A New View on Gravity and the Cosmos | Erik Verlinde

yeah welcome everyone in this great auditorium on this evening it's great to hear with so many today and it's an honor for me to stand here in representing the 50 paid study study Association of physics in Delft and studium Generale Adel to present to you our speaker of the night Eric falinda well to you he must be very well known especially for his alternative theory on gravity and he seeks to find an explanation for gravity that's consistent with both quantum mechanics and general relativity and it's interesting because he's been interested in gravity the smallest and the largest of the universe since he was I think 15 years old if I'm correct because then he was a TV show little toss at a low key to the universe and he saw there his great examples which are now his his colleagues I think such as here at Hope and Stephen Hawking well then he studied in Italy EFT and he also did his PhD there and he worked at Princeton CERN in a second and since 2003 he's a full professor at the University of Amsterdam in 2011 he won the Spinoza prize which must also be well-known to you it's the highest science prize that you can win in the Netherlands and today he will take us on a journey through his research and so it might be hard sometimes but bear with him and after the lecture which should take about an hour there's plenty of time to ask all the questions that you want to ask him there catch books is here so wait yeah they are shown now wait till they're thrown at you such that everyone can hear the question that you asked so thank you very much for being here and let's welcome professor Eric for Linda to the stage yeah thank thank you thank you for this kind introduction and it's feels very good to be here and to see indeed there's so much interest in this topic I became interested as Julie I was explaining already in my high school years and I knew I wanted to do physics and a particular work on problems related to gravity and quantum mechanics and and indeed we have made a lot of progress and what I'm doing now I could not have imagined that at that time but it seems like we're finally starting to understand better how to put these two subjects together because at the time when I started studying it seemed like gravity and quantum mechanics were totally different worlds and they couldn't be sort of United so the current developments really have a new way of looking at gravity a new way if even looking at the universe and what are its building blocks and I'm gonna start out explaining a little bit why are we changing every time our point of view on nature why is it necessary and it has to do with experiments with observations but also with the language that we're using because every century in physics there's a connection between what we do in terms of technology and what we do in science we use the language of the world around us and so in the 17th and 18th century people knew but mostly about mechanics of moving objects like while cannonballs then in the 19th century became we discovered steam engines and then you talk about temperature pressure and and maybe gas flow eventually it atomic picture arrives Rises and then the 20th century well a television one of the the technologies we develop then if you look inside of it it takes particles electrons it accelerates them and then it lets them hit the screen and then we get light out of this and sort of the the forces that I use are electric forces things like that actually that's the language of the 20 20th century particles forces and that is also still today very much the way we think about nature as in terms of elementary particles and fundamental forces but we live in a different time now I mean we have information devices I mean our our current technology is based on what we can store in terms of bits and we have a different language that's being developed and this is what I'm going to explain is that the basic building blocks even that we're gonna use to describe nature are going to be not particles or the fundamental forces we're going to think about something called information and I'm gonna explain more what I mean by information you may think information is what you read in a newspaper but for me something more abstract it has to do with really the microscopic information that's contained in everything that nature is made of even space and time so what does it need information I mean it's stored in bits and this is sort of for me unimportant what is written there you just count for instance what how many bits you have and that tells you how much information you in principle can store say on a chip or even in other parts of nature we can count information in terms of how many bits I'm going to talk about special bits not just zeros and ones we also are going to use quantum mechanics because microscopically or actually the whole world itself is quantum mechanical so if you ask how does nature store information it has to do it in qubits not just ordinary bits and qubits can entangle I shouldn't be explained this here people know this very well and this is the kind of thing that we're going to use an encounter also during the talk so I'm going to tell you a new way that we're going to think about the universe where we think about the basic building blocks as being information this is maybe a way of phrasing it that we live in an information universe not an information world the whole universe is revolving around information and you may wonder where is it and where are we gonna well find it because we may not be aware of all of this and some of the information is hidden from us and that actually bring me to another concepts I mean if we have information we don't see I mean how are we sure it's there first of all let me show you this you probably don't know what it is but if I make it smaller you still don't know it but it's the same thing but if you look at the bigger picture you start understanding what that was I mean it's part of a picture that shows you now mountains and trees and all kinds of things that begin give names but if you ask do these things exist microscopically no because everything is made out of pixels and it's only by making many pixels together that we get an image and that we are giving names to objects but microscopically these things may not be there and this concept is called emergence that when you build many things together you see structures arising that and you give it names that may not exist at microscopic level and this is how I describe it we need to use concepts and we observe phenomena and a macroscopic world and it's magical skills but they're derived from something microscopic where the same concepts are not well-defined and they have no a priori meaning so we do is all the time in physics for instance statistical physics is a way of explaining thermodynamics thermodynamics uses concepts like temperature and pressure or entropy but microscopically those things don't exist so the the macroscopic properties are derived by averaging over all the microscopic properties and so temperature can be defined as a measure of average energy for instance per degree of freedom or per molecule entropy then is associated with the amount of information that I'm actually forgetting when I go from the microscopic language to the macroscopic one when I look at the room here we're not really interested how all the molecules are moving and we usually don't look at that but we are interested in the temperature the pressure those kind of quantities but eventually you have to also count what are the number of possibilities that are present for all these molecules and that's measured by entropy and this is the link with information because what is an entropy it's basically the amount of information that's necessary to describe how all these molecules are moving and it sort of counts the number of microscopic possibilities that are present and therefore it's not an entropy that we can really have an information that we can really read but we can at least count how much there is so the connection between entropy and information actually is due to Shen and Shen basically said that if I have a number of bits that means zeros and ones but it can also be coins that you flip you have heads and tails and if your two points then there are four possibilities but then you can count the entropy and that's basically taking the logarithm of the number of possibilities and so that space it then it becomes in this case equal to the number of bits so that's an intuitive way of thinking about entropy of course it doesn't always need to be in terms of zeros and ones or heads and tails I can also use dice and then count how many possibilities I have here but still you can count it and this is how we associate the amount of information that would be necessary to describe all of these ways that these dice are being thrown in terms of an entropy so for me information is not as I said what I read in a newspaper or what is really useful it's something that I can count and I can think about in terms of bits or as I'll explain later in terms of qubits so what does this have to do with gravity I'm gonna tell you later that indeed we have a way of understanding gravity and it's connection with information and it's going to teach us something about the universe and it's going to teach us something about how things might be different then what Einstein is telling us so Einstein describes gravity in terms of curved space-time I'm gonna tell you that underlying that there is some information that is present and that will actually affect the way that gravity works so let me start with Newton of course you you all know that the law of Newton tells us how the force between two masses acts as a function of the distance goes like one over R squared at the same as how the surface of a sphere would grow as a function of the distance in a me it goes like R squared this actually is already a hint that gravity has something to do with this area of a sphere sore or yeah something like an R squared and later I'll indeed show you connections with that for instance with how entropy arises in black holes it's also associated with areas but it's basically this one over s R squared law that is telling us that so this law tells us very well how planets move in in the solar system and it has been tested very precisely if you look at how the velocity of planets behave as a function of the distance Newton's equations will tell you that the acceleration is V squared over R is equal to GM L for R squared and from this I can read off that the velocity should go down as a function of the distance and if you look at the planets that is exactly what happens now all of these planets behave very nicely according to Newton's law actually the most inner one has a bit of a problem normally planets would go around like this in an ellipse orbit where they have a near point which you call the perihelion and then there's the farthest point but the Peary Hylian should always be the same location and for mercury that doesn't happen this is an exaggeration there's every time that it goes around it has a slight rotation and in a century it's a lot like 43 arc seconds I think that is so this is a very tiny deviation but it's deviation from the laws of Newton and you might try and explain it by invoking or postulating that there is some other planet closer to the Sun Sun and that might actually cause this deviation to happen and this is what when people looked for but that's not the explanation it's not that we can save Newton's here this is an effect due to general relativity so Einstein indeed could explain what happens to mercury and he could explain many more things in particular also how light behaves in the presence of gravity so according to his theory gravity is the result of curvature of space and time and so objects no longer going straight lines they go around in these elliptical orbits and maybe small deviations from it that are due to the fact that indeed Einstein's equations are not exactly the same as Newton's equations he wrote down an equation that tells us that in most circumstances Newton tells us very well what's going on but in other circumstances when gravity gets very strong we need science equations and also to explain or understand what light does in in a so fun as due to gravity in particular light can bent and in this picture we see that light generally we think about is going in straight lines but when there's a heavy object then the light of an object that's behind the the mass here can bend around and we can see it but we then see it at an other location because we would think that the light that is coming to us actually is coming from this star so you see actually a dislocation or a displacement of the location of stars and this is called gravity well bending of light or you can have a certain effect we call gravitational lensing which is a sort of a same idea that namely light bends around and can come to us but it can bend around if there is an heavy object in the middle and more in one way actually can bend this way or that way and even go above or below and this is an example which indeed has really been observed where there's a galaxy far away and there's a big mass in front of it and the light gets towards us in more possible ways actually it forms a ring and that's called the Einstein ring and this is proof that light is being bent by gravity and can be explained by Einstein's theory so Einstein has explained Mercury can explain bending of life of course there are many more tests of Einstein's gravity in particular very spectacular one which you heard about which got the Nobel Prize last year is the detection of gravitational waves so where you can observe that space-time according to predictions of Einstein has ripples that are sent out when two black holes are colliding or merging together in the last moment they spiral so violently that the space-time itself gets distorted and these ripples they travel towards us with the speed of life and can be detected in this interferometer this is one of the LIGO ones and they were in two locations while about 1500 kilometers apart or it may be more even we're both sick found the same signal at the same time so this is what happens I think you can hear it can I no sound there should be sound No okay there is a sound of this that allows you to hear what is going on it's actually a a ringtone that you can buy which is indeed the detection of these waves so this is the Einstein's equation and here are the ways it has been tested and in any more circumstances of gravity waves there was already there in direct evidence of gravity waves from binary pulsars bending of light and what happens with Mercury and many other ways so you might say well this theory works and it seems to work in many circumstances but does it work in all circumstances I'm gonna actually tell you something about larger scales and here you might say well it should work as well because we don't know anything else Einstein's theory must be right so we're gonna look what it does but does it really look the same so when you look at galaxies they look in a certain way like a solar system in the sense that most of the mass is in the center if we look at the Stars the many more in the center and you can think about all these stars as going around in sort of circular orbits where you can look at each of those slices and ask what is the velocity you can measure this by by redshifts and then you see as a function of the distance you would have expected from the same way that planets behave namely that large this since the velocities go down that would do something like this but this is what's being observed now you can have true conclusions how do you say gravity works in a different way or if you assume that Newton's law should work there must be something well explaining this difference well what's happening here is that the stars are moving much too fast and they would well fly out of orbit if you rotate too fast with bit not enough force and so there must be additional force putting pulling it together otherwise we cannot explain why these stars would go so fast and so there must be additional gravity so this is another picture of it so this is what's called a rotation curve so this is the velocity and this is again the distance and this is what you would expect and this is what we observe actually in most of these galaxies the following thing happens instead of going down the velocity stays constant is called flattening of the rotation curve and there's a big difference between what is expected and what's being observed and there must be more mass actually if you want to explain this so this is indeed different from this equation actually you can determine what should be the additional mass by looking at the velocity and using this equation and this is what led to the idea of dark matter it's a hypothesis it's very much like what a planet that was assumed to be there namely it fixes Einstein's theory because we say there must be more mass and we would look for it and must be some particle that is forming a cloud sort of a halo it's called around the galaxy where the gravitational force which is needed to put to keep the galaxy together is required is obtained from the additional mass that's in these particles these particles cannot be seen here they're blue but that's just an artist's way of showing it but the particles have no interaction with life they should be only gravitational if have only gravitational forces well people look for it in accelerators they look for it in the detectives under the ground and so far nothing has been found and so you might wonder is this the way indeed we have to fix our in science theory or is there another explanation and so I will explain there are more things we don't fully understand in cosmology there's also something called dark energy I will return to that later so there will be questions that we need to pose and need to answer also well at large skills that might actually tell us that something else is going on then what Einstein might have written down but for me the main motivation actually of main indication that Einstein's theory might work differently comes not from these observations but also from theoretical well developments I mean indeed the work of Hawking which is the one I already became interested in his work was on black holes in particular and on Deedle cosmology but black holes is one of those topics that we theorist use a lot to learn more about gravity so what are black holes these are predicted also by Einstein's theory this is where mass is put together by in such large quantities and so close together that light cannot even escape I mean gravity becomes so strong that from a black hole there is no escape when you go too close to it there is namely some imaginary sphere around it people they store ricin that if you go inside that sphere then you well you have to go faster than light to escape and says nothing can go faster you cannot get out and light cannot even get out and this is why the name was given black holes so we know that mass goes in so we know the mass of a black hole black holes can rotate but otherwise we have no information of what's inside the black hole so everything we throw in disappears from our view and so black holes are really objects that we can only study from the outside and wonder what went in so this is what it looks like in terms of the space-time so a star like the Sun would have a curvature of space that looks like this it sort of makes it dent you can think about this as a lot of a rubber sheet where you put a ball inside and then it sort of bends through over and so it has some dent in it and they and the more mass the more you concentrated the deeper it goes and in a black hole there is a sort of a funnel funnel there's a hole coming in that goes all the way to the bottom or at least it goes so deep indeed that you hit this imaginary sphere where's the horizon so every all the matter goes behind that horizon so this is how we should think about black holes is naming it all the matter has sort of disappeared and only what's left behind what we can see is the space-time the curved space-time of the black hole itself so what would it be if we would be in a neighborhood of a black hole here is the earth and this would be a black hole and this is sort of what you would see it sort of looks like the earth is being distorted that's not actually happening this is the light that we see namely the earth is just rotating around the black hole but the light is coming towards us from all directions you in the way that this gravitational lensing worked and so we see the earth sort of going in this circle but of course it's just rotating that way I can also show you how what it looks like when we fall into a black hole and then I want to remind you of this bending of light so we're going to do it later I show you a little clip of how we move inside the in the neighborhood of a black hole the rise in this is red line we're going to look at the black hole which is here in the center and we're going to look at the light coming towards us so the light here is some background which is the galaxies but this is gonna move we're also gonna watch and what happens with the clock because black holes have another special property that not only light cannot come out also time goes behaves very differently so Einstein's theory does not only change space and curves it also the time goes very differently in a sense that actually clocks starts looking are going slower when you go close to the horizon actually it really stops even when you're on the horizon and so we're gonna watch this when we look at the movie so here's the same picture again so we start out from this distance and now we're gonna fall and the green region is where we can travel safely you go around in these closed orbits when you would go closer here you would need a rocket to get well stay safe but when you get to orange there's no way to get out because then you will fall into the black hole which is where you have entered the black hole so here we're getting closer we see also the horizon eventually that will be indicated with the red lines the north in the South Pole our little distorted because of the bending of light here we see indeed the light there's one distance where light itself can even go in a circle around it so light would even be captured by a black hole and here we indeed see the clock going slower and at someone want we cross the horizon and then we see indeed the last sort of light coming from outside and nothing is shown what's coming from inside because basically we don't know so eventually we hit the singularity that's what's in the center so the center of a black hole is where curvatures is so strong that we really don't know well what happens there because even Einstein theory breaks down but most of the interest actually of theorists is on the horizon and so that horizon I can actually show you this mu clip once more most people want to see twice so this is the same picture again and as I said I mean there is a singularity inside but the horizon itself is a very interesting place because of the way that the time indeed seems to stop from the outside but when you fall in yourself you actually don't know that you're crossing a horizon I mean the space actually looks pretty normal yeah you get strong gravity but it's not like there is something really infinite or something no there's a really normal space so you could fall in the only thing that goes wrong with you is when you hit a singularity or when the gravitational field becomes really strong that it pulls you part but the horizon itself can be analyzed in a very similar way as we analyze other parts of space-time and isn't it but what's bekenstein and hawking did this is a more precise picture indeed of this space-time around a black hole so a black hole has the property that there is one distance which we call a rice and here we draw the space actually at this as if it's two-dimensional so the rice and normally it's a sphere but here looks like a circle and when you would emit light it would normally go in all directions but in this case when you on the horizon it actually goes inward and this is how you would indeed fall in if you cross it now back in stand Hawking we were worried about the loss of thermodynamics in a particular what happens with the entropy of objects that you throw into a black hole namely this entropy is disappearing from our view it represents a certain amount of information I told you this and what happens to that information well if we throw it into the black hole disappears from our view and so you might say well this entropy disappeared and it you can do thought experiments that allow you to actually generate work by throwing in this matter with all the entropy in it and then you would even have a way of generating work and actually violate the laws of thermodynamics because the entropy would not go up I mean it would actually go down and so the only way to save this was to associate a certain amount of entropy also to a black hole now this was the idea back in stein and Hawking then came along and well he first didn't believe it because if you have an object that has a mass which is also an energy equals MC squared and it has an entropy and it also should have a temperature and Hawking was not convinced that this would be possible until he realized that he could actually calculate it and this is how he found the famous formula so actually he found actually that black holes emit radiation I should first explain that he actually found indeed that it has a temperature it's called the Hawking temperature and he found that by quantum effects because both of these bekenstein as well as Hawking reasons that we should use quantum mechanics to explain this amount of information associated to the horizon and indeed also the temperature involves quantum properties of both particles and enough space and time so in particular particles in the vacuum can exist even in the vacuum normally you think is empty because of the quantum uncertainty relations the vacuum contains we call quantum fluctuations means that some particles in their antiparticles can be present for a very short time and then they usually recombine again it is this picture but when there is a horizon what happens and this is what's what hawking showed one of the particles can disappear and go inside the black hole and the other B is being emitted and comes out as a particle that we can detect and it has a certain temperature certain this radiation it's like blackbody radiation with the temperature set by the acceleration actually at the horizon so these are the formulas that Hawking derived so the temperature is given by the acceleration the gravitational acceleration that's G at the horizon so this formula is just the same formula that you know from Newtonian mechanics this is the acceleration at distance R M is the mass of the black hole the radius by the way is set also by the mass I mean this horizon distance we call this what shield radius is also determined by the mass bigger black holes actually this radius becomes larger is actually proportional to the mass but if I calculate this and put it in this equation I would get the temperature and that is indeed the the Hawking temperature that that Hawking calculated I said it has a temperature but also an entropy and that formula is also famous and it's known by the names of bekenstein and Hawking here I showed in a picture I'll show you the formula in a minute so we think about entropy as information so zeroes in once and you can may ask well how much information is then stored by a black hole it's given by the area of this surface of a sphere and namely you have to measure it in planking units very tiny units and then if you put zeros in once on all of those locations you could store an amount of information and that amount of information is the entropy or the information that that black holes carry and in a way it hides the information because we cannot see it that we can still count it in terms of an entropy here it's explained how larger this is 10 to the minus 66 square cent meter so it's a very tiny surface and this is neat what the formula looks like so the entropy which is called s is equal to the area of the horizon divided by the units bye-bye well the Planck scale and this is written down in natural units containing Newton's constant Planck's constant and the speed of light and if I would have all the unit's right actually entropy has the dimension of Boltzmann constant so all of the constants of nature basically enter in this equation and so this tells us how many bits if information is associated to a a black hole and this was a very important discovery actually it led to met many discussions because the question was well does this mean that we can still keep track of this information and can be retrieve it back in sign repertory in particular Hawking actually argued that information is lost in the sense that information that we throw into a black hole cannot be retrieved and it would violate even the laws of quantum mechanics so Julia already mentioned the people that I watched on this show were Hawking and it hoped and feared that host actually when I started studying started worrying about this problem and he started arguing with Frankenstein 3 we're talking about this information lost paradox is it's the are the laws of quantum mechanics obeyed yes or no because if it quantum mechanics is obeyed actually quantum mechanics it works in such a way that it doesn't really destroy information we call this unitarity you mean probabilities have to be preserved but also information that's in a quantum state cannot simply disappear so in order to save quantum mechanics we have to understand what is information represents and how it well it may even retrieve it because when the particles are being read radiated out the information has to be sort of released from the black hole and it's up to this day that people are still discussing it because it's very well hard problem to solve but it teaches us a lot about how space-time how gravity works and what the link with information is in particular indeed that is information is stored sort of on areas on the surface say of a sphere these are some more complicated equations actually these I show these equations because we actually use them a lot and what they show is that the gravitational equation is the one that follow from Einstein's theory actually they are basically the Einstein's equations so what I've shown here is the formula that tells you how much does the area change when I change the mass of a black hole it's determined by the acceleration at the surface of the horizon by this equation so you might say this this equation follows from actually Newton's law or even Einstein's law actually you might say this is of Einstein's equation it's a way of summarizing Einstein's equations for black holes and therefore you might think it's a fundamental equation but when we make these substitutions namely we say the area is the entropy and the acceleration is related to the temperature then this equation is the same as that equation and that's the first law of thermodynamics and that is a law that we can derive we can derive by thinking about statistical mechanics and understanding what this entropy is we can derive this equation so if we understand this entropy we can derive this equation by statistical mechanics but then we have derived Einstein's equation and that's the idea of what's called emergent gravity indeed that gravity itself can be explained microscopically once we understand what this information represents and how we then can derive these laws because then we derive Einstein's equations from a more fundamental microscopic picture in the same way that we have explained the laws of thermodynamics by thinking about atoms and the way they behave statistically so that subject has been actively studied now in particular the last number of years I'm going to tell you a little bit more about what is going on there but this is really the way that we think that we have found a crack in a science theory that there might be a way of thinking about gravity in a different way than then that Einstein told us by thinking about the microscopic structure of space-time not in the language of particles not directly in the language of forces but thinking about more fundamental building blocks in terms of information and in particular its quantum properties so a toast indeed was one of the first people to start thinking about the implications of what we learned from black holes and he already made a very important what conjecture are basically stated the principles called the holographic principle that there's not there's no way that in any region of space you can have more information than what is given by a black hole and means also that this amount of information couldn't cannot be larger than the area of the surface around it in planking units so if I take this big lecture hall and I ask what's the maximum amount of information we can store here you might say I put a very big computer here with a smallest chips possible but that information can never exceed what you can put on the boundary in terms of Planckian bits in in terms of its area because if you would you basically would form a black hole as large as this room so that's the state of maximal information and there's no other possibility so this was an idea at that time but it has been made much more precise and actually being realized in string theory I'm not going to explain a lot about string theory but all to say some other things later I want to tell you a little bit about how I started thinking about these ideas some years ago in particular indeed the idea of what's called now called emergent gravity can we derive gravity by thinking about this information can be indeed derived Newton's law for instance and by assuming that indeed all the information associated with a part of space-time is counted or stored on the sphere of a surface around it you can actually do so you don't need to have much well math or even there's some steps you have to do where you make some assumptions but then you can actually derive Newton's law actually it's in a paper I wrote on the loss of Newton and on the origin of the loss of Newton and of gravity where I derived Einstein of sorry acted Newton's law by thinking about a thought experiment indeed by asking the question what is the amount of force that you can derive by thinking about information stored on a on a surface and ask well what happens when I put a massive it close to it actually I'll show you the equations in a bit there's actually this slide I should have shown so there's actually a calculation I'll go a bit to the steps there was one assumption about where I say that the amount of information is need proportional to the area that's this equation I'll call that area measured in terms of Newton's constant I have to assume that there is a force law that actually comes from the change of entropy is called an entropic force you can calculate that change of entropy by a very simple experiment thought experiment that tells you that there's only one bit of information associated to a shortest displacement anyway I'm not it's not my idea to go through all the steps but it fits some simple equations that I could derive Newton's law so this is a way in which the idea of having gravity come from information actually could be realized and since I wrote that paper a lot of work has been done and actually we know a lot more now and we have made well progress even in deriving Einstein's equations from quantum information so what is this information we want to know more about what is the information associated to the horizon and what kind of information is it and as I mentioned string theory a big subject that that I'll just have to skip because of time actually has realized this holographic principal but it also has led us to conclusion that we can indeed explain gravity but the information we have to use is called quantum information so it's not just zeros and ones as sort of all these pictures shows it's it's something different associated not to bits but to qubits so let me explain a little bit about that development so what is quantum information there we have to distinguish indeed a bit from a qubit a bit it can be zero and one but qubits can have super positions and you can either think about an electron with a spin up or spin down or just a state that is in between a 0 and a 1 so in a picture a bit has only two choices if it would have a certain probability of having 0 and the probability of having 1 you would have a sort of like a parameter that's the probability but actually in quantum mechanics we also have complex numbers here actually if you then count all the possible ways you can put 0 & 1 together they actually form a sphere it's called the Bloch sphere so I'll actually make a picture of a qubit as a little sphere instead of having only choice hero and 1 we have all kinds of choices in the middle so this would be pure 1 and this is pure 0 but then there are other things in the middle that formed this qubit and this is the way the reason actually why we can store much more information on a qubit or actually do even better calculations than in normal bits the other property that makes qubits very useful is called quantum entanglement where you have to probe the problem or the possibility of measuring something in one location and then the outcome of the measurement which is well probabilistic actually it's not determined directly but it gives you one outcome it determines the outcome of the other of measurement and that is called entanglement so this is what I meant by this notation there's a some way that if you measure 0 on 1 the zero must be on the other or if you measure one that's here as well or in terms of a quantum notation it looks like that the people that thought about quantum entangled the first time or Einstein Podolsky and Rosen already in the 30s a long time ago and they worried about it because it had strange action at a distance but it's only much later that we start realizing the importance of what they did actually in the sense that entanglement was not recognized in the beginning is very important but later on actually in recent years this has been well the most important thing about quantum mechanics and this kind of state is therefore called an EPR pair named after Einstein Podolsky and Rosen so we're gonna use this kind of language also now to think about these information bits that are associated to horizons and to to black holes and even to space-time itself so we're going to think about entangled qubits and I'm gonna draw a picture of it so this was one qubit an entangled qubits can be thought about as two qubits that are connected by a little line because actually the measurement that you could do on one determines the outcome on the other so it's something like a glue like the way we put molecules together we can actually put qubits together by entangling them so then what is this information the answer is entangled quantum information and I could have known this from the from the way that Hawking did his calculation so Hawking there is calculation by thinking about how in the vacuum the pairs of particles are being produced a particle and an antiparticle but if they are being produced in one stage since this one has spin up then this one must have spin down so they are actually entangled and so this is the way that indeed the horizon entropy is being built up actually from entangled particles because even entanglement by the way you can count how many of these EPR pairs do I have so in this EP R pair I have one bit here and not a bit on the other side that are being entangled with each other so I can count how many bits are entangled so that's an entropy and this is actually a more technical way of showing it is actually the calculation that hoping that Hawking showed that there is some energy eigenstates on the left and on the right which have a very particular way in which they are entangled so this is what the horizon looks like in special relativity and then you have sort of two states on the left in the right this is just to show you that there's really some meaning to the entanglement because this notation you should compare to what I had here and then we can basically count how much entanglement is in this actually it's given by the area of this horizon so this idea that entanglement has something to do with gravity even has name now and the name actually goes back also to another paper of Einstein around the same time he worked on horizons of black holes is this picture if you have a black hole I showed you there's a little curvature and there's some some tunnel where you go through but actually when you extend the Einstein equations and look at the full solution of the equations actually there's another space that opens up where the black hole forms a wormhole that exists for a certain amount of time it's called the bridge actually it's called einstein-rosen bridge because he wrote that paper together with Rosen the same Rosen from einstein-podolsky-rosen and they found this solution of course they didn't know anything about emergent gravity and so on but now in our present day we have actually made a connection between this entanglement idea and the way that space is sort of built in this way and this is called ER as EPR because it's basically telling us that indeed the entropy that we measuring here is and thangam and entropy and it's counting all these qubits and we sort of gluing space-time together through entanglement this is a big developments going on in the u.s. not now it's called it from qubit where we built everything from information qubits even space-time itself and we have a different view of thinking about it so now I have to hurry a little bit because I want to go to back to the questions I raised in the beginning and hopefully explain a little bit what has to do what we can learn now about these problems that we are observing in cosmology from this idea so what is the idea and what's the conclusion that I've given you sort of up to now is that indeed we can think about space and time as being sort of derived or build up from entangled quantum information in gravity comes about but can we think about links with observations so I told you about the observations in galaxies that we don't understand and actually all the observations that are associated to dark matter in total this is a way we have already determined that there's more gravity out there that then we can observe this is called a weak lensing in the sense where people can measure how much gravity there is by looking at this bending of light and they've determined that there's a lot of gravity here but most of the matter is actually in this region and so we have seen sort of well locations where gravity is there without having matter so this is where where must be something well like dark matter dark matter also forms an important role in the structure formation in our universe so people believe in this a lot but now if you look at what the universe is made of the ordinary matter that we see is only five percent of what we observe and dark matter according to the current observations of particular the Cosmic Microwave Background is about 25% but most of the energy in our universe is what's called dark energy so this is 95% we basically don't understand and we wonder what is happening there so this little white light of a sorry yellow line is actually the life that comes from the microwave background the earliest radiation we can observe and there are photons and that's a very tiny number but if we ask according to our current theory where most of the entropy is sitting in our universe it's not here it's not there it's not there it's actually in this yellow yellow blob blind people don't assign any entropy to dark energy they call it the cosmological constant they basically forget about all of this and our current theory only describing this a little bit and this is where we have I think made a mistake and I'll tell you a little bit what the idea so the way that people observe the universe we do it from our Center we look outwards and we see this radiation coming from large distances because when you look further out actually you go also back in time the universe is expanding which also makes clear that things are moving away from us and there's a farthest distance we can look and in in a way that gives us just like four black holes also a horizon so to think about it this way if things are a certain distance they move away but with us from a with a certain velocity but if we go further out eventually there will be a distance when it starts moving with the speed of light and that means that the light cannot travel towards us anymore and that's a distance we call the horizon of our cosmos so in cosmology we can describe this in terms of Hubble's law which tells you indeed that the velocity goes with the expect with the distance and the constant influence we call Hubble's constant and so the distance where this velocity is equal to the speed of light it's called the horizon distance and that's measured in terms of this constant age now why do I talk about this horizon this horizon has very much the same properties as black hole horizons and I told you horizons have information so we can you see a sort of an holographic idea of how much information can be put inside our universe so if we would think about our universe is a very large computer where we store a lot of information how much can there be in there well not more than the horizon of this area of this the area of the horizon and that actually tells you exactly how much information is contained in the universe so I'm gonna actually tell you that this may affect things that are going on in inside because I actually want to explain where this difference comes from so the idea will be that this information associated to the horizon actually will not be just sitting on the horizon but also in the center Oh actually over the entire universe so the following observation I want to explain I told you that galaxies rotate but then the velocities don't go down they stay constant but this happens at a particular acceleration always the same value for all sizes of galaxies so this is an acceleration according to two Newton's equations but I can express the value where they start happening in terms of the Hubble constant if I multiply C with the Hubble constant with the speed of light exceeds an acceleration and this always happens when this so did the when the acceleration drops below this value this actually when this starts flattening and this seems like galaxies know something about the Hubble constant actually know something about even the dark energy in the universe so neat this is the picture again so this is where this galaxies sitting and this is our cosmological horizon it had this distance this size and it has an area that we can calculate is the area of a sphere and we can calculate the entropy we can also calculate the temperature according to Hawking it's also given by Hubble constant and I say this entropy and temperature are actually due to the positive dark energy and actually are carried by the dark energy and they fill the entire universe I think I need to both okay all right five minutes okay okay then then that's about what I need so this is where I write the same equations as I had for black holes a temperature and an entropy and it's a entropy we have not considered actually it's a very low temperature it's also a very low of hot but it's a very high temp interferes who say this is a number which is called about 10 to the 120 well the amount of entropy that we have used for say photons is about 10 to the 90 so most of the entropy is actually sitting here and X is going to change the way I'm gonna think about these galaxies here are some pictures of phenomena which look very similar you probably can recognize that this is the galaxy this is hurricane is the whirlpool the reason I showed these pictures is that here we have water around it that's whirling we see only the form here we have air going around and we see only the clouds but we know that there's something in the middle that makes this happen here we assume that it's just space time and that this is rotating without anything around it because it's empty maybe it's not and that's actually sort of the analogy that I want to make here I want to make you tell you not a thing I mean we have been observing the universe for a very short amount of time so if we put the entire age of the universe in one year humans came into existence one minute before midnight on New Year's Eve and the amount of time that we've been observing the universe is about a fraction of a second but we've concluded a lot of things about what happened in that entire year but this is not always possible I want to do one experiment with you if I succeed because it's a little bit of tricky they'll let me actually first do it this way this is a bouncing ball and I can calculate that it bounces and it bounces every time in the same height so I know the theory of this which is elasticity I'm gonna do this again and it's going to do exactly the same thing but the material is slightly different I have to make it round actually does exactly the same thing but if I put this here and I wait this ball will stay round this one will strange actually it's silly putty it's actually a material out of made out of polymers and if I wait long enough it will start flowing the only way I can notice is by waiting if I would have measured it only by bouncing I would have drawn conclusions I would have developed a theory from of this thing which is identical to that one that the physics is very different because we have to observe it very very long time so if our universe has properties of debt we have not been able to even test this because we have made observations for a very short amount of time and actually this is the analogy that's quite precise and so the picture that I showed you in the beginning about a universe filled with information that information is actually the information that I associate to dark energy and it's filling the universe I know exactly how much there is because I know the size of the horizon I can calculate the information density there's also an amount of information I can calculate associated to mass actually this is something a calculation that bekenstein or did it already a long time ago and I can compare the two and then I can actually explain that something starts happening exactly when these rotations the curves are changing actually this is a paper I wrote last year where indeed I I made a calculation of what happens when mass is present in a in a universe with dark energy or without and there's a lot of difference in the sense that the dark energy actually contains much more information and you get sort of a back reaction which is due to an elastic force actually the mass is very similar to what happens in this material and I can derive an equation that actually explains exactly this behavior it behaves effectively as if there is some additional matter but exactly some additional force that's pushing the matter back so this is actually what's what's being indicated here is that there is actually an additional force due to the fact that the matter actually pushes away energy and that force effectively actually behaves like dark matter and it explains these flattening rotation curves it can be compared to data actually this is measurements of this relation that I found so what is plotted here is actually the acceleration that is observed so the acceleration that observed is this one and the mass that I put here on the right hand side is the Stars so I've not put in anything of dark matter so but I can derive the acceleration here from only knowing the barians the Stars and then I can explain this rotation change of these velocities and this is even actual data that showed the same relation its context has a name it's actually this equation it's called a dual offici relation or mass discrepancy acceleration relation and there's also measurements that that were happening were done in enlightened by Maha Brauer using well not strong Lansing is where your bending of light she looked used weak Lansing is where you sort of distorts background galaxies you can figure out the gravitational potential and she found nice agreement with the predictions of the theory that I wrote down actually are the blue lines and they fit the data very nicely there's unfortunately some error still in the data but that hopefully will be reduced so this is where to make clear that this theoretical it is actually connect to data and there might be some obvious observation of confirmation because this is still sort of after the fact you might say well I knew that these things to behave like that so the challenge will be to make a prediction that has not been verified but then you can indeed test things in our universe and so this is sort of the last picture one a sort of and leave you with is that my way I view that we have sort of changed the view of our cosmos is that our normal language of matter forces and space-time is one that a sort of 20th century we have sort of changed language where we won't unstained things like dark energy in dark matter but in order to explain it we have to indeed understand how these things emerge and then suddenly you sort of find that there's much more information present which is sort of impressive in this dark energy and can explain the phenomena that we associate with dark matter so this may be a way of sort of visualizing the the ideas have been explaining thank you yeah thank you very much for the show thank you for this very interesting talk and I think it's actually said that we you and started to look at the universe so late maybe we need generations more to understand that we actually may be a fluid and I think there are many open questions that's you would still like to work on that I think it's first time for questions of you to ask do professor Felina and the catch books will go around so who wants to start up or there's already a question you're in front maybe you want yeah hi I just wanted to ask about something that is there any super intelligence that is controlling everything and it's such a basic question because I'm not from cosmology but it's such a basic question that how the universe existed and how our how close are we in knowing the theory of everything so it's it's maybe two question two questions I think like kind of related I have to say that I think it's already surprising that we've come come this far as humans to understand our the universe around us but it's partly to do with the fact that we are very good at making things abstract in equations that we can handle but in doing so we ignore a lot of information I think we're smart but I don't think we're infinitely smart so for me the idea that we can have a theory of everything that really explains everything is sort of hubris in the sense that I don't believe that are we the only intelligent creatures in the universe I don't know I don't think so but I cannot prove it but I don't think we need to assume anything about that does the universe itself as an Intel heaven intelligence that's or the other question you're asking I told you there is a lot of information in the dark energy that are no idea of what it's doing or what is happening there and it might have some collective behavior that you might define in some way but I don't think it's important for us I mean so I I don't even want to go into the direction of religion or this kind of thing because me that's philosophy what I can do with my equations is only estimate how much information is there what is doing and for us that's enough and so I don't think that that question is part of what we need to answer as physicists thank you thank you there are also questions in the back I don't know where the other catch books is there's already yeah yeah hi my question is how do you measure or calculate the massive black hole that you mentioned in through your equations how do you measure and calculate measure or calculate the massive black holes one of your equations are the mass and the area relation of a black hole you want to know the relationship between the mass and the radius or something how do you you mentioned the mass of a black hole right well the mass of a black hole is something that you can measure on the outside because the gravitational field of a black hole is far away the same as what would follow from say Newton's equations even so if you measure so how do we measure the mass of a star we look at the planet nearby and then we look at the orbit there's a direct relationship between how fast that is and the mass of the object in the center so we can do the same thing we just determine the gravitational pull of the black hole and that actually tells us what is the mass so actually they are close to doing this for a object in the center of our galaxy there is a big black hole and another star is moving closer and what they're gonna do is actually look at how it behaves and one of the things they're very excited about is that they now discover this star has no companion we can do very precise measurements and can even determine the corrections to Newton's equations there but one of the things we determined very well therefore is the mass of this object it's just by looking how other objects in the neighborhood behave okay thanks then I don't know where they get your commands to here front are some questions in the back there more thank you so we're here you said you approved the Einstein's equation by using analogy to entropy and probability concepts is it ironic that Einstein himself would have said that God doesn't play dice I still think that Einstein would have liked this way of thinking about gravity if he would have lived nowadays it's true that his way of thinking about quantum mechanics and the fact that he tried to discredit it by thinking about entanglement that had sort of backfired in the sense that and thing among now is being used everywhere in sort of almost you as a proof of quantum mechanics that it works the way that people say so anyway I think Einstein was visionary and he had many clever ideas and many of them still come back and I don't think he would be unhappy if he would be still alive and Senath well there's maybe an interesting addition is that I tweeted this lecture today and there's a picture of you I think where you have your your hands to the back so people said oh it's so sad that it's a lecture another fight and then people started to make it epic rap battle do you know between you and I always I stand actually so they appear so now maybe that's interesting to read afterwards it was pretty nice I think you won there's a question here in the middle and okay so you told us that information is stored in zeros and ones and then you told us that it's probably stored in qubits but that's still two-level system it's still in some sense discrete why is it encoded in the two-level system why not in something else entirely I mentioned already dice as a very different different way of doing qubits bits so of course we don't notice that it's two-level systems but if you want me to use cute Ritz or anything of that sort I'm doing something arbitrary eventually it's not that important and I sort of compare it to the way that people serve first thought about atoms I mean an atom there are many atoms that we know but in order to derive thermodynamics any any model for that will do so for us it's not important where it's two-level systems of our other level systems we just can still count how much entropy is in there so they is a definition of entropy that's independent of the fact that it's bits or something else there's already the kitchen right there yeah yeah thank you for the lecture I had a question you talked about multiple phenomena across many scales you talked about the whirlpool you talked about the cyclone and then you showed us a galaxy and then you asked us if the physics behind them were similar you also talked about how the physics changes in scales from say the ones we see as properties of air properties of gases to the atomic scale so do you think the physics of larger bodies such as the cosmic bodies may have entirely different properties that we cannot see because we are quite small is there something else to that so people ask me I mean let me answer it in the following way so what I know is that indeed the physics at large scale can be very different than what is short scale so the predictions of this theory is not gonna tell us anything about gravity that works differently here at Earth so in order to measure that we really have to go to these large scales but to understand what is going on we also have to have a microscopic understanding I mean this is also with thermodynamics we have to know sort of that there's an atomic picture but then we can derive the effect of physics at large distances and it's true that different scales generally don't talk to each other very much but we can observe the effects say like in galaxies and so on of this large-scale dynamics without actually having to do the experiments here at earth we just observe what's happening out in in large distances and and just to give you a slightly other example I mean in order to understand what's happening in this material I also have to understand what is made of and what the properties are at very short scale so there is a way in which the short scale physics does affect what is happening at large scales as well it's very good than image there's just there yeah hi I you told us about the fact that your your result the your theory works well with results we have now but you know but any promising oh sorry oh maybe you can stand up then it's easier to see oh do you oh yeah you told us about that blend credibility your theory you'd need some more promising predictions that could be proven true are there any promising predictions you've thought of so far or anyone else's thought that we could have could test in the future or in very far future I have some ideas I mean they have to do also with developing the theory further I one of the things that need to be worked out which is important for what what dark matter now does I mean dark matter has been used in structure formation in explaining what happens in the CMB so I have to do calculations how to explain this using my theory and then see if there are differences between that and what dark matter will predict so there's one problem with that first of all dark matter is not a very precise theory in the sense that what people can assign many properties to dark matter that makes it behaves in all kinds of ways and that's been used a lot to explain any discrepancy that people see so you are fighting with a theory that is almost morphing itself into a solution every time but you have to make a very precise prediction which I'm not going to do now because I feel like I have to develop a theory first to the level where I know exactly what's coming out of this because as I make one prediction after the other without well being 100% sure I should do this so no I think that we have to wait and one of the questions I'm wondering about is actually the way that dark energy behaves it behaves as a function of time so I'm actually quite excited about data that are showing that the Hubble constant nowadays and what would be predicted from the Cosmic Microwave Background actually have a discrepancy other things about cosmology that starts to sort of become a little more troublesome I think there may be ways in which this theory can do better but we still have to wait and and and develop a theory to the point that we can be totally sure that we we have a fool complete theory thank you the other case focus there maybe you can stand up let's easier to see whose yes hello so my question is if the theory would be correct I for my brain it's a bit too hard to understand all the implications but would there be anything we notice in daily life that would so for example once we understood satellites then we had it had implications for phones and our stuff so does it have any meaning for things on earth yeah I mean like I mean here I think the chance is very small but I think we have seen other examples in science where it was not all totally obvious these implications may come centuries from now I don't know it's certainly not my motivation to do it that way and it seems to me actually surreal - did the answer I gave before that the things that I worry about which have to do with more cosmological skills are not gonna be immediately relevant for what we experience on the air they let except for one question I mean I haven't shown some of the cartoons I sometimes show in public talks which is why are we doing this and it's one of those questions that I think everyone wants to know eventually is where does the whole universe come from that question is now being answered using the theory of the Big Bang and it may be something that well you can think about so I think that when we know more about our origin of the universe and things like this this is something that everyone can be curious about and in that way it may affect more people than just the scientist I mean this that's my motivation for doing that is very much more motivated by these big questions than making things that immediately are applicable for our our daily lives maybe yeah the theoretical physicist meets the applied physics students yeah it's of course also something that the students here in definitely think more about yeah we have the great catch books which is there yeah please stand up it's a really in the middle yeah hello thank you for the lecture I have a question you considered the outermost sphere of the observable observable universe as the surface for your information calculation so my argument is is there a possibility that if there is something outside then outside the observable universe then there would be a little more dark matter but then again if your equation is actually satisfying with respect to the current gravitational observations then in that case we are saying the observable universe is the end of the universe is that true well this is a still a debate I mean I told you something about the horizon and what's happening there Eva for black holes people don't know whether when we're on the outside where they we should be talking about what's going inside yes and no so I say the same thing for our cosmological horizon it's really part of the universe that we kept no communication with and nothing that's there can affect us so I like to sort of not included in my considerations so I think it will not affect our our physics and for me there the fact that the universe has a finite horizon at a certain this is with a finite amount of information is actually quite essential to the ideas that I've been using here got any on the one more fish the blue one is there ya are you see you still yes hello yeah thank you for the talk my question sort of hooks into his question you said that the boundary of the universal defines information with the amount of information within it does that mean that the Greece expansion of the universe is directly related to the amount of entropy in the universe yes so the Hubble Hubble parameter which is the one that determines the expansion rate of the of the universe is directly related to the size of the horizon and therefore that connection has to be made so for me the Hubble constant becomes a fundamental constant of the theory very much like Einsteins called the Einstein constant so he did the Newton's constant and so the yeah the density of the information or the amount of information is directly related to that constant but does that mean that entropy is the only factor in the increased the increase increased increase in size of the universe we are let me say just yes I think this okay thank you the gets friction out there yeah so you mentioned something about ferret hoped holographic principle yes and that basically all information in the universe is represented at the horizon at the surface of the universe and since then this has been shown mathematically to be the case for an anti D sitter universe but in your talk you also mentioned that in your theory information is also included within the universe itself so how do these two ideas actually compare compared to each other so the holographic principle does not state that the information is on the surface it says that there should not be more information than the area the surface that could be on the surface so it's a it's a upper bound of the amount of information can be insight it's true that in anti-de sitter space which is a universe without dark energy it lives on the boundary and one of the main points i've made here is that the appearance of the horizon and the finite temperature has to do with the fact that we live in a universe with the positive dark energy and if you want to know more about the rest of the argument I say you would we have to read my paper because that's explained very in the beginning you have a great oh I'll do that maybe I will throw it okay yeah thanks for the very interesting very interesting talk I was wondering you talked about entanglement and about information and they say that entangled particles can transfer information faster than lights do you have any theories on that well it's not exactly true I mean entanglement is a state of the two particles and in order to transfer information which you can do say through quantum teleportation you still have to transfer a signal that goes with the speed of light so there is no fast communication possible with entanglement - one here yeah my question was also kinda really related to this one I was wondering what if you have this entangled particle two particles just on the edge of the horizon and one goes into the black hole and the other one stays out then into the universe but yeah it's literally your question no no it's not actually but well UF DS a thing of particles and they are related but one is a Eureka the other side of the horizon so you have exchange of information it's the kind of paradox but how do you see this well they're entangled which is not again exchange of information I mean entanglement is just a statement that an outcome of a certain measurement here is correlated with the outcome of an other measurement it's not a form of information that's being sent over I call it sort of sometimes shared information in the sense it's the same information that's available to both but you cannot use it to send information okay it arrives in the frontier yeah thank you for your lecture I have a question if we go ahead with the theory of Big Bang so during the beginning of the universe is a hot plasma and it started expanding and once it started expanding it it gets cooled down and and all the plasma ingredients in the plasma start coming together so mom can I have whites you can we have the other screen so my question is good could you please explain what what is the rasp our force is responsible for the ingredients in this plasma to come together is it gravity because we I really have to been doing just this here this is my interpretation of what that story is just look at this white I'm not gonna answer it I mean for me the Big Bang is story is not believable and it has to do with information it has to do with the fact that the statement there is that everything emerged from something it's a story of the universe that we like because we have been reasoning backwards and in doing so we have done what we normally do and already explained it to an answer we have done what we humans do is namely perhaps make things abstract ignore information throw it away so we have a very simple picture of the beginning of the universe and most of the information that's there is considered irrelevant if you would put it all back in again the picture would be very very different the mass may be similar but the story is very different and so I don't buy this I think this is really just a story that's being told over and over again in such a way that people start believing it and I think if you think about it logically it's not a very logical story actually nothing in other parts of physics works like this where something can begin at the moment without having existed before it I think it's very clear thank you yet there in the middle yes perhaps I'm missing this 30 sir but is it truly so that you suggest that dark matter doesn't really exist yes do we then also think that the same applies to dark energy somewhere out there no clear statement now for me dark energy plays a very important role it made the difference between this universe without the information and with it and I used the dynamics of dark energy to explain the phenomena that we attribute to dark matter so for me the dark energy is the real thing that makes that thing happening so the information I talked about is associated with debt and that's what's filling the universe and what we observe in what we call dark matter we think of it as a particle and it would be sort of something else than dark energy and so the current theory would make no connection between dark energy and dark matter but I claim that what we observe is actually due to dark energy and not due to dark dark matter but what I mean is like because I think there's so many questions we very little time so we can continue and then there will be drinks afterwards to discuss even further yeah so I think we do two more questions one blue question and one gray question yeah you're the lucky blue question um yes you see dark energy is composing the majority of the entropy of the University um but um but but but but then the other explanation has always been that is given by the cosmological constant which which I just understand it's a geometric argument is a geometric constant it's the same as saying that all of the molecules in this room can be summarized by giving it a temperature the motion of all the molecules it's a simplification of what's going on which effectively works very well because for our daily experience that temperature is a thing we care about and the cosmological constant summarizes what is most important for that description this is the way that it appears in Einstein's theory but I think it's an oversimplification of the actual dynamics that is going on so there's a lot of dynamics going on in this dark energy that is not described by general relativity so you're saying the cosmological constant is itself an emergent phenomena that's correct it's it's just like temperature is emergent in thermodynamics great things so there's a final question in the back do you have an alternative theory to the Big Bang I think I answered that question already that's something that needs to be developed I have I can tell you what my thoughts are all about so I think that indeed the universe did not start in a short moment but the idea of emergence is much more subtle it means that something cannot appear without out of nothing it must appear from something else so space and time have to be appearing from something that was already existent now if you ask me what is the mass that goes with it one of them mathematical descriptions I'm thinking about a lot is called chaos so in chaos what happens is that you have things that are exponentially growing namely it's like the bat butterfly effect if I have two things very close by they may end up in very different parts but generally when you look at this then they're also things decaying and some certain things grow other things become less important you can throw away the thing that's less important because you cannot observe it but then you are only left with things that grow and that's what the universe description now looks like but if you take the entire description you see that everything actually is preserved nothing really gets bigger as actually all of the volume even all of the information gets preserved so it's a much different description but effectively you might fight the equations in there that we're now currently using to describe the Big Bang that the theory itself will be much more complete in terms of computing track of all of the information that's there and but anyway I'm not gonna speculate too much about what the mass exactly looks like this is something that needs to be worked out thank you sure yeah it was great I think we will hear still a lot from you in from new theories and I think if I look at this room there are many young students that maybe look at you the way you looked at here a television program when you were young is there any message you want to give to the students like how they how they can be the next people that make great theories or do great physics well I think first of all you must be doing what you find most interesting with everything I think even if you start doing research later for your massive project or for any anything when you do something that you really like doing you are much more effective and much more likely to be successful and indeed ask yourself what what are the questions you're interested in and what is it what you want to do and if you go for that I mean I I knew it when I need to start it before I started studying and I kept the focus on that so if you have some idea but you really like and and you want to go after you should do it in focus thank you very much for being here it's it's been great you

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Length: 89min 45sec (5385 seconds)

Published: Mon Mar 19 2018

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[u/ResonatingThruTime]

Basically the observable universe is made up of information, the amount of which can be calculated from the size of the boundary which encloses it. This is similar to how the mass of a black hole can be calculated from the size of its horizon. This information is essentially the rapid fluctuation of "space" at the Planck scale, and starting from this concept, it is possible to derive relativity and explain cosmological observations that Einstein's equations and the standard model couldn't in their current forms.