A Thin Sheet of Reality: The Universe as a Hologram

here we are again good evening it's a beautiful gorgeous summer night in new york and here this place is full of people who want to talk about holograms and that's wow yeah world science festival's so great my name is john hockenberry first of all i'm the college dropout news guy who's going to hang out with nobel physicists tonight perfect for this job oh my god um how did i get here um but uh seriously you know we think of uh you know this season as a world science festival it's the beginning of june the weather starts to get great you know tonight at uh uh uh brooklyn bridge park it's supposed to be one of the best viewing nights uh in new york and there aren't many really fabulous viewing nights in new york so i urge you to do that i mean it's a beautiful clear night everybody's out in there some it's kind of like prom season we think of the world science festival as the prom for all the scientists who maybe didn't get any dates didn't know there was a prom and i actually pulled our panel tonight three clearly did not go to the prom uh didn't want to talk about it and one didn't remember uh at all you may be able to figure out who who is who tonight um i'm actually perfect for this uh gig for another reason because i actually inadvertently helped to solve one of the most serious problems in physics back in the 1970s i was on a team that helped to do that i was enrolled at the university of chicago as an undergraduate and i tested into the top of science section uh basically junior of science in in my freshman year and it was taught by a protege of david schramm one of the nobel laureates at the university of chicago late david shran brilliant physicist and uh part of the university of chicago program which gave us enrico fermi and so many others and uh chandrashakar and uh and i was in this program and very excited i go to the first lecture and uh it was taught by uh one of these proteges the central european fellow i can't remember his name now and it will become clear why he said hello everyone it's great to see all of you here we have very serious problem in physics uh the problem is a simple problem but the serious problem it is too many physicists and so in this course if you're getting b b minus you'll get f uh if you're doing a b plus a you will get a um i went into the news business and thereby helped to uh solve the very serious problem in physics of too many physicists so and a lot of the panelists tonight are possibly grateful for that so uh you are here to talk about uh and to listen to one of the most exciting fascinating also difficult uh principles that's uh now being kicked around in uh physics and cosmology uh the holographic effect and it involves a couple of concepts that actually we have a lot of intuitive sort of sense of uh and i want to present two of those tonight before we introduce the panel and get started here um one is the idea of of information uh information we we think we know what information is right information is very very like you know you go information right now now that isn't the new york subway system right but it is enough information to specify how to get from point a to point b and if you understand how to read the subway map you can get from point a to point b the information isn't exactly the same as the subway but if you don't have the information the subway is useless to you and and somehow it just it sort of maps directly and it is a map right it maps directly onto the subway and of course now the subway map nobody has one of these right it's all on your like smartphone which means it's stored on a tiny piece of silicon and so therefore what the the volume of this can actually be mapped directly to a volume you know a one millionth the size take for example this anybody got one of these anymore no i mean this specifies the number of synonyms i don't know what the hell it actually is but uh it's a thesaurus and it actually also fits in a tiny piece of code in microsoft word we got here the uh just the 8ms okay oxford shorter uh english dictionary information i'm going to set it over here just to remind you of what information is all about now information the dictionary isn't the english language right the the the the space the universe of the english language is all you people talking will you talk now just talk just turn to your neighbor and say hello how you doing right there see that is the that is the space called that is the universe of the english language that you are hearing it is not it is not the same as this book but it sort of maps on to this book and there's enough information in this book to make predictions about what it is that you're saying so that if you actually talk to me i know what the hell it is that you're saying um unfortunately i probably won't know what the hell it is most of the panelists are saying tonight so i may need your help with that nevertheless there is information in what they say the information maps onto a space where we can make predictions it is information that allows us to be conscious beings it is information that allows us to be living beings if you think of dna as information now the information we're going to talk about tonight is much more complicated but the idea of information as a map as a specification of a much bigger space is sort of the beginnings of what we're talking about here the other thing is holograms right you know clap if you know what a hog round i just said clap if you think you know what a hologram is yeah let me introduce our panel please welcome raphael busso let me tell you a few things about rafael rafael busso is a theoretical physicist at the university of california berkeley he's recognized for discovering the general relation between curved geometry of space-time and its information content a key idea of the holographic principle please welcome our next panelist hermann belinda rahman belinda is a physics professor at princeton university in 1988 berlinda received his phd under the supervision of gerard eth rolinda is renowned for his contributions to string theory and its application in particle physics cosmology and black hole physics some of his current work explores gravity in the context of the holographic principle our next panel is is indeed nobel prize winner gerard parrot hopes to receive the 1999 nobel prize in physics for his doctorate work in theoretical physics he's a professor of physics and of his many achievements he was the first to propose the idea that would later become known as the holographic principle and finally our fourth panelist leonard suskind professor suskind is professor of theoretical physics at stanford university and the first to give a more precise interpretation of the holographic principle using string theory he's well known for his book on the topic of the holographic principle the black hole war my battle with stephen hawking to make the world safer for quantum mechanics it's a fantastic book i highly recommend it please welcome the panel back in the early 1970s stephen hawking wrote down an astonishing equation it would include relativity it would include quantum mechanics and it would include information hawking's rather simple equation brought us a step closer to understanding the relationship of quantum physics and black holes when an object crosses over the edge of a black hole its event horizon the object enters a realm basically of empty space of darkness and it continues to be dragged toward the center of the black hole toward what we call the singularity where it gets crushed out of existence every object in some sense contains information because it contains a very specific arrangement of particles so where is the information that describes the arrangement of those particles where does it go hawking's description of this process was that the energy remains but the information disappears for many years for decades people wondered is hawking right is the information obliterated and disappears from the universe or is it still there and perhaps can be in some way retrieved the destruction of information was counter-intuitive and it didn't match the rest of the things we knew in all parts of physics we had a situation where information doesn't get destroyed so it was a bit puzzling this debate furiously went back and forth up through the 80s and into the 90s when people finally began to articulate this new principle this holographic principle and what it said is that all the things that were falling inside a black hole were somehow captured in a preserved image at the horizon itself so if the information is not lost on the surface information is not lost inside because they are equivalent all the information about those objects what they were like in their three-dimensional existence was preserved or encoded on the surface of the black hole and that's a little bit like a hologram well that suggests that maybe that idea may apply more broadly to the universe as a whole maybe the three-dimensional objects us everything in the world around us maybe all of the information in these objects is carried is smeared around a distant two-dimensional surface that surrounds us and we're just in some sense a holographic projection of that distant data the holographic principle tells us something quite astonishing it says that our ideas of volume of the the real world in a sense might be a kind of illusion so are we real or are we just holograms let's begin with that but uh in fact uh let's first of all remind folks you guys were direct participants in that argument that was described in that film which i think fairly characterizes the difficulty scientists have not only in in sort of grasping and fully understanding this holographic effect principle but also explaining it leonard susskind what was it like to get into essentially a pretty big cosmological argument with stephen hawking and be careful because hawking's one of my wheelchair boys yeah and uh we're really tight we're really tight it wasn't that physical what was it like it was fun and it was frustrating it was incredibly frustrating stephen had a view which was very very difficult to argue with his ideas were based on very very sensible ideas a black hole is a place where nothing can get out of but things can fall into it and if things can fall into it and they can't get out they're gone but then the black hole evaporates stephen had proven that beyond anybody's uh doubt and so things fall into the black hole they can't get out the black hole evaporates poof it's gone just exactly as brian said it was unassailable there was no way to argue the case and yet some of us particularly myself very very strongly felt that this really undermined everything that we knew about physics everything that we know about physics today and even much earlier was based on a principle of physics which is so basic that we sometimes forget to mention it to our students it's the idea that information never disappears and i'll tell you what that means information means distinctions distinctions between things um a hydrogen atom is not uh it's not the oxygen atom an oxygen atom is not a hydrogen atom there are distinctions between these things and it was a very very basic principle of physics that distinctions never disappear that they may get scrambled that they may get all mixed up but if you start with one configuration and you let it go or you start with a different configuration which has different information and you let it go they'll stay different and stephen was saying exactly the opposite no matter what you throw into the black hole in the end you get out exactly the same thing it was extremely difficult to see what was wrong with what he was saying it was even harder to make him understand that there had to be something wrong with what he was saying so it was very very frustrating but at the same time um it was very exhilarating to to come up against this basic problem of conflict of principles and if anything can break the impasses in physics if there are no experiments available it's conflicts of principle when conflicts of principle arise that's when major new paradigms concerns that's the excitement that's really the excitement howard explain to me why this problem with hawking this um uh you know the information can't go away as it seems as though hawking's mathematics suggests it does is different from something like say conservation of mass energy where matter can either be created nor destroyed it's it's different than that right yes it was a very fundamental problem and the way i always saw it is hawking was using quantum mechanics in particular quantized fields to derive his results so quantum mechanics went in as as starting point number one and then general relativity everything else and the use of that to derive the black holes radiate particles from that it was derived that was information and there was information disappearing well the fact that information disappears is at odds with quantum theory itself so he uses quantum theory to derive a result which basically was at odds with quantum theory so there had to be a mistake somewhere i shouldn't call it a mistake because what he did was by itself mathematically correct and nobody doubts that but the final result had something in it that couldn't be true and so this is what in physics you call a paradox and like my friend lenny has been saying as soon as you encounter a situation of this sort in the physical world we are very happy actually it is a paradox it means there's work for us to do we have to clear this thing up and if you look at the past you know quite well that when people start to clear up paradoxes new discoveries are being made so you guys are friends several cases and that's why we're all so excited about this thing is something wrong the deviation itself seems to be flawless but there's something wrong anyhow with the result you guys are friends then of course we are yeah herman let me let me ask you a question just about this issue of information briefly and i want you to go back i definitely want you to go back why why does the universe need information why does it need to to have this information why does a rock need some sort of information image uh what you call information we as physicists would just write as terms in equations right we think of the physical world as being driven by mathematical formulas in these formulas there are what you call degrees of freedom so things can be this that or that oxygen or halogen right as an example all these things should go on the equations and we are used in particular in quantum mechanics to the situation that if two things start up differently they end up differently that's a fundamental notion in quantum theory we can't get around that you can't have two different states adding up after a while to be the same that is that violates the principles of quantum mechanics now quantum mechanics itself is not such a sacred theory that maybe there are violations of it but then we want to know about this we just don't want to say well you know we have to clear that mess up later no no the mess has to be cleared up right now if there's a flaw of this sort in our results we want to know about it so what jorge was saying two different black holes start out differently in one of them a teapot is falling all the other an old shoe i saw this movie and if the teapot falls into a black hole or an old shoe falls into a black hole that's different people's not the same thing as a shoe nevertheless after a while they look exactly the same according to him i see so it has to be said that's that violates our equations that cannot be told there's something wrong something went wrong on the way and we want to know what it is thanks for referring to that because i can't tell you how hard it was to get the teapot in the black hole and then to get the shoe you know just get get the teapot we said well you got to get the shoe too and that was really hard hermione please all right okay let me first follow up on on sort of the because you were asking how was it to have this debate with hawking that was kind of your question maybe we can tell an a little anecdote about how it was in part it was of course all about science and we're all friends even if we disagree about the science but hawking is a very special person where he can think very deeply about questions but he also has a handicap he cannot speak so he has to speak with this by typing words and then sometimes the debate would go like this then an argument would be given and then hawking's response would be one word rubbish very hard to argue and that's very hard to hockey accurate yeah and you know you know and when i when i say rubbish nobody pays any attention you know but when hawking says rubbish it's yeah it's silent and you've lost the argument at that point capital r it's a big font there yeah right when hawking says it all right so hawking says rubbish to you do you like go home and tell your wife hawking said rubbish to me what do i do or do you like go to the blackboard or you sit down at the computer what happens you you go on with because you believe in your argument the other question about information the thing that i like sort of as a way of uh explaining what information is we live right now in the in the age of information this is the information age and um but the type of information that we're talking about here you say well it's more complicated but one way of imagining what kind of information we're talking about is i like again the movie the matrix where again there's this virtual reality where and actually i had kind of nightmares for myself when i was young okay well what if the whole world is just an a thing that's being projected on my brain or actually for all of us if we're sitting here in this room and who knows maybe it's just a computer that makes us believe that we're real and the kind of information that we're talking about is really sort of what what is inside of this computer imagine you make the this hall here with all the reality of being able to do experiments things fall uh you collide things things happen exactly the way we thought think about them as happening in physics but it's all just zeros and ones in a computer and in principle you can quantify how many terabytes how many gigabytes how many i'm not sure if i forgot what comes after gigabytes but there there's information in that computer and that's the kind of information that we're talking about so so when you say information you say that physicists believe and cosmologists believe that it is possible to map every aspect of reality that we are experiencing here into some sort of stored code that specifies precisely everything that's happening here what people smell like who is mad at who who who's wearing like dirty shoes and uh and and what they're even thinking about right you can imagine that that's the way it goes now just is that something scientists are imagining or does quantum mechanics insist that that must be so raphael uh quantum mechanics um in a way is based on information it's a theory of information uh the way that we would describe the world you know the room being uh full of people or not full of people and electron being in this place or in that place uh they these are different states as we call them and um it's it's as if you know you put one letter on the page or you put a different letter on the page it's a diff it you know it conveys information um so where a particle is is a way of of of conveying information and in fact quite literally when we write something on a page we put particles in particular places um and we we thereby convey information it's not very efficient um comparison let's explore that for a moment victoria do you have rafael's slides put up his uh first slide here because as a as someone who studied mathematics poorly um the understanding that i had was that as you go say say you're looking at the coastline of of of uh massachusetts and you're looking at it from a satellite and you you you see one line but then you come closer and then you begin to trace every little indentation and then you even get closer and you trace even any more indeed and try to specify down to the atomic level that the amount of information in the line that traces the coastline is actually unbounded and infinite um what is it that you've discovered well that it's not it's not infinite there's a limit um and so how do we embed this picture i i think there's one important thing that maybe we need to say in order to get from the black holes to this sure um i i was actually not part of this debate with hawking i became his student two years later um but you look younger as a result as a result yeah it's certainly certainly aged these gentlemen here so i i i i i i i the reason we're ordered this way is we came in we figured raphael could walk the furthest right and uh we decided we're just going to leave you here when we yeah and hawking couldn't be here so you got me you know yeah yeah yeah he was here last year yeah um anyway so so so these gentlemen had you know the crazy insight that um when when information is dropped into a black hole it is not in fact lost even though naively you would just think okay now it's in this black hole it's somewhere but we can't get to it they insisted that you still have to be able to get to it which you know lenny made it sound so easy but it wasn't that obvious it was an incredible intuition and um and for that to be true for that to be true that if you throw a phone book into a black hole that later on you can figure out whether it was the new york or chicago phone book two amazing things have to happen uh first of all hawking had to be wrong about about the idea that that no matter what you throw into the black hole the same thing comes out it's a very loose way of putting what he said but that's the that's the basic way information would be lost um a second amazing thing had to happen which is you know it takes a long time for a black hole to fizzle away and disappear and return potentially return information to you supposing hawking is wrong and in the meantime you've got this big fat black hole sitting there and what had to be true was that while the big fat black hole is sitting there that that black hole itself contains information while it's still sitting there and hasn't fizzled away yet all right so that to be true there had to be a limit on how much information there could possibly be in the region that was occupied by the black hole because you could presumably always convert that region into a black hole all right so let's let's back up for a second um so so hawking suggests that the information is gone uh you say that can't possibly be true hawking says rubbish and then you go about saying well no we're going to find where that information actually is leonard where and before we get to uh rafael's slide here um where did you find or where did we find that that information that hawking says is gone in the black hole is actually stored okay so one of the things that we found is i'm sorry to say this john but that turned out to be a bad question okay that in a certain sense bits of information don't necessarily have locations or at least they don't necessarily have locations which are objective and the same for everybody no matter how they're moving okay i'm all about questions the notion of a bit of information is a good one we believe it we believe distinctions exist and distinctions persist but the notion of where that bit of information is located turned out not to be a good what a physicist would call invariant question it might depend on who was looking at it now let me give you an example of where it is a good idea if an atom decays inside the sun everybody will agree it happened inside the sun it doesn't matter if you're moving relative to the sun it doesn't matter if you're far away if you're nearby everybody will agree if they do the calculation they see what comes out they'll agree the atom decayed inside the sun if the thing happened inside the sun black holes are different and what we found out is the whole notion of whether something happens inside a black hole or if it happens just above the surface of the black hole surface meaning the horizon is a question which is observer dependent somebody who falls into the black hole may have all of the experiences of seeing the event happen well in past the horizon somebody standing outside the black hole will reconstruct out of the hawking radiation that that event actually happened outside the black hole so the answer to your question is we didn't find out where the information was we found out that it was an improper question that bits of information don't really have locations in that sense and how do you know they weren't destroyed if you couldn't find them in a particular location well eventually eventually a lot of the power of string theory and other mathematics came to bear on it and confirmed that there was no expectation that it would be destroyed but as can i call you gerard it's so much easier okay as my friend georgia says i spent years learning to say harad but never mind i'm totally fine with her art yeah totally fine with it god i'm 70 years old 71 years old and i forgot what i was going to say um no no but you you were you you were saying that uh the the issue of where it was and the invariance of of of the question meant that or the the the variance of my question meant that you know you wanted to basically change the nature of the inquiry yeah right but you asked me how we know and i think the answer was given by gerard that so much would break down in physics the whole structure of everything we know about physics would break down and disintegrate if even you open the door a tiny little bit for the idea of information to be lost once it can be lost you can promote that and make it worse and worse and worse and worse and eventually the whole structure of physics as we know it will break down there are some things you can't have a little bit of you either have it or you don't you know we all know about pregnancy but uh but let me give you another example in mathematics can you have a theory a theory which means a mathematical structure arithmetic or whatever can you have a theory which is approximately consistent it's almost completely consistent okay well you might have some structure some set of axioms and you derive you you let your computer run and derive 10 000 theorems from it and it say oh it's approximately consistent only four of them were inconsistent with each other well no a mathematician would come and tell you once you have any inconsistency you can use that inconsistency to promote promote it anything is inconsistent with everything else basically i think the same thing was true about information loss once you had it once you had it in any form at all you could imagine situations where it would undermine basically all of physics and that's what uh i think that's what gerard thought that's what i thought and it's what stephen didn't think so we sort of battled our heads against the wall for a while all right so how in my imperfect uh question creating way can can we get to the point of either if not where was the information how did we learn conclusively that it wasn't destroyed and that if the phone book went into the singularity that uh there was a way to find out if it was chicago or amsterdam or you know soweto whenever i encounter a situation like this i try to approach it from all possible angles particularly angles that my neighbors here would not be prepared to look at to see what can be done we have as i said a paradox here and the resolution must come from a totally different point of view than previously now one thing was that quantum mechanics was used to derive a result that quantum mechanics somehow failed to be to agree with the pythagorean or something wrong so my attitude was we start from the other hand now let's assume that the black hole as a whole agrees with every anything we know about quantum mechanics that means information in is equal to information out it's that simple basically in important mechanical sense so that ought to be true as soon as you believe that this is true it's a relatively simple calculation to find how much information there is in the black hole and you do the calculation you find the amount of information in the black hole is exactly equal to its surface area it's like putting bits and bytes of a computer memory on the surface every bit every byte of information occupies very precise amount of surface which you can calculate relatively easily and that tells you big black holes contain lots of information small ones contain a little information still enormous amounts in any absolute sense but that was a very clear conclusion how much information there is in the black hole but the question where the information is is something else again all right but let me just back up here so so all you got if you got your black hole to study at least not to find where the information is but to to figure out if there is a a quantity of information that could be sufficient to specify what goes on in this black hole you've got yourself just sufficient the exact quantity itself exactly okay there's a few bits hanging around the side but apart from that the total quantity of information is very precisely calculable but you but but all you've got is the surface of the black hole and and and so you've got to test could there be enough information on the surface to specify what's gone into the singularity and what's happening beyond this event horizon that's the question right well the question was answered by this assumption that the black hole should obey quantum mechanics once you make that assumption you find that not only the information of things that went in and out the black hole but everything is in its vicinity should be mapped onto its surface in bits and bytes it's like saying that the surface is a hologram of the immediate surrounding space time so a a x dimensional object can specify an x plus one dimensional object yeah are you getting that is this working for you we're cool right all right all right good you're all with us okay so the surface is two-dimensional so surface space time is three-dimensional which is exactly what a hologram does you got your two-dimensional star wars movie and your three-dimensional looking princess leia who by the way did have a prom date i believe uh and and and so is but is that an illusion you know in perspective it's basically you're creating an illusion or is it actually a one-to-one mapping of all the information of the reality onto the 2d surface that gives you your 3d reality herman yeah again talking about the mapping then we don't know exactly how that mapping works at this point but i would say that the thing the principle that turns out to be very powerful in this context i call it the rumsfeld principle and and it's basically saying well it's better to deal with known unknowns than with unknown unknowns so so he was bad at all of them but yeah right yeah so so the the the unknown unknowns are stuff that you lose and you don't know that you lost it uh if you throw something in a black hole for all practical purses purposes you've lost it you've lost the information but what we're talking about is actually that i that we know that we lost it again i don't remember what i ate for breakfast yesterday but i i knew i had breakfast so at least i know how much information i lost by having a bad memory and so so the fact that we could quantify how much information is in the black hole and that it's measured by the area that turned out to be the surprisingly the the key insight so knowing how to quantify what you don't know uh is is a deep is a deep principle all right i think yeah that that's actually starting to work for me let's let's forget your slides raphael for the moment if you don't mind and go to leonard's slide which really gets us from this idea of there's a bunch of information and it maps into something that we might think of as a three-dimensional image victoria can you put leonard's first slide up okay what is this one uh that's a microscopic picture of the film of a hologram which in fact i made up myself with a microsoft paint so it's a fake but it's about what it would look like it's about what if you look through the microscope at the film not this thing that is being described by the hologram but by the piece of film itself it would look approximately like that and so then if you put light through it in some particular way well let's let's first it's got some information in it it's all scrambled it's impossibly scrambled you can't look at this and see what the what it is anybody any guesses what the the image is there anybody want to guess what leonard susskind donald trump okay great so it is a fake anyone say puppy anyone say probably a little horsey no no horses okay all right let's see well okay go through the next one let's go to the next one here's here's the stand by folks all right this is another fake i also drew that myself all right all right so if you do the right thing with the hologram namely shine light on it and so forth it'll reconstruct an image so the the the you got the flashlight uh yeah yeah maybe this is obvious but flashlight going through the film and somehow the the information in the film recreates the 3d image of the clown smoking the cigar right but the interesting thing about it is that the clown is three-dimensional you can go behind it and you can see whether he has hair on the back of his head you can go underneath and look at the chin underneath in fact if this hologram had been made not with ordinary light but if it'd been made by an nmr scan you could have coded on that boundary on that surface you could have the interior you could have all your guts and blood and everything else bones the entire full three-dimensional structure would have been mapped you used the word map and it's a good word mapped onto the boundary onto the film uh and the important thing is not that you shine light to reconstruct it but that the information about the clown is equally well and in fact in some sense better described more accurately described more precisely described by the little dots and dashes and structures that are entirely scrambled totally impossible for you to just look at but it's there it's there in that film there and and as you say you can add detail to that informational film infinitely or is there an upper limit okay so in the world that we're talking about which is the real world there's a limit no more than one bit that means a plus or minus one little dot per plunk area the planck area is a certain unit of area that's made up out of the fundamental constants of nature it happens to be about 10 to the minus 33 centimeters on a side it's far smaller than anything that physics studies experimentally but no more let it go it disappeared uh okay black hole i had something they went in the black hole yeah no more than one bit that means a black dot or a white white dot per plunk area all right so let's just back that up for a second um just as you need a certain amount of resolution on a piece of standard film or a digital ccd chip to produce an image that's recognizable of your lovely pets or your kids or something like that uh in physics one bit of information is it a traditional bit as though yes it's a yes or no question yes or no questions zero one bit yeah zero one is is necessary to specify a planck space which is an infinitesimal but measurable a little chunk of space well beyond our ability to measure at the present but yes aye and so what it says i mean in in essence what it says is this entire room everything that's in it can be in principle described mathematically in terms of degrees of freedom structures on the boundaries on the walls of the room with never needing more than one bit of information per plunk area that was very radical that was very surprising because people had always associated information with volume we have another picture but uh maybe you want to go around well let's go no let's let's go to uh this is the pixel the pixels and the voxels okay let's do the uh pixel voxels that's the next two slides so we're trying to come up first first the uh pixels all right this is obviously a two d can we jump can we jump to the other one first all right let's do the voxels first okay all right there's the room if you like there's the room and i'm going to describe the room everything that's in the room by dividing it up into little tiny cells a cell let's say no bigger than atom and what can we ask about a cell we can ask is there or isn't there an atom in it of course we can ask what type of atom but let's ignore that is there isn't there an atom in it and if we didn't have to worry about the type of atom that would be a complete description of everything that's in the room and so there would be one decision for each voxel a voxel is a word that means a little cube there would be one bit of information per voxel it's either empty or it's full all right so we've divided up this room uh in in each plank well i i was talking about atoms but yes all right in each bigger than a plank space that we've decided to choose right we're asking the question is there an atom in there and there's a yes or no answer to that and we reconstruct the entire space in information terms in a cube like this right and we got some place there are atoms some place there's not i would say in this room would probably be a lot of yeses probably right many more no's and yeses you think oh that's right space is mostly empty yeah the room is almost all empty space always it annoys me to hear that always but yeah anyway okay so so now now that's the 3d yeah so what's the other picture well what we found in essence is that's too much information no room can ever have as much information as is implicit in this picture here the amount of information that it takes to describe the room is more like this picture here one bit of information plur per surface area so i like to say the world is pixelated not vaccinated the world is made up or the degrees of freedom of the world the most accurate description we can ever have is in terms of a number of degrees of freedom which is proportional to the area and not the volume so it's actually the reverse of our intuition and help me out here so we like to think of gosh you know movies are great but wouldn't it be fabulous to to have imax 3d in fact what physics says is you can get all the information in your 3d high-res reality world on a 2d surface let me just one thing before i want to get these guys yeah the only thing is that the two-dimensional description is going to be monstrously scrambled very difficult to decode very difficult to see what it's a picture of that's the that's the cost of coding information in two dimensions instead of three right as a mathematician your first reaction will be there's much less space on a two-dimensional surface than in a three-dimensional world so the first reaction is that can't be right we will be missing enormous amounts of information if we try to put scramble everything on the surface however you have to remember that this is the planck length which is extremely small to for all standards 10 to the minus 33 centimeters is extremely tiny even in units of elementary particles so even this looks at first side to be very little information actually it is enormous it's gigantic but on the other hand you have to realize that not only what's in this room should be mapped on the surface but the entire universe can be mapped on the surface that's even more gigantically crazy because you would think that the surface of the universe would be much smaller than its volume but again these plank units are so small that still you have enough information on the surface to specify everything that goes on in the universe well it i mean it's so counterintuitive i mean every time i go into the holland tunnel i wonder how all of new york could fit in here but in fact that's kind of what you're saying um so it is very very counterintuitive so so you you you come up with these mathematical conclusions that are very robust and sound and you can defend them i mean do you go back herman to hawking and then does he say sorry about saying rubbish or i guess i was wrong about the rubbish credit he has started changing at least his opinion and he accepts a lot of these ideas um einstein for example had a much harder time accepting quantum mechanics i don't think he ever did but hawking uh i think he he realized at the time when he was proposing he was putting this paradox forward that by by stating the the contradiction that was in in black hole physics he realized that that was a way of making uh progress uh and of course he liked annoying his colleagues which is sort of what he was doing by making this particular claim but he put us to work so and then by the time that that answers came came forward he he has so he had this bet with one of his colleagues that i think it was for a year-long subscription to playboy but in the end the colleague decided to give him a a nice book instead because the bat the bat was settled and then hawking admitted that that information was there and so that's well the the whole 2d 3d thing if you bring playboy into it as a whole i don't that's a whole other information space i don't even want to think about um as a as a much younger researcher raphael what excites you about the holographic principle in terms of and we're going to get into its controversy in a moment in terms of what it begins to explain about other problems in physics i think what's exciting to me is that um the only way that information could possibly not be lost when a black hole forms and then evaporates was for there to be a completely universal relation between the information content of a region and its surface area in other words there was a relation between surfaces in space time which are described by gravity theory it's that's the realm of einstein's general relativity surfaces surrounding certain regions those surfaces their area specified how much information could be in the region that was enclosed by them that turned out to be not quite the right way of stating it but that was that was necessary if uh information was not going to be lost in black holes in other words it led to a statement about how much information there is in the world that was completely independent of what you were using to encode the information it didn't matter whether you used letters on a page or or or atoms or strings or quarks whatever your favorite uh physical ingredient was it was a statement that was completely universal if information was preserved then we were learning something about fundamentally how much information there is in the world well even beyond that let me just maybe say one thing just to put it in a class it's actually not very difficult to understand why this is so very roughly speaking any place like this room can be converted by crashing some shells of matter into it uh into a black hole that has the same surface area as this room and we know how much information the black hole contains so if information is not lost that means that the information in this room no matter what was in here had to be less to start with than the information of the black hole or at most equally much and so it's completely universal you don't have to know what we're made out of you don't have to know what the fundamental bits and pieces of physics are you already know how much information there is and so it's a deep relation between the two things that we don't know how to put together gravity and quantum mechanics quantum mechanics is about information gravity is about geometry and surfaces but is it is it true or is it uh a distortion to say and again for me for a moment here the idea of going to the black hole seems to confuse the issue because the the black hole is interesting because the way hawking described it information would be destroyed that produces the controversy which poses the question all right what is the relationship between information and all of the universes that's exactly right it's exactly right it was it was one of those questions where you know people were just asking an incredibly interesting question and as a consequence of resolving it stumbled upon something that was much more general and didn't really just hold in this particular context of the black hole in the end you can throw the black hole away because i think most of the people in this room you know the encounters with black holes are you know monthly at best um so so so let's just let's just say because of the black hole thought experiment uh controversy argument with hawking we have stumbled upon or discovered or now see that a fundamental feature of the universe is that a a two-dimensional space of information specifies everything in our universe well something like that initially it was to be clear how to apply this to the whole universe um again the context in which this was discovered was a very specific one where you're far away you throw some elephants in into a small region they form a black hole and it evaporates and you want to ask the question by looking at this hawking radiation that came out can i figure out if it was elephants or zebras that made the black hole now that was resolved i think by now pretty definitely we can look at this but our universe is nothing like that our universe is not like the like a black hole our universe is not um a place where you can go far away and study hawking radiation coming out and nevertheless it turned out to be true that that this was just the tip of an iceberg there's a completely universal relation between information and area of surfaces at first it seems like that can't possibly be true for example if you don't take the viewpoint of the person who waits for the hawking radiation to fizzle out of the black hole and then looks carefully at at the information that is in it suppose that i fell in with the elephants or with a star that was collapsing well that star has some information in it as it's collapsing to form a black hole that information can't disappear but we know from just solving the einstein's equations that the surface area of the star becomes smaller and smaller and smaller until it's zero at the very end when it's when it's when it hits the singularity inside a black hole so it seems clear that the amount of information of the star whatever it is at some point is going to become larger than this smaller and smaller and smaller surface area of the stars it gets more compressed deep inside the black hole so then does this mean that this was just some fluke it's something that applies to particular you know observers who live far outside the black hole and there's actually no general relation between information and surface areas well turns out no if you state the relation in just the right way then it's true even deep inside a black hole or in in regions of the universe that are very large and the way you have to state it is actually in a much more physical way instead of saying how much information do i have at this instant of time when my star is really small and has very small surface area how much information is there still inside the star you you have to ask well if i took a picture of that of that star at this time just before it got completely crunched into into a singular a place in space time if i took a picture of it how much of the star would i see and it turns out that you don't have enough time you're the light doesn't have enough time to traverse the whole star before everything gets crunched into the singularity and the game is over you have to actually calculate this you have to take my word for it right now but i'm taking your word for so much but the point is if you ask okay what can what can actual light rays see how much information can they see light rays that come out of the area in question and it makes absolutely no difference what area you pick anywhere in the universe any shape doesn't even have to be closed um what those light rays see is some piece of the star in this particular example and by some conspiratorial miracle it's always less information in that piece of the star than the surface area you started from it it's a much bigger conspiracy of which only the sort of tip of the iceberg was was was discovered in the context of it's a little bit like uh uncertainty in the sense that if you try to measure you're only going to get a piece of it but that doesn't affect the the the existence of all the information it's it's all there the fact that you can't get it or don't have a big enough camera is your own personal psychological problem it doesn't affect the universe at all well indeed if you if you wanted to ask how much information is there in the universe then again it's actually very useful that information is sort of encoded on on regions that are seen by light rays you could just ask well what is in our past what is in the region from which light could have reached us up until now and that that region is bounded by basically light rays that are just barely making it to your eyes right now and they've been traveling for billions of years since the beginning of the universe and those light rays well if you follow them back of course they come from a larger and larger region as you follow them back that's farther and farther away but at some point their surface area actually becomes very small again when when you follow them all the way back to the big bang because everything is small at the big bang the universe is basically contracting to a single point at that at that point and so there's a largest area which tells you how much information there is in the universe somewhere between the big bang and us that is spanned by these light rays so so we can say exactly what the maximum amount of information is it is the case on some level that the function of our senses i mean you know galileo looked at light rays and drove some conclusion about the universe are tiny sort of instances of the universe conveying in information something that's much bigger that you're now extrapolating to extreme states of the universe either in terms of the very beginning of time with the big bang or the sort of end of matter in a black hole that they're part of the same story a little bit well the interesting thing about the holographic principle i think i think all of us probably agree on this is that it's a statement that can be made in a situation where we think under we understand physics very well uh the the area that describes how much information there is in the universe that we see is not an area that lives somewhere very close to the big bang where we might not trust our equations the area that tells us how much information there is inside a black hole is not an area that's somehow close to the singularity inside the black hole which we don't understand as well as we would like to these are areas in regions of space time that are arbitrarily well understood they're completely harmless they're you know we einstein's theory of this is good harmless is always good i mean i still wouldn't jump into the black hole but right they are very you know well understood the whole statement takes place in a regime of physics that we completely understand but what we don't understand ultimately is why it is true it seems like a conspiracy every time you check it works out and and i think that by itself i think it was always a huge piece of support for the idea that information isn't lost all these miracles happen for information not to get lost it'd be funny if it was at the end but but you have to do it in a case i mean your sense of humor is not so i know yeah right well i love apocalypses like the next guy but uh um so uh herman what what is the counter argument here what i mean i've got sort of two questions one is what is the counter argument who persists with the idea that this holographic principle may be fun to talk about but in fact doesn't really help us uh or there's another explanation uh i wouldn't necessarily say that maybe that people have uh a counter-argument but right now you can state it as a principle because we have indications that it's there but again it's it's basically a from a from still from intuitive point of view it's absurd that this would be true uh because again if we want to describe what's going on for sure we're going to tell okay well something is happening here at a given time or something's happening there so essentially the information that you use to describe things for sure grows with the volume and indeed the equations that we're using uh to describe physics indeed have all those properties so right now we don't have a real uh real way of understanding how this is really true so we know we have no there's no evidence no we don't have a mathematical theory that precisely describes how it is we have strong evidence that it's true and i think i think so there were early times say in the early 90s uh where uh if you would and i think there was a conference in the early 90s where there was a vote okay how many people were actually believing that information was lost and then more than half of the hands went up and it was only a small group of uh people that were saying okay well we we don't believe that information is lost and that was only a couple of rubbish groups there was the yeah there was the rubbish group and then there was yeah okay right and now the rubbish group is bigger uh almost the whole room yeah if you call us the rubbish group well you were then you were then yeah we were called rubbish yeah yeah that's correct and um probably so how um i want to go back to this information i actually want you to go through those slides that i've seen before which i think are fascinating but uh let me ask you um is information up a particle in the sense that it's like matter is information akin to being like electrons protons quarks antimatter is it some sort of parallel phenomenon that goes along with the reality or is it something fundamentally different no actually i think it's about time that we start to disagree with each other and um no so i want to know um starting to get good because i want to bring in a notion which hasn't been put forward yet the question of dynamics you know when i first saw people windsurfing i loved also to go windsurfing so on one day i thought i'm a theoretical physicist i can work out how to stand on the board i have to hold the sale without falling over and i worked it all out and i stood on the board i could hand the sail and i didn't fall over and i went any direction i want except i only solved the static problem i didn't solve the problem what happens if a big wave comes and what what what you have to do if you want to make a sudden turn this i never saw so whenever that happens i fall over now here the problem is the same so far we've been discussing this static question what is information where is it and so on and you can discuss it at length but there's something else in physics the dynamical question how do things evolve in time and how do we phrase laws of nature and now we encounter a deep and fundamental problem which is the world looks to us three-dimensional if i make a disturbance here like i'm saying something or i'm shining a light the disturbance moves with the speed of light or slower to its environment and it never goes faster than speed of light from here to a point far away in the universe that is a fundamental three-dimensional property of the world as we know and it has been tested very very accurately in all branches of physics a very fundamental principle not only that disturbances move there's a certain maximum speed it also has causality that is whenever you cause some disturbance somewhere its effect never goes faster than the speed of light and it certainly doesn't go back in time now this principle we would like to keep and now holography is standing in our way it's not doing the thing we want if my friend landing here is right and information on the three-dimensional on the two-dimensional surface is completely scrambled how do you explain it if you make a disturbance here the disturbance doesn't spread faster than speed of light how would leah when she moves her arms uh in the hologram how come that the disturbances don't move faster than a given speed in his hologram there's still something basically wrong with the idea and that why would they have to move faster than the speed of light to uh to work that's relativity theory and relativity theory works extremely well we don't want to give that up too easily as a fundamental principle after all relativity was also a principle that went into steve hawkins derivation if you throw it away you saw you're throwing away black holes as well so life isn't that easy there's a problem here so how do we address that and then i'm coming back to quantum mechanics we say well we use quantum mechanics from the beginning until the end there's something not quite right about quantum mechanics and i've been thinking a lot last decades basically about there must be something underneath quantum mechanics some more basic mechanical system that explains why the world that we encounter today looks like quantum mechanical that could solve this problem because it could be that in a pre-quantum world the world is three-dimensional information gets lost all the time in fact a suspicion i have and i'm practically the only one in the universe today that has a suspicion that there's an underlying theory in which information gets lost to such an extent that if you have a bulk of material somewhere so much information gets lost that the only thing that you can retain is what sits on the surface and that is the reason why information-wise you have such a thing as a holographic principle the only amount of information that you can keep if you have a bucket of water is what sits on the edge of the bucket of water what happens inside will eventually get lost not according to quantum theory because it just realized all quantum theory preserves information but there may be a pre-quantum theory in which this information gets lost now is this it could be three-dimensional and then we might possibly find a resolution of this problem so is is pre-quantum theory something that happened before the big bang or is pre-quantum theory something that happens before you learn in the logical sense that there is something that some fundamental principle lying underneath so the principle of quantum mechanics i see saying we have molecules you have atoms we have things smaller than atoms but smaller than that are things which might not be quantum mechanical that is my premature explanation as to how to reconcile the idea that the three-dimensional world seems to be two-dimensional by holographic principle yet there is causality in the three-dimensional sense this is a problem that has not yet been properly addressed and i think something should be done about this if we don't yeah we'll never get to work if we don't right if you don't you'll forget homelessness you guys from times small distances well let's let's uh put that to leonard um is there the possibility of a a pre you know a more axiomatic kind of uh quantity all right but then some sort of more basic state than quantum mechanics the answer is i don't know the answer is i don't know what you're seeing here is an interesting thing first of all i would say it should be clear that this whole holographic story is the most radical thing that has happened to our understanding of space time matter since the invention of quantum mechanics and relativity it is really something very very different where is it going what is it going to explain how do we explain it well incidentally we all agree largely on what we've said until now and you'll find that in physics in general probably in science in general at any given time there are those things which have been made into established science that people agree on and that subset they will tend to agree on unless they're screwballs and outside the main mainstream of the community but that once you go past that once you go even just a little bit past what we really know you'll start finding it becoming a very very human subject a subject with uh let's put it this way good physicists are as variable as snowflakes every single one of them is different every single one of them has a different perspective and once you go past that point where we have confirmation where we do agree you're going to find that just about everybody has a different view of where it's going to go sure without that i can understand but let's focus on the radicalism for a moment because i think people can understand how relativity radically changed the newtonian view of reality in the sense that the straight lines in the newtonian world actually are curved in certain spaces and that curvature relates to the force of gravity in some way and so around stars space actually bends that's a radical notion it's probably only in the last 30 years that that's been internalized to be something that kind of everybody understands you can't really appreciate matrix movies like the matrix unless you sort of understand the sort of relativistic world how does this notion produce a radical change in in the way that we might see relativity i think it's still a work in progress and we don't know harad has his view i have my view herman has his view what's his name over there has his view and but i tell you if you go out of this it'll come to you but you go two blocks outside of this room there's a lot of people who have no view and a lot of people have no reason yeah absolutely no of you but my own view is not all that different than my colleague over here it's not that i think there's going to be some deterministic theory that's going to underlie quantum mechanics i think it is is going to inform how we think about quantum mechanics very deeply and it's going to change in an enormously big way the way that we think about quantum mechanics that i am sure of whether it will be the way that uh that raphael and i have proposed over the last couple of weeks or the way that uh hoofter has proposed for years uh herman has his ideas i think that remains to be seen and it is a work in progress i think there will be progress on it i think when we come back here maybe not next year but five years from now there will be more knowledge but it's very clear we're on the cutting edge of and on the cusp of i think a major paradigm shift in the way the world right all right that's great now uh uh how are we doing we're feeling pretty good about holographic principle and projection right right and we're feeling pretty good about how information is a much more complicated thing than maybe the the concept from our intuition right right okay good all right here's a question that's going to put you on the spot um but it relates to your issue of the each of you think differently the physicists are as different to snowflakes and hopefully they stick around longer than snowflakes if if i were to put a holographic principle t-shirt on each one of you that specified how each one of you represents a particular sense of what's going to happen what we're going to discover what aspect that represents your position what would your t-shirt say i believe in holographic principle and it's going to look like blank i i don't know i would like have something like i heart hp or something well i that's going to be on the back that the front is going to have to take you to quantum gravity on the back so your ticket to quantum gravity so i mean why do we call it a principle like you know i think the positive spin the most positive spin i can try to put on this and i am being optimistic when i say this is is um compare this to the equivalence principle the equivalence principle is something that einstein recognized you know a huge conspiracy in nature why do all objects fall at the same rate you know different particles with different charges do not do not get attracted to each other at the same rate but with gravity for some reason everything gets attracted in exactly the same way amazing conspiracy from the point of view of newtonian theory you just have to put it in by hand it doesn't contradict anything but it's it's just crazy it needs an explanation see elevates this observation to a universal principle you have to find a theory that makes this obvious to start with so for you that would have to be quantum gravity because what's involved here is both quantum theory and general relativity it would have to be a theory that knows about both so it clearly is a signpost maybe we need more signposts to fight the right find the right for you holographic principle is a suspect is a is a first step towards a a theory of quantum gravity that begins to explain what's so frustrating about gravity well then indeed what it what just said tells us why it's been so hard you have to explain where this holographic bound on information comes from while not destroying what we know about locality the fact that i get to know in this part of the room something independent independently of there i get to move particles around independently it seems like you don't have to know what's over there to do something here there seems to be a conflict here between holography and the way that physics has worked up until right on your t-shirt ramon what would it say uh i mentioned the movie the matrix probably something some image like these letters and and there's nemo what's his name the guy who he uh he goes and and he starts um uh uh flying uh with anti-gravity i think that's that's pretty good so let me let me explain why the matrix uh we talked about sort of things not being able to to move faster than the speed of light and i think the people that came up with the the name of the matrix actually had something pretty good in mind there because what is a matrix it's essentially something that relates something that's here with something that's completely somewhere else and um so i think indeed that sort of the the the future at least of this development will be that we start actually with information so information is going to be our starting point and space time is not something that we start with uh we we forget about what space is and what time and then somehow the information by thinking about how much information is what information is doing then the space time will what we call be emergent it will come out of just a bunch of zeros and ones and here's one one idea that i think actually i can put here just since no one's listening and i can just say what i want they're listening i guarantee you uh so so there's no non-disclosure yeah so so here's so we talked about information and one of the things by the way that information tends to do again it gets lost all the time actually that's that's this called the second law of thermodynamics uh the lost information we call it entropy entropy always increases chaos increases and that's that's a fact that's true in our universe and it's a fact that's true in other universes as well so it's a very fundamental fact of how things work and what's probably also true in other universes is that things indeed fall if you if you drop them they they'll go down and it seems that those two facts are very closely related the fact that information gets lost uh all the time and the fact that things fall so uh i think that that's lost is different from destroyed lost when i say lost indeed it's it's going to be the the known unknown right so it's got it the increase in the known unknowns uh that's responsible for for for for space-time for for curvature space-time from for gravity the fact that things i mean what you're suggesting is that you know when i forget something i'm instead of just having a kind of a pre-senility moment i'm actually participating in a grand march of our understanding of the universe right that's correct yeah that's correct that's i'm loving i'm glad i came tonight uh gerard what would be on your uh t-shirt or sign that would suggest uh where you fall on and i guess probably the pre-quantum theory uh uh uh the the proto quantum theory might be on your t-shirt that might be the direction that you would be headed yes i will continue to ask nasty questions and say well you know you could have this fancy beautiful idea but remember that there are fundamental principles on which the original idea was based that you're losing out of sight and so this was why i mentioned causality uh the fact of the author of cause and events that is to me a very primary law or rule of nature that everything that happens here has its origin in the past that's what we call causality there's a cause of everything happening in this world that's how laws of nature are being formulated if you don't have that you can friends go backward in time and you have circular situations in time like you can go and kill your grandfather if you could move back in time that's clearly nonsense then you get circular arguments and you get chaos in the laws of nature themselves nature cannot solve its own equations that cannot be right we must have the principle of causality now this is somewhat at odds with this holographic principle i don't say it's entirely at odds but there's some tension here and what we want the whole reason why we are doing this why we're making this all these considerations is that we want to have a better model a better theory of what happens in the physical world we want to explain why the particles that you have today behave as we have seen and studied them today and there are many things you understand the many things you don't understand we have the standard model of elementary particles is a beautiful rigid scheme of all particles known today and it is mindfully precisely described by this standard model but there are mysteries in it which we want to understand and solve as well we are very ambitious we've made a marvelous theory of nature it's not good enough we still know there are blank spots in this theory that we want to fill in and this is why we're doing this we want to find new basic principles to improve our understanding of nature that's what all of this is about but the only way to understand or to improve our understanding of nature is we're asking all sorts of nasty questions questions our colleagues you rather not ask because there's so confusing well let's ask confusing questions anyway and see if you can come close to answering them any question that has an unexpected answer might bring us help us go forward and make an improved theory of the world that we live in that's what the real reason is for this exercise and i love this idea that possibly one way of thinking about causality and causality and the forward branch of time is as a information state as a as a sort of a a an understanding of the march of time as a a set of information that that you know one event leads to another event that's a vision that the universe is very much like an information processing machine just like your laptop or any other computer i like to view nature as a gigantically big computer that has information going into it and information comes out processed the processors they are the laws of nature the laws of nature says say that something happens some particular configuration goes in it's being rearranged and other combinations of data goes out that's how in physics traditionally we consider the process of particles touching and scattering against each other but two parties come like this they hit each other and they go off in the other direction that's because scattering and scattering process is an important way of describing the laws of nature what happens when two particles meet how do they separate do they break each other up do new particles form and so on and so forth so that's a fundamental way of phrasing laws of nature and that's what we want to understand can i ask you a question on this so so again if we talk about pre-quantum mechanics in quantum mechanics we know that at least one of the foundations of physics quantum mechanics has thrown it out of the window because one of the foundations of physics was if you know what's happening at a certain moment what the situation is at a certain time that one step later in time you would know what happens next but in quantum mechanics you can have two completely identical situations that a snap snap second later would give you two different outcomes that as well uh is that a principle that you accept or is your pre-quantum mechanics going to be of the title i accept entirely within the language of quantum mechanics but my suspicion is it's only a suspicion is that quantum mechanics cannot be the entire story there is something else happening and you're exactly asking the right question which is how come that if two particles reach each other and in the beginning they were identically the same and then suddenly they must do either this or they might do that or other particles might come out and all that is described by a matrix in fact in the quantum mechanical sense and but nobody knows how to predict what which of the possibilities is actually being realized that i think is a weak spot in our present understanding of quantum mechanics why is it impossible to predict in advance what will happen and there are numerous examples of this which are typical for quantum mechanics and physicists today have learned to ignore the problem to say we solve everything except we cannot always predict exactly what happens what we can say is that you need all the possibilities to compute what happens after that so that that's a mysterious feature of quantum mechanics and you want to embrace the mystery rather than ignore they exactly a little bit okay they've learned to do that because it is so successful it works tremendously well in understanding nature but it cannot to my taste it cannot be the entire story there's something else happening but at a different level of nature and my belief is the quant the planck scale is so much different from the scale of elementary particles that that could well be the level at which things are fundamentally different there you have if two things scatter they have only one choice to make not many very many that's the idea of determinism which people laugh at when i mention this idea people just manage to keep the smile away from their faces but otherwise you know as soon as i'm away i'm sure they're laughing about this idea of determinism well we can check some of the comments on the website later crazy but it's an old idea it's an old idea and it has proven wrong about a million times and but always they prove wrong because they're making very conservative assumptions and i don't believe those assumptions so i still think there's a way to question it very very difficult and it's a dispute going on for years and years and years starting all the way back with einstein news board all historians of science say einstein was wrong boy was right and i believe it's not true that's right well nasty nasty questions on the t-shirt nasty questions does fit on a teacher that's good leonard yours well just with respect to what um gerard says um i wouldn't bet against what he says on the other hand i just can't see how it will work but uh it's those kind of conflicts which get us where we want to go but my t-shirt well if you can't say the brooklyn dodger dodgers i guess i would like it to say the uv-ir connection now the reason i think that i say that is to give me an opportunity to explain something else give me five more minutes to explain something else which we will probably all agree about but which is a very bizarre property of what the of nature at least if the ideas we're talking about are correct uh it's it's not totally surprising that as you try to get a more and more and more accurate description of nature it looks more and more scrambled uh to get the best description of nature you have to account for all the degrees of freedom and sometimes it's just too much of a good thing i mean you know we know what happens when you try to have too much information too much information can lead to a situation where you're just completely confused because you just flooded with it it would be like you you t you mount a camera over the city of new york you put a light on everybody's head and over time you specify where they go it looks great for about 10 minutes and then well even even even taking a sharp snapshot at an instant too much information will flood you you know we know the cia gets so much information that it doesn't know what to do with and uh it's just got too much it's not too surprising you know you'd learn much much less about a body of water with a surface and so forth if you if i gave you a description with a table which just gave you the position and the velocity of every single molecule that would be an impossible thing to deal with so it's not totally couldn't windsurf on that information it's not totally surprising that the better you try to do in a better description the more scrambled it's going to look what's also new here is something very different than in the other situations in the other situations getting more and more information usually means more and more detail about smaller and smaller distances what i think we now know is that at some point that's going to reverse itself and what's going to happen is when you look in more and more detail things will start to look fuzzed out over bigger and bigger distances and so in the end the most perfect the most accurate description and the most scrambled description of something is going to be stretched out over the whole uh boundary of space that's called the uv-ir connection and what it means uv stands for ultraviolet and it really just means small distances ir stands for infrared and it means very big distances and we're getting a little bit i don't say confused i'm not sure it's confused but something is happening where as you start to look at a system and more and more and more precision what you might have thought that you're going to see more and more tiny short distance small distance precision it's going to start getting fuzzed out and fuzzed out and fuzzed out until it's stretched across the whole uh and that's not simply a feature of the camera you're using or the resolution that is a fundamental feature fundamental aspect of physics that the better you try to look and the more detail you try to see with the more it's going to be stretched out and fuzzed out over bigger and bigger distances yeah i want to follow up on that so at least one of the reasons why we're now more and more convinced that the holographic principle is really something that works is constantly from string theory which is my field and what happens there is precisely if you go through this this step of looking more and more detailed at what happens in short and shorter distances you might be interested in say what happens inside of our nucleus inside of our atoms and there's a nucleus and their quarks and they're smaller and smaller particles and suppose again that for a moment you you would want to forget about gravity but you start looking more carefully at what we're made of and then then because of this this idea that that when you start looking at smaller and smaller scales or at least it's smaller smaller distances suddenly you discover that there's actually something new happening and that's something new at least in terms of your equations you recognize it as gravity so the amazing thing is that while you're actually interested in just looking at the smallest constituents of matter without putting gravity in gravity comes out as something that's sort of inevitable and and to me there's an enormously deep lesson there uh that that gravity is something that that you cannot do without clearly we cannot do without we would not be sitting here would be floating in this but although gravity for me and stephen hawking is kind of a pain in the ass sometimes but uh which is why we love to forget about it but but but gravity is is inevitable but it's also a door to this something else it's a door to this something else but but you can get it out of something where you don't put it in uh so it's not it's not the starting point it's it's the output all right well we're gonna we're gonna have to wrap this up um let's just pull the audience uh how many of you clap if you think that we are just a projection clap clap if you think that we are actually real and and clap if you don't care you know i would have thought that would have gotten the biggest clap of all uh this far downtown um first of all i want to thank i want to thank our panel um you've certainly taken us on a great journey tonight there's obviously so much to think about i would encourage if you're uh interested in these ideas tomorrow we're actually doing a rebooting the universe another exploration of the universe as an information space at a panel here i also encourage you uh on sunday in the uh kimmel space upstairs uh mary simon and the keystone dancers are gonna be doing a fabulous sort of uh mapping of uh of dance onto the messier calendar messier catalog and objects in the universe so this idea of one information space mapping onto another is a theme here at the world science festival i encourage you to explore all of it thank you so much for coming coming and thanks to the panel

Channel: World Science Festival

Views: 2,046,471

Rating: 4.6719341 out of 5

Keywords: A Thin Sheet of Reality, The Universe as a Hologram, reality, are we living in a hologram, reality is a projection, black holes, breakthrough in string theory, universe is a giant computer, Holographic principal, quantum mechanics, Gerard ’t Hooft, Leonard Susskind, Raphael Bousso, Herman Verlinde, John Hockenberry, New York, world, science, festival, NYC, New York City, full program, 2011, Big Ideas Series

Id: HnETCBOlzJs

Length: 90min 10sec (5410 seconds)

Published: Mon Dec 29 2014

Reddit Comments

[u/GodIsACoder]

SS: What we touch. What we smell. What we feel. They’re all part of our reality. But what if life as we know it reflects only one side of the full story? Some of the world’s leading physicists think that this may be the case. They believe that our reality is a projection—sort of like a hologram—of laws and processes that exist on a thin surface surrounding us at the edge of the universe. Although the notion seems outlandish, it’s a long-standing theory that initially emerged years ago from scientists studying black holes; recently, a breakthrough in string theory propelled the idea into the mainstream of physics. What took place was an intriguing discussion on the cutting-edge results that may just change the way we view reality.

[u/PineConeGreen]

String theory is a religion for NPCs.

The universe is a computer based construct and that is obvious.