After the end of SFT VI, I had one extra day in Munich, and I attended two public lectures associated with the Strings 2012 conference. The main conference was at the same time as SFT VI, and also there was a 35o Euro fee to attend, so I didn’t go to any of it. (I don’t understand why physics conferences often charge substantial admission fees, while mathematics conference usually charge little or nothing. Is it because of different funding models? Or just to keep the crackpots out?) Anyway I was lucky to be in the right place at the right time to attend the public lectures.
The room was packed with nearly 1000 people and uncomfortably hot.
The first lecture was by Prof. Heuer, director of CERN, on “Die Weltmaschine LHC am CERN: Einblicke in das frühe Universum”. I didn’t understand it very well because both German and physics are foreign languages for me, and the sound quality was poor (I could understand most of Witten’s talk only because almost everything was written on the slides), but here is what I got out of it: (1) CERN is awesome (I guess I already knew that). (2) What they just discovered might be the Higgs boson, or it might be just one of several scalar fields. They are hoping to discover more scalar fields which could be consituents of dark matter. (3) “The air is thin” for supersymmetry, but they might be seeing something beyond the Standard Model “in the charm regime”.
It seems like a dangerous public relations strategy to raise expectations too high (e.g. to raise expectations for finding constituents of dark matter), since no one knows what, if anything, the LHC is going to find beyond the Standard Model. Anyway they will soon shut it down for two years to double its energy, and everyone is hoping they will find something new after that.
The second lecture was by Witten on “String theory and the Universe”. It was mostly a review of standard things which I have heard before. The most interesting part was the question period afterwards. The first questioner launched into a very aggressive rant about how Witten was abusing his scientific responsibility by leading thousands of people to waste their intelligence on a theory for which there is no experimental evidence. The chairman basically needed to shut him up (and should have done so earlier). Anyway Witten answered: (1) Some things take time, look at how long it was from when the Higgs particle was predicted to when it was discovered, (2) [I think what he said is that] since quantum mechanics and relativity are incompatible we need to work on reconciling them, (3) [I couldn’t hear what he said.] (Of course, mathematics has benefitted enormously from Witten’s discoveries, even if not all the fundamental problems of theoretical physics have been solved yet.) Someone else asked (in a much more reasonable tone) about alternative approaches to quantum gravity. Witten said that some approaches which had been considered as competitors, such as twistor theory, had been absorbed into string theory. He said something else about loop quantum gravity which I couldn’t make out.
Anyway I was kind of shocked to see such an agressive attack from the general public. I’m glad I don’t have questioners attacking me because my work does not have enough real-world applications or whatever.