The Ghost in the Atom

"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. 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 10 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. 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. 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. 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."