String Theory and the Scientific Method: Interview with Richard Dawid
Luca Moretti · PhilPapers (PhilPapers Foundation) · 2014
Dear Richard, I'm delighted that you accepted to be interviewed by The Reasoner.Of course, I will ask you questions about your recent book, String Theory and the Scientific Method (CUP 2014).Before that, I would like to know about your intellectual story.I recall that you started your career as a physicist but converted to philosophy after a while.Could you tell us something about these events?Richard Dawid: My pleasure, I'm looking forward to the interview.After my PhD, I spent two years as a high-energy physicist at Berkeley.That period, the late 1990s, was a particularly fascinating time for String Theory (ST).Some new conceptual ideas developed in those years substantially changed the understanding of ST and paved the way for its further development until today.Watching those developments, I felt that they raised novel and interesting philosophical questions at various levels.Thinking about them eventually made me switch from physics to philosophy.LM: Did you have any background in philosophy?RD: I was always interested in philosophy.I had read some philosophy, had joined a philosophy discussion group during my PhD in Vienna and had attended a few philosophical university seminars.But at the time I decided to enter philosophy, my knowledge was quite haphazard.Thinking back today, I'm a little stunned on what meager basis I made that decision.LM: I remember you told me that you emailed eminent philosophers for advice.What did you ask them?Did you manage to meet any of them?RD: Right, once I had developed some first philosophical ideas about what I intended to do, I wanted to clarify two things before seriously moving into philosophy.First, I wanted to know whether my ideas made a little sense to genuine philosophers.Second, I wanted to know whether it was fun discussing with genuine philosophers.Since the only philosophers I knew at the time were really famous ones, whose books I had read, I just emailed three of them: Hilary Putnam, Bas van Fraassen and Hartry Field.I asked them whether they were willing to talk to me about my ideas.All three were extraordinarily kind and agreed to meet.Unfortunately, Putnam had to cancel the day before we met for urgent personal reasons, but I met van Fraassen and Field and presented a sketch of my ideas to them.Van Fraassen was very supportive and gracious and seemed genuinely interested, a real pleasure to talk to.Field told me right from the start that he wasn't interested in the subject but was ready to comment on the general soundness of my reasoning, which he did with impressive acuteness.Both meetings substantially strengthened my conviction that it made sense for me to turn towards philosophy.LM: Were your first philosophical ideas already about ST and the no-alternative argument?RD: I was mainly interested in two issues that were both related to ST. LM: Perhaps, before continuing, it would be helpful if you could shortly explain what ST is.RD: ST aims at providing a unified theory of all physical interactions.The nuclear interactions, which are crucial for understanding microphysics, are today described by gauge field theory, which is based on the principles of quantum mechanics.Gravitation is described by general relativity.A coherent overall theory that covers both regimes faces deep conceptual problems.There are reasons to believe that ST can solve those problems.ST starts from the basic idea that elementary objects are not point-like objects, as gauge field theory assumes, but one-dimensional strings.Those strings are taken to be so small that their extendedness cannot be measured by present day experiments.But if ST is right, the movements and topological characteristics of strings can explain all observable properties of elementary particles.LM: Thanks.Please now let's go back to my original question.RD: Yes.First, I was interested in the phenomenon of string dualities.In ST, one encounters the phenomenon that seemingly very different realizations of the theory after close inspection turn out to be dual to each other.If two theories or models are dual to each other, they are related in a specific way that implies that they are empirically equivalent.Dual theories or models can be different in all respects