Vlatko Vedral on The Quantification of Everything

Your first book is Quantum Physics: Illusion or Reality? by Alastair Rae.

This is a completely popular book about quantum physics: there is not a single equation in there, I think. What he does is to go through all the major ways in which we try to understand quantum physics, all the major interpretations. It’s extremely good in that he writes in a very objective way and it’s very difficult to tell which one he supports. It’s very passionately argued as well, and it’s a beautiful exposition, very philosophical. I think it’s the best, probably my favourite, popular account of all the things we argue about on the fundamental side of quantum physics.

There are all kinds of strange views on what quantum physics actually is.

Right. There are connections with religion, then there are extremes saying it’s all in the mind: basically that nothing becomes real until we measure it and look at it and consciously record it. On the other side there is a point of view that it’s as real as anything else, out there independently of us and so on. He talks about these two extreme views and what quantum physics tells us about this very old question: whether the world is ideal or real.

Does he resolve it?

He really leaves it open because, to be completely honest about these issues, I don’t think we have something that’s universally accepted as the view: each has lots of positive points but also something that makes it a not completely plausible view to hold. That’s a really nice book.

Your second book?

The Ghost in the Atom. This was actually a sequence of radio interviews recorded by Paul Davies, who’s probably the best populariser of physics we have.

He’s the Search for Extra-Terrestrial Intelligence guy?

Right. He’s written a book about that as well. I think in the 70s/80s he conducted a set of radio interviews with about ten of the leading physicists of the time. And the spirit is similar to the previous book in that it’s all to do with how we understand the unusual phenomena in quantum physics. The book is written as a dialogue – Davies asks a question and then the interviewee answers – and I would say this format is a much more exciting read than typical prose where someone exposes something. It also goes into personal issues, which you usually don’t get in these books, in that he asks each person about how they got engaged, when did they first learn about quantum mechanics, how did they learn it? It’s really fantastic, an amazing read.

To whom does he speak?

People like John Bell, who came up with Bell’s Inequality, which was one way of quantifying the weirdness in quantum mechanics; then David Bond who has one of those interpretations that tries to retain, I would say, some kind of reality in quantum mechanics, arguing that the world is still as real as it was in a Newtonian kind of framework. Davies chose a person to represent each of these points of view, and it’s really interesting how the interview is conducted and then where it leads – how different people end up in completely different parts of quantum physics, and what they find exciting, and so on.

Does it lead you to believe that maybe people go into quantum physics to prove an idea that they’ve already had?

That’s an interesting point. It’s difficult to tell what comes prior to what, right? In a way we do have these inner feelings, all of us, as to what we think the world should be like. And we usually carry this prejudice with us into our research as well, so it’s not clear whether you come with a prejudice and then you’re trying to use this theory to confirm what you already thought the world was like prior to that. In this kind of interview it’s easy to expose these kinds of things: you can see that people started with some ideas and then maybe changed them or didn’t change them as they did research.

All these unifying theories that quantum mechanics proves, seem to have already been posited in literature or religion or whatever. 

Yes, I don’t think there is anything really distinctly novel that was brought there philosophically by quantum mechanics. The key tenet I would say is this randomness that is at the core of our interaction with the world: there is an element that you can never make more deterministic. And, of course, randomness as a way of looking at the world existed for a long time. If you go back to the ancient Greeks I think you will see a spectrum of all of these world views already present there.

Your next book?

In physics we always study simple, inanimate objects, so physicists find it very difficult to understand, for example, weather patterns, or financial markets. Anything that’s more complicated, it seems that we don’t have the same grasp that we have with atoms or things like that, so I think that’s exactly where I would like to go to with the next three books. Firstly, What is Life? by Erwin Schroedinger. He was one of the founding fathers of quantum mechanics in the 1920s and then in the 1940s he began to think about biology. At that time the big problem was how biological information is encoded. This is just before Watson and Crick found the structure of DNA and explained the whole thing.