Neil Turok

Neil Turok interviewed by Alan Macfarlane 27th April 2017
[An update of an interview by Tina Košir and Alan Macfarlane 19th February 2008]
0:05:11 Partly due to my work in Africa and my physics here in Cambridge I came to the attention of somebody in Canada who was the inventor of the Blackberry and therefore the first smart phone; he had made a fortune due to that and had decided to give a large portion of that fortune to setting up a centre for theoretical physics; this was a very clever move because theoretical physics underpins all of modern science, whether its astronomy or cosmology, being based on Einstein's theory of relativity or electronics based on theories of the early twentieth century such as quantum physics, Maxwell's equations, and all of that; yet as fruitful as theoretical physics has been it has not been developed very strategically; people have tended to think that a genius arises anywhere; in a maths or physics department an exceptionally able student will appear and think of some great idea; so Mike Lazaridis, the Blackberry inventor, decided that he wanted to do this strategically by creating a place that would deliberately attract the most brilliant and adventurous young minds and challenge them to tackle the most fundamental problems in physics; so the Perimeter Institute for Theoretical Physics was formed - the name Perimeter obviously means the boundary of knowledge; it's a little joke because Research in Motion or RIM was the company which developed the Blackberry, but most people don't know that; Mike hired as a director, a young man not far out of his Ph.D. in physics, he had realized he was not going to be a top researcher but he was very entrepreneurial, and with the advice of a lot of people like Roger Penrose and Chris Isham and other famous physicists he founded the Perimeter Institute in 1999; in 2008 after I had won the TED prize I was approached to see if I would take over as the new director of the institute; at that time it had about seven faculty, a large number of post-docs, about fifty, and a beautiful building, but it was struggling to recruit; Waterloo is not the most attractive town in the world, but one of the very smart things that Waterloo did in setting up their university in the fifties was to invest in mathematics and so they have the largest mathematics faculty in North America now, mostly applied, and then they hired the key people from Alan Turing's team to go to Waterloo and found the computer science effort there - this was the team from Bletchley Park; they hired one of the team to be the head of cryptography at the University of Waterloo which is within computer science, and actually the unusual thing there is that computer science is a part of mathematics at Waterloo; rather quickly Waterloo became very well known in the world of computer science, so the first version of Fortran, called WATFOR, was Waterloo Fortran; it's a small town with a population of 200,000, and they built a university with maths as the core, and then around it a lot of tech companies grew up, including Blackberry; so that is where Perimeter is; a very ordinary town one hour west of Toronto, but with this very unusual focus; when Perimeter was formed one of the ways that were unusual is that we have public lectures; they used to be at the local high school which could accommodate up to 700 people in its auditorium, and from the beginning these were packed; the local town folk in Waterloo are really interested in maths and science and it is one of the reasons that I went there; I went to give a public lecture and I've never encountered such an enthusiastic audience, including at Cambridge where occasionally you get an audience of that size - Carl Sagan, for example - but not every month; Waterloo is obsessed with maths & science; so I went there in 2008 with the goal of turning this into one of the leading centres in the world; it is very well supported by an endowment that Mike Lazaridis gave, and equally by the Canadian Government and the Provincial Government of Ontario; Mike again established this very strategically, it's a well-funded initiative, and he gave the scientists, particularly the Director, a lot of freedom about how to implement this; in a way it was the opportunity of a lifetime, given, effectively, unlimited resources for what we do because theoretical physics is a very cheap field, how do you use them wisely, how do you attract the right people, what kind of environment do you create, how do you challenge people to tackle impossible problems, and these are the hardest problems in science, how to we go beyond Einstein, Maxwell, Dirac, and all the greats in theoretical physics, how do we discover what happened at the big bang, what's going on in the vacuum in empty space where there is dark energy which we don't understand, and what does quantum mechanics mean? so Perimeter is one of the few places in the world with a strong effort in the foundation of quantum mechanics, trying to disentangle the craziness in the theory; that was the goal and I think as I had had experience of setting up centres in Africa, which is a very difficult environment, and was used to, in that sense, rethinking academia; most academics are hopelessly stuck in a rut; they think the only way to do things is the way they are currently done organizationally; so when you ask an academic to set up a new institute, most will ask if it is going to be in a university and if so in which faculty, so immediately start thinking in traditional terms and structures; but these traditional structures were designed for a bygone era and they are not necessarily the best today, nor the most efficient; so I was used to rethinking everything and when I went to Perimeter what attracted me is its complete autonomy; it is not a university and has the freedom to do things in different ways, and I've taken full advantage of that to go faster than anyone else; the consequence is that we are now very widely regarded as one of the leading, if not the leading, centres of theoretical physics in the world; certainly we are growing faster than anyone else; we have probably as high a profile as anyone else and we are competing very successfully recruitment-wise for post-doctoral fellow, junior faculty - an offer from Perimeter is pretty hard to decline; how do we do it? it's very obvious things which most institutions don't do; so, what does a brilliant young scientist want? they want security, a reasonable salary and they won't be missing out too much compared to anywhere else they might go; so it's got to be internationally competitive for salaries; unfortunately the UK has fallen way behind and is not able to compete at the same level so you are immediately losing out on a lot of people, and that goes back to the insufficient priority the Government places on science at the moment in the UK, and is unwilling to support competitive fellowships; but it is not all about money by any means; Canadian salaries and fellowships are lower than the US but comparable; then what we do is provide a wonderful restaurant, so the heart of the Institute is a fantastic restaurant where we serve very high quality food, healthy local produce, organic; so we don't have burgers & chips; we have about 200 researchers and they pay more for their lunch, and we gradually persuaded them this was worth paying for; typically people will pay $10 on their lunch, and for that they get a great meal; then we have a gym, basketball court, wonderful interaction spaces in this beautiful building; 24/7 good coffee, so you can get a latte there at 2am, and that way people work harder; basically it is an environment designed so that people can optimise their research; then of course the key is getting some really driven people who set the example, and then other people then join in; so it takes a long time to build a culture like this; everything is in the culture; it's literally true that you can walk in the front door in Perimeter and I would say when you have been there for two or three minutes on a typical day, you get the feeling that something exciting is going on here from the way people talk and interact; then we did some obvious things which most universities haven't bothered to do; we asked the question - you want the best young people, you also want the best old people, so we created a special set of positions called Distinguished Visiting Research Chairs; so we invite people like Stephen Hawking or equivalence from round the world to come and visit four weeks a year and we pay them an honorarium to do that; now in theoretical physics generally people don't get honoraria at all, and our honorarium is very modest, the equivalent to what a junior faculty salary would be for that time; but nevertheless the people were so thrilled, and once you get a few of them to accept it becomes a great distinction and so everyone else wants to come, so now we have over 50 of the top theoretical physicists in the world coming to Perimeter every year for extended visits; that provides a great environment for young scientists to try their ideas out on a real guru in the field; strangely enough nobody had ever done this before and it has worked very well; another thing we are doing is creating a series of Chairs; in the history of theoretical physics there are all these great figures - Einstein, Galileo, Newton, Maxwell - nobody had thought let's make a series of Chairs with all these names in one place; this represents the entire tradition, and using these Chairs you can get the very best researchers; so now we have ten of these Chairs and we ask donors if they would like to support another, and they love it because they are joining in a very successful sequence; they have an identifiable contribution, can learn about the person whose Chair they have endowed, like Dirac; it is strange that in Cambridge there is no Dirac Chair, no Maxwell Chair though there is one at King's London, no Newton Chair, what a missed opportunity; I asked people at Cambridge if they would mind if I did this and they said no, go ahead, and I did
15:22:03 I made a bet with Stephen Hawking in 2002; he was betting that the gravitational waves predicted by his favourite theory of big bang, "inflation theory", these gravitational waves would be detected by the Planck satellite; I was betting against because I found the theory very unattractive, ugly; as time has progressed the Planck satellite was built; the bet has always been there; I have pressed him for terms of the bet, he never quite laid out the terms; about two years ago the Planck satellite had not yet announced their result on this question, but another experiment with a telescope based at the South Pole called BICEP2 announced that they had detected a gravitational wave; that experiment was led by a former student of mine at Princeton; so I heard the rumours and called up the student who was now the leader of this experiment and asked him if he was really going to announce this detection; he said he was on the following Monday; I warned him to be careful because in my view if you measure something experimentally don't tie it too strongly to a theory; what you are doing is finding the facts; don't contaminate it by claims that it confirms a theory; the facts stand on their own and that is what good experimenters should do; what is really there in nature; don't be too much influenced by theoreticians expectations; anyway he refused to listen to me, and he announced it with the claim that this confirms the theory of inflation; I saw the paper a few days later and then Stephen went on Radio 4 and said he had won the bet with Neil because this was so important, and I should now pay him $200 Canadian dollars; the reason for that was that he had lost the bet on the Higgs boson where he had had to pay $100 US dollars and he thought that this was much more important; the first I heard about it was that the BBC called me up saying they had heard I had lost $200 to Stephen; I said absolutely no way; the first rule in science is that any experiment has to be repeated, never believe one claim; secondly I looked at their paper when it came out which had five obvious flaws, even in the abstract it was self-contradictory; I don't think Stephen had read it; slowly people came round to my point of view that the experiment had not proven the case, and then as time went on the Planck satellite began to check using their data against the experiment and discovered rather quickly that the entire signal detected by BICEP could have been explained by dust, dust in our galaxy that produces a pattern on the sky which can look like the signal from gravitational waves; the two can be confused; as time went on that dust interpretation has gained support from a lot of evidence; shortly after Stephen and I had this little interaction on Radio 4 I wrote to Stephen suggesting we firmed the bet up; the claim is that gravitational waves account for 20% of what we call the anisotropies, the deviations from perfect uniformity in the temperature of the sky as we look out to the big bang; BICEP's claim is that gravitational waves is 20% of the signal; I said that if the signal turns out to be anything above 5% I will pay $200 Canadian dollars, but I am confident enough that they are wrong that I'm lowering their claim to 5%, will you take the bet on those terms? Stephen said yes, the bet is confirmed, there are referees, and during the last two years this limit on the gravitational waves signal has come down to 7%; so it's just above the threshold where I will win; I'm fairly confident that within a year or two it is going to go below 5% and he will have to pay me; I want to emphasise, however, that Stephen's good taste in a) identifying an important scientific question, b) his boldness and integrity; he is willing to say that this theory predicts x and if x is not seen you should doubt the theory; he is very unlike most other theorists; most other people who advocate inflation won't give you a firm number; one of them in California, Eva Silverstein, who has some level of what I would call scientific integrity i.e. being willing to say if this is not seen then I will begin to doubt the theory; anyway, she has made it 1%; other theorists say below .1%; anyway, the theory is in retreat; so this is about more than a bet, this is about the beginning of the universe, what really happened
22:15:12 I no longer hold to the theory I described in the previous interview; at the time I made the bet I was advocating a certain model based on string theory and a theory called M-theory according to which the world, the universe, consists of two parallel three-dimensional universes separated by a little gap, and the big bang was actually the collision of these worlds; now that theory may still be correct but I have become more conservative in the following sense; it turns out that even if you have this higher-dimensional picture of the universe formed by a collision there is an equivalent description of this whole process which doesn't require these extra dimensions; in a sense the extra dimension of space could just be a mathematical convenience, and the more we studied the theory the more we realized the issue we are really tackling is about the singularity itself; in many ways you can describe it in purely four-dimensional terms, three space and one time; even if there are four space and one time dimensions you can actually describe it in terms of three space and one time; so I have become more focused on a minimalist description of the big bang, and part of the reason is that the observations are so incredibly simple to characterise; we see the structure of the universe on large scale and amazingly it is unbelievably simple; you can describe the structure of the universe on the largest scale with essentially one number which is the level of fluctuations; they take a very particular form of what we call Gaussian random noise which is like the simplest distribution in statistics; they are scale invariant meaning that the fluctuations on any scale are the same level; there is only one number, this amplitude, one part in 100,000, characterises the whole distribution; there is a tiny correction as well which is called the tilt, but that is really a small correction; so to very good approximation the structure of the universe is described by one number; that's simpler than an atom; the structure of the universe is simpler than the simplest atom, it's insane, and yet our theories are unbelievably complicated; me too, I had extra-dimensions and branes moving around; people introduce all kinds of additional components of matter and assumptions; so the theory turns out to be way more complicated than the phenomenon it's trying to explain; so this has forced me in my own work to try to simplify and reduce, and make economical and minimal, everything I'm doing; and in doing so you come upon the foundational questions; how do you link quantum mechanics to space and time; what does it mean for space and time to have uncertainty as in Heisenberg uncertainty principle; it means there isn't a single time, there is no single space, there are many spaces and times at once; now how do you deal with that; so I've been developing a whole new picture of how you treat cosmology, the universe, correctly using quantum theory; we have a very important recent result which mathematically disproves one of Stephen's most fundamental pictures, it is a picture that he is particularly proud of and I've always been impressed with it; his picture, roughly speaking, is that space and time emerged 14 billion years ago from an event, a beginning; but this beginning has a very attractive mathematical form namely that if you think of space as running around, let's say an ice cream cone, and time running along the cone back to the tip, the tip is the big bang, singular, spiky and sharp, and all our equations fail; Stephen's idea was geometrically very simple; let's have a very smooth round tip; in order to do that you had to blur the distinction between space and time because on the round tip of the cone there is no real difference between time and space, it's a two dimensional surface; so he had a very clever mathematical way of doing that which was very appealing and has been very influential, not just in cosmology but in other areas of physics; what we have proven very recently during my stay in Cambridge is that that set-up doesn't work; that if you begin space and time in a smooth manner as he was envisaging then actually the quantum fluctuations in space and time are out of control; they are wild and the picture doesn't make sense; all you get is a universe which is wildly fluctuating; so this is a very fundamental result; I think is closes off a certain approach; in a sense is says that the beginning, if there is a beginning, is not describable in terms of a smooth geometry; there are two alternatives; one is you say it is so quantum you just can't begin to tackle it, or you say that actually it was a singular event, roughly like putting two cone tips together, and as you head towards this tip the quantumness of the world become more and more important, the universe manages to go through this bounce between pre-bang and post-bang in a quantum manner which you can describe; so I have got a very concrete proposal how that happens; roughly speaking, the simplest version looks like the post-bang universe has a mirror image pre-bang, and actually they are equivalent so you could turn it the other way; it's like an egg-timer universe; I call it the Causa Sui Cosmos; Causa sui was a word invented by Spinoza; Spinoza, Hume and philosophers of those times debated causality and causation, what came first, and if you are dealing with the big bang this is fundamental, it's all about what came first and causality; but Spinoza advocated a point of view that the universe causes itself, it just is and it is the way it has to be, and in particular his sub-agenda had to do with God - do you need a God to create the universe; he was more interested in a universe that causes itself; so that is the scenario I am developing; there is a lot of mathematical machinery; I think it is tremendously exciting that the most popular viewpoint that we could describe the beginning using Hawking's version of Einstein's theory of gravity, that scenario is now gone and there will be a very exciting battle for what replaces it; you could say that there was something before but it might be like a mirror image; so you might say from the before-universe point of view that time would be going this way and the after-universe, the other way, but actually they are both the same thing; you see, I am being driven by economy; the observations show us the universe is much simpler than anyone can have expected on the large scales; it's just spectacular; they also show us that we will be able to look at the big-bang and examine and answer this question; so this is the other thing I am really excited about that last year's detection of gravitational waves from black holes, spectacular detection made by the LIGO experiment, shows us that gravitational waves allow us essentially to make a microscope which will enable us to look back to the big bang; this is within twenty or thirty years we may be able to build a gravitational wave microscope to literally look back and see exactly what happened at the big bang; so this is not just philosophy at all; we are able to make very precise predictions and check them, so extremely exciting; but philosophically what's the contrast? The trouble with the cyclic universe, of course, is what set the whole thing going, what were the initial conditions? You can push back that question by a larger number of cycles, but ultimately you have to face the question, and we never really did in our work; we tried to push it back, and appealed to what looked like a natural attractor solution, the system would stabilize in a certain configuration, but ultimately we weren't really answering the question, whereas in this new picture, the Causa sui, there is a beginning but it's a little bit hard to define; the classical way of thinking about the big bang which I think is wrong is that you've got God or somebody, some law of physics, saying this is how it begins; then you set it going and its a piece of machinery and it runs forward in time; quantum mechanics really tells us that's wrong, the world is not a machine; secondly, the little thing from which it all emerged would inevitably have large quantumness; with small things it's very hard to localize anything; you tell me exactly where a particle is and then it's velocity is completely uncertain by the Heisenberg uncertainty principle; it makes no sense to start the universe at a particular tiny configuration; it's like the tail wagging the dog; the dog is the big thing, the universe; the big bang is this miniscule entity which should fluctuate around; so what I want to do is to have a big universe here, have it's mirror image here, this is very natural mathematically, and then it's like a soap bubble or a membrane between them which inevitably has to cross, for topological reasons you are forced to have this cross right in the middle; it can fluctuate around because it is quantum, but there has to be a big bang; so I claim this new picture explains why there was a big bang, explains why the universe is expanding because whichever way you look at it it is expanding; it explains the emergence of time and space and it's very economical mathematically; so it doesn't mean it's right, it may well be wrong, but I like it because of the economical mathematical framework which can be proven wrong, either logically or experimentally, and that makes it interesting; Einstein's aphorism 'Make things as simple as possible but not simpler' is a wonderful motto; I think what has happened over the last thirty years in theoretical physics is the theories we develop have become progressively more complicated; I was part of the membrane, string theory paradigm, and we've had extra dimensions, new fields, and super symmetry, all kinds of things; experiments, in contrast, and looking for all these embellishments of known physics, have found nothing; so the large Hadron Collider found the Higgs boson, but that was the minimal thing; you can't get away without a Higgs boson; it did not find any of the extra particles which most theorists were predicting; so I think nature is telling us it's much more minimal than our theories are; so that is great motivation for saying let's go back where we were 30-40 years ago and re-examine the foundations; why did we introduce all this complexity and was it really essential; so, for example, string theory was introduced with the main motivation being that when you do calculations in gravity, quantum gravity, you get infinities; but these calculations were you scatter one graviton for another and you find you can get infinity; but the argument is quite weak because technically it is only possible to do this calculation using what we call perturbation theory, it means by pretending the interaction is weak and then you find an infinity so there's an inconsistency; if you could do the calculation where the interaction was strong what would happen is you would have these gravitons colliding with each other and forming black holes; we are sure physically that would happen but it's just a really hard calculation and we can't see how to do it, and most likely that would cure the infinities; so in other words people leapt to the conclusion that the only way to remove infinities is to introduce extra dimensions of space, all kinds of new symmetries, all kinds of other problems, but you ended up creating more problems than you solved; that requires that you really go back, retrace your steps, and try to see could we not resolve these problems in a simple way, and I think that is where we are right now; it's a very exciting time; if we do resolve these problems, and I think nature is guiding us to the solution, this will be a revolution in physics every bit as important as quantum mechanics or relativity; we are at a similar moment in the history of physics where the paradoxes are building up to a point where all of the popular paradigms are in deep, deep trouble, and that is just wonderful