What is Life? Five Great Ideas in Biology. | A Conversation with Nobel Laureate Sir Paul Nurse

[Music] do [Music] do [Music] hey everyone good to see you all it's been a few weeks since we've had one of these live sessions so thanks for tuning in as you know from the alert that you got however you got it through i don't know email twitter facebook youtube alert of some sort i don't know we are having a conversation today with nobel laureate paul nurse who uh brilliant biologist geneticist he has a new book we're going to be talking about that book that book is called what is life some of you may know that a physicist named irwin schrodinger wrote a book of the same title back in the 1940s schrodinger as we know of course is one of the vital thinkers in the development of quantum mechanics and i might mention that this year right 2021 is a special anniversary year it's a banner year for quantum mechanics the famous double slit experiment of davidson and germa the inklings of that experiment began in 1921 and 1921 speaking of nobel laureates in addition to paul nurse albert einstein of course was also nobel laureate and einstein won the 1921 nobel prize in physics he was a he actually received the award in 1922 so sometimes people get a little confused by that but officially it was 1921 nobel prize and what did he win the nobel prize for this group of course knows the answer to that yes the general person what did einstein win the nobel prize for most people say oh of course it was relativity they don't actually specify which relativity of course 1905 was the special theory 1915 1916 was the general theory but as you all know of course einstein did not win the nobel prize for relativity one of her quantum mechanics were more precisely for the photoelectric effect the explanation of the photoelectric effect which many people look at that explanation is one of the key moments some people say the first moment in the development of quantum mechanics so we will be having a number of programs celebrating this anniversary of quantum mechanics many of you have asked me when i'm going to come out with the quantum mechanics course that will be a partner with the course on special relativity that's on world science u it's on now youtube we for a long time only had that available in sort of a dark corner of the world science u website people weren't aware that it was there for the most part so we put out the special relativity course as you know in two versions we put out a two and a half hour non-mathematical version we put out an 11 and a half hour mathematical version yeah it's been kind of gratifying you know get that material out there the uh the non-math version i don't know a little less intimidating now we put that out in early august now so i don't know it's about six months ago got about two million views so you folks and others seem to appreciate the approach that world science festival has taken to having a more formal presentation still informal because it's me i'm always kind of informal but a more formal presentation of the ideas of of einstein and so many of you have been writing to me because a long time ago when we first made that material i said i was going to do one on special relativity on general relativity and on quantum mechanics so rightly you have said where's the quantum mechanics course sorry been busy these things are not easy to put together but we are now starting in on the quantum mechanics course so there will be a highly visual non-mathematical version for those of you who just like the ideas and want the ideas to wash over you and there will be a mathematical version for those who really want to to dig in and i don't know if i should probably say this but whatever the quantum course i mean i've been thinking about it in this context the world science youth context for a long time and i've been trying it out at columbia the methodology at least so i've sort of tuned it up see what students understand what they don't understand so that course will be equivalent to what i teach at columbia university so you know i don't know if it's gonna be free it's got i guess it kind of has to be free i don't know it's kind of weird so much effort and so much so much financial resource i have to tell you goes behind the filming of these things the creating of the animation so if any of you are flush right if any of you are flushing can help support that activity then we can keep it free so i don't know i think there's a button somewhere in the world science festival website so anybody feeling generous uh we would be enormously thankful for any support you can give on this let me just take a a couple questions and give a little preamble to the material that we'll be talking about here today let me see what you guys are asking here's one from raghav anand what are the similarities between original matter which we see around us against familiar matter and dark matter what are the similarities well the only similarity that we can point to with confidence is that ordinary matter and dark matter both when you have ingredients of either sort that give rise to a gravitational field they tug on other material objects in fact that's of course how we know that there is dark matter or at least i really should say to be more precise that's the evidence that we have suggesting that there is dark matter dark matter is not the only possible explanation for the observations but when we look at the motion of stars and galaxies the motion of galaxies that motion cannot be accounted for if the only gravitational force operating on those objects comes from the matter that we can see that's the original matter ra gabanand is referring to the familiar matter it has to be other stuff that doesn't give off light and that stuff that doesn't give off light is dark matter the dark matter gives rise to the force of gravity but the similarities could end there at least in principle i mean there are candidates for the dark matter that are ordinary depending on exactly how broad your definition of ordinary is it could be collections of black holes it's a possible explanation kind of a dark horse dark horse explanation for dark matter but dark matter could also be less familiar particles a leading candidate for a long time but now it's under some experimental pressure are particles known as wimps all right you know of wimps weakly interacting massive particles so these are are they ordinary not really in the sense of we don't see them in the stuff around in the environment tables and chairs planets and people are not directly made of wimps but these particles fit into a version of the standard model of particle physics critical physics it's a natural candidate and you may recall from our conversation with frank wilczyk when was that i don't know three weeks ago i think maybe three weeks ago now yeah we had a conversation with frank wilcheck and frank put forward this idea of the axion this hypothetical particle that emerges from other considerations not from dark matter considerations rather a particle that emerges to resolve certain questions having to do with the strong nuclear force and that could be a dark matter particle as well and again i wouldn't call that ordinary matter in the language that raghav is using it's pretty exotic so so the differences can be substantial between ordinary and dark matter here's another question i see well let me grab it before it scrolls away oh i think i got it prom virac prom prom sorry vrak to professor green yes that's me does life need to have some physical reality yeah that's relevant to the conversation today does life need to have some physical reality as far as we know it does i am of a materialist physicalist perspective i suspect that paul nurse is as well but maybe we'll probe his views on that in our discussion but a physicalist perspective envisions that life and even mind are nothing but collections of material particles arranged in a particular organized manner allowing for the basic processes of life to take place and those basic processes while paul nurse will discuss his view of what is life but just to tip his hand a little bit since i've read his book i've got the punchline already in mind he does come down with a physicalist perspective as he'll discuss where life is any system that can carry out certain processes among those processes are the processes of evolving information processing as we will see and so from that perspective it's hard to imagine life via that definition existing without a physical form without physical reality but look we don't know everything you know sometimes people get a little bit i don't know if irritated is the right word it's probably too strong they they they wonder in conversation with me whether i'm too open-minded about things that science typically issues ignores tries to cross off the list of things that we coherently talk about but the bottom line is i don't know what happens when we die i think we're just gone i think it's like pulling the plug on a computer i think the processes that define life simply stop and that's it but who knows and you know oftentimes to hedge my bed i mean i sometimes worry that it's the very people who think that way that when they die the plug is pulled so just to hedge the bets i don't know maybe there is something else i don't think so but i don't know so it's a good question and one that we cannot fully answer as yet but we will ask paul his view on that in fact in his book he has a nice moment where he's talking about his own brush recently with his own mortal nature and how that can infect the way one thinks about their life so whether or not one's views allow for an afterlife confronting one's own mortality can have a deep impact on the way one thinks about the world all right so just a couple minutes of preamble introduction to the kinds of ideas that we're going to be talking about here today look if you think about life and i'm going to jump right off of proom's question if you think about life as a certain kind of physical system you still even in that physicalist perspective face a number of deep questions and one deep question is how does the existence of life square with the second law of thermodynamics and in fact in the earlier book called what is life written by schrodinger that is what schroedinger was worried about not not completely but some of the later chapters focused on this question and and schroedinger schroedinger came to this notion that yeah understanding entropy and life is a conundrum really worth thinking about because look entropy what is the idea the entropy is an amount of it's a calculation of the amount of disorder in a physical system and a physicist named ludwig boltzmann gave us the answer to how you do that calculation in fact he loved the answer he was so wedded to the answer he was so proud of the answer he saw that answer as his legacy perhaps he saw that answer as his answer to his own mortal nature that he chiseled the result into his tombstone right so here's a little image i think we have there it is there's boltzmann's grave i believe that's in vienna i could be wrong don't hold me to that i think it's true but maybe not but look at the top there you see that formula at the top that's boltzmann and s equal k log w he chiseled the formula for entropy into his tombstone you know my tombstone will probably say i don't know loving father hopefully i'm i assume i'm going to outlive my wife she's extremely robust in the sense of any illness seems to just bounce off her i have to ask paul nurse about that she's got this mega powerful immune system so i think my wife will outlast me maybe she'll put on the tombstone you know loving husband i don't know i'm just sort of setting it up right now but boltzmann on his tombstone just has s equal k log w and in that formula s is entropy k is a constant that we call boltzmann's constant and log is the logarithm mathematical operation and w counts the number of microstates compatible with a given macro state so you look at the world around you and has certain macroscopic properties like the air in this room has a certain pressure temperature and volume boltzmann said if you count the number of rearrangements of the microscopic ingredients compatible with those macro parameters take the logarithm multiplied by k that gives you the amount of disorder that gives you the entropy and he and others were able to establish that entropy has an overwhelming tendency to increase disorder tends to increase the number of rearrangements of the ingredients available tend to increase but living systems seem to thwart this drive toward ever greater disorder and that's what schrodinger was concerned about and the answer he came to he framed it in a unusual language that has created some kind of confusion over the years over the decades now he wrote that book back in the 40s he wrote the book during world war ii in fact it's kind of amazing schroedinger i think we have a picture of schroeder he's kind of a wild man do we have a shot of schrodinger that we can sort of bring out there he is i gotta get i gotta get that outfit i gotta get those shoes i gotta get a photo like that that is a photo so schrodinger wild man that he was in fact there are wild aspects of his personal life that i that i won't get into now because it's a family audience suffice to say he had non-singular tastes in the environment that made him most happy and um and uh yeah so he went to ireland and in the midst of world war ii he gives these lectures on what is life and the people that come out to the lectures it was stunning high government officials large public audiences would gather to hear a physicist schroedinger talk about life and one of the issues was how does life apparently thwart the second law of thermodynamics and schrodinger gave the answer in terms of what he called negative entropy negative entropy and what he really meant by negative entropy is that we living systems we take in from the environment highly ordered structures food plants things that our bodies can then use as fuel and release the resulting entropy from bodily processes to the environment so we take in low entropy and we give off high entropy that's really what he meant by negative entropy i've sort of given this my own little name is called i called the entropic two step right what's the two-step right you take in low entropy step one you release high entropy step two and living systems are able to dance that two-step and we dance it as long as we live and when we no longer are living then we can't dance the two-step and our entropy our order goes away we disintegrate into a disordered structure and so that was schrodinger's answer to this issue of how we can have living systems in a universe headed toward ever greater disorder and it raises to a very precise level the ways in which life can be thought of as a physical system even our brains right i mean we have this nice little graphic here i think our brains and our bodies are nothing but collections of particles that for a while have a certain degree of order and organization and so these particles here they don't seem to have any structure yet but if you arrange them if you organize them into the right configuration that's the kind of thing that you can get a human brain able to carry out the kinds of things that our conscious self-awareness is capable of and so this way of thinking about things yeah it's very reductionist unabashedly reductionist some people apologize for their reductionist leanings i don't because at one in the same time i recognize that this is not the full story it is the deepest particulate account of say what a brain ultimately at rock bottom is but you have to layer as we've discussed previously and as i write about in my own book until the end of time you have to layer story upon story above the reductionist account so you understand the chemists chemists i should say account the biologist account the philosopher's account the neuroscientist account all of those accounts the artist's account they allow us to have a fuller appreciation of the question what is life but at rock bottom life is a physical system life is a physical system governed by the laws of physics and that squarely points to this perspective again i'm open to other ideas but this perspective squarely imagines that there's no life force this idea of vitalism that people put forward a long time ago there doesn't seem to be any need for it and somebody there doesn't seem to be any need for conscious awareness to be anything more than laws of physics playing them out in a very particular structure called the human brain so we'll be talking about these ideas with paul in just a couple of minutes let me just take one more question before we do that so yeah tim greenglass says schrodinger did not like cats yeah that's that's another quirky quality but he certainly made use of cats to uh popularize an issue i think it well actually it's an interesting question i know i'm not completely sure if it was if schrodinger's cat if it was schrodinger himself who used the cat analogy i think he did something in this chat just tell me i believe that's correct but if you ask me what the reference or the source was i'm not completely sure okay what else we have um so ted says consciousness as a field and the brain as a medium yeah people do use that kind of language but by feel do you mean again a physical field like the electromagnetic field sure then maybe as long as it all fits within the rubric of physics either as we currently understand it or as one day we will understand it the issue that scientists often have with that kind of talk and i've had that kind of talk i mean a friend of mine i haven't had a conversation with him in a long time but matthew ricard he's a buddhist monk wrote a beautiful book called the monk in the philosopher a kind of debate his philosophy his father was a philosopher a french philosopher real french philosopher i had a conversation with him once and uh he kind of had no time for me he had his views and would not think about things in a different way but anyway so matthew ricard he thinks about consciousness in much the same way that ted m just described it that somehow there's this consciousness field as a fundamental substrate of reality and somehow in a way that i don't really understand physical structures can tap into that field and that's what the brain is doing is that possible i don't i don't know i don't i don't see any need for that but if you ask me does science truly understand what consciousness is i think the state of the answer is quite simple no we don't i know maybe maybe when i bring paul in he'll correct me and tell us that now we have fully unraveled consciousness but i suspect that is still an open question all right i see that paul is in the waiting room so i'm going to switch over and let me just give you a couple words um paul he's a english geneticist former president of the royal society former president of rockefeller university in new york which is where he and i first met some years ago he's currently chief executive and director of the francis crick institute and he was awarded the 2001 nobel prize in physiology or medicine for the discovery of protein molecules that control the division of cells in the cell cycle he has also been in many world science festival programs not not a little while because he moved it was great when we had him in new york all to ourselves but he he moved back to the uk he's also the author of a new book what is life that we will be talking about and with that let me bring sir paul nurse into our conversation hey paul how are you hi brian i like your background you have a lot of snow there yeah it's actually a real background so you could think you know is it fake no it's there it is i don't you can hear the solid window yeah we're up in um in the catskill mountains where it just never stops snowing it's actually even maybe a little too much at the moment well i'm a bit jealous here am i in central london and it's just gray and wet as usual yeah yeah i remember that all too well for my oxford days 35 years ago or so yeah no but how are you how are you doing through this uh this period of strangeness in the world well it is a bit strange but i have to say i'm sitting in um the institute now and we have been um very lucky because we could had pcr testing from march onwards and we've tested our um colleagues and staff every week now twice a week and so that's allowed us to be largely open for the entire period sometimes we've reduced numbers the infection rates are high in london at the moment so we reduced it to maybe half but it's allowed us to be active as a research institute all that time wow and i mean have you had any problems because of that we have not really i mean we've of course have people who got infected um infected from outside we've had almost no transmission within the institute maybe over a period of nine months maybe two times possibly three because we were sequencing the virus so we knew that so actually probably this is the safest place in london i would say because we only let people in who have been tested in the last three or four days otherwise they can't come in and we've managed to keep it a safe environment any reason you don't do um the rapid test every day yes because they're not really very reliable i mean the tests we do are very reliable if we get a positive we check it again um at the same time so we we know we've got a real positive so that leaves uh false positives down one in five thousand one in ten thousand and the rapid the rapid the uh test just cannot begin to match that um right so when you do when you do the pcr test do you how long does it take to get the result we get it within 12 hours usually um sometimes it may take depending on the robots and when the robots don't work and get behaviors they should um sometimes it might take 18 hours but it's a turnaround in less than a day wow well that's that's uh that is the way to do it i absolutely agree um so thanks for uh taking some time out to speak with us i want to see you brian yeah it's great to see you too for some time really good to see you yeah no i remember those times we would join you in your office at rockefeller university and just have a tea and hang out no those are the uh those are good my office is much smaller now i did notice yeah i wasn't gonna say anything but i did notice you know that's what happens um but you have this new book beautiful new book let me make sure i get in front of the screen here what is what is life and we're gonna spend some time talking about that but before we do you mind if we just have a little um it's often nice for the audience here to get a sense of your own personal journey not to go into a fantastic detail but uh you know where you were born what your interests were early on just to get the ball rolling with that yeah i'm very happy to do that well i'm would you believe from my accent i come from uk i mean really um i was brought up in london um i was brought up in a non-academic family working class family i was the only one in my family to stay on at school after age 15 got really interested in science quite early on mainly through uh you would you believe um astronomy physics and also uh biology and natural history and um managed to get into university took me some time i wasn't great at examinations and i i had some difficulty getting in i managed to fail a rather basic examination um which was required for all uh entrance into university which was a basic qualification in a foreign language yeah and i managed to fail it uh french six times it was a i think a world record i think a world record but anyway i went to university i don't know i think a quick question on that so so do you think this is a pet peeve of mine do you think it's important that graduate students have a second language how vital do you think that requirement is i would love to have a second language without anything but honestly if it was demanded of me i'd be um sweeping the streets right right right so you know let's put it in context um so yes i'd love it and yes of course it's right to expect um that type of breadth but um i'm quite good at other things so it's not that i'm completely hopeless and everything else but not foreign languages but presumably you failed it because you didn't study hard right i mean no no i studied so hard brian you've got it all wrong i really really tried and um and for two two of those failures i i i didn't have any other i was working as a technician in guinness brewery actually a brewery that made beer and that's my only task academically for the entire year was to sit this examination and still manage to fail it twice complete no hoper but they'll let you in obviously at some point yes they let me in i um i i made a case and but they they gave me one condition and the condition was i had to do french for one year at the university and this is quite entertaining i ended up being allocated one person in the class with the most junior french as assistant professor and i remember sitting down in front of him and he said paul you don't want to be here and i don't want to be here so we're going to do a deal and the deal is this uh at the end of this i have to give you an examination i'm going to give you 500 words of scientific french to translate into english about a third of the words are in english in the first place because it's signed right i'm allowed you to take i am allowed the examiner to let you take any book into the um into the examination and i'm going to allow you to take a dictionary and i am going to guarantee that if you just look up every word and put it in approximately the right order i will pass you not well but i will pass you and i don't think we need to meet again in the rest of this year that's been i don't think it would happen today though that is fantastic well look it's been uh it's it's humanity that benefited from that french teacher's generosity of spirit so uh we can't we can't uh fault him or her for that so so then you went to university and and um when did biology sort of grab you as yeah it grabbed me really science grabbed me and then um i wasn't sure whether to go to physics or or biology my daughter one of my daughters is a professor in physics in geneva in the large hadron collider and i i could have perhaps gone in that direction but what i thought was um working at physics the problem seemed so big and in biology somehow the problems were smaller and as a consequence of that what i felt is maybe even if i wasn't great i could make some contribution to knowledge whereas i wasn't sure i could do that in physics so i went for biology and maybe that's even true because you know we play around biologists with smaller things and you discover more about the smaller things and it builds up whereas when i look at my daughter and you know this big problem of the you know the basic nature of matter you do feel a bit uncomfortable in your stomach maybe you don't brian but um well that's the that's the allure of it all but then when you're actually in the field you realize that most of the work you do is smaller even though it kind of slots into those big questions so maybe there's more similarity than than difference from a day-to-day perspective you know it's hard to maybe you're right maybe you're right yeah but you know what i was doing i was wandering around the garden looking at where spiders webs were and you know i'd make a little map and then i could think why is the spider's web here or there and it's a bit difficult to think about bosons in one's back garden in terms of experiments so yeah right there's that difference too there's there's no question about that for sure um and then you uh you started to work on research projects oh yes yes yes sorry we're back at university i decided that i um wanted to work i was interested in what life is and we're going to talk a bit more about it because i eventually wrote a book and i thought if i was interested in life i should try and focus on the simplest entity which unambiguously you could say was alive and and that is the cell and we i i'm sure we'll discuss a little bit about that and so i decided i wanted to be a cell biologist i decided i would use genetics to take it apart and then the question was during my phd um what should i study i studied something really rather dull if i could be perfectly honest with you it was um amino acid metabolism in in fungi i did a first degree in plant sciences and that taught me how to do experiments it sounds a bit mundane but knowing what a good experiment is knowing what a controlled is knowing um when you can interpret data in particular ways all of this is actually really important yeah significant lessons and though you're not discovering something great about the universe you're discovering how to investigate the universe and with that background when i and i did that in in norwich it's in the east of england where i was born actually i wasn't brought up there um but where i was born and i then decided um what is an important question in biology and it was thinking about you know what is the difference between something that's living and not living and one of the characteristics is the ability to reproduce right and here am i interested in the cell and reproduction and then i thought how do cells reproduce how do they control it and i decided that in 21 22 and i stuck with it prion yeah and here i am half a century nearly later and i'm still working at that same problem yeah well i mean it's great i mean you know uh i mean einstein wanted to know the unified theory and he stuck with it for 30 years he didn't get anywhere you know so you've gotten somewhere so yeah a rather bigger problem though if i may well you know different problem a different problem yeah so that um that does take us to sort of the the main the main issues here of what is life what can life accomplish and um you know the one thing i have to say quickly is i noticed that so here's here's your book and it's beautiful skinny book yeah about three weeks ago we spoke to your nobel laureate colleague in physics frank wilcheck who himself has another skinny book and i'm starting to see a pattern that all you nobel guys have these really skinny books except then i realized that kip thorne wrote a book and um you know gravitation and it's not so skinny so so maybe that's not the key i'm starting to think that maybe uh and roger penrose they're pretty fat too yeah road to reality is about um not that thick yeah absolutely now the other thing you know i noticed obviously and you mention it of course in the book is that the title is one that has been used before erwin schrodinger wrote what is life in the 1940s or so haldane js haldane wrote a version of what is life at a at a later time in fact i think we may even have their uh their book covers here so we can sort of see the uh progression there's that this is i have that i have that one yeah the distant and then haldane's version you know and then your version so do you see this book following in a recurring attempt by scientists to try to answer this deep question like is this a moment where we now have learned enough to reconsider this deep question well i tell you what i was trying to aim at i i read a lot of popular science books and what i began to notice is that the books written by physicists such as yourself generally took on big questions ones that we we struggled with and which um uh are go to the fundamental nature of uh reality but often biological popular books tend to deal with um trying to look over the horizon to some new discovery that is going to rewrite biology or is going to lead to some fantastic application and what i notice is the shelf life of many of those books was very limited and i say that because they they often didn't get it right it wasn't some you know big breakthrough that they were thinking about and it didn't leave to the applications that of great interest to people of course you read the books and what i thought was lacking was a book that just explained what we do really understand about life and in some sense there's nothing new in my book um i hope i explain it in a way that's clear and i talk about things that are interesting but i am talking about established principles within which we have confidence and the sort of books that you write are sort of a bit more like that yeah and i hope as i'm sure you hope with your books that this still can be read in 30 years and it will still contribute to something so yeah that was my starting point and the question what is life just to return more closely to your your um your starting point is of course the big problem of biology i mean how do we distinguish between something that is living and something that is non-living and i mean that's that's really um troubled people or fascinated people since aristotle really and we're still addressing the question schrodinger um brilliant uh scientist as he was was wrestling at a time when some of the fundamental principles were there but he focused only on part of it which was essentially speculation about the nature of heredity hereditary absolutely critical yeah within a few years of him writing the book which is 42 or 43 became much clearer with the discovery actually at rockefeller university that the hereditary material was dna deoxyribonucleic acid and then subsequently in cambridge england that the structure the double helix famous watson and crick and i'm sitting in the francis uh crick institute with um with the others that contributed to that rosalind franklin and morris wilkins um which explained because of the brilliance of their interpretation so simple that the double helix is a essentially a digital information storage device that can copy itself and there we hey ho we have the nature of heredity we don't have to worry about the second law of thermodynamics quite so much as um as certainly um schrodinger was concerned about and it it is putting together those sorts of ideas the nature of the gene the cell and other things as well that leads to a picture of life it's not a tidy um sort of dictionary like definition but it is a collection of attributes that i hope can clarify what life is and that's what i wanted to do to really describe ideas that we can be sure of you know say where they came from because quite a few of them actually have quite they're not that new yeah that was what is quite shocking they're not that new to get a better picture of life that's what i was aiming at trying to do i think he did a did a beautiful job of doing that and i wouldn't shortchange you know the final two chapters do discuss ideas that are relevant of the moment and may well continue to be relevant in terms of future developments so it's both the established and also the the visionary side of things but i do want to ask do you see the question what is life as a question that we're really seeking the answer to or do you see it more as a motivating framework i mean how important would it be to be able to draw a line in the sand versus using this question as kind of a guiding principle is it the latter or the former i think that's a clever question brian you've sort of got into my in between my ears into my brain there really because i set it up as this most important question but of course a definition of life isn't quite as precise as we'd like and i do discuss the virus which sits in this hinterland of the living and the non-living to almost illustrate that but asking the question does give us a framework into which to think about the problems of biology and really that's what i'm doing with it but you couldn't make a title out of that which was at all catchy what is life with a question mark it's certainly more catchy i would say without a doubt without a doubt um so would you would you say that in the end of the day it's a continuum or is it discreet between the living and the non-living i think it is discreet with some life forms um such as the virus um which do give us a problem with discreteness and i had a bit of a cop-out in the end and maybe when we talked about other things i can go back to it because i sort of argue it's both alive sometimes and dead others right i've never seen that written down anywhere before so that's my one one contribution in this sort of area it is a cop out but it's not so stupid i mean and um it so life is much more of a continuum than sometimes we think because we think human beings sit some in some pinnacle and really we have a lot of relationships with the simple little yeast that i spent my life studying and there's little vignettes in this book about um my random experimental career that did lead to certain things that i hope entertains yeah very enjoyable very enjoyable every time one of those came along like you know really uh uh energizes the whole discussion so it was great to include those well you know it's it it can get a bit tiring just you know the grind of sort of the textbookie type of stuff and so i thought i would liven it up it's all true yeah more or less true yes close enough yeah but i think there is a discreetness but what it what it demonstrates is certain principles the connectivity of all life we're all related to all other life forms that's a i mean it's a wonderful principle which is important in our age of trying to protect the biosphere in the planet there are everything around us that's living are our relatives i mean we have a responsibility to care for our relatives but not only are we related by descent which is what that means um we also interact so closely with all other living things without them we couldn't survive we couldn't exist it wouldn't be possible so it is this uh being related to life interacting with all life which is really um uh i wouldn't put it as a principle but it's something we need to recognize about about life to go back to him with more adventurous in the sense of trying to take on a problem which hadn't been solved and he came up with um a sort of code script yeah a critical um a a concept but he could only talk about it in a theoretical sort of way and but luckily within a decade it was essentially done yeah it was realized in a in the most concrete of ways um so um among the chapters of your book you lay out five big ideas that allow you to piece together an image a vision of what life is so you talk about the cell gene evolution by natural selection life as chemistry chemistry and life as information now for this particular audience that we typically have watching these programs the first three are probably relatively familiar the cell the general structure the gene the information encoding molecule evolution by natural selection but when you come to for instance life as information maybe we can actually start at the end and work our way back what what do you mean by that well life is information is probably the only part of at least this section of the book the first five ideas which might have some controversy about it it's not how it's it's not what you find in the textbooks whereas everything else you find in the textbooks as i said i hope i explain them in a more interesting way than most textbooks yes that's what they are life is information is rather important to me and i i won't really want to explain why um i think that to describe what goes on in biology we're describing the workings of the cell and the classical way that that's considered is to think about the molecules the chemistry going on in that cell and the physics of course and to describe the molecular mechanisms that are operative there so it's a description of process but to understand that description of process in biological terms nearly always requires thinking about information and we've already touched upon this i'm going to give two examples i get in the book the first one is dna itself now you can do a molecular description of dna the beautiful double helix but we have to escape from the beauty to think about actually what it means sometimes the beauty can be a bit distracting and actually if i ever go to an uh another research institute with a a piece of sculpture looking like a double helix again i will scream because it it just drives me crazy but the point about the double helix is that you are describing in precision the position of atoms to an angstrom um accuracy but it is a description it has no biological meaning where does the biological meaning comes from well the biological meaning comes from a couple of characteristics that emerge from that structure one is that it's made up of a a a chain of nucleotide bases there's four of them a t c g um which are in a particular order and this of course is just like uh computer storage what we have there um are four letters and um they are arranged in a linear order and of course linearity of the storage of information is is is something that's really rather universal and we see it in language we see it in speech we are talking in linear uh form with words and letters that make sense and they make sense because they have information and that information is conveyed and of course in the dna structure you have information stored so that's the first thing and it starts making biological sense in terms of heredity when you've turned that structure into information then the second part of that is the fact that the double helix uh these bases only pair with another base so you have a a complementary it's like a ladder and you have rungs and and an a will only link with a t and the g with a c we all know this but what this means is tear the ladder apart then you have a template to make an exact um not copy a complementary copy and you make two molecules which are actually the same as the original one and that is the copying of the code that occurs every time in fact a cell divides which is the process that i i've studied most of my life and you'll see that both of these properties are are built around information the storage of information and the copying of information and the critical thing about it is that the the description is chemistry the biology is interpreting that it chemistry in terms of information and this is of course people have been saying this for for ever since 1953 but stated like that it just emphasizes the importance of information now another example completely different because that one's very common is that the lac operon which is a gene in the bacterium which makes an enzyme which breaks down a sugar it doesn't matter about the details what you have is a gene made of dna that makes messenger rna that makes a protein the protein it catalyzes reactions and then there's a feedback from those molecules onto the gene which uh controls whether the gene is active or not once again you can describe all of this in terms of molecular interactions what touches what what components are touching the the gene the protein and so on but once again that is only description it's not understanding but when you put all of that together and recognize that actually this is a negative feedback loop that when you you are have the enzyme and it's making too much of a component and that feeds back it binds onto the dna and switches off the gene then once that happens you've created created a negative feedback loop and then it's the management of the information because that's information again the information which is embedded in that feedback loop it becomes biological it makes sense in terms of biology so it's the shift from chemistry to biology i think is centered on information and that may be the only i wouldn't say original thing in the book but it is a way of thinking about it yeah which i think is has some originality you know the um it's particularly striking for me because as you as you may know there's been a movement in physics to think about the fundamental principles governing all reality as nothing but information laws information mechanics you know of a different sort you know we talk about the information encoded in individual particles which have an information of where they are and how they're moving and how they're spinning and so forth so it is interesting that we move toward information and one question i i have along those lines is there's a tendency in science to use the most up-to-date technology as a metaphor for how reality works so in your countrymen newton's time there was the clockwork universe because that sort of ticking forward quality was sort of the natural view of the world to hold on to now in the information age are we doing the same thing grabbing the latest technology and using it as the template for metaphorically describing the world or do you think it goes the other way around that you know information truly is the deep idea and everything else is following from it i think it is a deep idea but we have to accept we do think in terms of metaphors um but um some of these concepts i mean feedback controls for example i'm much older than the computer age i mean much much older i mean we feedback machines governors uh if i remember rightly maybe even huygens in was thinking about this actually in terms of windmills maybe i don't know yeah well i might have made that up so it's good though i like it but for sure james watt was thinking about it with governors on steam engines yeah we all know that one but i think it went back to windmills and 100 years before so the concept of of that of information was around a couple hundred years ago and if we move into the modern age that both dna and negative feedback control came about in the 50s and there's no doubt that cybernetics was uh was uh arising there not so which led uh in the thinking we had touring and the concept of computing so i think all of these things were interlocked so our minds were do think in these terms but i do think it's a fundamental principle although there's always this scary thing that you're sort of halfway saying you know that we tend to try and explain things in terms of things that we're comfortable with exactly and i mean we can't help that we're human beings how can we explain the world except in the terms of what we are right and we get into a quite difficult country i've never understood why maths is so important in physics in explaining reality i mean well the inverse square law i look at it and i wonder about the inverse square law right that one we can give a good explanation though because if think of the lines of force spreading out on a sphere the area of the sphere goes like r squared so they dilute by factor so there are some some things that we can give some insight into but do you think that the principles that you're laying out in the book say these five big ideas they seem to be general on planet earth but is that a special case i mean if there is life out there and i know we're getting a little bit hypothetical but the question itself i think does still make sense do you think that this is the only way that life can exist well what i did in this book is i i explained these five ideas which is it is really explaining uh basic principles underlying all life as we see it around us including that tree behind you right and you sitting in front of that tree then what i tried to do was to derive um some common principles that allowed us to think about um about life and i came up with um with three principles that i think are um are important and they uh they really are built on um the first is that and this wasn't my idea at all i i i i it was well known that living things have to be able to evolve um it's the only way we really know that we can produce um purposeful behavior without having a creator of some sort because evolution by natural selection allows behaviors to emerge that um lead to purposeful consequences for the for the whole for the organism yeah and to produce uh something that can evolve you have to have an organism that can reproduce sorry about that not at all amateur hour i forgot to turn my phone off sorry everybody i i just thought it was support for this idea yeah that's it someone's calling in saying absolutely right that's what i thought so a living thing has to be able to reproduce it has to have a heredity system um which determines how that living thing works and that heredity system must exhibit variability now the these were three ideas of hermann muller who was a um american um geneticist in the 1950s and 60s and with those three characteristics you will get evolution by natural selection and that will give you personal behavior then we have to think well what is a living thing then we go a bit material they are bounded physical entities we we have to say that because so we can escape from computer life you know right we'll end up in endless discussions about computer games and i definitely wanted to avoid that so it involves um physicality the simplest unit that we can say is unambiguously alive at least on planet earth is the cell yeah and that bounded nature of the cell means you can escape the chaos of the second law of thermodynamics because you can have order um at the consequence of disorder beyond that barrier so that is the second point and then the third one is just what we've been talking about living things are chemical physical informational machines and all of those things um operate together they have a metabolism they make themselves they maintain themselves they reproduce they act as a purposeful whole as a consequence of evolution by natural selection now that's what we see in life and i've described it like that because it has a sort of abstraction about it it you'll notice it didn't get into what we normally do in saying living things are made of protein and dna and rna which is the way nasa would think about it when they go and look for life uh somewhere else or they would look for um of course as you know the astrobiologists for an imbalance in the atmospheres of plants and so which focus on the chemistry rather than the principles of what life is or what you refer to as mrs gerd or grant mrs graham it is gren did you like mrs grant yeah that's what i was taught at school let's just describe what they are and we escape getting into principles now there's a couple of things that apply to those um principles um sorry there's a couple of notions i want to put on those principles that are important for for life on this planet and then think about other planets so i am going to get to your question now take your time but the chemistry of life that does all this stuff is built on carbon polymers and we see carbon polymers um as the basic structure of dna and we've already talked about the double helix and the sequence of nucleotides and this is of course an information device that leads to the protein carbon polymer and the protein carbon polymer is is rather different to the nucleic acid one yeah it is also a sequence of of of of components called amino acids but it's more complex than dna dna which has got four different base nucleotides in the case of proteins it's of course 20 different amino acids and those amino acids have very variable chemistries they have some are basic some are acidic some are bulky some are not bulky some of these amino acids like water some do not and what this means is that you've turned the rather boring chemistry of dna which is great for long-term informational storage into another carbon polymer which can fold up in a huge variety of ways and of course the way that it happens has been recently solved by google deep mind which is his wife was my graduate student actually is that right and we are now um exploring a collaboration actually i have to say addressing these problems but anyway what i was saying is that the chemistry is um formed by this diversity in amino acids folding up in different ways and why i'm stressing that is the inert chemistry of dna is great for stable informational storage the complex uh chemistry of the protein is essential for chemical action it's the machine of life yeah so now we've turned information into chemistry right and that i think is a fundamental principle to deliver this and to get back now to life elsewhere i don't know quite what the chemistry will be but i'm having a good guess that it will be based on polymers of some sort to encapsulate this idea of both information and chemistry which are i think central to biology yeah and i have to say when i read in your book i mean you know i've never studied biology formally yeah besides high school kind of thing but you know i've done a lot of reading over the years but when you encapsulated it as these two flavors of polymers you know one dedicated to having stability and one dedicated to having chemical activity so that the active part is on the outside versus the versus the inside for protein versus dna it really clicked for me in a different way i have to say so i really uh appreciated well i haven't seen that written quite like that anywhere yeah i mean it's not that it's very profound but it is it is an interesting way i think to think about it and something which um you know a 13 year old could understand yeah absolutely now in part of what you just described a little while ago you described how you wanted to talk about these bounded physical systems in order to not get caught up into these issues of computer games and life and so forth so i guess you have little patience perhaps for the question that i'm gonna ask so feel free to dismiss it at will but consciousness is a topic that schrodinger certainly took up in his what his life toward the end he kind of often kind of went into a an unusual place with it he brought in vedic ideas vedic scriptures uh you know my my brother is a hari krishna so this interplay between the vedas and physics is something i've kind of lived with for decades in those kinds of conversations so maybe imagine you in orange i really could actually yeah that's right that's right i can i can perhaps join as well i wouldn't look so good bald though i don't think uh i don't know but um but so stronger had certain you know obviously he was this deep physicist quantum mechanics is a lot of it's his handiwork he allowed his mind to go to unusual places of course but when it comes to consciousness what is your view because as you've been describing things my natural takeaway would be that the one that i agree with that ultimately we're just collections of particles governed by physical laws that manifest themselves as chemical relationships that manifest themselves in certain biological forms is that it is there more well you you'll note i did have one page ducking the question um because um i think it it's quite difficult to define consciousness i have to say let alone understand it and i would say this is going to be one of the great uh questions of of humanity for the next hundred years or more but my position is this what you just said that it is an extraordinary um development of this sort of uh chemistry and information leads to our neuro uh systems neuro uh systems that control everything we're doing including me talking to you and out of that emerges um feeling conscious of now this is spooky isn't it i mean it is it's really spooky and i i actually just put up the white flag because i wanted the book to deal with what i felt i had something sensible to say about without having um uh to speculate i seem to remember our mutual friend roger penrose thought about consciousness and thought it had something to do with a structure in the cells called microtubules correctly some years since i've read that and i happen to think that's extremely unlikely um but something about the you know the trillion whatever it is nerve cells that we have in and a zillion um connections that they make and the electricity the conductivity there gives rise to me looking at you and knowing you are brian green and knowing that you are like me but different and that i can talk to you and we can make sense and make sense of the world around us i mean einstein said that the most mysterious thing of course is that we can make sense yeah of this world right and i decided that for this book this is the english version of it which is awesome can i see the cover again look at this it's got all the tree of life uh very nice yeah yeah and it's got a butterfly on the back i talk about it oh because you talk about butterflies when you're a kid yeah i do so um i thought i would leave consciousness for a bit later right right all right so i totally i totally respect that position but in that um can we let the white flag down just for one second but uh so so we spoke about information and we nodded at least to the other basic biological gadgetry within which that information is processed in a living system the cells the genes and so forth um if one is really committed to the information view it may lead one to the conclusion that the substrate's not that important ultimately if the information is processed in the right way then all of the qualities including consciousness perhaps would emerge even without the wet wear out of you that that you are warm to or well um depending quite on what you're suggesting there i i think it um is dependent upon physical reality so i i so let's imagine that we could reproduce the information processing in a completely different substrate the key thing is information and the connections yeah and that is um that could be completely divorced from the nature of the chemical reality if that's what you're saying with that i could imagine i don't know how it would all work i could imagine a conscious being which is based on a different sort of chemistry and i mean what follows chemical and physical laws but a different nature of chemistry you know the science fiction authors often they get they quite like silicon as a sort of the capacity to um four bonds i get all that stuff and so you know you can have these sort of silicon life forms but i think the information i thought just for a moment you were going into a completely abstract world that one might have life forms which were divorced from materiality and i'd have a bit of a problem with that detail but as long as it's grounded in physicality right in physicality it could be quite different um and it could still work since it's based on information yeah we don't even have to go to consciousness actually to say that because i'm sort of saying that about the simpler problem about what is living so well the only reason to go to consciousness is because it raises a slightly curious question which is i think i believe but this is not based on any real knowledge beyond extrapolation from where we've been so far i do think that a computer computational system if it had the right connections and processed information in the right way would have the same kind of inner sensations that we do would be conscious now how would you ever prove that all very difficult questions but if one does take that perspective which is a very information theoretic perspective then one comes to the possibility of a consciousness in a computational environment but by your definition it wouldn't be alive so could you have consciousness without life well i that ian mckeown who's a friend of mine novelist has written a book about oh this one i robot that that robot i have not read it okay so he he takes this full-on and addresses the question exactly as you could imagine um about whether you could devise um a conscious being um who would be behaving like us but built in this case on um on silicon and information and uh it's a very very interesting i know him and he is very interested in science and it it does tackle um this this problem i i do think that we could imagine um a life form built on different chemical principles which is got information embedded in it which would have the characteristics of life if we now take the sort of the touring sort of test yeah which is really where you're you're going to um that you could imagine it now for the life forms that i'm thinking about we've got to build into that also the ability of these systems to um reproduce and undergo natural selection and so on yeah and that is a bit complicated to put into a purely uh sort of a digital type framework but i do think what is good about this is to imagine it yeah as you are doing and as as ian did in his novel and um to imagine it helps us think about what actually we are ourselves anyway and the i i mean that the the the you you should read this but because in the queue and ask the question you know uh should you kill such a robot or is that murder basically and i mean just to yeah i mean it's full of drama of course in slightly um ludicrous sort of situations but ask a very good question right right absolutely so then where do you come down and i'm not going to dwell here so don't think that we're going to be off in deep philosophical land but in your book the word free will appears but just before it is seemingly or apparent i don't remember but some qualification of that so so clearly you were in that space of is it real is it not how do i square this with everything i've discussed in the previous chapter so where do you come down yeah you do like difficult questions ryan i should have realized that before i came on so first of all um i did use a word like a parent and i use a word like apparent um because um definitions of free will have built within them um the notion that there is something the ghost in the machine um that is um that is deciding something outside material contingency essentially of dependence upon physical laws because if it's dependent upon physical laws it's all all there and predetermined and so i hedged my bets being a careful scientist with the word apparent because it may be what we think is free will is not free will but it's important for us to believe that we do have free will and within the limitations of what we are we have free will within the societies that we built around us so i think the way i would start to tackle this uh term of free will is to sort of try and think about it in terms of our community our society our societal restraints within which we have free will but we are within that a machine i mean we're back to descartes but uh we're a machine that is still subject to the physical laws because if we try and push free will back that far i think we're going to have trouble with um with physical laws in fact i agree you know it's interesting because um i feel that way very strongly in the conversation i had a few weeks ago with frank wilceck physicist um it came up and he was unwilling to go as far as i or as you he he was somehow unwilling to give up that notion i couldn't quite get to the core of where he was seeing free will beyond him saying that well we certainly feel like we have it it's very important that we feel like we have it which we would all agree with but i think it's also important to see the truth and i think the truth is that a lot of that at rock bottom at least the conventional way of thinking about free will is speaking to something that is illusory and i like your framing of it in terms of how we as a collective in a in a society in a civilization engage and react to one another which does lead to the next topic that i'd like to spend a little time talking about which you mentioned toward the end of the book which is we now have capacities as you as you describe in the book they're not really new capacities to modify the genetic makeup of a living system but they have gotten to a place of power that we didn't have 20 years ago or so crispr cash9 this capacity to go in there and snip out particular segments of a genome change it replace it with something else do you see this how should i say it let me frame it this way so in your book you made a distinction a natural one between evolution by natural selection and intelligent design an intelligent design was not the trial by error approach of evolution by natural selection rather there was an intelligence designing the car designing the computer are we nothing but the mechanism by which the universe discovers intelligent design and are we in some such as carrying out the natural progression from random change evolution by natural selection to an intelligent version of that emerging from that very process from the gecko well um sort of yes i mean i mean we have evolved um in this random fashion to a a state a state of being a being in fact that can control their own destiny um in the way that we manipulate the world around us and of course other animal and plant life manipulates the world around it it's it's um its environment but we've taken that to several logs higher in how we can manipulate that and how we can design things and now as you've rightly um indicated we have methodologies that means we can contemplate even designing our fundamental code script to go back to schrodinger's term i mean these this ability to modify genes very precisely again as you rightly said um it was not invented with crispr cass in fact um it was invented um in in microbes including yeast in fact i invented it from the yeast i work on uh back in 1980 and that's the main reason i worked on such a simple thing but a fantastic revolution for crispr cats is you can do it in everything and very simply and indeed we now use those techniques because they're simpler than the ones um that we that we devised um long ago and the of course the the rubicon here is modifying our own genes in precise ways and that in turn brings about this notion of design of designing ourselves and this is something we do begin to need to talk very seriously about because we as scientists can say well we now have the technologies which are close to um being able to say this type of technique can be used safely we're not actually there yet i mean i of course i'm aware of um what happened in china a couple of years ago um but that really that wasn't um responsible we're not yet yet there we we can do so there's no um feeling of error of what i'm saying to use these techniques to change um somatic cells which might have a cancer or some disease is i think perfectly acceptable it's like a therapy you change your egg that turns into you which changes everything about you or sorry every cell within you which defines everything that is about you is quite a different thing and introduces the problems that perhaps you wanted to get to at least touch upon that we can change our nature our personality i mean to cure a monogenic disease like cystic fibrosis if we could do that i'm not sure most people not of course some religious people might have an objection but to stop that suffering with a single disease gene that we could change i think it's something that most people would accept but it has to be discussed in society to come to decisions but to have designer babies you know tall with blonde hair blue eyes or whatever is somehow a bit distasteful and then to go further even more distasteful i need to say something about this though we simply do not understand the um genetic basis of so many of those characteristics to do it in any sensible way to be able to deal with a simple monogenic disease which are not that many is one thing to be able to design perfect pitch or um creativity of a beethoven or whatever quite a different matter and um we are in no position to meddle as yet but wouldn't wouldn't i i mean i agree but wouldn't you also agree that it's highly likely that if we were having this conversation a hundred if we're still here 500 years from now this will be a this ship has sailed this ship has sailed i mean it started saving with uh frankly with um dna yeah and rockefeller university is um finding out this dna it started we now have the tools um when we have the understanding to go with the tools we will be able to contemplate what you're saying so what do we do we have to start talking about it and we have to start talking about it now before the train has gone too far down certain tracks because now we can talk about it in a rational way because it's not just over the horizon it's still quite a long way away and we can talk about it in an abstract way which where emotions can be controlled and if we leave it too late then we will be overcome um i think by an inability to discuss it in a cool way in a careful way which is absolutely required for problems and of this sort we must talk about it now and we must talk about it in a sensible way and we must have talked about it in a in a in cultures and which respect truth and honesty and rationality and i'm very pleased to say that the us has now turned a corner into a a greater possibility of of that type so you know i'd be fine to leave the conversation there but if you mind like just to push half a step i couldn't stop you even if i wanted so i i i agree with with the sentiment question a would be how do we have those conversations and then question b is we faced a similar type of issue with the advent of the atomic bomb we had let that genie out of the bottle not with dna but with a deep understanding of uh fission infusion and there was a worry back then in the 40s that these kinds of weapons would be used repeatedly that would be the end of the earth now the reason why that didn't happen is partly because we have the conversation partly because there is mutually assured destruction and that helped people but the third leg of the stability is it's not all that easy to build an atomic bomb it's not that it not impossible and it's becoming easier but it's not all that easy but my understanding is that there are kits that you can buy to modify and it's not like you're doing it you know in the germline you know as you're saying but isn't it too easy for people to undertake these genetic modifications for the conversations however positive they might be to actually stop what's inevitably going to happen no you're right because i i to bring this up because we we've got to accept that there's going to be behaviors that are not entirely um sensible and you could do this in your garage i mean to do it in the germ line and then produce an embryo isn't quite as straightforward as that it does require um skills but they are not skills that are required and resources to build an atomic bomb so that's right so this does emphasize the need for the discussion now because we will have those rogue people who just might do it and i mean so in some areas of the world where there isn't restraints i mean this could just happen so we need to have frankly a sort of world discussion about it yeah i mean so that's the first thing i would say we need a world discussion we need a discussion now we need a world discussion and we need to devise ways of doing it now i'm not going to try and offer you a solution to it but i think that's already a start yeah um that we need that discussion and it needs to be on a world basis and us scientists have to really um promote that with our political leaders so that that is taken on and should it be the scientists through the political leaders or should it be the scientists you know taking the stage and i mean what what is the mechanism that you think would be most effective well what i think about these science sort of public issues is the scientists are there to inform and to explain and then to enter into a normal political debate and have no special status within that debate beyond knowing what is possible and what is not possible so i'm clear about that it doesn't mean that scientists cannot have political opinions and participate in that debate but they shouldn't have a special authority in the nature of the debate they have a special authority in explaining what the issues are and explaining what is possible and explaining what the consequences might be and then it has to enter into a a proper public and social debate which has to be undertaken in rather careful ways not through a sort of lobbying culture it's got to be a a rather restrained environment for it and and it's an interesting one of how one would do that given that i think it has to be on the world stage somehow do you think that scientists have the skill and the inclination to transcend the nationalistic tendencies that usually grab hold of the political machinery of the world well i i think that on the whole scientists are not terribly strongly nationalistic so i i i think that's probably not the limiting factor what i think is probably the limiting factor is having enough scientists who are capable of participating in the debate in this way with the politicians in any sense at all because most of us um our nose is very close to what we do and this requires the knowledge from this but in an interpretation which is much wider and frankly there's not so many scientists who are good at that has the uh has the world's response to covet 19 giving you cause for a hope or is that moved in the uh move the needle in the opposite direction well we can argue it both ways in a sense um i'm the optimist i think played right this is a a return to rationality i mean the debate about vaccination it is going to be a linchpin in this yeah and i do think we have an opportunity as scientists to to create a new enlightenment which based on the principles of rational thought and observation and experimentation of the 18th century which in the 18th century was confined to a few people we sometimes forget that yeah but most agricultural laborers on the laborers on the land were not thinking much about um the enlightenment principles but today the bigger challenge is to have the enlightenment principles but to though see that within the population of the world as a whole and that's going to be the i think something after kobe that we scientists should try and promote a discussion of how we can create a new enlightenment built on the the principles of rationality and tolerance and all those good things but this time across all the population and not just an elitist few yeah no i uh i second that and uh you know i know you've had a lot of engagement with world science festival over the years that's certainly one of the things that we're talking about and one of the goals that we set for ourselves too one of the other things you discussed in the book is this interesting it's not really a paradox emerge and evolve you need to have death these these phenomena and do you think that that is a principle that is as general as perhaps the other three principles that you use to define life will we always face mortality well i i didn't put it quite into the same category right so he didn't yeah and if i can explain why and it won't perhaps be quite the reason that you might have thought um it's because um without death you can't replace one generation with the next and without being able to do that you cannot evolve by natural selection unless you have an infinite resource yes so if if you don't have death but you have migration and separation as long as the resource is not um limiting then you could have it you could continue to evolve by natural selection that's obvious but um we it it would soon run out of space to be able to do that at least um in in anything we could imagine so that's why i didn't quite elevate it but in a situation where you are bounded to a certain um like planet earth yeah then we need death and it's only through death that we have life which is the what i sort of said i think yeah you know in fact that was actually the thought that i had in mind you know there is work of course headed toward some claim extending the human lifespan not just to 200 years but perhaps even indefinitely and then for that to jibe with our general understanding of life obviously you'd need these individuals to migrate you know and populate you know and space goes on infinitely far so in principle the capacity might might be there but uh of course that's uh does rely upon the supposition that these approaches to eradicating mortality will succeed do you think that the work that's being done toward that holds promise um no um obviously it's thought to be the case in california or at least somehow parts of california but no i don't i think that um it will be possible to prolong life um a bit um you know maybe 100 years 110 100 you know that sort of order 120 it has to be combined with a healthy life i would say otherwise it's not worth having yeah of course um and that's often thought about but when i read this notion that um we could just be um as as we are immortal i mean my yeast cells are immortal in that sense but i don't think i'd like to be a yeast cell i'd rather be a human being if it was only three score years and 10 than a yeast cell so you have immortality with a single cell organism or you can do but i prefer this particular conglomeration which has the ability to think and to talk to brian greene well let's hope it's more than three score a year and ten for certain um i want to finish that yes right um so final final question i just wanted to touch on a number of places in the book you use the word purpose right dude when you're talking about the kinds of biological processes that various complex molecules are are crying out so that's the purpose in the sense of there's a very specific goal and the structure is aligned with reaching that goal and it it's able to achieve that goal of course purpose in the human sense as we all know has a broader connotation do you see a link between those well i i use the word purpose to actually sort of aggravate or irritate a little bit because you know scientists are not meant quite to talk like that and um get uncomfortable but um you rightly positioned it i mean a living thing does behave with purpose and it responds to the environment it moves towards where there's food it avoids um dangers and all of this is built around the purpose of survival and maintaining itself and the word purpose is perfectly good there yeah i have no problem with it and um it's it's something that can arise from design like designing a clock as we mentioned already in newton and the clock um but it also can arise at random we've already uh covered that when and this is the reason really it becomes a bit of a problem and i think it is a non-problem is exactly as you said when we think of purpose we start wandering into sort of notions not unlike free will and so on and we're behaving with a particular purpose and that gets in the way of this um of this description so i don't actually see uh that as a problem and i think life behaving with a purpose we we don't have to get um you know too agitated right at least i don't right so i said that was the last question i actually want to ask one more if you don't mind so when i think back to when i first learned the basic ideas the weird ideas of relativity quantum mechanics you know that's going back for me you know like 40 years something like that now i'm getting old too you know so that's how it happens uh and um but yet i still am amazed by the results like if i sit down i think about even special relativity after all these decades if i really think it through it still just blows my mind fills me with spectacular joy when you think about in fact we have a little video of the working of the cell this this company you may know xv but there's this beautiful uh secret life of the cell i don't know if we can bring that up just as a final little image here when you think about or see this kind of stuff happening within cells that particles governed by the laws of physics can come together to carry out these kinds of crazy wondrous processes that are at the foundation of life does it still fill you with that same sense of awe and amazement well that's an interesting question because i have to say when i think about relativity or quantum mechanics like you i i s well unlike you i struggle but like you i am faced by splendor the or awesome uh contribution that humanity's made to try and understand that i do think that biology on the whole is not occupying quite the heights of that abstraction that is always impressive and we and that's one reason why we tend as a as a as as a group to get involved in lots of description with the hope of saying thinking well the complexity of it all the wonder and diversity is is awesome and of course it is awesome but it's not awesome in the same way as the ideas of physics that you were talking about however i do think there are principles which aren't quite the same thing as the animation that we saw there wonderful as that chemistry and physics was there are principles which do approach um the wonder of the of quantum mechanics is not in the same territory in terms of raw intellectual power but in terms of understanding and making sense of the universe i think they are also awesome and in a very small way i was really trying to get somewhere towards that with this book what is life and the principles there and i don't claim to have got there but it is really in that direction i wanted to go well i would say you did a great job and you did get there so again folks i never know exactly where the camera is but i think i'm now in front of it what is life this is the u.s version paul nurse already showed us the uk cover it's a beautiful book explaining these principles these ideas with great clarity great energy great style together with life experiences of one of the great thinkers of our age so sir paul nurse thank you so much for joining us today and everybody should go out and buy and read this book thank you brian great conversation good to see you thank you and we'll see you hopefully sometime when the world allows us to do that you guys are already good great okay good talking to you all right folks that was our conversation with sir paul nurse i'm going to take a few more questions before wrapping it up these can be on our discussion or it can be in physics anything you want i'm not going to unfortunately last very long for the usual reason that i won't excapate play what the hell does that mean explicate enunciate i tell my son that all the time enunciate um i won't be able to last very long unfortunately but let me just see if there are a few things that um might uh give us some questions to talk about um um yeah here's a question about black holes so gen z whatever that means gen z asks what's the latest on the tensions between quantum mechanics entanglement and black holes yeah it's a very different subject from what we're talking about well in the way it is i mean quantum mechanics underlies all of the physical processes that paul nurse and i were talking about certainly even in that video of the inner workings of the cell sure you can talk at the level of the molecules but the molecules themselves are made of atoms the ammunitive particles all that's governed by quantum physics so ultimately it is just one big quantum system but you're right gen z there has been some tension i like that word good good choice of word between our understanding of black holes and quantum mechanics that has emerged in the last few decades and the main issue that people have been struggling with is if you have quantum entanglement two distant particles attached by sort of this thread like quantum link quantum connection what if one of those particles falls over the edge of a black hole and the other stays outside do they continue to be quantum linked together in a traditional interpretation of einstein's ideas in general relativity the link would persist the edge the horizon of a black hole doesn't do anything it's not actually a physical thing in einstein's theory it's a location of no return but it's not as though there's something there that would disrupt the quantum entanglement between two particles however as people investigated that further over the last decade or so you realize that that answer may be too simplistic because if you want information that falls into a black hole to have a way of ultimately getting out and without that even quantum mechanics itself is challenged so if you want information to get out then it turns out that you need not only entanglement between a particle on the outside and inside a black hole but you need entanglement between the particles on the outside among themselves that's where the information would be stored in the correlations in those quantum connections and you cannot have a situation where particle a is entangled with particle b which is entangled with particle c inside the black hole you can have that triple maximal entanglement so something has got to give so either the entanglement across the horizon of the black hole snaps which would release energy which is where this notion of a black hole event horizon as a fire wall a wall of energy comes from or maybe information doesn't get out or maybe our basic understanding of the physics is just missing something essential and that's where the problem arises so if you ask me what's the view today most people at least that come at this from the particle physics string theory perspective are not willing to accept that information is lost okay so that solution goes out the window and some are willing to accept the possibility of a firewall but some have even suggested more exotic circumstances where the information could get out maybe even through wormholes connecting outside and inside so it's up in the air i would say it's not exactly a done deal as of today but yes it is a deep and important question having to do with quantum mechanics and space time itself ultimately comes down to trying to understand general relativity in quantum mechanics that essential conundrum that has driven physics for many many decades all right i'm going to wrap it up there i'm a little uncomfortable after sitting for two hours or so so we will pick this up again at some point perhaps two weeks from now you will note again sir paul nurse was on the list of names that we extracted from your suggestions so we do listen to what you guys say in terms of who you'd like to be part of these conversations so continue to make those suggestions we will continue to look at them and try to choose future guests from that list as we go forward okay guys that's about it please check out sir paul nurse's book it's a wonderful read keep an eye out for the next of these conversations going forward and until then take care [Music] do [Music] you

Channel: World Science Festival

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Keywords: Brian Greene, Sir Paul Nurse, Geneticist, the Royal Society, Francis Crick Institute, Nobel Prize in Physiology or Medicine, protein molecules, division of cells, What is life?, best science talks, New York City, Live stream, world science festival, World, Science, Festival, world science u, biology, genetics

Id: 4eVzJbxMZao

Length: 107min 31sec (6451 seconds)

Published: Thu Feb 11 2021