taken place that is supposed to explain various things which are hard to explain in cosmology in other ways let's not go into that but the current view is that the universe didn't just start with a Big Bang there was the Big Bang then there was this inflation then it suddenly turned off and then we had this more sedate expansion and then we see this exponential expansion again now now in my view this original inflation didn't happen but there is something very much like it which is the exponential expansion of what I'm calling a previous Eon now what is an eon this is a term I was glad to see when I look up in the dictionary didn't really designate any definite number of years it's an indefinite term so I was glad to pick up on the term what an eon to me is a Eowyn that is it is our eon started with the Big Bang no inflation the universe expanded and then you have this exponential expansion which goes on indefinitely that's one year I claimed there was another Eon before ours and it's exponential expansion in this remote future was what looks to us like the inflation that we seem to see but it's not after the Big Bang it's before it now that's a crazy idea but this idea is crazy and often we find that ideas seem crazy turn out actually to be right so the idea the hope here is that this crazy idea does turn out to be right and what is the crazy idea the idea is that each yeon starts with its Big Bang very hot very concentrated hugely hard I should say expands out cools down the universe then goes into this exponential phase cools down cool down cool down gets a very very cold what happens to the universe well the most exciting thing that's left over when the universe starts expand away are these supermassive black holes our galaxy has in its center a black hole which is about 4 million times the mass of the Sun there's very good evidence that right in the middle you can see the stars going around it there is a point you don't see it itself but these stars are going around it and you can plot these out and you know right in the middle about 4 million times the mass of the Sun is that little thing well it's little by comparison but the whole galaxy but it's big by comparison with the solar system it's not that small anyway that's what we believe to be a black hole now other galaxies have bigger ones as far as we know all galaxies are pretty well all galaxies having their sensors black holes now as your weight and the universe ages and the stars die and the galaxies get very dire in the middle will these be these black holes the black holes swallow stars they will swallow down most of the material in the galaxy and it's a very boring state of affairs now it gets more and more boring though because the black holes according to Stephen Hawking and I believe him the black holes are not entirely black he says they have they radiate energy but they radiate energy at a very very very low rate it's as though the black hole has a temperature and that temperature is so cold but certainly for the big black holes it's so cold that it's colder than any temperature ever made on the earth and the bigger the black hole the colder they are now as the universe expands the background radiation gets colder and colder and colder and the black holes become cold of it cold that they are they've become the hottest things around so they radiate away they radiate away and eventually they disappear so that's what happens how long does that take for the biggest ones well think in terms of a googol years what's the Google the Google is one followed by a hundred zeros it's a made-up name and that's the sort of time you've got to wait before these black holes will disappear maybe longer than that for the really big ones and when they've gone what's there well that's the very boring era it's extremely boring and I didn't like the idea of thinking that this is almost all of the universe's lifetime would be such a boring state of Phares but then I began to think well who's going to be bored by this universe not us we would be long gone but things that are around will be photons and photons are very difficult to bore partly because they probably don't feel anything but that's not the point the point is that photons don't experience the passage of time that's because they go with the speed of light and because of the effects of relativity that clock moving with this faster and faster closer the speed of light slows down if it reaches the speed of light it doesn't register any time at all so as far as that photon is concerned right out to infinity is no time at all so they'll never be anything well what happens to this world and because of ideas as I've been playing with a lot when people were interested in me energy in stars running around each other in black holes and so on how do you measure the energy radiated and the way to think about this was to go all the way out to infinity and you can do a little trick which is a mathematical trick you can squash infinity down maybe some people will have seen these Asha pictures where you see angels and devils interlocking and you see as they get round to this boundary which is a circle they get seen to get smaller and smaller and smaller right down to the edge as far as there's angels and devils are concerned they're all the same size as each other but they're squashed down and away which they squashed in all directions by the same amount and then the boundary represents their infinity but you can see the boundary it's just there and if you had a kind of geometry which didn't know distances but the only knows shapes and angles then infinity you can represent in this finite way so I'm taking the view that our universe is very much like that the remote future is just a boundary and that things which have no mass have no way of telling their size they have no way of measuring time that is the boundary they reach now this is a crazy thought but the idea is that that's what our universe is like and when there's nothing around such as photons which have no mass and therefore they can't keep time their infinity is that boundary then you can ask what's on the other side of the boundary and what I'm saying is what's on the other side is the Big Bang of another Eon now you might say well why doesn't the Big Bang know where it is if you like the answer there is similar but the opposite in a sense when you get near the Big Bang the temperature gets hotter and hotter and the hotter the energies get bigger and bigger and bigger and then the particles which have their mass and which makes them behave like clocks that mass becomes irrelevant because the energy is so much larger than the energy in their mass then you can forget it that's just to say they behave like photons they behave like particles with no mass and therefore they don't register its passage of time they don't register sizes so the Big Bang doesn't know whether it's big or small anyway any more than the remote future knows whether it's big or small so it makes sense to join them together now that's the crazy thought but it makes mathematical sense so it means that the remote future of our expanding universe becomes the Big Bang of the next yawn and our Big Bang was the result of the remote future of an eon prior to ours and it seems like a crazy idea but it does lots of things for us one of the things it does for us is it creates a universe which is very uniform which is a great puzzle why the uniforms universally being so uniform and it's one of the reasons people introduced inflation another thing it does is it produces Dark Matter now you see this is a one of the current mysteries in the universe most of the material in the universe seems to be invisible to us we know that from galactic rotation that there's more mass in galaxies or almost all galaxies then you see in stars and this mass has been very puzzling you can tell from the orbits of stars that there is more mass around than you see in the actual stars and it's been christened Dark Matter that's quite different from dark energy this is dark matter and that matter is a kind of matter but it doesn't seem to fit in with any theory of particle physics it's something else now according to the theory I'm talking about when you cross over from the mote remote future of the previous Eon that the Big Bang of the next one you have to the equations tell you you have to have a new matter created a matter which interacts with other things only through gravity and that is what I believe is the dark matter now this dark matter eventually has to decay away because you don't want it to build up for me on to Eon so it got to all gone by the time you get to the next year and this decay rate is something which has an effect on the next Eon and you can tie all these things together and it seems to make a theory which not only makes sense once you've got the idea of going from money on to the next which is okay a crazy idea but it makes mathematical sense and if it really is true then you can explain where dark matter comes from you can explain the features of the Cosmic Microwave Background this radiation which is coming from all directions which you previously needed inflation to explain you don't need inflation you need the previous year and the things which we've been looking at recently a Polish colleague of mine Christophe Meisner and South Korean colleague Daniel Ann who's been doing a lot of a computational analysis what we think we've seen are points in the sky which were calling Hawking points why are we calling the Hawking points because the black holes eventually evaporate away and the energy in those black holes has to go somewhere well it comes out mainly in photons those photons concentrate the energy in little points so that they should be things that we you can see the remnant of what used to be a supermassive black hole coming through on the other side to see these as little points in the sky and we seem to see these points which are hotter than the background and they spread out because of the it's because it's before it gets to the place where you see the cosmic microwave radiation according to this scheme the black holes in the previous Eon when they finally evaporate away by Hawking evaporation all the energy that used to be in the supermassive black holes will come out in radiation mainly photons others will be concentrated in little points which the previously on crosses over into hours they will look like little points in the sky now they won't be action to the points because they will spread out you have to think in terms of from the Big Bang time until the radiation which causes the microwave radiation that we see that's about 380,000 years so in 380,000 years what used to be a point has spread out to about eight times the diameter of the moon so that's the kind of size it would reach and what apparently we see our region's like this there would be about from a little bit less than the moon's eight times the size of the moon to maybe about three or four times the diameter of the moon but splodge is in the sky of that size which we seem to see when I say we seem to see them these are regions in the Cosmic Microwave Background where the temperature is slightly raised in the middle and then as you go out from the center cool down and the evidence for these points in the sky is really quite significant and we have an article in the on the archive which we give the evidence for these points but it's hard to explain on the basis of current cosmology because the current cosmology the temperature variations which you see should be the result of inflation this exponential expansion which took place in the early universe according to the theory and according to sit in my scheme that the inflation didn't happen and so if you did have inflation you have to explain how these are the points of raised temperature nor regions of rage temperature came about and it's very hard to explain it on the inflation review because the only way they could come about on that scheme would be at the very moment when inflation turns off and it's a bit of a challenge anyway for inflation because there's this problem they call what they call the graceful exit problem which is how does inflation know to turn off all over the whole universe in this sort of mild way and if these points are recognized people isn't really there they have to work they have to make the inflationary scheme produce these just at the graceful graceful exit place and a bit difficult to see that can be done anywhere my view is that the inflation didn't take but what we're really seeing is evidence of the hawking of apparition of these supermassive black holes which would have been there in the eon prior to ours and it will be very interesting to see whether this really stands up or whether there's some other explanation for these points it's hard to see that the points aren't there because the evidence from them is statistically very strong did you know that the institute of arson ideas also has a podcast philosophy for our times brings you the biggest ideas from the leading thinkers around the world every week search for philosophy for our times and subscribe today on your favorite podcast platform SoundCloud or iTunes to make sure you never miss an episode

Channel: The Institute of Art and Ideas

Views: 80,652

Keywords: big bang, black holes, aeons, cosmic inflation, string theory, quantum physics, quantum mechanics, roger penrose, sir roger penrose, stephen hawking, science, philosophy, religion, cosmology, origins, education, interview, live stream, roger penrose nobel prize, roger penrose consciousness, big bang theory, nobel prize, quantum theory, nobel prize in physics

Id: YTttUigXulk

Length: 20min 26sec (1226 seconds)

Published: Sun Feb 03 2019