A Beer with Stephen Hawking - Sixty Symbols

so I'm sure lots of people who've given talks with Stephen in the audience will both have felt the same you're giving the talk a it's nerve-racking Stephens there you're talking about real things I was talking about cosmic strings and he'd worked on these and and I was thinking I wonder what he's thinking and then you hear the click click you're thinking it's fountain error mistake or he's gonna say this is rubbish and you've got to sort of carry on and you stop and then the organizer carry on it's ok and you carry on and then it's not that he puts his hand up rent he can't do that so just the the speaker turns on and out comes these words and I was okay it was a question and I had an idea of the answer to the question and so but that feeling of I think has it discovered something or not that I was wrong I heard that very well in some sense it is a sad day but actually in other ways it's a triumph in that given that he was a cup given a couple of years to live in the 1960s the fact that he made it into his 70s is a truly amazing achievement he was so determined to succeed so determined to keep alive I mean he was told he should be dead within whilst he was doing his PhD and along the way he did all this truly astounding physics and which you know for somebody with no disability at all would have been an amazing achievement but to do that from wheelchair without access to you know when I'm thinking about something I've often scribbled something on a piece of paper or I'll just fiddle around with things not being able to do that having to do the whole thing essentially in your head is a truly astounding achievement so I think probably the main thing to be doing today is sort of celebrating a truly exceptional and completely unlikely life so packing what he did and to make the contributions that he has is just staggering but he's a huge loss you can tell from the coverage he was a very charismatic individual I actually only met him once so I met him when I was an undergraduate so back in the 1980s before he lost his voice so I I heard him give a talk in his own voice even then the disease have progressed to a point where he couldn't talk clearly and so he actually had one of his PhD students along with him who was kind of interpreting what he was saying so he was giving the talk and then the student was sort of repeating what he was saying so that people who weren't kind of tuned into being able to understand what he was saying could hear the talk as well to be honest I remember absolutely nothing about the content of the talk itself but I do remember Stephen Hawking and it really it wasn't just the fact that he was somebody you know in a wheelchair who was hard to understand who were saying all these amazing things there was something about him that kind of he did have that sort of charismatic personality yes whether it be from his book of course brief history of time which I think has sold twenty million copies through to the lectures he gave through to the broadcast see he gave his media contributions you know his efforts with the National Health Service you know supporting that he he touched everything and people listened to him they wanted to let's just described a couple of the things right because they're just so extraordinary what he did from his PhD days where he he I think was influenced by roger penrose roger penrose who who was a is also a genius but working on general relativity and hawking and Penrose realized that if you thought of our universe as containing sort of ordinary matter the kind of things that you and i are made of and that that matter would evolve in such a way that if you traced it back in time the universe simply had to have a singularity it had to have a region where the space and time diverged they had curvature singularities that meant the equations broke down so many ways general relativity itself predicted its own demise because the equations brought down and the what Penrose had done was he'd spotted this for black holes and what Hawking did was he he extrapolated it to the universe and and in doing so he basically sure the universe had to have at least at this classical picture what we'd call a Big Bang where space and time emerged from so that was the first major thing he did but then he went about trying to address it and he was interested in in black holes naturally because of this this type of work and in that in the 70s he did something quite extraordinary he basically brought general relativity quantum mechanics and thermodynamics together and he in and in in this mix he demonstrated that because of the the influence of quantum mechanics that a black hole that we always think of has been black because nothing can escape from it from its event horizon he demonstrated it I mean this must have been such a dramatic calculation to do what I'm about to describe he demonstrated that it's not black actually the black hole has a temperature and if something's got a temperature it will radiate and it was radiating particles so the black hole because of quantum mechanics was radiating particles so it was actually shrinking it has revolutionized the world of theoretical physics this concept of hawking radiation and there's no question that if they'd have been able to discover it he'd have got the Nobel Prize just him it had been a solo a Nobel Prize for him and they haven't found it because a typical star the the temperature of this radiation that's being emitted is so low that we can't detect it we just kept a typical star like black hole above a solar mass we just can't detect it but the the the idea is so firmly rooted in quantum mechanics and relativity that it's accepted that this this will happen that black holes will evaporate in the 1980s he turned his attention back back again to the beginning of the universe and the he asked the question you know okay if the universe's got this singularity what can we do about it and he came up with a proposal with another wonderful physicist called Jim Hartle that actually the universe effect we didn't have a beginning that is called the no boundary proposal and he what he argued was as I go back in time to what we would have said was this singular point at which that actually the time becomes imaginary and in becoming an imaginary time it actually affects you allows you to round off this singularity and so there is no boundary and so he would turn this on its head and you'd say that the universe began from a quantum fluctuation which produced this initial starting point which then emerged to give our universe today and this is the wave function of the universe he in quantum mechanics we use wave functions all the time to describe positions of particles at different times he decided along with Hartl that there should be a wave function describing the universe and so you did it and and we don't know if it's right that I think Jim and Stephen certainly believed it was right people are working on this all the time to try and understand it but it these three areas just transformed our feel even things like his voice which clearly since that voice synthesiser was created he could have if he'd wanted to moved over to something which would have sounded much more naturalistic but that was it defined him and it was actually all that Stephen Hawking and that's that's kind of a unique personality was even printed in him in all those well you know in in the way he sounded and the way he looked and he traded on it is the wrong word he you know he used it as a way to to present the subject to present science in a way that was sort of accessible and different and made people think about things and through a whole variety popularly the you know the Big Bang Theory the Simpsons you name it he was on it at some time or another he did something else which people that are in danger of forgetting it did a couple of things I just like to add in one is in the in the 1979-1980 time early eighties there was a an idea called the inflationary universe emerged with people like Alan Guth and Andrei Linde and Paul Stine hardened and and the old break but Hawking was there Hawking Mawson Stewart wrote this fantastic paper on inflation but in particular at a workshop which Hawking helped organize a whole group of cosmologists got together and they basically discovered that inflation could give us with the seeds the perturbations which led to the structures that we see in the universe so Hawking was involved at the ground level here sorting out the perturbations we seed the structures of our universe and which seemed to have been confirmed by the beautiful details that we see from the Planck Cosmic Microwave Background the detector so he did that but he did something else which had to forgotten about until today that back in the very early days of his visa research when he was thinking about black holes he thought about what happens when two black holes merge together now these black holes have got an area associated with them and he showed that the area of the of the combined black hole had to be bigger than the sum of the two smaller black holes and that meant he could put a bound on the amount of radiation gravitational waves that could be emitted and it's sort of really nice that within the last two years this has been detected precisely these gravitational waves have been detected by the LIGO detector and from the merger of two black holes and they fit beautifully with the ideas of Hawking demonstrating these bounds which people have tended to forget about but he was there thinking about gravitational waves from black holes way before these experiments were done I was lucky enough to meet him I didn't meet him so much in the last few years our past didn't overlap very much and he wasn't that well but in the 80s and 90s I met him a lot so there's a yeah I've got some happy memories I mean one of them in life in general you you have periods of luck and I've had many of them and one was that I went to Newcastle to do a PhD and at the same time a postdoc arrived that's someone that's just finished their PhD and that postdoc was Ian moss and Ian Moss was Hawking student and they'd been working on inflation and I I think they got so into it that ian had run a bit late with his writing of his PhD so he came he'd missed the usual job cycle and arrived to with us at Newcastle well he was still working with it with Steven and Steven came up with in a few weeks or months at least to giver to give a seminar so this was so exciting for me right that Stephen Hawking coming is it early 82 or 83 and he came and he gave the seminar is it was the time before he became ill and had to have the truck up to me and and so the voice synthesiser he could still speak and so for the first 20 minutes of the talk you could listen to him who's actually giving the seminar but such as motor neuron disease it's a muscle wasting disease so his muscles gradually would weaken and so his speech would become slurred at which point the graduate students then took over his graduate students but Ian was doing it because he had been his graduate student so Ian finished off the top from in other words what would happen Stephen would speak very quietly it's the yin would be listening and then Ian would say what Stephen was talking about and it was about the wave function of the universe they'd just come up with this idea of this wave function describing the whole universe anyway so the talk was fantastic and then we went had tea biscuits and and and we said to Stephen well we usually take the seminar speaker for a beer afterwards he went yeah okay well the beer was down at the key side it was in the cooperage arms down at the bottom of the key side which is a long way from where the physics department was so we went off off we went Stephen in his wheelchair we went down and for those under no no Newcastle it's very steep so we're coming down this big steep hill to get to the Cupra stand onto the key side and about three crosses our way down this and even steeper steps and we said to Stephen well if you go you carry on down there just follow the path down and we'll just go down these steps and he went no I'm coming down the steps now these were really narrow steps and there's loads of them down sit and we're going no no it's really not not good this and he said no I'm going down these steps you're taking me we took a corner reach of the wheelchair and it was a heavy wheelchair and we very very slowly went down the steps with him and then we carried on and the cooperage had another set of steps to get in and we lifted him in and then he said and it was packed downstairs and people were coming up to him immediately of course and even in the 80s it was really well known and they were coming up and it's Stephen Hawking having patting me on the back and we said well we sometimes go upstairs I said let's go upstairs and so we went up and then he brought us all around and we had it we all had a great time with him and then we all brought him back down again afterwards and we went back and went to his van so that they could then drive back to Cambridge and and and the the striking thing is and I think it sort of sums up what Stephen was was like was this determination this determination not to let obstacles get in his way and he knew he could have gone down there but for some reason which really he wanted to come down these steps and that drive that determination I think it says a lot about why he survived as long as he did that ability to just keep going yes it was a great experience and give seminars if you had lunch a few times when I've been there nothing I'd had lunch and he would just come up and join you because he he he wanted to chat he wanted to talk and that was a that was when that first happened I remember thinking it must be no one else around but now I just wanted to talk about physics and wonderful man it's called an antiparticle literally pop into existence so the particle escapes and the antiparticle falls into the black hole

Channel: Sixty Symbols

Views: 192,667

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Keywords: sixtysymbols, stephen hawking

Id: EsNjHaKwN5E

Length: 14min 53sec (893 seconds)

Published: Wed Mar 14 2018