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00:00:00 So thank you Martin for your willingness to do this interview. A pleasure to do it.
00:00:08 We are in a very special location we are in the heart of Vatican City Why are we here
00:00:13 Well we're here in the Vatican because the Vatican has a Academy of Science called the Pontifical Academy of Sciences which has
00:00:22 conferences on various topics and the members seventy or eighty scientists from all over the world of all faiths
00:00:30 and non so it's a really global academy and we have scientific discussions
00:00:36 but I think one useful thing we can do is address issues of social import where if we can interest the authorities in
00:00:44 the Vatican it can make a difference
00:00:47 and to give one example we had a conference eighteen months ago in May twenty fourteen on sustainability climate
00:00:57 and the environment and this got traction within the Vatican
00:01:01 and it then led to the Papal Encyclical in mid twenty fifteen which of course was a very important influence on the
00:01:12 Paris environmental
00:01:13 and climate conference in December twenty fifteen because of course the pope has immense traction especially in Latin
00:01:21 America Africa and East Asia
00:01:24 and I think the fact that the pope would come out strongly in favor of the importance of concern about climate
00:01:31 and our duties to the environment had a big effect in easing the past a consensus at the Paris conference so that's an
00:01:38 example where the pontifical academy can I think have a more distinctive role than other national academies
00:01:45 but you also have meetings on the cosmology and other subjects like that.
00:01:50 Were you kind of surprised that particular in this kind of climate change debate Pope Francis kind of came out as such
00:01:57 a strong I would almost say voice of reason. In a world that's sometimes very confused.
00:02:03 Well I think it was surprising and gratifying because the other point that came out in that
00:02:08 encyclical was the humanities duty to the environment and of course although
00:02:13 Franciscans have had that view the Church itself has had the line that men have dominion over nature as it were so
00:02:21 the statement fairly clearly that the environment has a value in its own right
00:02:26 and we have an obligation to defend it is something which I think was not clearly apparent in earlier Catholic
00:02:33 statements so not only I would say kind of the environment
00:02:37 and you know human beings taking care of nature there was also a very specific angle in terms of global inequity
00:02:46 and the fact that the poor were mostly affected by these issues Yes Well that's right I think of course the things that
00:02:54 everyone can agree about the church is that it's got a global perspective it thinks long term
00:03:00 and it cares about the world's poor
00:03:02 and in the context of climate change of course the main victims of it will be the poor
00:03:09 and the concern is something which is not short term we're concerned about future generations because they're the ones who
00:03:16 will bear the impact of climate change
00:03:18 and so the church really has all the prerequisites to be a body that can have a real global influence on this debate.
00:03:27 Do you feel any tension between faith and science particularly if you're here.
00:03:33 I don't think there is any tension because of course the Church used to of course be concerned I mean until twenty five
00:03:40 years ago it wasn't good to talk too much about Galileo but things have changed completely now
00:03:45 and the church is very happy to engage in debates on
00:03:50 Issues like evolution
00:03:51 and cosmology etc and I am a cosmologist so they're quite happy to talk about the big bang. So talking about the big bang and cosmology
00:03:59 It's kind of striking that one of the previous presidents of this Academy:
00:04:06 George Lemaitre he was both an ordained priest
00:04:11 but he was also in some sense the father of the expanding universe and the big bang.
00:04:19 So that's something that's perhaps that's a surprise for people to hear it is surprising
00:04:24 and he was in fact a remarkable scientist who started in Cambridge at MIT and then he worked at Louvain.
00:04:32 In Belgium his career and he became president of this academy
00:04:36 but he was indeed one of the early people who applied Einstein's theory to models of the universe
00:04:44 and had the idea of a big bang which he called the primeval atom and he thought very deeply about these questions
00:04:51 and came up with models which are still part of the.
00:04:56 Folklore of the subject as it were and Einstein did not like his ideas in the beginning
00:04:58 no it Einstein actually was rather reluctant to accept all the most exciting
00:05:05 conclusions of his theory he never liked black holes for instance
00:05:09 but he didn't like the idea of the expanding universe he wanted a static universe
00:05:15 and also he although he introduced this thing called the cosmic constant which is a latent force in
00:05:22 empty space he didn't like it and then Lemaitre tried to argue that it was some effect that might be genuine
00:05:31 and Lemaitre turned out to be right because
00:05:32 one of the great discoveries of the last fifty years has been that this force in empty space does exist and is very important for
00:05:39 the future of the universe. So what do you think of the fact that Einstein was clearly very brilliant.
00:05:44 But in some sense could you say that his theory was even more clever than he was? It was because Einstein of course through his
00:05:52 huge insight developed this theory but its consequences took decades to be fully.
00:06:00 Understood and things like black holes the Big Bang
00:06:06 and gravitational waves which are regarded now as the great confirmatory tests of the theory in all three cases
00:06:14 Einstein was negative or ambivalent
00:06:17 and also in all three cases it's only recently that we got convincing evidence can you say something about the state
00:06:25 of cosmology if you really think about it in terms of a long term development I mean human kind has been thinking about
00:06:32 the cosmos for
00:06:32 millenia Yes Yes But what's happening right at this moment? Well of course it is interesting as you say that
00:06:39 Einstein's theory was special and he was uniquely original as a scientist because he came up with this theory.
00:06:48 As a result mainly of pure thought it was not stimulated by puzzling experiments. Did it come like a hundred years too early
00:06:55 Yes fifty years too early had it not been for Einstein then the theory would not have been
00:07:02 developed for decades and indeed it was not untill the nineteen sixtees.
00:07:08 That astronomers found the first entities in the universe where Einstein's effect was important well than just
00:07:15 being a tiny correction to Newton's theory in the nineteen sixties.
00:07:19 We found objects called neutron stars. stars the matter of some
00:07:23 but squeezed down into that down if you have a few kilometers
00:07:27 and also black holes objects which had collapsed cutting everything off of the rest of the universe
00:07:32 but leaving a gravitational imprint frozen in space where they left and evidence for these things emerged in the sixty's
00:07:39 and seventy's
00:07:40 and also evidence emerged that our universe had evolved from some very dense hot state this was so-called background
00:07:49 radiation which fills the universe and is a relic of the hot dense beginnings of the universe
00:07:54 and this is what Lemaitre had speculated about much earlier but the evidence came in the sixty's
00:07:58 so from the sixty's onwards.
00:08:00 there were phenomena which required Einstein's theory in order to interpret them properly
00:08:07 and so the theory changed from being rather sort of backwater out of the mainstream of physics to being one of the
00:08:14 real frontiers of theoretical physics. I read somewhere in a obituary of Einstein that at the time of his death in
00:08:22 1955 people admired his work as a great piece of art which is something for scientists it's quite a quite a
00:08:29 putdown right because you don't want to be a you want to actually be a theory of the world of the Universe yes
00:08:35 but it was a great piece of creative thinking of course
00:08:39 there's a lot of discussion about creativity in the sciences versus in the arts of course most creativity in the
00:08:48 arts is more distinctive but in the sciences
00:08:51 and Einstein was more creative in that he made more difference normally in science if A didn't do something B.
00:08:59 Would do it very quickly.
00:09:01 That was true of quantum theory - that was more a collective effort. Yes
00:09:05 but in the case of Einsteins relativity if he hadn't done it then the idea would not have emerged for decades
00:09:12 particular I think for general relativity. That's right
00:09:14 and one of my favorite scientific writers Peter Medawar who is.
00:09:21 who is a great biologist and he put this rather well he said the difference between the arts
00:09:27 and sciences are like this that if you are doing science then if you don't discover something then someone else will
00:09:35 discover the same thing soon whereas when Wagner was.
00:09:39 In the middle of the ring cycle he took ten years off to write Tristan and Meistersingers
00:09:45 and he didn't think anyone would scoop him on Gotterdammerung
00:09:48 and so I think there's a difference that in the arts your work is individualistic even though it doesn't last whereas
00:09:54 in the sciences your work is durable is part of some growing edifice but it loses
00:10:00 its individuality and if you hadn't done it then someone else would have done it fairly soon
00:10:05 and Einstein is perhaps one of the few exceptions in that he did make a more distinctive imprint on twentieth century
00:10:11 science than anyone else
00:10:11 and one thing that is just fascinating I sometimes use the metaphor of finding the beginning of a roll of scotch tape
00:10:18 you know which is very difficult and then you can unroll it is yes
00:10:21 and so if you think of this unrolling tape particular for cosmology which is now.
00:10:28 Like a hundred years since Einstein's work on general relativity we have this explosion of results of ideas where are we
00:10:37 so to say in understanding the big picture do you feel we are just at the beginning we're half way what's your
00:10:45 well of course we are always at the beginning of science because as the frontiers advance their periphery gets longer
00:10:50 and a new set of questions comes in. Particular about understanding the fundamental principles of the universe Yes Well I think
00:10:57 people made huge progress certainly since I was a student forty years ago
00:11:02 when we didn't know if there's a big bang at all one thing we've learned of course is that the universe in the
00:11:09 scales that we can observe does have a certain uniformity yes we've learned that the atoms in a distant galaxy are just
00:11:16 the same as the atoms in the lab. were that not the case of course the universe would be anarchic we would not make any
00:11:22 progress at all but we've learned about that we've also learned that all the galaxies in the universe
00:11:28 and all the stars can be traced back to a common origin in this hot dense beginning the so-called big bang
00:11:35 and we can now date that to being thirteen point eight billion years ago
00:11:40 and so we can trace out the history of the universe from the hot dense beginning to the present
00:11:46 and we can also understand how from these amorphous beginnings the first structures formed as the universe cooled down
00:11:56 and condensed into the first galaxies and stars.
00:12:00 And we have a very good theory for this
00:12:03 and we can actually test the theory a number of ways we can look back with our telescopes to objects so far away
00:12:11 that their light set out when the universe was a tenth of its present age
00:12:15 and we have evidence of the much earlier universe from studying in detail this background radiation to the beginning
00:12:22 and we get a very consistent picture going back to when the universe was smooth apart from tiny fluctuations
00:12:29 and to the stage when those fluctuations have enhanced their density contrast to make again galaxies
00:12:36 and this is a consistent picture
00:12:38 and it also tells us that the universe contains the ordinary atoms that we know about
00:12:44 and also contains about five times as much stuff in the form of what's called dark matter. particles which have no
00:12:51 electric charge and don't interact much as they move around under gravity we don't know what particles they are they're still a
00:12:57 mystery but we know for sure that the dynamics of galaxies is dominated by this dark matter.
00:13:06 Are you personally surprised that we came so far that we have such a complete picture of.
00:13:14 The universe I mean you could imagine
00:13:16 there are just formidable obstacles in learning about our own universe well I think it is it is gratifying in a surprising
00:13:24 number of ways first of course we owe the advances ninety five percent to improvements in technology
00:13:32 and instrumentation. arm chair theory doesn't get you very far by itself. none of us are as wise as Einstein we got
00:13:39 further because we had better instruments. and he didn't even believe his own consequences of his theory only after
00:13:45 experimental evidence Yes that's right became it clear for him too yes that's right
00:13:51 but I think that a more fundamental level what is gratifying is that our minds which haven't changed very much since
00:14:00 our ancestors roamed the African savannahs tens of thousands of years ago.
00:14:05 Can cope not just with the everyday world that we evolved to cope with
00:14:08 but can cope with the counter intuitive world of the quantum
00:14:12 and also of the cosmos so it's surprising that the world is such that we can understand both the micro
00:14:19 and the cosmic. what we have not yet quite understood is how to link those together as you know better than me the
00:14:24 challenge of twenty first century physics is to have a unified theory which combines what Einstein did which gives us a
00:14:32 good picture of the large scale universe and gravity with the quantum world. Are you optimistic that this will proceed
00:14:40 or you are you expecting at some point there will be a sign forbidden for human beings.
00:14:46 Well. for human scientists
00:14:47 well you can judge far better than me how likely it is that string theory will deliver the goods or that some other theory
00:14:53 will. I think it's very good that there were some people who believed that this may happen because otherwise they wouldn't be motivated
00:15:00 to try if they're not motivated they would never succeed so it's very good that there are people including many of our friends
00:15:06 and colleagues who are working on ideas of Unified Theories and I hope they will succeed
00:15:13 but I think we have to be open minded about whether there are deep aspects of reality which are going to be beyond our
00:15:23 capacity to grasp because after all I mean a monkey can't understand quantum theory and there may be some
00:15:30 Deep features of reality which we just can't comprehend. we are as hopeless as monkeys to get there. You think that we will ever
00:15:38 discover these things or that they are almost by definition outside our realm because monkeys probably will also not lament
00:15:45 that they can't understand quantum mechanics. Well that's right we are not aware of these things
00:15:51 but there may be aspects of nature which we are not aware of
00:15:54 and that of course may mean that there are discoveries to be left to.
00:16:00 Brains better than ours some kind of post human entities which may come into existence one day. We'll come to that. Clearly though
00:16:06 this is quite amazing this is. Human beings on planet Earth.
00:16:12 Looking at the universe. Do you think there is science elsewhere in the universe?
00:16:18 Scientists elsewhere? well of of course we don't know I mean I think we can say more in answer to that question
00:16:27 than we could have done twenty years ago because one thing we've certainly learnt which is a great discovery in the last
00:16:32 twenty years is that most of the stars which we see are orbited by
00:16:38 retinues of planets just as the sun is orbited by the earth and the other familiar planets
00:16:43 and it's quite likely that in our Milky Way galaxy there are a billion planets rather like the earth
00:16:50 like the Earth in a sense they are about the size of the earth
00:16:53 and at the distance from their parent star such that water can exist neither boiling away
00:16:58 nor staying frozen. So they are as comfortable to our kind of life. Right as potential habitats
00:17:05 but of course being habitable is not the same as being inhabited
00:17:09 and of course one of the key scientific questions which is not understood yet
00:17:14 is the origin of life even on Earth I mean we understand how from this simplest organisms over three
00:17:22 and a half billion years or so.
00:17:24 our biosphere of which we are a part has emerged
00:17:27 but what is still not understood is the actual origin the transition from complex chemistry to the first metabolizing
00:17:36 replicating structures and that's one of these problems everyone has known is important
00:17:42 but it's been put in the as it were too difficult box. it's very difficult to say of course
00:17:48 but do you feel this is a problem that it's kind of it's foreseeable that say within the next decades we make a breakthrough. I think it is
00:17:54 yes because I think unlike the past now there are serious people working on it .
00:18:00 So I'm hopeful that within ten
00:18:02 or twenty years we will understand how that key transition from biochemistry to the first replicating metabolizing
00:18:10 structures happened I think we will understand that because it's no longer thought premature
00:18:15 and so chemists aided by experiments and computer experiments are making progress and of course
00:18:23 when we understand that which of course is an exciting discovery for even the most earthbound biologist it will tell us two
00:18:31 things it will tell us Was it a rare fluke or would this have happened in some other planet like the earth
00:18:38 because life originated remarkably fast after the moment it was possible. it seems simple life did
00:18:45 multicellular life took longer and that of course does indicate that it wasn't a rare fluke and did happen
00:18:51 and so we will understand that
00:18:54 but another thing we might understand ten twenty years from now is whether the chemical basis of all life on earth
00:19:01 and RNA and all that is sort of uniquely special
00:19:04 or whether there could be life out there which could be quite different yes could there even be methane-based life on
00:19:11 Titan which is a moon of Jupiter. Of Saturn. And it is exciting that again we are in a position that some of these questions
00:19:17 can be asked and answered experimentally. Well that's right because
00:19:22 well we can't quite do it yet within ten years we have telescopes powerful enough to actually take the spectrum of the
00:19:29 light from a planet around another star and get some feel for is there oxygen there is the surface green
00:19:37 and things like that so we will learn whether there is vegetation
00:19:41 or life of some kind some kind of photosynthesis going on on these other planets around other stars
00:19:47 and that will be a huge discovery. I know that as a scientist you have to you you're very much aware of all the uncertainties
00:19:54 and that experiments will tell us what. but as a cosmologist if you think about the cosmos
00:20:01 What is your personal kind of I would almost say gut feeling
00:20:06 what is your personal intuition you think that the universe is populated. Also with intelligent life?
00:20:15 Well I think we know so little that it is it would be foolish to lay. yes OK
00:20:22 but leaving that aside I mean I think if you asked me to bet yes I would bet that sort of simple life is probably
00:20:29 widespread but of course going from simple life to
00:20:35 Life like us which are self-aware
00:20:38 and intelligent we don't know how likely that was because evolutional biologists debate about the contingencies that were
00:20:46 involved in our emergence they ask the questions the critical points where in some sense life has to go over a certain threshold
00:20:52 that's right and you know if the dinosaurs had not been wiped out you know would
00:20:59 intelligence have developed somewhere else or were these contingencies crucial so we did
00:21:05 and if evolution were rerun on the earth then would it end up the same or would it end up quite different
00:21:12 and so that's an uncertainty which means that even if the simple life we don't know.
00:21:18 How likely it is that it would evolve into anything that became intelligent but then of course there's another question
00:21:24 because one thing which astronomy does tell us is that the time lying ahead exactly is at least as long as the time that
00:21:32 elapsed up till now our sun has been shining for four and a half billion years
00:21:38 but it will be about six billion before it flares up and engulfs the inner planets and wipes out
00:21:44 any life remaining on the earth
00:21:46 and so no astronomer could really believe that we humans are the culmination of evolution.
00:21:55 So it continues. it continues and we have no idea of what's going to happen I mean if we if we.
00:22:00 Think of what might happen on the earth then of course the pessimistic outcome is we wipe ourselves out
00:22:06 but the more optimistic scenario is that the developement continues
00:22:12 but if development continues beyond humans like us it won't be Darwinian selection it will be.
00:22:21 Controlled technology driven evolution by future developers in gene editing and also cyborgs
00:22:31 and artificial intelligence
00:22:32 Can we talk a little bit about that. I think that is a very interesting phase that our civilization is. You know technology
00:22:38 was always around yes but you can definitely say that now it's kind of growing.
00:22:45 Exponentially fast
00:22:47 and I want to come to the topic where I feel personally that we are moving away from a phase where we understood
00:22:55 basically the building blocks of matter and life
00:22:58 and perhaps the universe towards a phase where we start kind of rearranging these building blocks right now so you
00:23:06 already mentioned. We understood living organisms but I think now in the lab we try to create parts or perhaps whole.
00:23:17 Living cells and so you feel this is kind of in some sense a phase transition this is a radical change
00:23:24 I think that this century is special for a number of reasons it's the first when we could.
00:23:33 Create species quite different from anything that now exists it's the first where maybe artificial intelligence electronic
00:23:40 intelligence may start to compete with the level of intelligence in the hardware in our skulls
00:23:46 and it's also of course the century
00:23:48 when for the first time life can spread from the Earth to other places in the solar system so this is a special century
00:23:58 even in the cosmic
00:24:00 Perspective where there have been forty five million centuries already since the earth formed
00:24:05 and there will be at least that number in the future so this century is very special
00:24:10 and can you say something about what you see as future developments not in many many centuries
00:24:17 but say for instance the next next decades because some of these developments are going incredibly fast
00:24:23 and perhaps we are not even the general public is not even aware what is possible right now so for instance thinking both of life
00:24:33 and intelligence How do you see this happening in the coming coming years how will it impact us
00:24:40 well I am not an expert on either of these topics but I think right but
00:24:44 but I think it's clear that our understanding of genetics and our ability to actually synthesize new genomes
00:24:52 and modify existing genomes is developing very fast to the extent it will be possible to almost design new species
00:24:59 or design very heavily modified species and adapt our progeny
00:25:04 and that's going to happen in parallel there is another quite separate development which is.
00:25:11 the advance in computers from being just calculating machines to being.
00:25:17 Objects which can undertake what's called generalized machine learning and we've seen developments of this and
00:25:25 spectacular .. well indeed
00:25:27 and of course to think of some key steps in this it's twenty years since a computer beat Kasparov the world chess
00:25:36 And that was done by a program being made by expert chess players etc
00:25:43 and the computer could work through millions of moves fast
00:25:46 but we taught the computer how to play chess. what happened this year was a computer
00:25:54 beat the world's champion in the game of Go and this is another very challenging game
00:26:00 more challenging yes but the big difference was in this case
00:26:04 and the computer was not programmed in detail
00:26:07 and it was a really given the general rules then it watched hundreds of thousands of games
00:26:15 and then played against itself and got better so the people who devised the program they didn't understand why it made
00:26:22 some particular clever moves which enabled it to beat the world champion
00:26:25 and so this is an example where the computer is sort of teaching itself by being able to crunch huge amounts of data
00:26:33 and in the same way translation is now done not by giving the computer the details of vocabulary and syntax
00:26:42 but by getting it to read millions of pages
00:26:45 and then if they give it millions of pages of European Union documents of different languages it never gets bored it just reads
00:26:51 all of these kind and eventually learns to translate. it's a perfect civil servant. that's right so this
00:26:58 generalized machine learning is. Are you worried about the fact that these machines who beat people at Go
00:27:04 or in language skills they're basically not able to tell us how they did this right I mean they are not able to instruct us
00:27:13 they just intuitively learn how to do this
00:27:16 in fact in the way a child learns to speak a language you can speak a language
00:27:21 but you're not able to write down the grammar Yes yes Are you worried about that when machines are doing more
00:27:28 and more of that stuff which is really extremely convenient that they are kind of autonomous that they just go their own ways
00:27:35 well I think there is a worry because there's some things which they will be able to do better than humans like
00:27:41 well already the the way the quantitative hedge funds steal money of us is by being able to analyze more data than the
00:27:48 human being can and of course that's going to get better
00:27:51 and better as they can see tiny correlations They will take advantages of our weaknesses. that's right they are doing that already
00:27:58 but they do it to a greater extent. but I think we got to bear in mind that still they don't really have.
00:28:08 Human level general intelligence to do some things and of course.
00:28:13 The whole point is that robots are still clumsy I mean they can't move around the pieces on a real chessboard
00:28:22 as well as a child can so there's a long way to go before machines can actually interact with the external world. One thing
00:28:28 I liked of this.
00:28:30 Game Go game between the computer and the. that the fifth game actually was won by the Go champion because he felt.
00:28:39 I'm not going to win I have to do some crazy stuff so he actually did something so this fifth game might be
00:28:45 something that somehow brought out the unique human qualities well that's right a human is more flexible and
00:28:54 and of course there are many things which.
00:28:57 machines can't do
00:28:58 but of course the problem as I understand it it's going to be to ensure that machines have common sense because there
00:29:06 are many things that we understand. About the world for instance I was told that the. Computer that had beaten the.
00:29:17 The American champion in this.
00:29:21 TV game called jeopardy. Watson. yes and I did not know this game
00:29:27 but it is less mindless than most computer than most T.V.
00:29:31 Games but it was asked a question which is bigger: a shoe box or mount Everest
00:29:36 and it couldn't say because it has no conception. It could be a gigantic cosmic shoe box.
00:29:43 it had no conception of the every day world
00:29:46 and another simple example it's given is that if you have one of these robots in your home which is supposed to sort
00:29:53 of make sure that your fridge is stored up and the heating is on and the food is ready for you when you come home you know.
00:30:00 If it's run out of meat it may put the cat in the oven you know because it may not realise that this
00:30:07 is something not appropriate and so. the chicken in the oven is fine. yes
00:30:12 but right so one of the issues really for the people developing AI is to ensure that it does learn what human ethics
00:30:21 and human attitudes are. intelligent enough to be able to learn those sorts of things. I know when
00:30:29 Garry Kasparov was asked you know when he lost this game this chess game against a computer that's you know it's
00:30:35 not man against machine but he said well it's me
00:30:38 and the machine to against somebody else so yes in some sense is that a better image in our mind that we
00:30:45 should kind of start to collaborate with these machines
00:30:48 I think so because I think Kasparov says that a human plus a machine is best
00:30:54 and I think that's going to be the habit but there's are these nightmare scenarios of the machines taking over
00:31:00 and of course the kind of thing which I think is not too futuristic is if we have a system of a city where all the
00:31:10 public services and the transport is controlled in some smart way and the whole thing could go wrong
00:31:17 so we're very vulnerable and one of the downsides of course of all these developments and indeed of the modern
00:31:23 interconnected world is that we are more vulnerable because everything is interconnected. just we go there in a
00:31:31 but if you think about this issue of. we talked about nature about the origins of life the cosmic evolution Yes
00:31:40 Now we are developing technology again from a cosmic perspective.
00:31:45 Is there do you see a difference between what nature is doing what we're doing
00:31:50 Well I think in a sense we're going to take over from nature because if we think of what may happen not
00:31:57 in the next fifty years but maybe in the next. Two or three hundred years then it may well be that humans.
00:32:08 turned into sort of cyborgs or that the electronic machines take over completely because obviously.
00:32:17 They don't have all the features of the human brain but they have the advantage of speed compared to the human brain
00:32:23 and so it could be that the future will lie with.
00:32:29 Electronic machines not organic creatures like us
00:32:33 and I personally think if you ask me my most likely scenario for the next hundred years I think that.
00:32:41 There there will be in a hundred years a few people living on Mars and they will be people who.
00:32:48 are real adventurers that have to cope with a very hostile.
00:32:54 and conditions. old fashioned explorers. yes right but they're in an environment for which their bodies are ill
00:33:03 and I think they will use all the technology we will then have to adapt to that new environment whether that will be by
00:33:12 Cyborg techniques by downloading their brains into a machine or something like that
00:33:16 and I think it will happen there because we're probably going to want to control for ethical or prudential reasons the
00:33:25 adoption of these technologies here on Earth where as if you have these people beyond the range of any such regulation
00:33:32 you would wish them good luck
00:33:33 in proving this there they got the biggest motivation But my scenario would be that within a few hundred years there
00:33:40 will be.
00:33:42 Entities that we would call post human in that they would be very different from us so they'd be a new species and if they are.
00:33:51 and not organic then of course they may not want to be on a planet at all they may be happier under zero gravity
00:33:57 somewhere else and that will be the future.
00:34:00 And so if you then think in terms of the cosmic perspective of time
00:34:04 when there are millions of centuries ahead then the way things will look is that we had forty five million centuries
00:34:14 and then for a few tens or hundreds of centuries organic civilization evolved developed technology
00:34:24 and then it was taken over by machines and they have billions of years billions of centuries ahead
00:34:32 and so this has an implication also if we are thinking there might be intelligent life elsewhere in the universe
00:34:39 I mean as I said I think there will be probably simple life but if it is intelligent life will be
00:34:44 and I think if we detect any kind of evidence for something artificial.
00:34:50 Beyond our solar system then it is more likely to be these machines because if the evolution on this other planet
00:35:00 had tracked what happened on the earth then it's unlikely to be synchronized
00:35:05 if they are a billion years behind then. because there is only this brief window in some sense where nature
00:35:10 and technology are working at the same time which is our current age. Yes that's right if
00:35:16 if they're behind us then there would be no evidence for any technology if they're ahead of us then they will have got way into
00:35:24 this machine age and so I think it would be unlikely that we would detect any other.
00:35:32 External Intelligence which is anywhere like us so I think the normal talk about you know these
00:35:40 aliens who are sort of bipeds with eyes on stalks maybe that that's not realistic. All unnecessary.
00:35:47 This phase that we are currently in is just a phase of the evolution of life which is necessary to spread from planet earth
00:35:57 through the universe. it's only through technology that we can actually really spread around.
00:36:06 That's right because clearly as humans we're not adapted to long voyages whereas if you're a machine near immortal then these long
00:36:15 and distant voyages if you want to make them are going to be possible but of course this leads to another.
00:36:23 Point. the famous Fermi paradox which is that if indeed life on earth was not unique then why haven't we seen
00:36:32 evidence for the aliens which had a head start over us and if it indeed is a serious constraint
00:36:39 and just does lead me to suspect that perhaps intelligent life is rare and if that's the case of course then it.
00:36:48 Makes what happens here on earth even more important because it clearly matters to us as human beings
00:36:54 but it could be cosmically important because in this century.
00:36:59 What happens will determine whether life takes its next step
00:37:03 and jump starts post human evolution away from the earth and in inorganic form or whether we sort of snuff things out
00:37:11 or go back to the Stone Age
00:37:14 and that would foreclose these potentials for what might happen in the far future. Martin thinking about this
00:37:24 Phase where technology is becoming more important it might even be
00:37:28 taking over what we do here how do you see this from the point of view of evolution is this another phase in evolution
00:37:38 it is a different kind because we've evolved from simple life through Darwinian selection over three
00:37:44 and a half billion years but ofcourse for human beings Darwinian selection has stopped anyway
00:37:50 but future evolution will be technological it will be through modifying the genome
00:37:56 and cyborg technology where we plug into machines etc and so.
00:38:00 This will happen in a directed way on the technological time scale
00:38:04 and therefore much faster because in Darwinian selection it takes about a million years for a species to fully evolve and
00:38:12 go extinct Where as changes to humanity and the emergence of post humans could take just centuries.
00:38:21 Talking about centuries you wrote a book with the title Our Final Century I think in the U.K.
00:38:28 It was Our Final Hour or the other way round. The other way around. the americans like instant gratification and reverse so. An hour.
00:38:37 but it's.
00:38:39 There you talked about the dangers that are coming with these rapid developments in technology can you say
00:38:48 something about what you see as the dangers
00:38:50 and why is this particular century this twenty first century so crucial yes well I think there are two kinds of dangers which
00:38:57 are new to us this century One is that we are collectively putting graver pressures on the environment which then while others
00:39:05 each of us more demanding of energy resources and that is why we worry about climate change. Loss of biodiversity.
00:39:14 And issues like that. is that dangerous to the planet or is it dangerous to us. it's dangerous to us I mean not to the
00:39:21 planet the planet will survive yes
00:39:24 but maybe in a depleted state because if biodiversity is reduced it will be a less exciting
00:39:29 but it happened before this massive extinction Yes that's right so they may have to start again from an early stage
00:39:35 so one class of threats are those we are causing collectively But the other kind which I focused on a bit more in my book
00:39:42 are the threats that
00:39:44 emerge from powerful technologies which empower individuals or small groups of course we had the nuclear weapons
00:39:52 which are the outcome of twentieth century technology which of course changed the global political scene
00:39:58 but. Which was also a pretty close call.
00:40:00 it was a very close call yes. if you would rerun history it's not obvious that we would survive again. absolutely we were just
00:40:06 as McNamara said they were lucky as well as wise at the time of Cuba yes and then we might be less lucky next time
00:40:14 and of course that threat is just in abeyance because we could imagine a new standoff between new super powers
00:40:20 had less Luckily than the Cuba crisis so that's one threat
00:40:24 but I think twenty first century technologies face us with new threats in particular biotechnology because
00:40:33 biotechnology of course is very powerful but we could now edit a genome
00:40:38 and there's something called gain-of-function technology where you can make say the influenza virus more virulent
00:40:44 and more transmissible and these techniques are widely understood biohacking is even a students sport in some places
00:40:53 and they don't need huge special purpose facilities so whereas you can monitor the misuse of nuclear technology
00:41:00 you can't make an H. bomb
00:41:02 in your garage as it were and it's very hard to monitor the misuse of bio and cyber
00:41:07 and that's what worries me that by error or by terror then a small group
00:41:11 or even an individual could cause some sort of global disaster. what about the whole realm of information
00:41:19 and the way we are sharing information our communication technology perhaps also intelligent networks. what do you feel about
00:41:27 well we are vulnerable of course because we depend on global networks for manufacturing etc and this
00:41:33 financial system etc And we know that cyber attacks can already be very serious for these
00:41:40 and that's going to be aggravated I think as time goes on as we become more dependent on information
00:41:47 and networks. Do you feel we are in a certain kind of arms race with technology between kind of the good and the bad applications
00:41:54 because many of these issues you mention need again technology to control. well
00:42:00 They do indeed it's a kind of an arms race
00:42:01 and I think the worry I have is that it's not obvious that the good side is going to win
00:42:08 and I think we can predict unfortunately a growing tension between.
00:42:16 Freedom privacy and security. yes. if we are to avoid the misuse
00:42:21 and I worry not so much about organized state actors as about individual disaffected groups
00:42:28 and my worst nightmare for instance would be someone who was an ecology fanatic who thought there are too many human beings in
00:42:37 the world
00:42:38 and someone with those attitudes combined with fanaticism might say well let's cut down the number of human beings in the world by
00:42:44 releasing some engineered virus. Technologically this is feasible. It's becoming feasible yes. Do you feel is this
00:42:53 is this a purely technological matter or is there also some kind of a moral dimension to it.
00:42:58 Well obviously it would be immoral to do anything like that
00:43:03 but can we do something there also as scientists. Yes Well I think obviously politicians have an extra incentive to minimize
00:43:14 the number of disaffected people with grievances
00:43:17 who are just the kind of people who would do this so the challenge on politicians is much greater because a small minority which
00:43:25 could be overwhelmed by traditional power and they can of course fight back using these technologies
00:43:31 and I think this is a real problem but as regards what scientists can do as such I think scientists.
00:43:40 They're not tremendously wise forecasters always but they can look ahead a bit more
00:43:45 and foresee what are going to be the threats indeed the book I wrote thirteen years ago I'm glad it stood up quite well
00:43:51 in that sense but I think we can foresee what the threats are going to be
00:43:56 and perhaps distinguish better than lay people.
00:44:00 Between what is science fiction and what is something we need to worry about. is it just sketching scenarios
00:44:05 or is it also taking the next step
00:44:08 and perhaps try to convince people to take a certain direction. Well I think it's trying to convince people and politicians
00:44:17 and here again I think we've got to think that. scientists have an advantage because their work is more global
00:44:25 they're more international even in the depths of the Cold War there were fairly open links between scientists
00:44:32 on either side of the iron curtain so science is a global culture which transcends all barriers of faith
00:44:40 and nationality more easily than other cultures so we have that advantage and we share common attitudes
00:44:48 and we can advise our governments
00:44:51 but I think you've got to bear in mind that most of the decisions which politicians have to take.
00:44:58 Involve some science whether they are energy health environment etc
00:45:03 but they're not just science So they have to combine the various components. that's right
00:45:09 and of course on those other components scientists are just citizens they have no special right to be heard
00:45:15 and that's why I think it's very important that.
00:45:18 All citizens should have enough feeling for science and probability
00:45:24 and risk of things like that so they can't be bamboozled too easily by experts
00:45:29 and that they could take part in the debate. if you look at this kind of conversation between science and society
00:45:35 you might argue even looking back on 2016
00:45:39 it was not such a good year for reason. right. so are we losing that debate.
00:45:48 I'm not sure I think the challenges are getting harder but I think.
00:45:53 In an issue where science is an important component like climate change. Energy Policy. health.
00:46:03 Use of genetics. I think we're doing not too badly
00:46:07 but I think the important thing to realize is that scientists can't themselves decide
00:46:14 and here scientists could probably have more influence not by talking directly to a politician or a minister
00:46:21 but through influencing the public consensus because politicians they could dismiss experts
00:46:28 but they can't so easily dismiss something which is in the press every day or which is in their inbox every day from the public
00:46:33 so you mean engaging the public at large. Yes engaging the public at large is a prerequisite for these science related issues to stay on
00:46:41 the agenda especially when they're long term and global like climate change
00:46:47 and environmental energy so I think that's crucially important and
00:46:52 and I think if the public doesn't understand the basics of science then this debate can't really get beyond slogans
00:47:01 and the public can't really be informed citizens. Do you feel that we also should be able to share some of the values of
00:47:08 science and.
00:47:10 Actually what are the values of science for you personally Well of course the values are fairly limited in the sense.
00:47:18 of honesty
00:47:19 and curiosity etc So I don't think there are many values which a scientist needs to have which are not also demanded of other
00:47:28 professionals but I think in science there is this tradition of transnational contacts and open debate
00:47:37 and willingness to be proved wrong and I think we should encourage those use
00:47:42 and also a feeling of probabilities because one of the difficulties in public discourse is that people don't distinguish between
00:47:50 something which is so unlikely that it's not worth worrying about
00:47:54 and things which are worth worrying about because even if unlikely they are so catastrophic.
00:48:00 If they happen that we need to be concerned about them. So one thing I'm personally worried about is there's kind of this
00:48:06 paradox that when science or technology is progressing we learn more
00:48:10 and more the things we learn are kind of quite detailed and technical
00:48:14 almost by definition they are because they're new they are not easy to understand. on the other hand all the
00:48:21 applications of science are more
00:48:23 and more in our lives. so science in the one hand it's kind of moving away from us because of increased complexity
00:48:31 on the other hand it's coming closer because of its relevance So how do we deal with it. how can we make
00:48:38 people understand science if on the other hand only a few individuals might actually fully understand all the details
00:48:45 Yes well I think with difficulty
00:48:46 but I think it's not quite that bad because even though the technical details the mathematics etc of some of the
00:48:54 science we do is very hard for the non specialists to understand I think it is possible to get over the key ideas fairly free of
00:49:02 technicalities I think we can. You are a master of this with cosmology. Well we try it is
00:49:08 and in fact it's more difficult than people realize because you have to obviously avoid too much mathematics Yes
00:49:16 and you have to avoid technical words You are not a hundred percent truthful
00:49:20 it is very difficult to be honest totally honest sharing your results yes but
00:49:25 but you've got to simplify obviously but hopefully in a honest way
00:49:29 and as Einstein or Bohr said you should make things as simple as possible but no simpler and that's that's a good rule
00:49:36 but I think from my own experience of doing this I think I managed to understand you've got to avoid mathematics
00:49:42 and technical words but there is one particularly difficult thing to avoid which is every day words being used in a special
00:49:49 context and let me give you two examples one is the word
00:49:51 degenerate Yes which we know has a particular meaning in mathematics. A negative meaning.
00:49:59 In mathematics it has
00:50:00 In mathematics it has a tactical meaning a line is a degenerate case of a triangle etc.
00:50:05 and another example which comes up in climate change is. is feedback because if you want to say that.
00:50:15 As the earth warms then it may release methane from the tundra. And it makes things worse.
00:50:20 and it is positive feedback We use the word positive feedback where to most people positive feedback
00:50:27 sounds like what happens after you've had a job appraisal you come out well so positive feedback sounds as a good thing
00:50:32 you did a great job. so that's an example of where the technical phrase can be misunderstood so we got to be careful about
00:50:38 avoiding using everyday words in a sense which is different from. It's like a medical test that comes out
00:50:45 negative which is a good thing. that's right yes. so talking about kind of science
00:50:51 and being a scientist. What would you say are some of the qualities successful qualities that a
00:51:00 What are some of the qualities that a scientist should have or can have.
00:51:07 Well obviously the ability to understand some technical details or certain mathematical skills
00:51:13 and now of course computer skills as well.
00:51:17 But also I suppose the motive to try and understand something
00:51:23 and accept that most of your early ideas are going to be wrong
00:51:27 and also accept that there are some problems which you will never solve I think one of the differences between
00:51:34 lay people and experts is that.
00:51:38 Lay people don't realize that some problems are really too difficult to solve I mean and.
00:51:44 The balance between what is easy and what is difficult is rather surprising. I could give you an example from my own field astronomy
00:51:52 that I expect people to believe me if I tell them about what happens when two black holes a billion lightyears
00:52:00 Away collide with each other and that we got evidence for that
00:52:05 but on the other hand you are foolish to believe any experts on child care
00:52:10 or diet which are things that everyone cares about
00:52:14 and understands
00:52:15 and that's because it's a fallacy to think that every day problems are the easy problems they are also the hardest problem
00:52:24 anything to do with human beings is far harder to understand than any things in the inanimate world
00:52:30 and it's a fallacy to think that they are easy to understand just like people sometimes say that.
00:52:37 It should be easier to cure the common cold than other diseases just because it's common
00:52:41 but that doesn't mean it. so people don't have a feeling for what can be done and what can't be
00:52:47 and of course one of the knacks of being a scientist is to choose a topic to work on which is not trivial
00:52:55 nor on the other hand so intractable that you won't make any progress at all. So talking about the motivation of scientists I
00:53:03 think these motivations come in. Various kind of flavors.
00:53:09 Some people want to understand the world others want to change it. how do you see this.
00:53:15 Well I think as human beings we want to change the world but our understanding is separate from that
00:53:22 but I think among scientists there is a great variety of mental types
00:53:28 and I've been surprised by this because you know my professional life like yours is lived among a fairly homogeneous
00:53:35 group of people with many common interests
00:53:38 but even among them I think we see quite a variety of personality types in those who think pictorially
00:53:46 and those who think in terms of equations those who like computers those who don't like computers
00:53:51 and also those who like to solve problems in a sort of step by step piecemeal way and those who are happy to sort of.
00:54:00 think in a more open ended way What do you think is the role of imagination in science.
00:54:09 I think imagination is crucial
00:54:12 but it's sort of constrained imagination it's not quite like art. Well perhaps is rather like sort of
00:54:19 composing in a fugue or writing a sonnet where you're trying to do something creative but within a standard form
00:54:25 and so science is something where.
00:54:29 Any idea has to be embedded in the huge edifices already built up by your predecessors
00:54:35 but clearly you've got to make some insights.
00:54:39 And unless you make some new insight then
00:54:42 all you do is going to add something which anyone else could have done as well. Rick Feynman said science is
00:54:49 creativity in a straitjacket. Yes. What about playing playfulness. Well I think that is part of it
00:54:57 I think Feynman also said that you got to keep some childhood instincts alive and if I think of
00:55:05 one of the most creative scientists I know who is Roger Penrose he's a good example of someone who
00:55:12 thinks very visually He thinks not only deeper than the rest of us but more differently more pictorial than most of us
00:55:19 and he's an example of someone whose recreations of being creative in thinking of his tiling and antagonal
00:55:27 or quasi Crystal patterns and also he
00:55:31 and his father who was a psychologist invented these impossible figures which inspired Escher who already knew to devise
00:55:42 some of his new new dials on the endless staircase etc So Penrose is an example of someone who you can't really meet without
00:55:50 as someone who is especially creative in a sort of playful way as well as obviously a very deep way. I think this famous
00:55:58 quote of Einstein basically.
00:56:00 to the effect that imagination is more important than knowledge because imagination is capturing everything that is yet to
00:56:05 be known. So do you feel that in some sense we also have to be made aware of the opportunity to
00:56:14 understand something that there are certain questions that perhaps you know current generations aren't even aware is a
00:56:22 question that could be answered
00:56:23 well I think that's true that you've got to be aware of some problems which have become tractable and become timely
00:56:31 and work on them but at the same time you don't want to work on something which is impossible
00:56:36 but I think one thing which has happened
00:56:38 and this is perhaps something which is a downside of being a scientist is that science has become a much larger
00:56:47 enterprise with more mixed motives involved
00:56:51 and the number of new insights has sadly not gone up in proportion to the number of people who would call themselves
00:56:58 scientists and that's partly because science is.
00:57:03 Becoming more tactical more detailed needs bigger equipment etc but partly also because there are more commercial pressures
00:57:11 etc so it makes it different. What about the social elements to it I think these days I think you can probably argue that
00:57:19 being a scientist is much more well the interconnectivity of science
00:57:25 and the fact that collaborations are becoming larger Do you see there another development.
00:57:32 Well of course the type of science which is done if you're in a big team is different
00:57:37 and you know it's certainly true that many people who have been original scientists worked in the primary stage of a
00:57:44 subject they would not like to be part of the group at CERN where you are one of a thousand people who are working on a big
00:57:52 experiment that's a quasi industrial organization
00:57:55 and I think one has to warn young people that if they want.
00:58:00 to do science they've got to realize that some kind of science is like being in the industry with some of the downsides
00:58:07 without some of the benefits where as some allows you to be more individual
00:58:11 and to make your own reputation independent of. What about the global element you know we are here in the Vatican
00:58:20 but we have colleagues all over the world.
00:58:23 Do you see some kind of convergence happening if you look at science across the globe Well I think
00:58:30 the benign change is that science is being done more globally I mean it used to be done mainly in North America
00:58:38 and Europe where as now the rise of science in Asia and other parts of the world is surely benign
00:58:44 and I think we must except that the hegemony of the Western world which has existed for four hundred years is
00:58:54 going to end because it's going to be in Asia that the world's economic
00:58:59 and intellectual capital is going to be concentrated from now on and so it's going to get more global
00:59:04 but of course the problems which science needs to tackle are very often global problems
00:59:10 and so it's very appropriate that scientists should collaborate with people all across the world in dealing with the
00:59:17 energy resources
00:59:18 and climate Do you see there's truly one global community There certainly is because some scientists ofcourse I am part of
00:59:24 it yes
00:59:25 but I think clearly the scientists who we have at Vatican meetings who work on the environment or on health care etc They're
00:59:34 part of some global community and what they care about are global problems
00:59:39 and the key thing is to ensure that their voice spreads beyond academia to those who can really change the world
00:59:47 thinking about. coming back again to your own field cosmology so let's kind of zoom out
00:59:54 and looking at the universe and we see here planet earth and we have this group of scientists.
01:00:00 Trying to understand well the planet ourselves but also the universe.
01:00:06 How do you see us from a cosmic perspective what are we exactly doing here on this planet.
01:00:13 Well ofcourse we don't know I think the more one understands about any phenomenon the more amazed one is by it I mean
01:00:20 I think.
01:00:22 When I look at an insect now I'm more amazed by an insect
01:00:26 when I realize all the chemical processes that have to happen if it's just simply to move his leg you know
01:00:33 and one realizes how amazingly intricate the natural world is and in that sense the physical world of stars
01:00:40 and galaxies is simpler than the biological world but of course it's got this sort of scale
01:00:45 and I think it's been a privilege to be working in a subject where our perspective has changed
01:00:53 and expanded in a few decades and of course.
01:00:59 We've really had revolutions going back to the Copernican Revolution originally when we realized the Earth wasn't the center
01:01:06 and then we realized that our sun was just one star in the galaxy
01:01:12 and then our galaxy is just one of billions you can see with a large telescope
01:01:16 and I think we are now perhaps going to be due for a fourth Copernican Revolution
01:01:22 when we will learn that physical reality is much more extensive than the domain we can see with even our biggest
01:01:29 telescopes because we can see with our biggest telescopes out to sort of horizon which is limited to the distance of light
01:01:37 kind of travelled to us from since the Big Bang
01:01:40 but there's nothing physically real about that horizon anymore than there is about the horizon around you if you are in a boat
01:01:46 in the middle of the ocean you don't think that the ocean ends beyond that and there are good reasons to think that the.
01:01:52 Universe extends probably at least a thousand times further than we can see and probably much much more than that
01:02:00 And that's not all because that's all.
01:02:04 The aftermath of our big bang and then the other question is whether our Big Bang is the only one
01:02:10 and there is a popular idea called the multiverse whether there is variance according to which there may be zillions of
01:02:18 other big bangs of which ours is just one
01:02:21 and that they may all be governed by different physical laws from ours we don't know so it could be that there is an
01:02:28 ecology of Cosmoses on a scale far bigger than what we can observe so our perception of overall physical
01:02:36 reality is rather like the perception of a plankton in a spoonful of water of the entire earth you know we are very
01:02:44 limited. take this perspective which is all kind of making us kind of less special Yes On the other hand in the
01:02:49 beginning of our conversation we talked about the special nature of life on Earth we don't know how special it is
01:02:55 the fact that we have intelligent life and the fact that we have life that is intelligent enough to look at the universe
01:03:02 and have thoughts exactly like this so the title of this series we've chosen the mind of the universe.
01:03:11 Perhaps we should have said a mind of the universe which is this special role of us on planet Earth because.
01:03:19 Certainly I think this is one of the few places perhaps the only one we don't know where these kind of thoughts as
01:03:27 you just kind of shared are generated yes so again looking at this vast hierarchy
01:03:37 And our little little you say a little plankton in a drop of water in a huge ocean.
01:03:44 What is that special role we have in observing all of that yes.
01:03:49 Well it we clearly are special in being able to at least grasp the glimmerings of these huge ideas
01:03:57 and it may be that post human intelligence is needed to grasp it more fully but clearly.
01:04:03 Even though we don't know how common life is it's clear that we are living on a special planet this pale blue dot in
01:04:12 the cosmos and it's also equally clear although less well appreciated
01:04:17 that we are living on it in a special time. this century is very special it's the first
01:04:21 when one species namely the human species can determine the planet's fate and also this is a century when we can perhaps.
01:04:32 Start a transition to a completely different form of intelligence based on electronics and machines
01:04:39 and perhaps spread beyond the Earth so this century is special so if you think of a space
01:04:44 and time diagram you know this little dot in space and time is very special
01:04:49 and if we spread around we could be actually could be the mind of the universe Well our descendants could be yes
01:04:55 yes. thank you very much.