I''m utterly, completely shattered so apologies if this post is a little non-sensical. Having arrived in the office at 8 this morning, it's now 9.30 at night and I've just got home. This doesn't mean I've been working all day, far from it, I think I've done two hours solid work today but it's been tiring none the less.

At ten this morning was a slightly more technical talk by Glashow about the puzzles and problems of particle physics. He listed what he thought of as the eight most prescient questions that should be tackled over the coming years. Most of these were particle physics, but some were cosmological. Having talked to him some more, his greatest question relates to the topic of his nobel prize. He's most concerned about the nature of spontaneous symmetry breaking in the standard model. Hopefully in the next five years, this question can be answered. At the end of the talk he listed three reasons why high energy physics should be studied and specifically funded. This is a question that the media and the general population often pose. His reasons were the usual reasons of 1) Technological spinoffs 2) The training of people in a very rigorous discipline which teaches analytic, numerical and communication skills to a very high level, and 3) Obligation.
He gave examples and extended his argument for each of the three reasons but it was third one which as most elegantly put. He quoted Primo Levi on the obligation of scientists and this quote is something I would like to track down to put in here. If this rings a bell with anyone I'd be very grateful. I guess it's from 'The Periodic Table' but Im not sure. If I wasn't feeling so tired I'd try and remember what it said but right now I can hardly type.

So after the talk we went for another banquet lunch, again with superb food. I've come across a new spice which I've never seen before which has various names from Szechuan pepper to paralytic pepper, though it isn't really in the pepper family at all. I guess from it's properties that it may be in the clove family. Anyway, it's effect is to make your mouth go completely numb and tingly, a really bizarre feeling and one which I'm now trying to avoid whereever possible. Again if anyone knows what this is, I'd love to know it's proper name. I say it may be related to cloves as cloves certainly have a mild anaesthetic effect and chewing them is supposed to be good for tooth ache. The flavour in Chinese is called ma la and is supposed to be good for the health.

So after lunch and a little work, the postdocs had a meeting with Glashow to ask him questions. He was clearly very tired by this point and understandably so with the amount he must have been rushed around Beijing, photographers in tow and the constant barrage of questions he's getting.

Nobody was asking much at first so I asked if he had any regrets in his career upto now. He said that his two biggest regrets were that, while sharing an office with Goldstone, the two of them didn't try to bring their work together as they would almost certainly have come up with the Higgs model of spontaneous symmetry breaking of the SU(2)xU(1) group, way before Weinberg. His other regret was, and he conceded that this wasn't his fault, that proton decay still had not been seen.

As I mentioned in a previous post, group theory (the mathematics of symmetries) plays an essential role in particle physics. Symmetries tell you about structure in nature and the more symmetries you have, the more particles of nature can be related to one another. Each of the four forces of nature (electromagnetic, weak, strong and gravitational) is described by a set of symmetries (though the latter should be left out of this discussion). One of the aims of particle physics is to find a large set of symmetries which relate all of the forces and particles of nature into a single 'group'. This is partly an aesthetic longing but it is a major goal none the less. Anyway, most of these theories which manage to group all of the forces and particles together predict that the proton should be unstable though with an unimaginably long lifetime. Using giant detectors proton decay has been searched for but still not found. This may be because its lifetime is so long that we need even bigger detectors (a million tonnes) to spot a single proton decaying, or it may be that it is truly stable.

Anyway, if proton decay had been seen, this would have been a fascinating signal of 'new physics'. Incidentally, though these detectors didn't spot any proton decay, they did turn out to be vital in uncovering the fact the one of fundamental particles of nature, the neutrino, has a mass. This was not thought to be the case for almost 70 years and this discovery earned a nobel prize for physics in 2003 (I think).

Anyway, after my question, more flowed though all of them very technical and Glashow, having been bombarded with questions for such a long time, was clearly not in the mood. Even if he had come to it fresh, the questions were all from left-field and generally involved somebody writing down a Lagrangian (which I won't expain now as I can hardly see now let alone type) and asking him technical questions about its consequences.

This went on for three hours by which time the debate had heated considerably, caused mainly by such obscure and circuitous questions on subjects that Glashow either wasn't an expert on, or was opposed to on grounds which I'm becoming more and more convinced are vital. These grounds are that physics isn't physics without predictions which are directly linked to experiment and can be verifiably tested. Sure, he admits, the games of string theory, and GUT model building can be fun, but are they science if they don't make firm predictions that can be tested within our lifetimes?

After all this we went for another banquet dinner, this time in a Cantonese style restaurant. I guess we must have tried something like 60 dishes today. The other problem is that though the beer is weak, the waiters keep topping up your glass while you're not looking which means that a single drink can end up being quite a lot. Anyway, I must rest now. Apologies for the rambling nature of this post but this is a true reflections of how I'm currently feeling!