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The Brian Cox and Robin Ince Sort of Chat Show – Episode 4


The Brian Cox and Robin Ince Sort of Chat Show Continues…

Robin – What for you is…there’s a beautiful moment where Peter Higgs is sitting in an audience in CERN and they’re going through the results that are basically, actually, confirming the idea that a man in his thirties, now in his eighties…and there’s a little bit where you could see that he’s, obviously, tears, why not, fifty years’ work, all that thing.  And I wondered what for you has been anything near that in your life, where you thought, what an incredible piece of science, what an incredible discovery, something where, cause, you know, we’re given all these cliches of the cold scientist and, of course, you know, Peter Higgs is one of the many examples where there was no coldness in him, seeing those things come to fruition. 

Brian – You mean in work that I’ve done?

R – For you personally: have you ever had moments where you’ve thought, whether it’s just about the universe itself, or where…

B – It can be the smallest things, cause most scientists only don’t have the…I suppose, the skill or the fortune or whatever it is, to come up with something like the Higgs theory, you know, most don’t.  But every scientist who does a PhD has some moment in there where they discover something that no one else knows and it can be the tiniest little thing, right? But it’s something from the data that nobody’s seen before.  And those are great moments and you realise how powerful science is.  And particularly in particle physics it tends to be through…you simulate what the collisions look like using computer programs and so you put all the theory in, you do simulations, and you get something that you can plot on a graph or something like that.  And then you run other computer programs to go and look at the data which is real, real particle collisions and you see how they fit and you know everyone will have discovered something that nobody knew, a little twiddle on the theory, and that’s why you get a PhD, you can’t have a thesis unless you’ve done some original work.

So everyone will have gone through that, and it’s a very wonderful thing cause it shows you the power of science.  I don’t think you can really appreciate the power of science until you use a prediction…you get a prediction, you compare it with reality, with nature, and you find that that prediction works.  And behind that prediction there can be layers of elegant mathematics or there could be layers of assumptions or guesses or theories or whatever it is, but when a prediction matches data, it’s a very beautiful thing.

R – Again, we won’t go into the details but you’ve just written a paper with Jeff Forshaw.

B – Oh, yeah.

R – Again, if this works out…

B – It’s great!

R – It’s exciting…

B – It’s a great story.

R -…and important.

B – It’s a nice story, cause year ago, two years ago, I gave a lecture on television based on a book I wrote with Jeff Forshaw called The Quantum Universe.  And in that we take a very…it’s quite a different approach to quantum mechanics but it’s based on Feynman’s approach, so it’s not unusual but it’s an unusual way of teaching quantum mechanics, cause you jump in in the 40s and 50s, I suppose, and in Feynman’s so called path integral approach to quantum theory, which emphasises that particles are particles, so it’s a very particle way of thinking about quantum theory, they jump into different places and what we’re concerned with is the rules that tell you how likely they are to jump from one place to another.

And in that picture you get a very surprising kind of picture of quantum theory now and how it works. Although causality is respected, so although you can’t transmit information around the universe faster than light, you can…quantum theory itself describes a universe that changes…actually, I was going to say but in some sense it changes instantly, so it can reconfigure, it’s what’s called a nonlocal theory, so you can do something here and something has to change over there instantly, essentially, and these things, they’re well known, there are things called EPR paradoxes Einstein used to get worried about which is the E in EPR  where you get these things that change.  And so I’d said something along these lines about the exclusion principle and some physicists are like, well, mainly not physicists, but one physicist in particular called Sean Carroll, who’s an excellent physicist, took issue with the way that we’d presented.  Now, you know, you can take issue with things sometimes because you oversimplify things, but the general point I believe is correct and the general point he believes is wrong.  So myself and Jeff, it’s in our book, this idea to prove it in quantum field theory.

So his main objection was something we were talking about: what’s called simple quantum mechanics, non relativistic quantum mechanics, and he said, well, now relativity is included, it’s all quantum field theory and this will all sort itself out. So we…two years we’d been doing it and it turned out to be an extremely interesting and complicated question.  We got two great post-docs to work with us and then the four of us finally…mainly actually one of the post docs, a very technical, brilliant mathematician, has come up with huge framework which we’ve just published today, actually, so it will be on and around on Monday.

So it’s a very technical paper but, basically, what it shows is if you do something here in the universe and you try and detect it here, and then how does that work, is it causally connected, you know, is it…and basically it turns out it is causally connected, so you do something here and something here. But if you ask, I want to do something here and here, so different places, then there can be these rather strange kind of a-casual connections between them. So it’s a really nice framework.  And the full implications of it…we have to do some calculations now but what it is is a framework to ask the question that Sean Carroll asked after the lecture I gave, which is, if you do something here, and you measure something there, what happens? And that is basically a framework to answer those questions.

Link to Brian, Jeff and Co’s paper