Brian Greene and Harold Varmus: World Science U Q+A Session

[Music] [Music] hey everyone welcome it's been a little while since we've had one of these sessions so i'm glad to see all of you and as you may know today we're going to do one of the sessions in which we'll have some q a in fact we're going to start with some of the q a in fact i'm going to start with some thoughts about the recent announcement just the other day just a couple days ago the nobel prize in physics and then we're going to have a conversation with harold varmus who i'm sure you know the name if you don't you should know the name nobel laureate 1989 in physiology or medicine who has a deep understanding of science a deep understanding of the politics of science really brings a fantastic perspective on questions that really matter to the future of the world right the things that are pressing down upon us right now so harold will join us in roughly an hour maybe a little less of that sort so definitely stick around for that but let me begin today's session by just making reference to the announcement that i'm sure you guys already saw about the nobel prize in physics for 2020 being awarded to a real you know a champion group of thinkers and researchers roger penrose from oxford who is almost a cult figure to to people like yourselves to me too actually right i mean penrose when i was growing up i mean i even knew that name it was just this individual who could use the power of mathematics to gain deep insight into the nature of space and time gravity black holes in fact when i was a graduate student i was a grad student at oxford and i went to oxford to study with roger penrose and it turned out that the things that roger happened to be interested in that little window of time when i was at oxford were things that i wasn't all that excited about and i switched over from roger penrose to the particle physics group at oxford led by graham ross and there is where i got involved in string theory and extra dimensions and things of that sort which in the end overlaps quite tightly with the arena of research in which roger penrose has made his mark but the nobel prize was awarded to roger half the prize that is was awarded for the so-called the the the singularity theorem results where he showed that the prediction of black holes which you all know goes back to carl schwarzschild back in 1916. right schwarzschild writes the first paper having the first analytical exact solution to the einstein field equations even einstein himself did not find an exact solution to his own equation schwarzschild does and as as the analysis as soursop does his analysis of the solution it's the solution for a spherical mass embedded in otherwise empty space and schwarzschild solution shows that if that mass is crushed down to a sufficiently small size then the warpage in space-time will be so incredibly severe that nothing will be able to escape and this is what we ultimately call black holes that name actually didn't come until excuse me a bit later on the name black holes as some of you may know maybe you've heard me say it before the name black hole was coined on um 112 street and broadway in manhattan new york city this is not a joke this is true that is the location of the it was location of the goddard institute for space studies i actually worked for that institute when i was in high school doing research on satellite imagery and how you can use satellites to understand various detailed features of the topography and erosion of sites on planet earth but anyway there was a talk at the goddard institute for space studies in 1968 i think it might have been john wheeler has given the talk and an audience member responding to what wheeler was talking about says oh the thing you're talking about it's like a black hole a black hole in space and wheeler likes that name he had a good feel for marketing in physics and he starts to promote that name and that's where the name black hole comes from and roger's work showed that schwarzschild's solution the black hole solution doesn't require the highly idealized and therefore perhaps unrealizable conditions that schwarzschild was invoking to have a black hole created roger showed they're a fairly general phenomenon of the general theory of relativity under very mild assumptions you will get black holes as the result of certain physical circumstances and that really made it clear that black holes were a generic endemic feature of the general theory of relativity the others who shared their prize ronald gertz and andrea guezz they were the first individuals to perfect means for observing with great precision the center of the milky way galaxy and in those observations they established that there has to be an enormously massive black hole at the center of our galaxy a black hole weighing in the order four million times the mass of the sun how they do that well you look at stellar orbits i don't know if we have any visuals we could bring up if we're able to that would be amazing but you have stellar orbits and you watch these stars going around the center of the milky way galaxy and they are whipped around at such incredibly high speeds you know tens of millions of miles an hour and when you look at the center and try to figure out what is it that has enough gravitational pull to whip those stars around in that manner you find that whatever it is it has to be incredibly massive to give rise to the gravitational pull whose influence you're witnessing in those measurements of the stellar orbits and you realize that that incredible mass must be in a very small region because you can measure the size within which this source of gravity resides and so when you put those two numbers together the huge mass and the small size you come to the conclusion that there has to be a black hole there of course we've gone even further today the event horizon telescope has taken a direct image using radio telescopes of the black hole at the center of m87 you know 55 million light years away but the black hole i'm referring to now that these astronomers won the nobel prize for is you know whatever fifty thousand light years away at the center of our galaxy and in particular andrea guess i was actually just talking to her the other day i'm not trying to name drop here but yes i was talking to the new nibble laureate andrea guezz just the other day about a celebration that she's going to be having for the 25th anniversary of the project that led to ultimately the nobel prize i was speaking to her she didn't know she was about to win the nobel prize or maybe she had an inkling of i don't know but she's only the fourth woman fourth woman to win the nobel prize in physics so that is a wonderful well-deserved achievement and i couldn't be more excited for her and excited for all three of these great scientists for receiving this award okay so that that's an exciting moment in the development of physics that happened this week with that let me now turn to some of the questions that you have and again the conversation that i'll be having with harold varmus we're going to probably begin that sometime near one o'clock if you're if your questions start to run out of steam it's never happened actually but if your questions run out of steam maybe maybe i'll bring harold in to re-energize the conversation sooner but uh have a feeling that you will not have a paucity of of questions okay let's take a look at what we have here um martin topinka asks professor brian could you explain to me why a uniform soup of particles at the big bang has very low entropy it's a good question while structures have higher entropy why does gravity act this way and what it is how does gravity and entropy interact with one another so martin is a very that's a good question because when we learn about entropy as students and i suspect that many on this chat many on this video discussion have had some undergraduate experience in physics but in a standard undergraduate course in thermodynamics or statistical mechanics we learned about entropy and we are told entropy is a count of the number of rearrangements of the microscopic ingredients that leave a system's macroscopic features unchanged and we're told that in the form of equations we're asked to look at the sum over all states that are compatible all microstates that are compatible with the macro quantum state of a system right all available quantum states i should say all available quantum states that are consistent with the macroscopic features of that of that system okay so that's what it is now when we start to look at examples the primary examples of high entropy configurations are configurations where the particles are all uniformly dispersed when we look at gas in a box we learn that the high entropy configuration is when the gas is uniformly spread throughout the box and we learned that the low entropy configuration is say when the gas is all clustered in one tiny little corner and we learned the second law of thermodynamics which tells us that the low entropy configuration of gas all clustered in the corner will typically disperse outward toward the state of higher entropy entropy tends to increase so the high energy state is the one with the particles all uniformly dispersed through the box now that's curious because as martin is pointing out when we talk about the big bang we talk about the big bang having low entropy you've probably heard me say this in previous of our gatherings we always say that it's the low entropy ordered configuration of the big bang which allows for entropy to increase over time which allows for other structures ultimately to arise if the big bang itself was totally disordered high entropy there'd be no potential for the universe to then evolve toward higher entropy if it already had the maximal entropy to begin with so we'd be we believe that the big bang is a state of low entropy high order and yet as martin is pointing out when we talk about the big bang we talk about particles that are uniformly dispersed throughout space or energy that's uniformly dispersed throughout space namely we're talking about a low entropy configuration but the state of that seems to resonate much more closely with the high entropy configuration that we learn about as undergraduates in physics so what gives what's going on here as martin is rightly pointing out gravity is the essential new player you see when we learn about entropy as undergraduates or if you've yet to do so when you learn about entropy as an undergraduate there will likely be no mention of gravity whatsoever when we first learn about entropy we learn about it in a context in which gravity is not a dominant player and that kind of makes sense right the gas in this room the air in this room right now is it affected by gravity sure but not that much right because the particles the individual molecules are so light that they get buffeted to and fro by other forces thermal forces agitation electromagnetic interactions and those are just much stronger than the influence of gravity so we typically as a first approximation just ignore gravity in everyday circumstances but at the big bang you can't do that at the big bang the density of matter and energy is so high that the gravity is so strong that you cannot ignore gravity and when gravity comes into the story the discussion of entropy becomes a little more subtle what we learn is that because gravity is this universally attractive force it can take what appears to be a high entropy configuration in the absence of gravity uniformly spread out particles and it can drive it to yet higher entropy configurations by causing some of those particles to fall together into structures like stars and planets and in the process of crushing those particles together gravity causes the system to heat up and therefore emit heat light other particles to the wider environment and so we get a highly non-uniform highly non-homogeneous configuration when gravity is strong enough when there's enough matter for gravity to be the dominant force because you get clumpy things here and then spread out particles there and that's the dynamic that we believe allowed structure in the universe to form you and me in stars and planets galaxies we are the beneficiaries of that uniform configuration in the early universe that then through the action of gravity clumped up into stars and planets and on certain of those planets smaller clumps formed and some of those clumps grew limbs and some of those clumps with limbs and brains began to walk around think about things and come up with the explanation that i just gave you so that's the the basic answer to martin's question about entropy and gravity okay going back to the the chat here if you have a question just put it in the chat um abbay kumar please explain singularities by i wish i could explain singularities i can explain some singularities and i can explain the generic the general idea of what a singularity is but there are many singularities that we have yet to fully understand and one of the most pivotal is the one at the center of a black hole the very topic that was this the focus of work that won the nobel prize so anyway what is a singularity a singularity is a euphemism it's a euphemism for we don't know what the heck is going on that's all that it is right now more specifically we typically talk about singularities in the general theory of relativity although not exclusively and in the general theory of relativity there are certain mathematical solutions to einstein's equations where the curvature of space time blows up it soars toward infinity it's a curvature that approaches one divided by a number that itself approaches zero so the curvature approaches one divided by zero which of course is infinite put one divided by zero in a calculator it says error or infinity or something like that so that's what a singularity is now why do we call them out we call them out because they're meaningless they're mathematically meaningless infinity is not just a big number infinity is a number that in certain contexts we understand when we talk about the natural numbers going up to infinity yeah we sort of understand that well when we talk about the real numbers going to infinity we pretty much have that under control but when we talk about a curvature of a space going to infinity that's like having infinitely curved part of space a kink in it or a location where it no longer looks like a smooth environment which is what general relativity requires for physics to make sense so a singularity in the general theory of relativity is a diagnostic it's a mathematical tool that assures us that something deep is wrong so what we try to do is cure singularities we try to make sense of them and for instance some of the work that i've done some of the most fun work that i've done was going beyond the general theory of relativity into string theory that combines general relativity and quantum mechanics and in that setting we found that certain singularities that einstein's theory could not cope with the math of string theory could cope with in other words the infinity of general relativity was tamed into a finite value a finite number and that is generally what we view as a success story where a new theory goes beyond a previous theory and allows you to address things that the previous theory was impotent to address couldn't address at all but when it comes to more exotic singularities than the ones that we have been so far able to handle like the singularity at the center of a black hole or the singularity of the big bang nobody has really convincingly figured out how to resolve those singularities and so those are open questions what truly happens at the center of a black hole what truly happened at the moment of the big bang we'd like to get to a point where we don't just shrug and that's the goal of a lot of the cutting edge research that's going on today all right what do we all have here why does time only move in one direction somebody asked that question but it scrolled by too quickly so i don't know who who asked that question so sorry about that i should keep my fingers off the chat every time i touch it it scrolls too fast um all right why i'll answer the question is why does time only go in one direction again we only have partial answers entropy which martin asked about earlier is part of that answer we believe that although the laws of physics are agnostic about past and future they treat past and future in exactly the same way completely symmetrically even though the equations don't care about what we humans call past and future entropy this measure of disorder does have a bias it does increase toward the future so if you anchor entropy at the beginning of time call that the big bang if it's anchored at a low value then entry people typically have a graph that just goes upward now and then it can come down it's not an iron-clad law of the second law of thermodynamics it's a tendency but that tendency is so overwhelming that indeed entropy toward the future goes up and so that's part of the answer but is it a full answer i don't consider it a full answer for instance i can't answer the question why was entropy low at the big bang now some would say maybe that's not even a question worth thinking about it's just an environmental detail an environmental quality of the universe and you just accept it for whatever reason it just happens to be that that's how the universe began but we physicists how we don't like answers like that we're not satisfied by answers that are just so stories we want to find deep fundamental principles and many people have worked on the question of why the early universe had low entropy i wrote a paper a couple years ago that i thought was kind of fun in the end i don't think it actually works but it goes back sorry to keep referring back to you martin but your question has proved to be pivotal and a lot of what i'm talking about right here but martin's question we were led to talk about gravity and entropy and noted that when gravity is part of the story entropy has different qualities so imagine that in the very early universe there was no gravity and so the uniformly distributed particles would have been the natural state of being it would have been the state of high entropy in the absence of gravity and then imagine that somehow a flip not a flip a switch is flipped not a flip is switched a switch is flipped a switch is flipped and gravity turns on and then when gravity turns on my answer to martin's question comes into play things start to clump together and you reach a yet higher entropy disordered non-homogeneous state of being and that could be an answer it turns out that in the flipping of the switch there are entropic considerations too that you need to think about that wind up suggesting strongly that the resolution that i just described is really assuming the answer i don't know if there's some version of that story that could work but suffice to say people still think deeply about this question and i don't know the answer to it okay um let's see uh yeah back to a black hole since that seems to be a good topic for this nobel prize announcement week so kuchal asks what is inside a black hole what is it actually and i love the questions that are coming today they also make me feel a little less than sage like because many of these questions i cannot give you the full answer to but i can at least give you the state of play the state of the art so in einstein's general theory of relativity the inside of a black hole nothing particularly special so by inside i assume you mean inside the so-called event horizon of a black hole now in einstein's theory the event horizon is not some [Music] unusual place in the sense of there's something measurably different about being at the event horizon you and i could just now have crossed over the event horizon of a really large black hole and we would not have known it that could be what's going on we could right now be heading toward doom heading toward the center of that black hole where we will be crushed out of existence and we would not have known that we crossed over the edge of that black hole there's no sign post in space that says warning event horizon beyond this point it doesn't work that way the event horizon is an absolutely ordinary prosaic location in space from the perspective of someone who is passing by that location and that hints at the answer to your question because if the event horizon isn't some special sign posted location then when you cross over the event horizon the space that you encounter will pretty much be like the space that you were just passing through so the inside of a black hole inside the event horizon looks pretty much like the outside of an event rise and it's just empty space and you only really notice something unusual happening when you get closer and closer and closer to the center of the black hole where the tidal forces that is the strength of gravity on your feet if you're following feet first versus the strength of gravity on your head will be much stronger on your feet than on your head so your body will be under tension tidal force tension your feet will be pulled downward toward the center of the black hole with a greater force than your head which is a little further away from the center and you will be what we call spaghettified spaghettified that's a technical term of art which says that you will be stretched more and more to look like a piece of spaghetti and ultimately you will be pulled apart into your constituent particles but in this classical description the inside of the black hole other than the uncomfortable nature of being near the center other than that it'll look like space pretty much anywhere else now when we have tried to put quantum mechanics in this story that classical description has undergone various proposed revisions and we're not sure which proposed revision is necessarily right or if any of them my my friend samir mather wonderful physicist at ohio state university we were postdocs together in the early days back at back at harvard in the 1980s or something and he has proposed that black holes are actually big entangled balls of strength and that's a very different picture of a black hole he's saying that we have long been confused by the pure classical einstein description of black holes and he says that there may not even be an event horizon he thinks a black hole is sort of more like a star it's got stuff in it like a star and the stuff is this big and tangled ball of strings so he calls these fuzz balls so samir suggests that black holes should be replaced by fuzzy things called fuzz balls others have suggested that the event horizon of a black hole may be a location of extreme temperature this is called the firewall picture that emerged from a paper whose authors are usually referred to with the acronym amps the p in there is joe polczynski who tragically passed away not that long ago which is a enormous blow to physics enormous blow to everybody who cared deeply about him but in that paper joe and his collaborators realize that there's a tension between quantum entanglement and black hole physics and one resolution to that tension they found is to imagine that the event horizon of a black hole is a real place that has a high temperature so that anything that gets too close to the black hole is incinerated by that heat and indeed there may not be any space on the other side of the firewall the firewall could be the end of space in that region and then the answer to the question that was asked would be what's inside the black hole what's it like the answer would be there isn't an inside to a black hole and that would be another possible answer so this is a a completely open question and a fruitful area of research and one that maybe some of the younger members of the discussion we're having will one day have impact on that kind of question okay moreno san guanini asks will primordial black holes ever be detected and i got to tell you guys thank you for asking all these black hole questions it feels so relevant to this week but again feel free to ask anything you want but it's kind of nice so will primordial black holes ever be detected so first off what is a primordial black hole primordial black hole is a black hole that would have formed right around the big bang so often when we think about black holes stellar mass black holes a black hole with a mass of whatever 10 times the mass of the sun we imagine that there's a star maybe it's a red giant star and we envision that at some point it uses up its nuclear fuel that's important because it's the nuclear burning in the core of a red giant that creates the outward flowing pressure that supports the star against implosion against its incredible heft it's incredible weight when the star uses up its nuclear fuel that outward pushing pressure goes away and the star implodes in on itself it gets hotter and more dense at the core ultimately setting off an explosion that ripples through the star blows off the surface supernova explosion and what remains is a dense core that has no capacity to support its own weight at all so it collapses in on itself and creates a black hole so that's the procedure by which we believe that many black holes in the universe form primordial black holes would not form in that manner because there weren't any stars there weren't any supernova there weren't that there weren't those kind of clumps of matter at that point instead the idea is that clumps of matter could just immediately come together and collapse directly into a black hole and these primordial black holes the thought is might still exist now here's the issue black holes evaporate when you take quantum mechanics into account so this is something that stephen hawking taught us in 1974 that even though black holes are completely black according to einstein's vision einstein's equations i should really just say einstein's equation because einstein didn't actually believe that black holes would be real that's a separate story but einstein's math says that nothing gets out of a black hole but stephen hawking showed that when you include quantum physics which einstein's math does not include stuff can get out of a black hole so if a black hole is sufficiently small then as it radiates it'll just evaporate all its heft we don't know exactly what would be left at the end but we suspect that the black hole itself would be gone so if all primordial black holes have evaporated finally to the question that was asked by moreno san guanini like to say that name then if they've all evaporated they won't be around to be detected if any have persisted and there are ways that they might have persisted then yeah in principle one day we might detect a primordial black hole which would be uh enormously exciting enormously exciting okay uh session asked please ask the questions one by one i i can't do that because they're scrolling by maybe there's a way in which i could you're right it would be nicer i guess to have first come first served on the questions but we'll have to figure out a way of doing that i can't do that easily right now um let's see so m5 m5 says i just expected in the first step you would interview one of the nobel laureates in physics professor guez professor panos oh come on m5 there is an ample opportunity for us to have conversations with all sorts of thinkers and at some point we will have uh the newly minted nobel laureates in physics but if uh as harold no doubt will tell us in the next part of our discussion once the announcement is made life as a noble as a new noble lord is incredibly hectic so i'd rather have a conversation with them when things settle down just a little bit okay what else do we got here uh upgrade says if nothing can move faster than light how does anything go into a black hole upgrade i'm not exactly sure i understand the question because if something goes into a black hole it can fall in at whatever speed it likes it doesn't have to go faster than the speed of light so it's more the reverse story in fact let me tell you that there's an interesting analogy that i sometimes tell my students when i'm teaching about black hole physics which is you can liken falling over the edge of a black hole to falling over the edge of a waterfall what do i mean by that well imagine you're in a boat right and there's a there's a big waterfall right over there and you're like well i i really don't want to fall over that waterfall what do you do is you turn your boat and you start to paddle upstream and you hope that you can paddle faster than the water is flowing because if you can't paddle faster than the water is flowing you're doomed right you're going to be dragged to the edge you're going to fall over the waterfall now what's the analogy with black holes there is a real sense this is not cartoon physics this is a real sense in which you can describe a black hole the edge of a black hole as a region where space itself is falling over the edge space itself is flowing over the edge of the black hole and indeed at the edge the speed of space is equal to the speed of light think about that why is that important well if you happen to find yourself at the edge of a black hole and you don't want to fall in you're kind of in trouble right because you can't go faster than the speed of light nothing can no material object can so if space itself is flowing at a speed equal to the speed of light you are doomed and that's why you are doomed if you get right to the edge of a black hole if you're outside the edge then the speed of space is less than the speed of light and therefore in principle you can get away in principle you can turn on your rocket engines and paddle upstream as the person in the boat would do with the waterfall but once you get to the edge of the black hole can't go faster than the speed of light space itself is flowing over the edge at a speed equal to the speed of light and that is one way of thinking about why you cannot get away why you cannot get away okay all right couple more before we turn to uh the main event for which i am the warm-up here today uh vinod asks is there anything faster than light and the answer to that question vinod is yes in a sense so so you should bear in mind that even in einstein's special theory of relativity the precursor to the general theory of relativity that einstein wrote down in 1905 in that theory the only prescription is that no material object can go through space at a speed greater than the speed of light and it's important to hear the first half of that sentence because just to give you an example when i say that nothing can go through space at a speed faster than the speed of light that for instance does not restrict the speed of spatial expansion to be less than the speed of light so if you have two galaxies in space right and if space itself is swelling and thereby dragging the galaxies apart like poppy seeds and a muffin that's expanding the poppy seeds are dragged apart similarly if the galaxies are being dragged apart by the swelling of space there is nothing that says that the speed of recession of those galaxies needs to be less than the speed of light the galaxies are not moving through space the galaxies in a sense are stitched into the fabric of space and they're only moving because the fabric of space itself is swelling and there's nothing in einstein's declaration that restricts the speed of spatial swelling the speed of spatial expansion and bleed and and we do believe that and our cosmological mathematical theories support this that objects can move apart faster than the speed of light because of the expansion of space so the answer to your question the note is yes in that sense raghav asked why does string theory stop with ten dimensions why not more or less than ten and first off i should say that just to be clear the most modern incarnation of string theory often given the name m theory involves 10 dimensions of space and one of time so 11 11 does come into the story so right there it's bigger than 10 if you were referring to space time but there are what are known as non-critical string theories in which it's a little subtle but in a time dependent scenario where a certain field called the diletton field if it changes in time in a particular way then the math does allow the number of dimensions to differ from the critical value that you make reference to so there are versions of string theory that i think fit well into an affirmative version of your question as opposed to the negative version that in those contexts you can have different numbers of dimensions uh nervisa says i'm taking my lunch time to listen to this is that crazy i'll let us i'll let others weigh in on the state of sanity of somebody who would waste their lunch thinking about space time matter black holes energy the universe why would anybody want to spend their precious time thinking about things of that sort well as well you can guess from someone who has spent a lifetime thinking about these things there is a reason for doing so and i think everybody who's here understands those reasons quite well so enjoy your lunch and stay with us and hopefully your lunch break lasts long enough that you can stay with us for the conversation that i'll have with howard pharma starting about 10 or so minutes okay the vivec asks what about warp drive and you know there there is i look anyone who's watched star trek you know at least in the original version james t kirk talking about warp factor 5 which if i remember the conceit of the scriptwriters warp 5 meant 5 cubed times the speed of light and the rough idea if one tries to make sense of this is that if the speed of light truly is a speed limit to go from here to here if you were to go in this direction you're never going to go there fashion the speed of life but if you're able to bend the fabric of space taking that destination and bringing it effectively closer to your origin so that the new journey that you take is different shorter then you're going to get to that destination quicker than the speed of light and therefore effectively you would have traveled faster than the speed of light even though there would never be a moment when your actual speed would exceed that of light and that's sort of the vague idea that i think the scriptwriters had in mind scientifically there have been people who have written down mathematical versions of warp drive i i can never i should look it up because now i'm embarrassed but the there's a you know interesting physics paper by a physicist alcubierri i hope i'm not saying his name incorrectly someone can correct me in the chat who put some mathematics behind the idea of a warp drive and now has a warp drive named after him whether you can ever realize this general relativity version of warp drive in the real world is certainly an open question but it is at least interesting that similar ideas to the ones that were introduced in a completely fantasy world science fiction world of star trek is something that in the physics world people have um thought about so yes uh has has written down the spelling of al kubiari but i don't know if i'm pronouncing it correctly so what i really need is someone to give me the phonetics i know how it's spelled i just need the phonetics uh mark asks me if i did i read the book that i sent to your secretary in the u.s called path to life i've not mar i've not read it mark i'm sorry i didn't even know that it came in and that should not be taken personally a lot of a lot of things come in that i just don't have time to look at everything but um now that you mention it i will remember to um ask uh ask her and uh we'll take a look so maybe by next time i will have had a chance to take a look um what do we got here 12 46 let's just do a few more minutes before we move on to the main the main event um chevouch how many dimensions can a black hole have and that's a good question because when when schwarzschild wrote down the black hole solution that i mentioned back in 1916 he was imagining three dimensions of space in one of time and you know for the most part that's where a lot of the research on black holes have taken place but with theories of extra dimensions like kaluza klein theory and string theory and various super symmetric particle physics theories people have written down black hole solutions in a whole host of different dimensions so black holes are not restricted to three dimensions in fact in higher dimensions people have studied all sorts of black objects that are called black brains b-r-a-n-e-s and black brains are objects who have various numbers of extended dimensions but have the property that if you get too close you can't pull away so black holes are a very general phenomenon they're not limited to three dimensions of space and they're not limited to the form that we usually have in mind you know this spherical event horizon around a singularity at the center that is a good image to have in mind but it's not the only image for the form that black holes can take oopal what is the heat death of the universe so the heat death of the universe is a distant time when going back to martin's question at the beginning where we imagine that the low entropy starting point of the universe entropy has grown and grown and grown over time some orderly structures have formed because of gravity as i mentioned crushing particles together but in the far future we do imagine that ultimately entropy wins out completely and everything disintegrates into a bath of particles that just waft through an ever larger and ever colder universe so it's kind of weird we call it the heat death because we're talking about entropy and thermodynamics but we aren't imagining that it's very hot the heat depth is very cold the heat death is when everything has just thermalized in the sense that everything comes to pretty much the same very low temperature uniformly throughout space and then the idea is not much happens from that point forward it's not that nothing can happen and that's an interesting footnote to that answer and again i'm not as you know from these previous sessions i'm not into advertising things here but if you are interested in the heat death and the various possible fates that life and mind and the universe might have check out my book get it from the library you don't have to pay for it find a bootleg pdf copy online they do exist unfortunately but they do exist and uh and you can read especially chapters um uh 9 10 and 11 really turn from today and take you right into the future with the heat death being one of the possible fates that our universe faces all right um does friction exist in space shanti asks and yeah it does not not exactly in the forum that you have in mind i mean sure there are say a planet moves through space yeah it can brush up against the microwave background radiation in principle there's a little bit of friction there but the friction that i have in mind is of a different sort it's a friction which answers the following question you all have gone to the science museum when you've done that little demonstration take a quarter or a nickel or something you put it into a funnel shape trajectory and it rolls around around and real fast and it goes right down through the funnel and that demonstration has led many to ask me about look in the general theory of relativity the sun kind of warps the space like the funnel in the science museum and we always picture the planets sort of rolling around this funnel-like shape why don't the planets like a quarter or somebody from out of the country a coin why don't the planets like coins spiral into the center and the answer is planets do spiral into the center why do they do that well the coin does it because of friction that's what the relevance to shanti's question is you know there's friction with a coin you hear it right you hear the coin rolling so energy being dissipated from the coin into sound waves among other things as well when planets are in orbit around say the sun they jostle the fabric of space and send out gravitational waves gravitational radiation not not sound radiation but gravitational radiation and that carries away energy just like the sound waves carry away energy from the coin and so if you wait long enough a planet like the earth will spiral into its star if it isn't destroyed before that by some other process and for the sun you can calculate how long it will take the earth to spiral in and the answer is about 10 to the 20 10 to the 23 years so you know it's a long time right now we're only 10 to the 10 years since the big bang and we're talking about 10 to the say 20 years before the earth will spiral into the sun like a coin into the funnel but in principle it will do that and therefore you can think of that as a kind of friction in space woody tells me to turn on super chat i don't know what super chat is is there a thing called super chat this thing called live chat maybe that's what i should have had on i had topchat on i never really know the difference between those two but i've now taken your suggestion woody and i've got live chat on for whatever it is worth um uh akash says what do you think about zeno's paradox and asks that question with more question marks than anyone has previously used and therefore you win the award akash kumar for the greatest number of question marks what do i think about zeno's paradox it's a nice paradox how do you solve this paradox well it's not that hard to solve this paradox you see xeno is saying that motion should be impossible right because for my hand to go from here to the camera it has to go halfway and then it has to go half of the remaining distance and half of that and so forth and it seems like there are an infinite number of steps and therefore i will never be able to make it but of course the error in zeno's reasoning is to not take into account that the smaller the step the less time it requires for me to take that step and indeed if you take into account that as the distance goes the remaining distance goes to zero the remaining time to cover that distance goes to zero and use a little logic or a little calculus you realize that of course we can cover a finite distance in a finite time so the era is the implicit assumption that every single step will take an amount of time such that when you add up all of the increments it will be infinite no an infinite number of numbers need not add up to an infinite value you all know that right a half plus a quarter plus an eighth plus a 16 plus a 30 it all adds up to one doesn't add up to infinity and therefore even though are there an infinite number of steps because each step takes an infinitesimal duration of time when you add up all those infinitesimals you can get a finite answer and motion is possible so that is the end of zeno's paradox okay so with that let me just take a drink of water here all right one more now everyone's using a lot of question marks perhaps i shouldn't have said that vince and now i'm sort of rewarding question marks a little bit foolish of me why haven't we found the graviton what would change if we could prove that it exists vince asks and first of all what is the graviton for those of you who may not be familiar with the term the graviton is meant to be the smallest packet of gravity the messenger so to speak of the gravitational force the photon is the smallest packet of the electromagnetic force the photon is the messenger of the electromagnetic force and so the graviton is to gravity what the photon is to electromagnetism why have we never found the graviton we have found the photon completely understandable gravity is fantastically weak so much weaker than the electromagnetic force i love demonstrating this fact experimentally it's the only experiment that i as a theorist have complete confidence that i can carry out here's the experiment are you watching please watch that's it i just proved that the electromagnetic force is much more powerful than the gravitational force y all of earth's gravity is pulling on this piece of orange rubber here okay all of earth's gravity earth is big my little puny muscle over here i'm not a strong guy my little puny muscle just beat out the entire pull of earth gravity my muscle is using nothing but the electromagnetic force and the reason my muscle can do that is because the electromagnetic force is much more powerful in the gravitational force it's you know depending how you measure these things but it's roughly a billion billion billion billion times stronger than the gravitational force so if you're looking for the smallest packet the graviton the smallest packet of the weakest force man that's a challenge that's an incredible challenge to find the smallest packet of the weakest force so am i surprised that we haven't found the graviton no in fact there are some who suggest that maybe there's a sense in which we will never literally find a graviton and yet it might still exist it might just be always so washed out by other influences in the world i don't think that's i think we'll probably one day where one day might mean ten thousand years from now have experimental evidence for the graviton and the way that we have experimental evidence for the photon but that's the answer vince to why we have never found the graviton all right guys so thanks for all of those questions and you continue you can continue to ask them as we now turn to the next part of the discussion here and you know this is a little bit of a different discussion than some of the previous ones that we've had but in many ways it's the most important discussion that we've ever had in this series of your daily equation or world science you interviews or whatever you want to call it because this is a discussion that you know doesn't just tickle the mind this is the one that is relevant to our very existence so i'd like to now introduce dr howard varmus who's currently a professor at weill cornell medicine he won the nobel prize in 1989 for his work in cancer research and is head of the national institutes of health the national cancer institute and the memorial sloan kettering cancer center in new york city prior to his nomination to the nih dr varmas had been a member of the ucsf faculty for over 20 years and received degrees in english literature we'll talk about that and medicine from amherst college harvard university and columbia university he has long been a voice at the intersection of politics and science and with that i'd like to welcome harold to our discussion hey harold how are you doing how are you brian thank you very much for having me i'm very good thank you where are you uh well usually i'm up in columbia county new york not too far from your place in cairo um and uh right now i'm in my apartment in new york but heading up north uh as soon as we're done yeah i mean how how we've been in new york now and then sometimes it's uncomfortable as i'm dodging people in the street who aren't wearing masks most people are wearing masks up here and it's it seems it's it's opening back up we're dining out we're going to museums that are much less crowded than usual yeah actually my pleasure to be up against your favorite pieces of art without a thousand people crowded around you whether they're infected or not right the silver lining of it all so when you when you've eaten out have you eaten indoors or only outdoors only outdoors so far the weather's been nice and uh it's very pleasant to be outside for the most part yeah so i'd like to turn to the pandemic in just a moment before we get there i thought it'd be well i would find it interesting if you're willing to spend a little bit of time talking about your own background which is of course rich and unusual in in a wonderful way so as i mentioned in the uh introduction just a moment ago you majored in in english in college you know many people who go on to have illustrious careers in science to win the nobel prize in science where kids like me who did science fairs you know the math team you know all that sort of stuff so so that wasn't your upbringing right you wouldn't i grew up with a father who practiced uh family medicine and i thought i was destined to be a doctor someday but um i was interested in reading and politics and other things sports um and i went up to college and found myself even more diversified interested in philosophy briefly in physics until i found out how hard it really was and then i went off to graduate school literature after writing a thesis about the novels of charles dickens and while i was a medic while i was at graduate school i had an epiphany thinking that you know if i went in to medicine and didn't turn up for an appointment patients would be actually disappointed if i was a teacher and didn't turn up for class students might be happy to go home and i also felt that the part of my brain that did have some aptitude for science was atrophying whereas i thought i could manage to continue to be a thoughtful reader and an engaged reader at a time when i was doing science doing science or medicine so went off the medical school at an interesting time when molecular biology really hadn't yet begin to permeate the thinking about disease but i was seeing clues that we were going to understand genes and begin to understand disease at a much more fundamental level i got exposed to some people who were doing such work and working at studying at columbia college of physicians and surgeons where i began to see that we were going to learn that a disease like sickle cell anemia was going to be understood as a mutation that the result of mutations affect very few genes and yielding prospects for thinking about diagnosis and prevention and therapy in ways that were really unprecedented yeah and i chose the right area to go to get into to to work on this problem namely cancer which is a disease of the genome and emoji has had huge effects already so i want to talk about that in a minute but there's one there's one thing i read that you you wrote that it was actually in an interview i believe in a 2012 journal of clinical investigation if you don't mind i just want to read it because it's a really wonderful and unusual way of getting into a scientific frame of mind you in speaking about columbia medical school you said i went there thinking that somebody who liked words and books was interested in the workings of mine would be a psychiatrist but then i became interested in internal medicine because of its narrative aspects can you flush that out when you're sure well you know first of all i i still think that uh somebody who had a who has more patience with individual um ill individuals uh would uh be attracted to to psychiatry with uh under some circumstances but i when i first found myself in a room alone with a patient who undoubtedly had an interesting story but whose mind was too chaotic to be able to relate it i realized that i really wasn't built for that kind of thing but but when you went to talk to a patient who had uh a disorder of the heart along with the kidneys they were able to tell a narrative that um that allowed the astute physician which i wasn't necessarily at that point to try to unravel a story and make sense of it and think about the relationship of the patient's experience to the physiology of disease and then i think as at a later level even though i never ended up practicing medicine the ability to relate that story to something that was happening at a molecular and genetic level that individual gave rise to new ideas about how one might do a better job in trying to repair the defects or coming up with public health measures that would reduce the incidence of disease yeah so 1989 you win the nobel prize for the insights that you were briefly referring to insights into cancer it's relationship to viruses we had a conversation just a couple of weeks ago with adam reese another nobel laureate in physics and one thing i asked adam was i said look you know you won the nobel prize at that point you've kind of reached the pinnacle in some sense of your field did you think about doing something else at that point adam was like no it's like i do fit i do astronomy that's the only thing for you though am i wrong in saying that winning the nobel prize was a turning point of of a sort is that accurate i think i think it is accurate not because um of some change internal to me but because of the pers the world's perception of me up until then you know i was a i was successful i can't deny that but but uh i was you know a scientist scientist people who were interested in the molecular biology of cancer were interested in what i did but i wasn't in any sense a public figure but the prize did change the way the world viewed me and the way the government viewed me i was called upon in part because i was a nobel laureate and because i had had some experience with the nih to begin to advise the nih about how it was organizing policy and helping to to support career development and other things and once i got engaged in that process not only did i find it interesting once i was presented with the opportunity to help craft policy but people who were working with me decided that maybe i would be a good person to help lead the organization and then when that that uh offer came at a quite a high level asking up from from the president to be at to be offered the directorship of the nih uh frankly i i jumped at it i was in a good position because uh donna shalala my boss at the department of health and human services and clinton himself were amenable to the idea that uh i could continue my research career at some lower pace so i didn't have to give up research which many people do at that stage so i've actually maintained a laboratory to this day as i enter my 80s wow so i you know i do laboratory work not with my own hands but with through the hands of post-docs and students and technicians but i'm engaged in research and i've despite the the litany of leadership positions that i've held over the last 30 years or so i've been able to keep an active interest in science which i'm which i'm quite grateful right now let me uh if you don't mind i would like to turn to the elephant in the room if you will the pandemic yeah and i just want to say you know i you know back it must have been 20 years ago i was at a talk at the new york academy of sciences and there is um lori garrett i believe is the journalist's name yes talking about the ability of of of of tragedy hitting us with some sort of viral pandemic and i left that that lecture kind of terrorized and of course an hour two three i thought about it and then it dissipated away and i stopped thinking about it right and then i there was a world science festival program where you and i believe laurie was also in that program maybe others in it as well and again it came back to mind this possibility of and so the point i'm making is you and others new this was potentially coming and and yet it's it's happened now and it's clear that we really weren't prepared so so is it that we weren't prepared or were we prepared and we botched the response what's your view you know from 30 000 feet of why we find ourselves in this predicament yeah well your description of your own reaction is actually emblematic of the way society responds to pandemics especially at a time when we think science is very powerful and we're not really threatened by the kinds of of plagues and uh and outbreaks that have uh been recorded uh during history from the time of the 14th century plagues in italy to to the influenza epidemic of 1918. and indeed there is a story to be told here about what happened after the influenza epidemic of of 2008 and 9. at that time i was a member of obama's council on scientific advisors science and technology advisors and we wrote a couple of fairly stern reports about how the nation not only needs to up its game to deal with the the influenza epidemics of that period the first year or so of the obama administration but also uh to prepare for the next one and one of the things that has happened during the current pandemic is that about half of the old obama p cast as we call that group uh got together um and we've been talking about um what we should be doing in during combat 19 and how we try to prepare the the country and the world for what will inevitably be the next one you know in between the flu epidemic of 2008 and 9 and current time we've had a number of other significant outbreaks they haven't endangered all of the world the same level sars and mers and ebola and zika but it tells you that because people travel rapidly because the the interaction of humans and animals is still a very intimate one and because viruses in particular do have the ability to spill over from uh infected animals into human populations and spread uh word we're going to have more epidemics and there's no doubt about it and the question is whether this one with this tremendous severity and the incredible attention that everyone's given to it will actually sustain an interest in doing the things we know we should do and could do to be better prepared we were somewhat prepared for this but right mostly the disaster is just the consequence of botched oversight right so and you have been quite forthright and critical about certain aspects of the response i just want to read from your own new york times op-ed a particularly telling description you wrote that the cdc the federal agency that should be crushing the pandemic is promoting policies that prolong it that means that local state and organizational leaders will have to do what the federal government won't now that's pretty i mean from someone who's been in the positions that you have held that is a that is a pretty telling description of what's going on so what's the source of this i mean those of us on the outside conjecture what's going on here but what's your view how could the how could an organization that was the premier disease focused organization on the world stage have gotten to a place where someone in your position is basically telling people ignore them they're doing the wrong thing how cool well it's painful to say that because the cdc indeed is you know one of the world's if not the most uh prestigious organization one of the most and uh it's painful to say that it's it's advising the wrong thing to happily our op-ed and many other statements by other public health public health engaged people have led to a reversal of that policy but what they were saying was basically we don't need to test asymptomatic people which is you know idiotic in the in this in this context where we have a pandemic caused by a virus that that becomes highly transmissible before it produces symptoms people don't know they're sick and you know we're seeing that on a big stage uh in the last couple of weeks when people who are in the news anyway every day are being prepared before the public as people who say they have no symptoms they're fine but of course they're producing virus and they're at risk of transmitting that virus especially if they don't wear a mask don't respect social distancing and uh i don't know how often they wash their hands but the fact is that that the virus is being transmitted in a terrible way uh when we we know what to do uh you know obviously if we could uh if we had a vaccine to put into effect if we had uh drugs that really protected people against viral infection uh i think this is the place actually there's there is a teachable moment here that goes well beyond uh thinking about this coronavirus and that is related to the nobel prize that was announced on on monday to investigators who played an important role in discovering the cause of we call hepatitis c infection and allowing for the development of diagnostics in the late 1980s and a few years ago therapeutics to prevent death from hepatitis c people often don't realize that we knew about viral infections for 100 years before there were reasonable therapies and now molecular biology and new kinds of drug development have allowed the development of drugs like the hepatitis c drug drugs against hiv that do an unprecedented thing they they allow us to combat a viral infection i'd like to see that happen in the case of carbon 19 as well now tony fauci as i understand it is is a friend of yours you and you're one of my closest friends well so i so i i in no way i'm asking you to be critical but i do have a following question if you're willing to address it early on were there any moments when the response that he was giving when the administration was saying nutty things did you ever in your living room watching him on tv say come on tony really push back we gotta push back harder than ever well i i i i guess i respect tony too much to say that i was being critical but you know i was aware that he was under a lot of tension and my assumption was that he was saying what he thought was reasonable to say in the inner sanctum uh without publicly antagonizing the people he needed to reach if he was going to make any headway and i think he's been a pretty good purveyor of what needs to be said to the public um you know in the very beginning of this pandemic we didn't know a whole lot about this virus we know exactly how it's being spread there was concern for example about how we should best deploy the the masks that we had there was no doubt that the the stockpile was somewhat depleted of some of the most important personal protective equipment that we needed to keep our healthcare workers maximally safe so there was a period in which really had to be established that this virus was being transmitted largely by the aerosol route and figure out the best way to transmit it and to up the the supply of the kinds of materials like mass that can be used to protect people yeah now look i i think we all can agree i think that we know how to end this pandemic we could end it in a few weeks right there there's this interesting way of thinking about this problem if everybody stayed away from everybody else for two weeks that's it wrong right right virus is not trying to kill anybody the virus is trying to survive and only survive if it finds a new host right but nobody's gonna go along with that even for two weeks we're not gonna be completely yeah so what do you do you know if you had a vaccine so everybody was immunized immunized that's the other way to solve it we don't have that if you had a good drug so that nobody got seriously ill that would help then you could get infected and still survive but but so we're trying to find the right compromise and this brings us back to the point about asymptomatic people so if we can identify everybody by testing everybody every day that itself being somewhat implausible but if we could do that and everybody knew within a day of their becoming infected or being infectious that they were in an infectious state then we could say all right you stay apart from everybody else for a couple of weeks that's a small partial portion of the population yeah so in our heads we can fear how to do this but but putting it into practical terms yeah you know i mean i have to say part of me feels like and of course you're right this is completely unrealistic but if people would just fully embrace the fact that in two weeks this could be over if we just have a certain radical change in behavior of course that's just not how most people think about things that's what i said now that and that i'll bet you quoted from that's what i wrote peace in the atlantic a few months earlier in which we said i have the atlantic here yeah so is is that an unrealistic hope to ever get the public into the frame of mind where okay a new pandemic is spreading across the world here's what we need to do and everybody just isolates for two weeks and it's very difficult but i do think that it is possible to get people in the frame of mind understand that if they get tested anybody who you've got to prioritize too because you can't just produce 300 million tests a day and execute them and get the get the sample to the lab and the results back to people and and do the follow-up testing but if you can say this cohort of individuals needs to be tested because they they're going into a situation where they're at risk these people need to be tested because they're likely to transmit the virus in a certain in a certain circumstance you test that 5 or 15 that's at the greatest risk of continuing the transmission the virus then you can get control of it maybe it's not perfect but uh all we have to do is get the the transmission rate down to a an acceptably low level and then the virus goes away maybe it doesn't go away in two weeks maybe it's six weeks but look it's been seven months more than that actually but yep exactly now i have the atlantic article and there is one one quote that i wanted to just quickly read that you wrote you wrote that we believe that expanding current testing capacity remains a matter of extreme urgency one that justifies a level of intense coordinated work at a national even international scale that resembles the campaigns we associate with world wars very powerful way of describing the need for the kind of testing that you were just mentioning now however in contrast with that right president trump at times he's been advocating slowing down testing and we already discussed how the cdc had been suggesting curtailing the kind of testing that we're doing and i don't know did you watch the debate last night the vice presidential debate a little bit yeah so here you've got vice president pence castigating kamala harris saying that she was politicizing vaccines bring politics into a domain that that really affects people's lives it's the it's the epitome of hypocrisy here you've got these particular political goals influencing the most vital way that we can deal with this pandemic i mean well i think he was pretending to miss the point about um being cautious about a recommendation that comes not from the fda not from tony noche not from the scientific community but only from frankly a disorganized disoriented leader who has in the past told us that we should uh be taking drugs that have not been validated who himself once he got sick uh took every possible therapy including things that if he weren't particularly ill he shouldn't be taking like dexamethasone and what do we do i mean because the fact of the matter is the various polls have shown that something like only one in five people would take the vaccine if it were say available today that low but that uh but i've seen hundreds under 400 i saw the number 21 of pulse i don't know how accurate it is to ask the question who you ask but yeah of course no doubt but i guess my question is i don't know a lot about the details that you are intimately familiar with regarding the kinds of protocols that are generally in place to assure that a vaccine is safe so when i hear the president talking about operation warp speed and rushing things and getting a vaccine before the election if you were to ask me would i take that vaccine if it was available today you know kamala harris had a funny remark she said you know if trump says it's okay i won't take it but if the doctors tell me it's okay i will i sort of have a similar frame of mind but what does the general person do how do you know in the context of a country that now is trying to circumvent the usual protocols in order to rush a vaccine how do you know if it's safe to take yeah well i i i have some residual faith that we're going to be told at least something about how effective uh any vaccine is in a clinical trial all the vaccines that are being considered for approval are in phase 3 trials and i think there are enough people who are concerned about transparency in this process even if they're not in government and will have access to the data to reveal uh what the the consequences of taking the vaccine actually are i do think that that side effects are going to be infrequent i don't think i think we have a hard time knowing exactly how infrequent um but i think we will know but have to know understand how to respond to is how effective it is yeah fda has quite reasonably said that the vaccine has to be at least 50 effective with respect to either blockage of infection or the development of serious uh illness after you're infected uh and i think people have to begin to understand that a decision about a vaccine is not a binary decision it's not we have a vaccine that we don't we could have a vaccine that's pretty good worth approving worth using but we have to retain other kinds of precautions to try to reduce transmission because some vaccines may not be perfect nevertheless sufficiently useful to to use and i think we have to mainta if we if that becomes the case and it is true that we have vaccines against some diseases dengue fever malaria that have gotten approvals when they're not all that effective but they're helpful and once that is the case people have to understand that we want to encourage people to make better vaccines we want people who take the vaccine to be first of all alert to the possibility of of adverse events when you take them it's hard you know just so you're responsive to changes and symptoms and you've got to be sure those folks understand they still have to take some precautions they still should be aware they could get infected and if they're infected they can transmit the virus uh so i think you know for the next year two three possibly people are gonna have to be adaptable enough to say these precautions we put in place and you know here in new york city i would say most people are wearing masks most people are distancing we're behaving pretty well like ninety percent i would say i'd say ten percent uh raucous youth in the village it's different than if you're in the sedate upper uh aging upper west side yeah no no certainly that uh has has an impact um let me ask you so we learned this disturbing fact from uh the bob woodward book about the trump administration knowing certain features about the virus and holding it back that certainly played a role in the debate last night when it comes to transparency how do you make a decision about what information to share with the public and what information should somehow be kept under wraps do you have a a guiding principle for what to do with that kind of sensitive information yeah i mean i i don't think it's a huge problem but i do think people have to understand that that in under conditions like the pandemic the natural tendency for most scientists who have new information is to try to share it quickly and one of the one of the delicacies about or delicate situations that has arisen here is that scientists especially under these conditions are more and more likely to divulge information at a pretty early stage before they actually have what we would call solid solid data to support a conclusion and we do i think all of us have been aware of conclusions that have been proposed uh results that have been posted before uh conventional peer review that turned out not to be correct and science is a self largely a self-correcting enterprise in physics or biology uh and the mistakes do occur and here the the stakes are high because we're talking about the pandemic and people's health is at stake and you have to achieve a balance which i think varies very hard to write down as a series of principles between being transparent about about early results and convincing people that you're not you know that uh you're divulging information but you're not yet secure about the conclusions people have a hard time accepting they think science knows things and when you're a science supporter you think if a scientist says it and writes it down and puts it into even into online as part of a preprint server as you would in archive for example and we do in bio archive um then you know this is somehow now written in stone which it's not yeah yeah i know i find also you know people have the view that science is all about one revolution after another overturning everything that came before and i try to emphasize to people that science is generally about just expanding the domain that you can talk about with precision and typically the ideas of the past are not overturned they're simply extended so i do think that we have a bit of a mismatch between how science actually works and i mean not people who are audience for this discussion typically but for the general person it's a it's a pretty different view compared to how science actually does work and but the issue that you raise does bring to mind the question look pandemic is obviously something that doesn't care about borders science is a field the beauty of it is that it doesn't care about borders you know and we work on something and we look at the pre-print server that you just mentioned the pre-prints come from all over the world every morning there's new work coming in so it's vital that there's international cooperation and trying to combat something of this sort how has america's response and america's leadership in this pandemic affected our international rep reputation among the very scientists that we need to work with to to really stamp this out yeah that's an incredibly important question brian i've been mulling a lot about that because one of the reasons people are so perturbed by the terrible performance of our of our country in this epidemic that that is we have uh four percent of the world's population but uh over 20 percent of of covered 19 deaths how could that possibly happen and i i don't think yet we've eroded our reputation for doing important science indeed most of the things that have allowed us to identify the pathogen characterize it develop interesting tests uh produce vaccine candidates at unprecedented speed using not just virus that's been killed or virus that's been attenuated in its potency but by using viral nucleic acid and viral proteins and having a pretty sophisticated view of how this virus enters cells and grows some of that based on antique work or 20 year old work with coronaviruses but some of it based on incredibly rapid advances that have been made through the technological tools that that only we in a few other places in the world mean in europe and some places some in china uh i think that's all still viewed as remarkable and that the botched performance here has a lot to do with american attitudes toward public health something we want to talk about a little bit more detail and uh the the the incredible mishaps that have occurred because of mr trump and his colleagues yeah yeah it's uh it's sort of astounding i mean as as someone who has had high level government posts under president clinton under president obama i mean we all know that politics always casts some kind of shadow over science these are not independent realms but have you ever encountered the kind of influence and the kind of meddling and the kind of manipulation that is going on with this administration absolutely not yeah you know you know i haven't been in the republican administration but i've watched you know george bush and we were very critical of george w bush um not so much his father but uh um but in fact uh george w bush looks like a scientific messiah by by comparison you know he ran the pepfar program um developed it on his own uh and that was one of the great public health efforts in history of man um and uh you know he did have some bizarre policies with respect to stem cell research and a few other things but uh he was in general supportive of the kind of research done across the board and looks like a rational human being which i think he is right right which uh now is the low bar for uh respect for before we have a little more respect for the biden harris ticket than that i think yeah so that would be a big improvement so you know i mean trump fed off and feeds off a certain view at least in america among a certain fraction of the populist that distrusts expertise that puts dogma in front of evidence and approaches the world in a highly non-scientific way and so i'm often asked the question you know what do we do about science literacy or illiteracy in america and i kind of tell you i've got sort of two views on this because on the one hand as you know this is a world science festival event we run this festival and hundreds of thousands of people out to the events millions of people watch the online programs that that we post which is which is great so there is a hunger and an interest in these ideas so it's not universal that there's no interest in science and then the flip side and i know that you've written about this too and i'll just give my version of it you know i know a little bit about genes i know a little bit about dna but i don't know anywhere near what you know and so you could call me illiterate in certain areas of science because it's just too deep for any one individual to be everything which is for instance when people ask me about climate change i am reluctant to get into a deep conversation about i'm not a denier by any means but i know that a really smart denier could probably wipe the floor with me because if they've done their work and their research they may know details that i won't simply be able to respond to how do we deal with this puzzle if you will is there a certain body of science that you think every single person should at least know that or is it more that we just have to inculcate a sort of scientific mindset that allows people to recognize that there's a rational way of looking at the world and there's an irrational way i mean what do we do i think this is an incredibly important issue and i i struggle all the time with colleagues of mine who say you know we're living in a scientifically illiterate society well you know scientific literacy is uh you know is hard to define and whatever my colleagues who work in molecular biology might think is an illiterate uh state of mind actually could be pretty literate so i give a course as you may know in the mcauley honors college at the city university of new york on science and society where we try to take up this issue and my view is if you can teach people to learn some of the principles that go go into how science is done to learn what the liabilities of scientific exploration are how science is funded how science is is disseminated how we get access to information how it's taught what uh what forces economic ethical and other otherwise are influencing how scientists make decisions what scientific truth is because uh as you know from thinking about the philosophy of science uh it's hard to prove something and people can learn these principles of what a rational exploration of the world is all about and what experimental evidence tells us and how interpretations change uh that there are imperfections there's fraud there are all kinds of things that uh undermine the credibility of science and if we learn that science is a human activity that that we have to defend ourselves uh to uh avoid um perpetuating as though any scientific paper is written in stone yeah when we we've taught people about uh how the scientific profession operates what its pushes and pulls are and i think that's the best we can do and then there you know i would say there are some things we ought to know a little bit about you were illustrating gravity a moment ago people have some sense of where that concept came from what it means what the major forces are and you know i would say likewise that it's really a mark of of of poor education not to know something about what genes are how they're encoded what they do um you don't have to know a lot of a lot of individual genes you have to remember remember the base pairs the sequence of base pairs in your dna but you do you want to know something about the general principles involved and that's where we have to depend on our educational apparatus which is uh somewhat deficient in this country especially uh below the university level um what would you be in favor like of a surprise question in one of these presidential debates where you know trump or biden has asked you know what what is a gene what is dna i think it would be great but that would it would raise the level of this discourse quite a lot and of course the answer might be something about something totally irrelevant just as last night some of the most interesting questions which was totally ignored people pulled up their two minutes and more was i don't understand why a failure to answer the question or to try to answer the question to say i'm not going to answer that question but i'm going to say this because i need to say this right right yeah now uh that that's uh the the dynamics of its own little universe of uh political science what is that science yeah right exactly but speaking of which so there are many scientists who would not go on the journey that you have in your life there are some scientists and i'm around many of them and i used to think this way myself we are about discovering truth right transcendent truths that are so beyond these little noisy things about policy and life on planet earth and we're not going to spend our time in that domain so so the question is should we in the educational system have some encouragement that allows scientists to know that it is important to go on the journey that you've gone on the variations on that theme that others have gone on too should in graduate school should there be courses like perhaps the one that you're teaching where policy and and the politics of science and the politics of funding is part of the the training because i can assure you that in graduate school and physics that's like infinitely far away you're learning quantum field theory quantum gravity as best you can the electrodynamics and none of that other stuff matters yeah well my view is that yes people should have an opportunity to learn about these things if they so choose i some of my colleagues feel it should be mandatory and i take a somewhat dim view of that i think i have i'm perfectly happy to know that a certain percentage of my colleagues just want to do their science they don't want to get engaged in politics i i see this frequently especially in this election year with the pandemic and all the other things revolving around us uh when nobel laureates for example are approached about signing a letter uh that either takes a position on the election or condemns the current administration for something and i find about three quarters of maybe eighty percent of of laureates are willing to pitch in and make a statement i this time when we put together a letter in support of vice president biden uh over 80 of the new laureates of the nobel laureates in america were willing to sign on to a letter which is a record and i think not surprising because you can't ignore the fact that the survival of the scientific enterprise is closely linked to politics and the most primitive level we know that most science in america is paid for with federal dollars so yeah that's a requirement to have a congress that is receptive towards scientific work and uh but i think at a time when the findings of science that are essential to the survival of our citizens is being abused um most scientists i know except for you know there are a few who are simply too old to think about what the letter says or have taken a principle position that they're scientists they don't know enough about things and you know i draw that line too i get approached about uh signing on to some political uh event in a country i know very little about and uh i'm hesitant to sign something of that sort but i do think that you know first of all we are citizens as well as being scientists and if we have influence perhaps we should use it when we care about the issue and secondly we can't we can't ignore the fact that that society is intimately linked through its politics it's governance uh to the scientific enterprise and we'd be foolish i think to ignore those connections yeah i know we experienced the same kind of thing you may recall years ago when we were just starting the world science festival we approached you tracy day and i approached you would you be an advisor on and you graciously said yes which we greatly appreciated but we had been told that there were going to be very few nobel laureates that were willing to sign on for much the reason that you're you're saying that you know signs for the public taking a political position exactly it was just the public about these ideas and but it turned out that not a single nobel laureate that we approached turned us down so so there i felt there was a nice shift toward the recognition of how important it is for the public to know about these people you may take up controversial topics right i wouldn't say we've got a position the science fair is a controversial thing exactly exactly precisely right did you experience any pushback from your colleagues when you first started to at least spend part of your time outside of the traditional academic world i don't think so because frankly i think most of my colleagues feel that there's a risk to having people who are no longer doing science or may not have been strong scientifically helping to run the the agencies that give out the federal dollars so you know my i've never spent too much time in some of the more garden variety things that deal with issues that help microbiologists to survive for example so my interest has always been federal agencies and how the government works how congress comes to support science how it provides oversight and i think most of my colleagues are just concerned about having people who have a reasonable point of view and i guess i can take it as a mark of commendation that people didn't object to my doing on the ground so i wouldn't be any good at it so i've never had much problem with that but you know i have occasionally when we weigh in on things like the recent kerfuffle about the rescinding of a grant to an organization in new york that was right about that yeah how viruses transmitted from bats to humans in china in particular and that grant was was uh in a sense withdrawn money is no is not money for that grant doesn't go to the investigator at this point and that's all a consequence of trump having been asked a question uh at a press conference uh that he didn't know what the grant was obviously but he felt he was being told that the grant provided money to the institute of virology and wuhan and he said we'll we're going to discontinue that and then word went down and that's what happened sort of end of story happily it hasn't been hasn't recurred but uh you know i don't like calling out my esteemed colleagues and my own favorite agency the nih in public but i think if if we didn't stand up to that and make it and say this is not acceptable we don't want this to happen i think it's important that we speak our mind and recognize that this is not um the kind of action we want to see our agency leaders to take and it serves has the potential to serve as a very unfortunate president because there are countries in which science is undermined by overt political interference and we can't allow that to happen yeah and look november third obviously is a pretty critical time critical date when we're talking about how this country is going to go forward you know if it goes in the trump direction it's probably going to be business as usual which would be catastrophic but if biden prevails and let's just for argument say because it could well happen he calls upon you to head up the viral task force to deal with the current pandemic and the next one that no doubt is heading our way what would be your guiding principles for what we should do to be ready for the next time around well let me say first of all that i think there's no doubt that uh and possibly even in the trump administration there would be a a commission called by congress and the the group that i mentioned earlier of former members of obama's pcast have actually written a long and thoughtful essay about what the commission the co the kavit 19 commission should take on and it's clear that uh there are a number of things to worry about one is how we organize the underlying science to cope directly with making good tests and new therapeutics and vaccines against the next pandemic and we do know that there are new ways to to do certain kinds of science especially in the infectious disease domain that would be even more efficient than what's happened this time secondly we need to be much more conscious of being prepared with the kinds of materials that you stockpile and and store up we need to think about how testing and contact racing in particular is done we ought to have a cohort of people who are ready to put in place the cohort the the contact racing that is essential for testing to make sense because testing is obviously not very valuable if we don't follow up with people who've been in contact with infectious individuals uh so there are hope there's a litany of things that need to be done and one of which i think is often forgotten but fundamentally important we i mentioned it very briefly earlier and that is we need to change public consciousness of what it means to protect the nation's health it's not just about curing a case of cancer or curing a person who's got an infectious disease we need to pay much more attention in this country in particular to public health as to prevention of disease and to the understanding of what aspects of our behaviors contribute to disease they're countries that are much less wealthy than we are and you know what they are taiwan and iceland and south korea and quite a number of others that have coped much more effectively vietnam another good example much less effectively with this much more effectively than we have within pandemic because they have a public health system that doesn't cost all that much and maybe less sexy to to prevent a case of disease than it is to cure it but nevertheless we just need to change our perspective the cdc is under ordinary circumstances a very valuable organization it doesn't have the resources ever that it ought to have to to protect the country and you know we do depend heavily on city and state public health departments unfortunately in this circumstance we have to depend almost entirely on them and of course the quality varies across the country which accounts for why uh you know as you said before virus doesn't respect national boundaries or state boundaries or urban boundaries and we need a coordinated response and we haven't had that we can change the public perception of what public health does for not a whole lot of money and that should be one of the underlying themes in any commission report so we only have a few minutes there are two other things i wanted to talk about each of which could fill a full conversation but you mentioned cancer obviously that's an arena where you've had a profound impact can you summarize just give us a sort of state of play in your view i mean i know that you said that obviously curing cancer versus preventing cancer perhaps we really should be focusing more on the louder than the former but where do we stand in in that battle yeah well let me just say a couple of things about that first one of the things that has really impressed me in the last five or ten years is the rapid development of new technologies that can allow us to understand cancer in a much more profound way using new approaches to look not just at the molecular gyrations in in a cancer but in individual cells and when you start to do that you begin to see how how much heterogeneity how much variation there is within a cancer that mutations are continually occurring cancers are evolving and have a kind of plasticity that makes for an evolutionary universe that that makes the new therapies that we're very excited about drugs that specifically target individually mutated genes new immunotherapies that that that allow the immune system to attack cancer cells that that have foreign-like proteins on their surface these are remarkable developments but the the ongoing plasticity the generation of new new attributes of cancer cells as cancers grow and metastasize is truly extraordinary but we now through what we call single cell biology have a much better approach to understanding this incredibly difficult problem because we don't cure as many cancers as i'd like to see us cure um you know i use prevention as a as a concept that i think we need to do more with in in human populations and how effective could that be and you're thinking about the way so yeah so i think you know we are limited in in our approaches to cancer we know that if nobody smoked we'd have much less lung cancer there's no doubt about that one of the biggest uh reducers of the incidence of cancer in this country and the reduction of mortality in this country has been through smoking cessation that's only one example unfortunately cancer a disease of the genome in which in which it's hard to prevent the damage that occurs because some of it is part of the natural process you know people cells reproduce themselves many many times during the course of a lifetime and every time they do that they've got to make a perfect rendition of three billion pairs of nucleotides and segregate 23 pairs of chromosomes to daughter cells they don't do that in a in an accurate manner and so there's an implicit tendency towards genetic change as normal cells grow we now know if you take the first two cells that are that develop during embryogenesis when the fertilized egg divides into two cells those cells already have mutations really yeah because everything yes right most of those mistakes don't matter because a lot of our dna has minimal functional penetrance yeah what's the rate the rate is sort of at the level of you know a half of a percent and well no no much less than that but remember the number three billion base pairs yes a number i got the number wrong um yeah they're right there's a lot there's a lot of copying to make there bible repair systems but it's not enough you know one in 10 to the seventh that's a lot right of course now that we have these technologies allow us to do something really extraordinary take one cell we'll let divide into two sequence the dna in one of those daughter cells single cell uh you can do that and you can find that the mistakes are occurring all the time and when those mistakes change the function of an important gene doing damage so we're getting a handle on some of those things yeah i think that's going to be helpful i mean some of that will be helpful with regard to understanding how cancer arises learning having a mindset about the plasticity the variation of cells in a cancer uh and the cancers are not uh they're not monolithic they're not uniform sets of cells they have the potential to undergo the kinds of evolutionary changes due to election that's imposed by giving a drug so we have all these new drugs putting these drugs together is going to be very powerful yeah combinations so the one thing fails on somebody else succeeds it's hard for a cell to escape two obstacles to its growth rather than one yeah it's sort of amazing and wondrous and frightening at both the same time that the very process that allows for evolution to yield the kind of species on earth you and i wouldn't exist brian there weren't mistakes and speciation exactly if you want i'm going to do that you've got to tolerate cancer as well exactly exactly let me ask one final final question with all of the absolutely spectacular new developments in in all of science but certainly in medical science medical technology and so forth that's happening if you were right now a young medical student just starting out what direction do you think you would go with the playing field as it currently is yeah no i you know to me the biggest scientific problem has to do with energy if you're thinking about problems that affect the future of mankind getting get finding ways to store energy to get more energy out of the sun for example uh relieving our dependence on fossil fuels these are the things that really i think are going to affect the future of human life um if i were confining myself to medical things you know like many of my colleagues i probably would be focused on neuroscience i actually entered medicine we talked about that earlier psychiatry but like freud i took an interest in the structure and function of the brain but i just found it too difficult i think it's still awfully difficult a lot of progress has been made in the last 20 years but that's you know understanding how the brain works what consciousness is these are these are the problems that uh are at the vern being approached now genetics cancer infectious disease these are still fascinating topics but i do think we have the basic repertoire of principles and technologies uh now it's a matter of working things out and you know they're people who differ i like to start things and the starting genetic exploration of what drives cancer was part of my contribution to science what's going on now is fun it's interesting that you know i work for example on forms of lung cancer that are still very difficult to treat that's an exciting thing but i don't feel as though we're at um at a frontier in which we're going over a fence that's too hard to see over i think we have some sense of what the landscape is like it's just a matter of working out incredibly important aspects of these phenomena that will allow us to to treat maybe even prevent some of these diseases more effectively but i think in the in the neurosciences in particular they're going to be fundamental discoveries and let me just conclude on one thing the other nobel prize in my field that occurred this week was the prize for crispr yes um which is a you know a resonating reaffirmation of the importance of basic science we now can all envision using the crispr editing systems to treat prevent cure human disease but this would never have happened that people have not been obsessively looking at the at the chromosomes of bacteria and trying to understand how they become resistant to infection by bacterial viruses and that began in the 1980s this nobel prize went to two people out of about 20 or 30 who were prominent in the development of this story i'm really pleased it went to two women that's great um and i think it's it's it's an opportunity for um for storytellers to say yes these people did something that was pivotal in the history of this field but there were it was the graduate student who was just looking at organisms that swim around in very salty water uh and who saw these strange sequences and people who began to apply the principles of crispr to the editing of dna in in human cells that you know represent a full the full glory of science from fundamental stuff to things that are highly applied and are going to be useful in agriculture and archaeology and many other areas of human exploration so i said that was the final question but do you mind me asking one more since it came up so you mentioned neuroscience the brain consciousness as you know a frontier that at some point will be able to explore in some systematic scientific way what's your your gut feeling is consciousness something that we will understand by virtue of deeply understanding neural processes or as some say it will it forever be beyond the reach of that kind of a mechanistic description yeah i think we're going to be able to say that consciousness is reflected in certain can be linked to certain um physical attributes uh whether it's uh the configuration of rna or movement of electrons through some kind of molecular cycle but i think it's still going to be hard to connect the experience of having a consciousness to those molecular events and i'm that i think remains to be seen let's let's let's try to figure out a way to understand what the objective correlates of consciousness are yeah and then see if we can link it back and make a theory of the whole yeah now the hard problem of consciousness why we have these inner worlds is certainly well described as a hard problem and yeah maybe some of the young folks listening to this will one day contribute to that so harold thank you so much for joining us on this conversation you know about science politics the pandemic cancer consciousness critical issues your insights are incredibly valuable and thank you for sharing them with us today my pleasure thanks for your good work with the wsf thank you thank you okay talk soon all right everybody so let's uh do a little more q a before we uh wrap it up today uh again that was a bit of a departure for the kinds of topics that we usually talk about let us know if that's the kind of thing you'd like us to do more of and again this one is so vital to the future sorry for those of you on the international side of the viewership that it was somewhat america-centric but what happens in this country has profound ripple effect across the world so i suspect that many of you even if you don't live in the united states are uh deeply concerned with what's happening in america which is deeply distressing to many of us so again we uh we thank harold varmus for sharing some time with us so heading back to the kinds of things that i can talk to directly we do another 15 minutes or so of questions before we uh before we wrap it up let's see um [Music] um aditya asks what is a naked singularity and a naked singularity this is nice because it ties right back to our initial conversation about black holes in the first part of today's session black holes according to the math have a singularity but the singularity is encased it's kind of shrouded within what we call the event horizon we mentioned this earlier as well and that shroud you can almost think of it as clothing that surrounds the singularity a naked singularity would be a singularity that doesn't have an event horizon surrounding it it doesn't have any clothing surrounding it therefore we call it naked and there's a lot of debate about whether well as i mentioned earlier there's a debate about singularities how best to address them what they mean how to deal with them there have been questions about whether naked singularities are even allowed within the general theory of relativity and there's been a lot of work done on that no one's ever actually seen a naked singularity so it's not as though it's something that we can point to the way we can point to black holes which now we've actually taken radio telescope images of but it is a potential quality of the general theory of relativity nobel surfer ass what do you think about the ccc cosmological model advanced by sir roger penrose um you know i wish i had something intelligent to say about it i know roger has been putting forward that idea for a while and he has a book on i've not read his book i've not really studied the idea so unfortunately i i don't feel qualified at the moment to give any real evaluation of that but at some point i'll look into it more fully so if we have if you join us again in a subsequent time feel free to ask again maybe i will have something more useful to say about it um cj enjoyed the covet 19 discussion an excellent witness to the insightful perspectives from dr varmus thank you i appreciate your response to that um uh raghav anand what is a string made of that's a that's a good question natural one to ask we know that matters made of molecules molecules made of atoms we know atoms of course all you know are made of protons and neutrons in the nucleus with quarks and quantum orbits and you've got with electrons and quantum orbits and quarks inside the protons and neutrons and so with strings if string through is correct which is big if the next level of description would be inside those orbiting electrons you'd find this vibrating filament inside those quarks inside those protons you'd find these little vibrating filaments and you say okay so sequence upon sequence we find something smaller when we get inside of a string is there something that it too is made of and we don't really know the answer there are people who have pursued more refined versions of a string if you will using things called d0 particles it's a natural consequence of a formulation of strings that strings themselves might be in some sense a necklace of these little d0 zero means zero dimensional as opposed to d1 which is one dimensional string that a string might be sort of a necklace of these d0 particles these d0 brains but it could be on the other hand that a string if this idea is correct at all that's the big if strings might be it they might be a truly fundamental entity and there might not be a notion of something finer within them it's a kind of unfamiliar idea because for most everything we encounter in the world the idea of it being built up from something finer makes a lot of sense but look i mean just by analogy if i give you a book the book has pages on which there are paragraphs and the paragraphs are made of sentences the sentences are made of words the words are made of letters but if i then say okay what makes up a letter i mean sure you can talk about the ink on the page i guess but if i ask you from a linguistic standpoint like what makes up a letter you know in written language a letter is a fundamental ingredient should have strokes and lines but they don't hold any linguistic meaning so the final meaningful ingredient in that linguistic reductionist germany journey is a letter and that's it and you know there are many letters in a given alphabet they're all fundamental so the fact that there are many of them doesn't necessarily mean that they are not fundamental so that could be this same thing with strings strings may be the end of the line in that progression in the sense that there's nothing more meaningful to point to when your question is associated with the elementary ingredients of matter that could be the end of the line again i i can't help but stressing that we don't know if string theory is correct it's a mathematical theory we don't have the experimental verification all things that you already know but i don't want it to somehow go by you that it's a very speculative idea as of today um what else we had um uh my ten-year-old according to kisa asks my ten-year-old asks why is space dark that's actually a very deep question uh dakisa and your 10 year old son or daughter because there was a time when a fellow named uh oblers was his name i forget his name first name maybe sometimes william william oblers and he put forward oblar's paradox which asked why is space dark exact same question what was alders thinking over saying hey if you look out into space and if space is kind of uniformly filled with stars then if you look out into space your line of sight should hit some star even if it's far away and that star give off gives off light that will travel along that trajectory to your eye so obelisk was saying in every single direction your eyeball should encounter an incoming photon which would mean that the sky would not be dark the sky would be bright and this was a puzzle that people began to think about and the answer speaks to the finite age of the universe because if the universe was infinitely old and light could travel infinitely far because that journey could take as much time as it needs to reach your eye then yeah you should encounter photons from every direction in space but if the universe is a finite age then in various directions light simply may not have had enough time to reach your eyeball in the time since the big bang and that would suggest an explanation for why regions of the sky would be dark so i think the best answer to your child's question to keith as to why is space dark space is dark because the universe isn't infinitely old and not being infinitely old means that light has not had unlimited time to reach us and there could be light everywhere out there traveling toward us but it simply hasn't had enough time to reach us very good question and whatever the name of your ten-year-old is please tell them to keep on asking questions as that's what it is all about um what else we have um uh tony silva there's no expansion between particles that's true and that is a puzzle that some people ask if the universe is expanding space is stretching and you've got two particles even two particles i don't know within this little piece of orange rubber that i'm holding why aren't the particles in this material moving apart there's space inside of this why is it not moving apart and the answer is that this is held together by forces that we've discussed the electromagnetic force the nuclear force is holding it all together and because of that force being much stronger as i demonstrated earlier today you know electromagnetic force remember stronger than the gravitational force it can hold things together it can withstand but that i should note need not always be the case so the kicker is that if the accelerated expansion of space that we are now witnessing if that picks up in magnitude if the acceleration of space accelerates then it's conceivable that in the far future the expansion of space will be so powerful that even particles within an object will be pushed apart by the swelling space even the electrons in those quantum orbits around the nucleus the space between the electron and the nucleus may swell driving the atom itself to rip apart and so it's not impossible although we do consider it deeply unlikely but it's not impossible that in the far future everything will be ripped apart by the expansion of space that's what's known as the big the big rip one of the other earlier somebody asked about the heat death of the universe so in addition to the heat death of the universe the universe could die through the big rip through everything being ripped apart all right a few more questions before we wrap it up for today uh here sorry hurry if space expanded where's the whole space and i understand the question we normally we normally think of an object expanding into an existing container or realm like when bread expands when it rises it rises into the space within the oven you know if i have a piece of material rubber and i stretch it it's stretching within the ambient environment when we talk about space expanding it's odd because we want to picture space expanding within an environment too because our brains are so used to thinking about expansion in that setting something expanding within something else space we think may be profoundly different from that picture of ordinary objects in the universe within space space may well be the entirety of reality no container no external space is the be all and end all the whole shebang when space expands what's happening is the fabric of space is stretching and thereby creating new space that the universe then inhabits it's not as though the space is expanding and encroaching upon pre-existing territory that the universe somehow hadn't earlier acquired no space may be stretching and creating the new space and in that manner not filling more of a pre-existing domain rather creating a larger domain than previously existed that's the difference all right uh so jacob says but professor greene i'm not sure what to do with but professor greene i guess i could take that question anywhere but jacob if there's another half to your question feel free to include it somewhere else um spin foams do the people in the chat know about jj sakurai spin foams i don't know jj's sakurai of course a vital force in the development of physics quantum mechanics has a great textbook on quantum mechanics i i don't know i'm not exactly sure why you're asking but uh i don't know maybe uh saad raza if the universe is 13 billion years old then how can we see 92 billion light years away yeah it's a that's a sounds puzzling at first if the universe is 13 billion years old right then you'd think that from any given direction at most you could see is 13 billion light years in every direction because as i said before you can only see in directions where light has had enough time to reach you right i shouldn't say seeing directions you only see at distances from which it's a better saying it you can only see distances from which light has had enough time to reach you farther away they wouldn't so what do we mean and i often say this too when we don't actually say that the universe's radius is 92 billion light years we see we don't say that it's radius we say rather it's diameters 92 billion light years we said its radius is about 46 billion light years so we could see 46 billion light years in each and every direction why is that well it has to do with what we spoke about earlier the universe is expanding so if the universe was static right it was just this big thing that was out there then you're right the farthest that i could see would be 13 billion light years because that's how far light could travel in 13 billion years period end of story but in in a dynamic universe an expanding universe light can be emitted from one location and the source of that light moves away from us so when i see that light the actual object that emitted that light is now further away because it moved away it could be 45 billion light years away so i'm seeing it from the moment when it emitted the light but its location when i then receive that signal is much larger than 13 billion light years because it has been moving away while the light has been traveling to my eyeball that's the basic idea all right woody final question i'm going to do woody asks i think woody had a question before it's a double question sorry for everybody else who didn't get any in how do you think the universe will end how do i think the universe will end well i think it's quite likely that the heat death that we already spoke about will be a key moment in the far future of the universe i do believe as far as i can tell based on my understanding of physics that ultimately planets will either spiral into their star we discuss that earlier from gravitational radiation or they will wander off into space and then stars will supernovas some will turn to black holes ultimately all of these clumpy objects will disintegrate i think it's likely that protons have a long but non-zero lifetime before they fall apart into more fundamental constituents like pions neutrinos electrons and things of that sort and so ultimately all structure will dissipate into particles that will spread wider and wider and it's likely that that will happen on the order of 10 to the 100 years so it's a long time you don't have to worry about it but in a fundamental sense that is a vital step now is that the end of the universe not necessarily there are weird things that can happen after that because when you have a lot of time and you've got a lot of particles wafting around and we may have a source of energy coming from the accelerated expansion of space yielding a cosmological event horizon analogous to a black hole event horizon way out in space that cosmological event horizon according to stephen hawking and gary gibbons gives off heat in the form of particles in form of radiation so we may have a source of radiation within this large large cosmos allowing particles to interact ordinarily most of the time the particles interact not much will happen one will bounce off another they'll pass by each other but on occasion on rare occasion a couple particles may stick together and on rare occasions still clumps of particles may stick together on rarer rarer occasions still those particles may clump together to yield interesting structures we've spoken about the possibility in other of our gatherings even a human brain may on rare occasions spontaneously form in the void so-called boltzmann brain by putting all those crazy ideas to the side it's also possible that on rare occasion the conditions necessary to ignite a new big bang may happen so it's not impossible that the universe may go through cycles where the big bang that gave rise to our realm maybe the conditions necessary for that rare as they may be may happen again and so things may start over we don't know for a fact one way or another what will happen sensitive to this question is whether this accelerated expansion will continue forever and thereby have this endless source of radiation and particles but that's certainly a possibility for what may happen in the very very far future all right it's about 2 20. i think i'm gonna wrap it up for today guys um i enjoyed this discussion with you all your questions i enjoyed my conversation with harold varmus again my thanks to him for joining us if you guys have suggestions for people that you would like to have me uh in conversation with please send them to us you can put them in the chat you can send them to the world science festival you can find our contact information right on the website or put it just in the youtube chat if if you remember to do that later on or tweet it at us but we have a number of people lined up going forward and i look forward to those conversations and continue to address your questions going forward so keep an eye out for our next session it may be next week or the week after we're going to try to do every week every other week or so forth but we'll keep these going and uh i enjoy your in continued engagement with these ideas so until until we meet again take care see you then

Channel: World Science Festival

Views: 45,386

Rating: 4.7379913 out of 5

Keywords: COVID-19, Anthony Fauci, Dr. Fauci, coronavirus, CDC, Trump, Biden, WHO, NIH, Brian Greene, Harold Varmus, Nobel Prize, Nobel announcement, dark matter, cosmology research, Special Relativity, Albert Einstein, Free online course, Special Relativity course, physics, best physics course, space and time, Relativity of Simultaneity, Clocks in Motion, World Science U, WSU, World, Science, 2020, entropy, black hole, event horizon, speed of light, heat death, pandemic, public health

Id: lcsLMvNTGeY

Length: 139min 44sec (8384 seconds)

Published: Thu Oct 08 2020