Brian Greene - The Mind-bending Physics Of Eternity | Modern Wisdom Podcast 308

when you realize how unlikely it is that collections of particles would come together to yield a living system called a human being and how spectacular it is that this collection of particles called a human being can invent manufacture Notions of value and meaning and purpose how spectacular is that Brian Greene welcome to the show thank you thank you for being here I am a massive fan of your work I'm very very glad that you're joining me today oh thank you it's great to hear we hear a lot about the big bang and the beginning of the universe 13 in a bit billion years ago but I want to start at the end have you got any predictions for the end of the universe if the Big Bang is when time began then when will time stop well we don't know but there certainly are ideas that people have developed so it's not as though we're just shooting in the dark the most straightforward interpretation of the data and the mathematics suggests that the universe may continue to expand forever forever is a kind of funny concept it's an idea where time would literally end but enroute to that eternity everything that we know about will end every Star will end every Galaxy every planet matter itself will According to some of our Cutting Edge theories disintegrate into a spray of more refined particles electrons neutrinos that will just continue to waft through that ever expanding Cosmos so we don't know that that's how things will end up but if you were to ask me to place bets based on what we know today and what we've observed today that would probably wear the bulk of my money would go is that what's referred to as the big freeze it is because the universe will just continue to get ever colder as it gets ever larger and weirdly enough it's also referred to as the heat death it seems to be a kind of tension between the big freeze and the heat death but they're actually the same thing because the idea is that you'll reach a kind of equilibrium where every place in the universe will come to the same temperature and it's that equal distribution of heat that is what we refer to as the heat death but but the temperature the common temperature will be so low that you can also think of it as a kind of big freeze what is a way that people can wrap their heads around how far away from us that is now uh it's a tough one I I have a metaphor that I like to use when taking people on a journey toward the far future I use the Empire State building in Manhattan where I Envision at every floor is 10 times the duration of the previous floor and this sort of poetic representation so the ground floor is one you're the next floor 10 the next floor 100 so it's an exponential scale where 10 to the floor number is representing the year that you're on at a given floor and that approach takes you to 10 to the 100 years into the future today we're 10 to the 10 years from The Big Bang so we're on the 10th floor so everything that we know about from The Big Bang till today only gets to the 10th floor and exponentially far into the future as you climb now by the time you reach 10 to the 100 years into the future we'd be enroute if the ideas that we currently have are correct we'd be enroute toward that heat death we'd be on Route toward that big freeze but again if it keeps on going forever then even the 100th floor of the Empire State Building 10 to 100 years in the future at some point that will be a mere blink of an eye and route to the time scales that will ultimately encounter so it's hard to have a metaphor it's hard to have an image but I think the Empire State Building on that exponential growth at least takes you part way toward the incredibly long time skills that we're talking about here what are the final things that are going to be around there is it black hole Decay is it little um fluctuations in space-time what's left yeah so black hole and black hole Decay which is an idea that comes from Stephen Hawking that's really what made Stephen Hawking Stephen Hawking he realized that black holes are not forever right you would think that if a black hole I think is everybody's familiar if it's always pulling in more material and getting bigger and bigger as it swallows up stars and planets and things in its environment you would think that a black hole might just last forever but Hawking realized that black holes can also evaporate particles can actually escape a black hole through certain Quantum processes and if you wait long enough every black hole will disintegrate through this dissipation into particles and indeed by 10 to 100 years into the future in fact that's why the Empire State Building analogy is really well suited basically all black holes by that point will have just evaporated and they will have given off these particle sprays that will waft through the void so when you ask what will be left in the far future even black holes will not be left as far as we know we suspect that all black holes will be gone so the only thing that will be left will be the most refined the most stable Elementary particles around may be refined is the wrong word it's really stability that matters and so these particles will be wafting through the darkness and then you're right there will be Quantum fluctuations that's what I mean so quantum mechanics that's still around in terms of a governing law will allow small energetic fluctuations to appear disappear and sometimes those fluctuations might be large they're more rare if they're large but if you have infinite time on your hands then rare things can happen and so rare fluctuations where particle Collections and energetic collections momentarily form stick around for for some period of time and then dissipate that can happen too and root to Eternity so if you wait long enough some weird things can happen because weird things can fluctuate out of nothingness that's something I took away from reading your book that when you scale things up either in terms of time or space you get some incredibly odd outcomes there's only a there's a relatively finite number of combinations of how you could piece particles together within the volume of space that you make up right which is one of the reasons that people think if the universe is infinite that there's essentially an infinite number of brines and and Chris's having yeah slightly altered versions of this conversation yeah that's a very strange idea but one that naturally comes out of the mathematics it's again one of those ideas that it's hard to fully internalized because it's so bizarre but if space as you say does go on infinitely far so not in a temporal quality but in the spatial Direction which is I think if you were to survey most physicists who think about this and say does it go on forever does space go on forever I think the the reaction among the majority would be it does go on forever is that right that's really where the the general Zeitgeist is when it comes to thinking about the grand expanse of space and you're absolutely right so in any given finite volume of that space there's a finite amount of energy a finite number of distinct ways in which that energy can be manifested in terms of particle configurations and so if space goes on infinitely far there aren't enough distinct configurations to continue to populate those different regions with a different configuration of particles the particle arrangement has got to repeat and if it repeats then the universe as we know it would repeat we are just collections of particles you and I right so if the configuration repeats you and I are out there too as you're suggesting and we're out there even more times with slight variations on the reality that we know about so maybe you know I've got I've got the show and I'm interviewing you you're the business you know that that kind of thing would happen out there so so yeah I mean these these bizarre ideas are not just flights of fantasy they do emerge from the laws of physics under certain modest assumptions like space goes on infinitely far if that's the current on trend uh idea amongst physicists are they talking about the universe with matter beyond the observable universe or are they talking about some sort of structure Beyond a universe our universe that is outside of the observable universe both both and again I'm I'm I guess maybe I spoke too quickly I don't want to speak from my colleagues they may like do a survey and say hey Brian Green you're wrong right the vast majority of us don't think in this way but it is the case that a commonly held notion is that number one space can go on perhaps infinitely far in which case you would have these other domains of reality that are contiguous with ours right and that's that first version of other stuff Beyond the Horizon beyond the observable universe but the common view for cosmologists today is that a theory called inflation inflationary cosmology May well be the explanation for the Big Bang so what banged in the Big Bang is a big question and there's a proposal on the table that there's a certain kind of fuel called the inflaton field and the energy in that fuel may have driven a period of repulsive gravity that pushed everything apart and if that's the case the interesting conclusion is the math shows that it's virtually impossible to use up all the fuel which means that the fuel that gave rise to our big bang would be left over there'd be some left over to yield other big bangs and those big bangs would leave over some fuel which would drive yet further big bangs and that's that second version of beyond that you're referring to those big bangs would would be outside the domain of reality that we would think about even if we're allowing space to go on infinitely far you might think well if it goes on to Infinity far then that must exhaust everything right I mean there can't be something beyond the infinite of space going on infinitely far but that isn't correct the weirdness of the space and time allow for our domain to be infinitely large and yet there to still be other Big Bangs giving rise to other Realms which themselves can be infinitely far so yeah kind of an Infinity of Infinities did it take time for you to dispense with the common person all of the assumptions that me and everybody that's listening has when we're talking about this stuff that you're having to remind us about the biases that we come into this our lack of capacity to understand what Infinity is and stuff like that time scales is there like some sort of deprogramming the advanced physicists and mathematicians go through some sort of like onboarding camp that they need to go through to get rid of that thinking pattern yeah in fact it's not even as easy as you suggest I think it's a lifetime of reprogramming I mean our intuitions are built up from the very same experiences that everybody else has in everyday life where you know there's a beginning a middle and an end to things you know there's a finite size to things there's a finite lifetime to things right since that's how we live that's how our intuition has been built up and it's more than just the intuition of a given lifetime we have behavioral perspectives and predilections that emerge from our own deep physiology our brain patterns our brain structure the the details of our DNA all of these things carry an imprint of our collective experience across thousands of generations and our forebears wandering around the African Savannah they had the everyday experiences that matter to survival And yet when we go beyond the everyday experiences and examine the quantum realm we examine the relativistic realm the cosmological realm everything that our math some of which has been confirmed by observations tells us is that the everyday experiences are not a good guide to have the world actually works so we are in a lifetime as a physicist a lifetime of tension between what we experience collectively as a species and what we learn about the universe through observation isn't it interesting that the Consciousness that we have maybe it's there so that we can correctly predict what other people are thinking so that we're more social beings or maybe it's there for any one of a number of other explanations why Consciousness is here isn't it insane that one of the byproducts of that is that it's given us this capacity to be able to start to grasp at infinities to be able to push the limits of something if we were not designed to think about this and yeah we've gone beyond our design specs it's we've all we've overclocked our brains the same way that computer hackers overclock their computers we've overclocked our brains the same way that a light gives off light but as a byproduct it gives off heat maybe this is because it's given us this particular structure of things to do one service social animals whatever it might be that's also just got this slight side effect and you guys in your industry are just leveraging that and twisting that as hard as possible yeah no I think there's I think there's a version of that idea that applies to many fields but I think it is most pronounced for physics and Mathematics I mean what what we do is as mathematically oriented scientists physicists we seek out patterns in the world right that's what we do we are pattern recognition machines that take in the world and try to find the regularities and by encapsulating those regularities in mathematical equations we're then able to go even further in our understanding now clearly pattern recognition served us well in the ancestral environment I mean those of our ancestors who knew where to go the next day to get the food those who knew what was going to happen when there was you know thunder and lightning and recognize the pattern that that was the signal to seek shelter right those of our forebears who could catch the patterns had a leg up in the battle for survival and therefore pattern recognition became intrinsic to what we do but you're right we are pushing that capacity well beyond the needs of survival and trying to find patterns and things that just don't seem to matter to our everyday survival right I mean you don't need to know about the Big Bang or the the weirdness of the electrons Magnetic Moment you know or Quantum tunneling or quantum entanglement or inflationary cosmology or the Infinities the space you don't need to know that stuff to survive and you can make an argument that those of our forebears who did think about these things perhaps they're the ones that actually were the ones that got eaten right I mean if you if you sat down on the African Savannah to contemplate the the Schrodinger equation and Quantum evolution of electrons you didn't notice you know the the the lion that was about to eat you right you know so so you could even say that it goes against survival but but we've gotten to a place in the modern world where we've got the luxury to do things that do not help us in the ways that pattern recognition was initially meant to help us and it takes us to some pretty weird and wonderful places it's so fascinating that for a long time the environment shaped our Evolution because it caused The evolutionary forces that required us to become Fitness adapting creatures but now that we shape our environment we are shaping what we will evolve and adapt into in the future I often think about how Evolution at the moment when the world is changing as quickly as it is is basically pointless because if you did get a slight genetic mutation whatever environment it grew up in that was adaptive by the time that it then passed that on to its children it wouldn't be useful anymore it was not completely true you would you might think that and there is certainly controversy on this point but there are some researchers who claim that there is real world Evolution that we can measure and see today they claim for instance that the heights of certain males in certain parts of the world is growing over time because females are selections selecting males based on height and so there's a small differential in the reproductive uh yield among males that are taller seeding the world with uh you know for someone like me average height you kind of like go off to the corner and hang your head low when you hear that kind of data but uh but but but the other side of it though is it's not only that we are shaping the environment that then is back reacting on our own evolutionary progression we're interceding in The evolutionary process itself so it used to be that mutations were these randomly occurring events and those that happen to enhance our ability to survive and reproduce were the ones that hung around and the mutations that didn't do that they quickly died away but now you don't just have mutations from random events we're going in and we're affecting the human genome directly I mean these are this is only going to become ever more prevalent toward the future uh and look they're they're they're clearly some very powerful things that we can do with that I mean look at the thing that we're dealing with right now right the coronavirus so now we have vaccines that have been manufactured according to the techniques that allow us to get in and have a molecular control over certain kinds of nucleic acids right so so so it's powerful but it also suggests that when we start to do these manipulations on human beings which are already we're doing that's going to have its own evolutionary trajectory that will be somewhat different from the one that has been in control for you know millions of years yeah we're not just cargo aboard Spacey Humanity are we we're crew as well yeah yeah exactly contributing to the direction how do you explain time to people as a phenomenon well I think most people have an intuition about time so the battle is to leverage that intuition and convince people that the things that they hold dear about time some qualities are correct but some quality Sciences revealed to just not not be the right way of thinking about things so most of us have a sense that time for you time for me time for everybody else is basically the same the time elapses at the same rate regardless of what you're doing where you are the gravity you're experiencing the motion that you may be executing that's plain wrong right I mean Einstein taught us now in 1905 what are we now 2021 or something so you know I can't subtract but what 115 116 years ago he he showed us in the most direct way that that's just not correct if you're in motion your clock takes off time at a different rate compared to somebody who relative to you is at rest if you're near the edge of a black hole time elapses for you at a different rate compared to someone not experiencing that gravitational field that's an extreme example but to go back to the Empire State Building if you're at the top of the Empire State Building your watch is taking off time a little more quickly than the clock of someone on the ground on 34th Street and Fifth Avenue that sounds crazy but that is how time actually works so I find that if you take people sequentially through these new qualities of time that are unintuitive we haven't directly experienced them and then explain experiments I mean literally people took atomic clocks put one on the tarmac put one on on an airplane and flew that plane around the world and then they compared the clocks when that airplane landed and these incredibly precise atomic clocks did not agree and it wasn't because the plane was kind of jostling the clock it wasn't like it's a smooth ride smooth sailing and yet because that clock was in motion and experiencing a different gravitational field because it was up in the air compared to the clock on the surface of the Earth grab it against a little weaker up there a little further from the center the clocks ticked off time differently there it is so so yeah that explains the weirdness of time but what about it as a fundamental phenomenon what is it what is it which phenomenon sorry as time oh I don't know what time is I wish I could tell you that's the weirdest thing at all right so we can measure this quality of the world call time we can measure it to incredible accuracy and when we do that we can reveal features of time that are unexpected you know ticks off at different rates in different environments but if you ask me what is it that you are measuring I don't know I mean people have struggled to give an answer one answer is well time is that quality of the world that allows change to take place okay you can sort of figure that that sort of makes sense uh time is that quality of the world that ensures that everything doesn't happen all at once okay yeah kind of but does that really fill you with a deep sense of understanding of what time itself is it doesn't do it for me and and so I think many of us suspect that the next Revolution and understanding will be one where we can finally give a deeper explanation and and there are some who suggest and my own field string theory is starting to give evidence for this some think that part of the reason we're unable to give a real compelling definition of time is because time itself is not as fundamental as we might have thought that there's a deeper level of reality where we'll find that time is made up of something finer something more fundamental I mean you look at any piece of matter and if I asked you like what is I don't know what is what is wood you could start to give me some answers but there may not be that compelling but then if you get down to the molecules and atoms and you talk about the atoms that make up the molecules that make up the wood and you talk about the protons and the neutrons in the nucleus and the electrons and you talk about the quarks inside of the protein now you get to a place where like okay I get it that's like the the most basic ingredient you put that together and if you put it together in the right way you get wood ah I I I can sort of get that and maybe the same thing with time so maybe the time is made up of some molecule I put that in you know air quotes I don't really know what that means that that molecule of time may be made up of atoms of time again air quotes they don't really know what that means but but if we could identify those fundamental constituents then we could say and if they come together in the right way voila you get time and if we could do that we can't yet but when and if we can do that I think that would give us that deeper Sensation that we more fully understand what it is we're talking about when we invoke the word time that's so cool that's awesome can you talk about the relationship between entropy and evolution that you go through in your book I thought this was absolutely fascinating yeah I'd be happy to do that and uh as you see me bobbing back and forth I clearly didn't calculate the angle of the sun setting yourself around if you need to blinding me hey whatever position I said but uh yeah so so I'd like to think about the unfolding of reality as this kind of interplay between these two conceptual Frameworks one of which is the drive toward ever greater disorder which is encapsulated by this notion of entropy and perhaps people have heard of the second law of Thermodynamics which gives us a nice mathematical and intuitive understanding of why objects and things and situations tend to go from order toward disorder that move from an orderly environment to a more disorderly environment which we can frame mathematically that's what the second law of Thermodynamics encapsulates so that's a kind of breaking down a withering away a disintegration the flip side which is entropy is a force that drives things to get ever more refined structure when you have a battle among living systems or even before that battle among chemical systems where those configurations that are best adapted to their environment are the ones that are going to win that are going to Prevail you can see a drive toward ever greater nuance and refinement because the more refined you are the better adapted you are the better chance you have of surviving and so you kind of have these two forces at work entropy tends to drive toward disintegration Evolution tends to drive toward ever more refined configurations and you can trace these two forces right through the evolution of the Universe from just after the big bang Evolution we tend to think about at the level of living systems but as I mentioned once a molecule learns how to make copies of itself to replicate those molecules that can replicate faster with greater economy and stability those molecules are going to win in the sense that they're going to be able to grab in more raw materials from the environment and make more copies of themselves so this drive toward increased refinement that evolution by natural selection gives us is something that has been with us even before living systems living systems are an interesting development along that evolutionary trajectory and so there is this interplay and you can trace it from The Big Bang till today and what I do in the book is I trace it also from today arbitrarily far into the future where again we see these forces at work guiding what takes place as we walk that trajectory toward eternity is it fair to say that humans locally reverse entropy then in a sense yes but you have to be very careful with what you mean by that I like to think of it as a kind of entropic dance that I've given a name it's called the entropic two-step and what I mean by the entropic two-step is the second law and you hear the word law you'll be like okay then it has to always be true that's not even completely true the second law is a little bit different what the second law says is that there's an overwhelming likelihood that overall entropy and disorder will go up but that doesn't prevent entropy and disorder from going down in some regions so long as there's a compensating amount of entropy that goes up in the wider world and that's the two-step entropy can go down over here so long as it goes up over there in some surrounding region and so human beings sure we constantly force entropy to go down we've constantly forced order to go up in our local environment but when you look very carefully at the detail process by which we force entropy to go down there's always entropy that's generated heat and waste that is generated that we expunge to The Wider environment so we can maintain order for a while because we can cause disorder to be emitted outside but sooner or later entropy does catch up with us so it's a local phenomenon that we can carry on with for a period of time ultimately we lose that entropic battle I remember speaking to Adam Frank on the show and he was talking about how one of the universals he thought we would find with any intelligent civilizations on other planets would be an increase in heat would be some sort of global warming because inevitably when you try and Wrangle the environment to do what you want it to do whatever that is you're going to give off these waste products yeah yeah uh so Adam I agree with that statement then it actually goes back to a statement of Albert Einstein so Albert Einstein once said that he viewed all understanding of the universe as provisional right theories come along they get developed they get replaced he even viewed his own general theory of relativity as provisional that one day it would be replaced but he said when it comes to the second law of Thermodynamics he said I don't view that one as provisional I view that one as one that will always be with us and indeed the second law by virtue of saying that entropy goes up means that heat will ultimately always be generated by any system and certainly a civilization of intelligent beings who want to preserve order in their local environment they will only be able to do that at the expense of generating heat that wafts outwards and so yes that is a a general tendency and you might ask well so why was Einstein so confident about this idea and that takes us a little far afield so I won't try to go into the detail but I'll simply note that when you look at how you establish the second law of Thermodynamics it doesn't involve really any detailed math or complex ideas it's simply the statement that there are more ways for a system to be disordered more ways for its ingredients to be arranged that will be characterized as disordered compared to the number of ways that those ingredients can be arranged to look orderly so it's simply a counting of the number of configurations of the particles and there's an overwhelmingly large number that yield disordered systems very few relatively speaking that yield ordered system I mean you know this you go into a kid's bedroom right it's a mess usually because it's just so much more likely that the ingredients The Good the games the books the choice will be in a disordered Arrangement it takes a very careful arrangement of the ingredients to look orderly and that's in a nutshell why Einstein had such confidence in the second law of Thermodynamics because of a toddler's bedroom toddler's bedroom that's all it was that was the inspiration but you draw a line between entropy and thought and this impermanence of thought as well could you take us through that yeah you know so if you push these ideas even further and you say to yourself look any physical system of any sort has to generate heat to preserve its own inner order if you take that as a as a given and as I said they're very simple basic arguments that lead us to that play they can say to yourself look let me consider a thinking system any thinking system regardless of what it might be a human brain a computer a weird thing in the far future that we can't imagine right now that's able to think any thinking system in order to have thought must generate heat because it's a physical process and if you follow that through into the far future of the cosmos you find that in the far future about the 50th floor of the Empire State Building to go back to our little analogy 10 to 50 years into the future a thinking system that generates heat the universe will not be able to absorb that heat it will not be able to take that heat in at a sufficiently fast rate which means that any thinking system in the far future if it thinks one more thought it will burn up it will fry in the heat generated by the entropy produced by the very process of thought itself and that comes to the weird conclusion then that thought will come to an end thought itself is a product of physical processes that cannot be sustained indefinitely in the universe isn't that fascinating that thinking is the thing which allows us to get the insight into How the Universe Works it's also the process by which we may be able to slow down some of the processes that would lead to our destruction but ultimately it is the cause of our destruction yeah yeah it is funny how you know the snake eats its own tail you know once again you know um and you can even say it's also kind of remarkable that through the process of thought we can understand that this is the Fate that awaits the process the tail going into your own mouth predict it happening yeah yeah yeah and there's nothing you can do to sort of divert that tale from entering the mouth there's no way that you can subvert the physical processes that ultimately will spell our own destruction I've read some Stephen Baxter sci-fi and in those he likes to play around with alien civilizations very very far into the future and one of the propositions that he puts across is these civilizations would basically upload themselves into some form of computer and then put themselves to sleep until the universe is significantly colder and then they would be able to run their operations and it wouldn't get so hot I'm guessing that's something you've come across as well yeah in fact it goes back to insights of a famous physicist named Freeman Dyson who sadly passed away not too long ago he played a key role in the early developments of quantum mechanics and had all sorts of interesting creative ideas and one that he had was exactly what you're suggesting that perhaps a living system a civilization could preserve its existence by going through long periods of hibernation so they think a couple thoughts and then they go to sleep and allow the heat generated by those thoughts to dissipate and it may take a long time for the heat to dissipate in the far future when the universe is you know very cold when things are moving very slowly but then they'll wake up and they won't even know they've been asleep because they weren't thinking while they were asleep right so they will wake up and they'll have another couple thoughts and then they go back to sleep and allow those thoughts to dissipate and in that way Freeman Dyson thought he had established a strategy by which any living system could exist forever but what he didn't know at the time was that our universe is not just expanding it's accelerating in its expansion this is a discovery in 1998 that won the 2011 Nobel Prize and if you take that idea seriously and imagine that the universe will continue to speed up in its expansion then it turns out that Dyson's argument doesn't quite work and the reason it doesn't work is because there's a source of heat that the accelerated expansion gives rise to and that source of heat permeates the universe permeates space and it's that heat that prevents the universe from absorbing the additional Heat that a thinking system would generate through the process of thought and when you take all that into account you see that living systems cannot live forever unfortunately or maybe fortunately depending on your perspective yeah what's a a boltzmann brain a balsamin brain is kind of a weird fluctuation of a particle configuration going back actually to the very first question that you asked me we started this conversation so in the far future there will just be these particles wafting through the void governed by quantum mechanics and and every so often and route to Eternity those particles can kind of bang into each other in an interesting way it won't happen often because these particles are mostly isolated but again if you're waiting infinitely long times or arbitrarily long finite times weird things can happen and one of the weird things is particles can Bang into each other and create or recreate a human brain out there in the void and that brain floating in the void can have a thought or two and these are called both membranes Ludwig boltzmann he didn't actually describe these things but using his ideas physicists of more recent vintage have developed this idea and the weird thing is imagine that that brain floating in the void just happens to have exactly the same particle configuration as my brain does right now right you might say well that's rare and I said yeah it's rare but and root to Eternity it's gonna happen rare things will happen with essentially probability one so that brain floating in the void is gonna think it's me is gonna have my memories because my memories are just configurations of particles inside my head right it's going to have my personality my personality is just the configuration of particles inside of my head so that brain out there in the void is literally going to be me saying oh my God how did I get here what am I doing you know floating out here in the void um and that's kind of a weird a weird idea and and the reason we come to this it's not like for you know some kind of comedic turn or something the reason we we think about this idea is because you have to ask yourself what is the most likely way that a thinking system such as of ourselves comes to be and you come to a weird conclusion when you invoke both brains because there's only one biological brain that we know of that's going to say be me right because there isn't enough time for multiple means to form in the natural biological way but because eternity is so far along both membranes and my brain forming via this boltzmann random manner that can happen arbitrarily many times and root to attorney and so will happen arbitrarily many times so they're going to be like a gazillion Brian greens floating in the void if you can think about all of time and only one of me that forms in the biological manner so if you ask me like who am I and where am I how do I get to be a dispassionate look at the numbers would lead me to say I'm a boltzmann brand that just formed in the void and the conversation that I thought that we'd been having for whatever the last half hour or so it didn't really happen it's just the configuration of particles inside my head making me think that I've been having a conversation with Chris Williamson but in reality I just formed right now with those memories of fake things that never actually occurred it's kind of a weird place to get to wow that's almost weird but even further the even weirdness is it winds up being a self-defeating conclusion because the only reason we even anticipate the possibility of both membranes is because of our understanding of the laws of physics quantum mechanics and cosmology and we extrapolate but if both of them brains are real then my recollection of Having learned quantum mechanics and Having learned general relativity that's also false and the data that I thought supported quantum mechanics and general relativity and because that's also just a fiction of the particle configuration of my brain right now so so so so so is winds up being a self-defeating conclusion where you kind of come to a skeptical nightmare where you can't trust anything at all so most physicists who take these ideas seriously are not really envisioning that we're both brains rather we use it as a kind of diagnostic tool to interrogate our theories and hopefully we believe will come to a point which we've not reached yet where we'll be able to suppress this possibility of both membranes getting our confidence back in the laws of physics as usually configured but as yet I would say we're not we're not quite there so this is really a a moment of physics in progress as we try to eliminate this this possibility of both brains but we have not fully done so as yet boltzmann brain is still on the menu yeah it reminds me a little bit of the simulation hypothesis this kind of like root and then a number of different child universes or child experiences that could be going on yeah no it's very similar you know this idea that we might be whatever like in The Matrix or something that we are just a simulation on some futuristic super computer um and it's a similar kind of set of considerations where if we ever are able to create conscious beings in a simulation then they will follow the same trajectory as with bolts membranes and say look there are a gazillion simulations that can be run but there's only one real universe that actually formed and therefore it's overwhelmingly likely that we're in a simulation just by sort of counting the numbers just by the laws of of probability and that that's also a weird one and how do you get out of that one well maybe you don't maybe we truly are simulated beings and maybe just have to bite the bullet and accept that or Nick Bostrom who's the guy who first came up with this simulation argument out of Oxford you know he says well maybe any sufficiently advanced civilization that could simulate conscious beings on a computer they also develop Weaponry maybe they go hand in hand and they blow themselves up and so you never get to that to that place or some suggest maybe the universe comes to an end before boltzmann brains or perform simulations actually arrive on the scene that's a possibility too right again we talked about one way in which the universe could continue to develop and evolve effectively for eternity but it's not the only idea about the far future there are other theories that suggest maybe the universe expands for a while then collapses in on itself a big crunch the Big Crunch could wipe everything out before boltzman brains even have a chance of forming it's so good it's so good do many physicists encounter existential crises when they start to think incredibly deeply about this sort of stuff I mean some have you know I mean Ludwig boltzmann the boltzmann of boltzmann brains you know he died by his own hand did he really die by Suicide now look I don't want to be armchair psychologist and nobody else can we don't know what was going on inside his head that day and uh it was interest Italy I believe it was 1905 1906. he sent his uh wife and family I can't remember how many kids maybe one or more out and when they came back they found him hanging you know um so you know was that some other you know just mental illness that that was driving I don't know but certainly he was confronted with these weird ideas he's confronted with the physics community that didn't accept a lot of his ideas that certainly may have contributed to it um but in terms of you know otherwise stable physicists who go to a dark place because of their realizations in physics I don't know that many I do know some and I I don't want to get too hyper personal here but I certainly am one of those that on occasion has found myself in a less than happy place a dark place by by taking in these ideas in a really full sense my sense and again I don't want to speak for the community so I can only give you my personal sense and and experience of the community is that most physicists don't take these ideas in at a fully emotional level some do don't get me wrong some do but many just see it as a mathematical game where what we're trying to do is have a better explanation of that piece of data a better explanation of the expansion of space better explanation of uh Stellar processes that yield heat and light and Spectra that we can measure with with great precision and so if you view it just as sort of a game of symbols that you write down trying to understand the external world then that's it you just play the game you enjoy it if you're lucky you come up with some equation that explains something it gets you a trip to Stockholm you know you meet the the royalty there and so forth and and if it's just that game then that's the level at which you take it in but I don't do physics for that reason not that I wouldn't mind getting the Nobel Prize don't get me wrong but what I'm saying is I do physics because I want to understand reality I mean I really want to understand reality and so for me these ideas are not just about making a better prediction or or maybe being used for a better Gadget if you can apply these ideas to me it's about what can this tell us about the universe reality and how we fit into this Grand Cosmic schema and if you take it in that way then for instance to learn that all structure will disintegrate to learn that thought itself will come to an end to realize that your life is this momentary blip on this cosmological landscape most of which is not inhabited by thinking creatures at all most of which is not inhabited by complex structures because they've all disintegrated when you really take that in fully yeah it can take you to a dark place I can tell you that for sure I have some friends who are nurses student doctors recently qualified doctors and I asked them the question as well do you ever get training about how to separate yourself emotionally from the things that you have to do at work you have some old lovely lady who comes in one day she's fine the next day she's blue the next day she's dead and you watch this unfold in front of you and I think there's a parallel to draw that that they see it as well this is my job there are some inputs there are some processes and there's some outputs that I need to make with it but on the flip side I have some friends who on the verge of leaving or decided to leave or sometimes get troubled by the fact that there is a there's an emotional layering on top of the job and um yeah oddly it makes me feel it makes me feel warm towards the physics community that the those guys yourself included are having to pay this existential price internally in order to further our understanding of how the physical world works well I deeply appreciate your empathy for us uh and I say that seriously but I would also say that I think I don't know if it's an occupational hazard or a selection mechanism I I would not call physicists the most introspective of human beings and again I hate to generalize because there are some that are deeply introspective um obviously I didn't know Einstein I only know Einstein through his writings um and some of his writings suggest that he was deeply introspective now the way he he lived his life in the way he treated some of his um Companions and his female companions suggest that there was a a disconnect between the introspection that perhaps allowed him to be deeply philosophical about the universe and the introspection that would have made him a a better human being in a more conventional sense so so it's hard to know um but I I've had so many students for whom this is just math and it's just calculations and they would have no patience for for thinking deeply about what these ideas might mean to them as a human being and what it might mean to their place in some Grand cosmological sense and and certainly my my colleagues you know I've got some colleague I'm at Columbia University some who are very open to these more expansive conversations and some who just roll their eyes if we were to head into anything that had to do with an emotional response to to our understanding of the earth oh come on give me a break it would be be their their kind of response and that's fine it takes all sorts to make a community a rich and Vibrant Community I'm certainly more on the on the end of of willing to talk about the emotional response to these ideas I mean I mean the reason I wrote the book is because for my whole life I've been experiencing an emotional reaction to the Deep ideas of quantum mechanics and cause cosmology and have felt the need to put down on paper a kind of Journey a journey of a physicist who is open to philosophical ideas who's open to psychological ideas open to Artistic and emotional ideas because to me the richest way to be in the world is to hear all these voices and to participate in all these conversations but I would not say that that's a dominant perspective among my colleagues so we talked about the matter and we've talked about the minds where how where does the leap come here to get to meaning and why did you decide to put meaning into the book well I don't see how you can think deeply about these ideas without at least having an urge for them to inform some sense of meaning or purpose and what has become so clear to me over many many decades but I felt like I sharpened it in articulating it in in a written form in the book is that well it's an idea that's old I'm not claiming any kind of novelty in the idea that I'm about to mention but I certainly felt like I got to it through a novel trajectory a cosmological trajectory and it's simply the the idea that there is no fundamental notion of meaning in reality in the world there's no fundamental notion of purpose there's no fundamental notion of value all reality is is collections of particles governed by quantum mechanical laws that evolve from one configuration in the early Universe to a different configuration in the late universe and in between there's a moment when those particles come together and they look like human beings on one particular remote planet in a non-descript galaxy and when you think about things in those terms it can take to that dark place or it can take you to a place of great appreciation and a place of gratitude because when you realize how unlikely it is that collections of particles would come together to yield a living system called a human being and how spectacular it is that this collection of particles called a human being can invent manufacture Notions of value and meaning and purpose how spectacular is that that particles can do that and when you think about things in those terms you recognize that there is a sense of gratitude that we should all have for the mere fact of existence and to go beyond that the spectacular fact that we can do things like create Beauty and understand the universe and illuminate mystery and experience wonder and the fact that particles can do all that I feel strongly if you take it in fully can fill me and certainly I think can fill others with that sense of thankfulness for existence however fleeting that existence may be and if you can get to that point I feel that it can really change your perspective on the world and I've seen this with students I teach my book to students in fact I was teaching it before it was a book and the book emerged you know from you know all that kind of thought and experience and I have students you know in the classroom who come to me and said that this has been a very different experience from say organic chemistry or even from you know English literature or from psychology because this can be a life-changing perspective and I've seen it happen and it's the most gratifying moment to me when I see students come to that realization it's so counter isn't it to the way that we as humans first phenomenologically as an individual experience our day-to-day moment-to-moment existence of the world it feels like it's bestowed with specialness like there's curses and blessings that come from on high and we have these all manner of different things going it feels like more than just matter interacting with Mata and then yeah when you layer on top of that the fact that we have cultural artifacts that are coming in you have these stories that you've been told were dispensing with or some of us are dispensing with religion now and the the stories that that had attached to it and there's people that are into astrology and there's people that are into all manner of different different ways to be in the world and um it's interesting to think that by getting rid of all of the things that add narrative and personify our experience in that way that put it into sort of human language that actually there's potentially even more Beauty to say that I am just Mata interacting with Mata and that's even more special yeah I I I agree with that and the only caveat that I would include in there is for those who feel that certain narratives are absolutely vital to their appreciation of their world and their lives for those who want to embrace the theological accounts or those who who find that that propels them to a better place I'm all for that I'm not of the new atheist Community perspective that the goal is to wipe say one particular narrative the religious narrative off the face of the Earth I do see that narrative as a natural outcome of the cosmological progression that through Evolution and entropy gave rise to living systems that themselves reflected back on their existence and sought to place that within a larger story we are storytellers that's what we do and among the largest of Stories We Tell are these religious narratives that imagine that the end is not the end that imagine that there is a larger purpose that is coming to us from on high I don't subscribe to that perspective but I see the power and the value of that perspective and so I like to think about reality as these layered narratives to use the language that you were mentioning a moment ago where you've got the reductionist story that the physicist comes along with and the the chemist comes along with trying to build larger structures and the biologist puts those together into larger structures still and then you come along to the psychologist the neuroscientists the philosopher the artist the Theologian these are all these layered accounts of reality and I think we as individuals have the power to figure out which of those narratives are most compelling to us which of those narratives give us a clearer sense of who we are and how we came to be and use those narratives to invent our own sense of purpose and meaning because in the end we are the authors of whatever purpose and value and meaning that we ascribe to it comes ultimately from ourselves and we have the power to pick and choose among those stories or to invent new ones in order to give us that sense of grounding I love that I absolutely love that can you talk to just how finely tuned our universe is there's a way in which it's incredibly finely tuned because what we have found in recent decades is that if you were to change any of the fundamental numbers of reality that we have measured and these are really concrete numbers like the mass of the electron the mass of the proton the charge of the electron the strength of gravity those are all numerical values that we have measured and it turns out that if you change them by even a small percent some of these numbers the universe as we know it simply goes away Stars don't light it up for instance if you start to play with the strength of the electromagnetic force and the nuclear forces and without Stars right the universe as we know it would be a completely different place so some have come to the conclusion that there must be some guiding force they're in the universe that carefully adjusted all of these numbers have just the right value for stars to light up planets to form and on at least one such Planet life to exist others however have a different perspective they say look you know um maybe there are many universes as you and I were talking about earlier in this conversation and maybe those other universes have different values for those numbers and among the collection of all universes effectively all values are represented and only in some of those universes will stars and planets and people exist and of course we live in one of those universes because we're people and therefore there's nothing fine-tuned at all when you look at the larger landscape of this Multiverse of this reality that has multiple universes so those are sort of two ends of the spectrum our universe is highly tuned maybe some god-like being picked it to be the way it is or every possibility is out there and we simply inhabit that part of the larger reality that allows us to exist is that the observation selection effect in a sense it is because clearly we couldn't observe one of those other universes where the conditions were such that we couldn't exist so you can say of course we're going to observe a universe that has the particular numbers that we've seen because we couldn't exist in any other universe and therefore we couldn't be there to observe the different values so yeah it's definitely an extreme version of that idea just how fine are we talking like how much of a knife edge are the numbers on it depends which number and it also depends on some assumptions so there are certain numbers and I wish I could rattle off precisely which ones and which percent off the top my head but I'll probably get it wrong so I won't do it but there are numbers like the strength of the electromagnetic force of nuclear force where it's just a few percent or called 10 percent difference would really uh render inoperable the processes that give rise to the things that we are familiar with however there have been papers recently that have shown sure if you just change one number then yeah you can mess things up and that may make it seem finely tuned but if you allow all of the numbers to vary they said like they're all these islands of possibilities that would yield systems that are not so different from the ones that we are familiar with and so it can be misleading they say to just look at one Dimension One Direction of change because that makes it seem more special than it actually is um so so it's somewhat up in the air exactly how how special it is but the fact is you know if you were to randomly choose all those numbers you know if I had like 20 dials here that you could change those numbers at at random I believe that it's unlikely that you'd hit upon one just randomly that would be like the universe that we know it's crazy when you think I'm trying to drive home the meaning in a Russian list World Point basically that the unlikeliness of our existence cosmologically individually genetically whatever it might be is so so vast I did a I did a tedx talk um at the start of last month and looked at some research that worked out the likelihood of your specific combination of genetics existing and it works out that the numbers 1 in 10 to the power of two million six hundred and eighty five thousand um which is obscenely large it's a ridiculously large number um and then when you think okay and that's within a universe where the cosmological constant is this and the gravity force and blah blah blah and you just realize that there is an awful lot to kind of be thankful for and I understand why it gives people I think awe and Dread are kind of the kind of sort of dance in tandem a little bit with this that I I can't believe how rare it is and oh my God I can't believe how rare it is at the same time and it came it terrifies you at the same at the same moment no no totally in fact there's another way of framing the the unlikeliness I mean one way is as you say just look at the sequence of letters in your DNA and figure out how many possible sequences of letters of DNA and you've got three billion base pairs Each of which you know could be one of four letters or a lot of combinations um but another way of looking at it is we are the end product of a series of quantum processes that stretch all the way back to the Big Bang that's all that reality is it's a series of quantum processes and in quantum mechanics there are many possible outcomes in any given Quantum process so each and every event that has happened from The Big Bang until today is an event that could have turned out differently and those different outcomes of those Quantum events would yield a different reality when you look at the long sequence of events that stretch back to the big bang and reach until today and so right there you've got just a gargantuan number of possible trajectories that the Universe could have followed that would not result in say you and I having this conversation right now you and I not even being here so so there is a great deal to be thankful for when you frame it in the DNA approach or the quantum processes approach it it just so it's so unlikely that we would be here and it'd be so unlikely that we would be able to even think about the sequence of events that result in us being here right I mean if a if an asteroid hadn't slammed into the Earth 65 million years ago it could still be that the dinosaurs would be the dominant species walking around and who knows maybe the dinosaurs would have evolved to a place of self-reflection I think it's unlikely right you know um and so and so right there again you see how that chance event astrophysical event was vital to changing the course of how life evolved on our planet allowing mammals to take over and allowing through other chance events our species to to Prevail and to take the form that it currently does so all of it suggests that it is so unlikely that we would be here having this conversation would be so unlikely that there'd be libraries full of Reflections on what life is and how life came to be that yeah if you if you take that all in you can do nothing else but stare and wonder at the fact that we're here at all beautiful given the fact that it's so right given the fact that our appearance on this planet and there being a planet is so unlikely what are your thoughts with regards to us moving forward like How likely is it do you think that we make it to space-faring civilization level given that it's so rare that feels almost like an imperative for us until we answer the Fermi Paradox we potentially are the only corner of the universe which is lit up with its own self-awareness which means that we have a duty and I know Nick Bostrom talks about um is it the the waste of our uh Galactic potential basically every moment that we're not spending colonizing the Galaxy is uh is a waste as far as he's concerned do you think about that do you think about our potentials for future I I do and I've read some of of Nick's writing on this I I do see it a little bit differently um I don't see a temporal pressure like I don't feel like we got to get out there we got to start spreading you know life I don't sort of feel it that way but I do feel the weight of responsibility which is at the root of of what Nick is talking about and what I'm talking about you're talking about there is a sense of let's not squander what the universe has been able to do at least once and maybe only once which is to have living systems that can reflect back on the universe understand the universe and take that understanding and begin to manipulate the universe to control aspects of the universe let's not squander that in the way that we clearly have and are right I mean I wouldn't say it's a waste of every moment that we don't start our journey to the stars but I would say it's a waste of every Jewel that's j-o-u-l-e every unit of energy that we expend on building weapons that we expend on war that we expend on killing each other that's the astounding waste that's the profound waste and and I think it's our responsibility as as thinking individuals who think this way to try to spread the word to the rest of our Brethren our brothers and sisters that we have this incredible opportunity that emerged from this incredible sequence of events to to reach out to The Wider universe and to understand more fully and to to seek other life and see what's out there I think if people could just be inculcated with the thrill of that possibility and the weight of that responsibility then I think things in principle could change but of course we're like infinitely far away from that on planet Earth at the moment and so you know some of us you know the conversations that you're having books that I and others are writing I mean it's all geared toward trying to spread The Wonder of these ideas and so we just keep going and hopefully we'll be successful it's only in the ignorance of the unlikeliness of our existence and the potential existential threats that we have that can stop our continuation plus the hubris that allows us to believe that we can continue to just Wrangle stuff around us that I think anybody could consider it not our duty our imperative to be focused on this um it's such a shame I often think about this I had this discussion with uh existential risk guy I don't think that you would be able to find a civilization out there in the universe that is much more emotional than we are I think that if you turned our emotional um set point up to be more reactive by maybe 10 to 20 percent I I don't think we get anything done which is crazy because that that that suggests that we're close to the upper bound of how emotional a slightly 0.7 on the uh kardashev scale civilization could be how insane is that to think it is an interesting way of framing it and I'd say it becomes even more interesting when you look at the other end of the scale I feel that if we were significantly less emotional that we would be that much less successful as a species because if you were a spock-like species like from planet Vulcan and your take on reality was all about logic and all about having a completely unemotional interpretation of the facts of the world and processing them through a rational logical perspective I don't think that that species if that were us I don't think we would have gotten to this place I don't know that we would have been able to spread across the world I don't know that we would have been able to invent the things that ultimately have transformed modern civilization in the ways that they have I think it's the creative Spirit the the Ingenuity The Innovation that comes from not approaching the world in a completely rational way that has allowed us to come upon unexpected discoveries and unexpected developments I mean even just take Albert Einstein as a case in point right if Einstein was just taking a purely logical rational approach to things I don't know that he would have had the leap of imagination that gave rise to the special theory of relativity and the general theory of relativity and the and the photoelectric effect is 1905 paper I mean he was a bundle of emotion that had access to this powerful rational intelligence and it's the union of the two that I think has been the source of our of our success you're right too much emotionality whatever we'd be at each other's throats even more than we are right now and we wouldn't have been able to make any progress much less than that I don't think that we would have gotten to the place that we we currently have so so if you're right and emotional beings are kind of rare in the cosmos maybe it'll be either a kind of boring Galactic exploration we're like oh yeah it's another rational civilization on this planet you know yeah it's another spot what are we doing out here yeah this is like awful or or they just will never develop to the point where we'll even be able to have that kind of communication something tells me that our capacity for emotion is directly proportional to the amount of enjoyment and utility that we get from the thought of exploration and from exploration itself like the goal is not simply to exist when Nick talks about the trillions and trillions of potential future human lives he's talking about the utility that they could get the the flourishing the eudaimonia the happiness that they could experience if we go on for X number of millions trillion years so it's not about just existing it's not about just exploring it's about using the our capacity to experience exploration to enjoy it and um yeah that's interesting that it's it's both the poison and the tonic yeah and and again I can give you a concrete example with with Einstein again so in November of 1915 as Einstein's heading toward the general theory of relativity right that's the final month of of research and work he he's going at it day and night day and night because there's a competitor named David Hilbert who he learns is hot on his tail now a completely rational logical being would be like well it doesn't matter who discovers this it's just we want to get to a deeper understanding and wouldn't have worked anywhere near as hard as Einstein did and maybe wouldn't have had the logical leaps that he had in that in that final month and at the end of that Journey he said something like you know the last few weeks of um exploration toward General activity he says have left me exhausted but he then said the success is Sublime and it's that feeling of the sublime which I think has driven so much of human achievement and I would say to to to underscore what you just mentioned and also perhaps to reshade the conversation that we were had about Nick and people needing to to space Fair across the cosmos I don't think that every human being needs to be concerned with extraterrestrial life I don't think that every human being needs to be excited about a journey to the Stars you know if you have a uh Johannes Brahms who's composing you know a spectacular Symphony let Brahms compose brahm's fourth Symphony Brahms doesn't need to be thinking about extraterrestrial intelligence so so that that emotional that Sublime quality of creation and creativity I think that's what you want human kind to respect and to Revere and to participate in but it doesn't have to be all focused in One Direction yeah okay again I absolutely love that one thing that I was researching recently the buetes void have you had a look at this I don't know what that is what is that so it's a super void it's the largest super void that's been found yeah yeah yeah have you had a look at much of these supervisors I I I've not followed that at all I mean certainly our uh our understanding of cosmology is predicated on the assumption that on the largest of scales the universe is homogeneous and isotropic and the voids have provided an interesting way of wondering whether that's true because the assumption is on margin of scales the voids would average out together with the arena that are not void that are full of stuff that on average it'll all be the same is that wrong if that's wrong then it causes us to go back and rethink some of our cosmological ideas there's some awesome YouTube videos about it absolutely fascinating I suppose they'll have to check it the crazy thing is it's it's massive it's a it's the biggest super void that's been found the the gaps are absolutely huge but I suppose if that's just the head of a pin if our observable universe is the head of a pin then perhaps that fluctuation is so low that actually it doesn't matter and perhaps it still is compatible and talking about from from the biggest to the smallest why do you think the Planck scale exists well um it's an interesting mathematical fact that if you just take certain constants of nature that we've measured Newton's Universal gravitational constant usually called G H bar Planck's constant that speaks to the quantum effects and C the speed of light if we take these constants and you combine them in just the right way you can make the units come out to a length and the particular length we call the plank length and it's a particular number 10 to the minus 33 centimeters and so so from a from a purely methodological perspective we understand why there seems to be a fundamental length built into the laws of physics you need units and those units are such that they can conspire to yield this fundamental length scale from a more philosophical perspective we suspect it's because the laws of physics as we understand them only work down to a particular length scale as we probe the Universe on ever shorter scales we've encountered newer and unexpected phenomenon but it's possible that the very notion of a smaller length doesn't always make any sense there may come a length where the notion of a smaller length is a concept that doesn't mean anything any longer and if that idea if that chain of reasoning is true then that is another rationale for the plank length the plank length would be that length below which the notion of below which doesn't mean anything and and so if there is such a length the plank length would be it it's so cool I saw a um a Theory online where someone said that the reason the Planck length exists is because we're in a simulation and that's the size of the pixels essentially that that's the smallest amount of bit information that could be transmitted so that's that's why it's there I thought that was quite a cute a cute way to put it yeah but whenever I hear things like that my rejoinder to that is but if he had a really clever programmer the programmer could make the sentient beings in that simulation think that there wasn't a plank length because the programmer is in control of the reality and therefore can make this stimulants you and I think whatever the programmer wants us to think so I'm less convinced that real constraints from the physical Universe necessarily have a home in a simulated universe or maybe he's put it in as a red herring so that you think that Brian green guy thinks that he knows what's going on yeah so that's the other the other the the the flip side is that the simulator can again conjure things that have no basis in reality um so yeah the interplay between physical reality and the reality of the simulator creates that's a that's a subtle one and I suspect it's in the hands of the simulator in the hands of the Creator and therefore crossing over between the two always feels to me suspect can you just explain for me the Copenhagen interpretation I really want to try and cut through this seems to be like the woo-woo element of physics that gets thrown around and is excuse for all manner of bad thinking can you just try and break down what it is and what it isn't well different people will answer this question differently in the community today so it's not a fully well defined notion the Copenhagen interpretation but my view and it's shared by many other physicists as well is that look Niels Bohr who was one of the founding pioneers of quantum physics who was working in Copenhagen had a particular attitude about quantum mechanics and any interpretation of quantity mechanics that captures that attitude is what we call the Copenhagen approach and his attitude was quantum mechanics is not about describing the universe as it is this is almost a quote of his quantum mechanics is about describing the universe as it is it's all about just making predictions for what we'll see on devices on counters on on measures on on instruments so Bohr was basically don't think about the meaning of quantum mechanics don't think about the Deep nature of reality just think about quantum mechanics as a tool and as a tool you should just use it to make predictions about the world and and so he viewed quantum mechanics as a mathematical algorithm follow these steps and we can teach these steps to any undergraduate even high school kids we can teach them follow these steps and it will yield a number and then compare that number with what number you get on a dial and that to me is the most concrete form of the Copenhagen interpretation now others will say things like no the Copenhagen interpretation is about you know you look at an experiment and that causes the quantum mechanical wave function to collapse onto this result or that result and therefore it's all about in uh interrelationship between an observer and The observed eh yeah I get it some people will say that but I don't think Bohr ever really felt that he'd gotten to grips with that relationship and so I think the the most um accurate description of the Copenhagen approach Bohr's approach is just use quantum mechanics as an algorithm don't worry about what it means perfect I think we've fixed a lot of bad thinking with that Brian today's been fantastic I really appreciate having you on we will be linking the brand new paperback version of until the end of time in the show notes below anything else where should people go if they want to keep up to date with what you're doing oh well we're doing a lot of stuff with my uh organization called the world Science Festival creating all sorts of programming so yeah people check out worldsciencefestival.com sign up it's all free some really cool science programming coming down the pike perfect thank you very much my pleasure thank you enjoy the conversation thank you very much for tuning in if you enjoyed that then press here for a selection of the best clips from the podcast over the last few months and don't forget to subscribe it makes me very happy indeed peace

Channel: Chris Williamson

Views: 212,880

Keywords: modern wisdom, podcast, chris williamson, brian greene joe rogan, brian greene string theory, brian greene quantum mechanics, brian greene time, brian greene neil degrasse tyson, brian greene ted talk, science, string theory, physics, black holes, quantum mechanics, world, festival, einstein, until the end of time

Id: k_nraMULtBA

Length: 84min 30sec (5070 seconds)

Published: Thu Apr 15 2021