## Tuesday, March 14, 2006

### Frank Wilczek and weak gravity

I plan to write a few words about the insightful and entertaining colloquium by Frank Wilczek - once I have some time.

The talk included a lot of classic material about QCD, the spectrum of hadrons, pictures of jets from the LEP, pictures of workers from the LHC - our civilization's answer to the age of pyramids (which is moreover driven by curiosity instead of autocratic rule and vanity), bubbling animations involving the averave topological density "Tr (F/\F)" as a function of space and time computed from lattice QCD, and justifications of the statement that 95% of the observed mass is due to QCD effects. We have also heard various jokes - for example, Frank Wilczek mentioned that the eye was only designed to see distances much longer than 1 fermi. Later he corrected himself that he should have said that the eye had evolved rather than having been designed. ;-)

In the second part of the talk, the weakness of gravity was explained by the fact that you must walk before you run. In the case that you don't know what it means, it means that near the Planck scale, the strength of the QCD coupling constant changes very slowly, and it only starts to run quickly when the coupling constant is of order one, which is near the QCD scale, which is where the proton mass has to be found.

This cute mechanism (that I have appreciated for a couple of years, much like Frank Wilczek himself) based on logarithmic running only explains the gap between the QCD scale and the Planck scale. Of course, the gap between the electroweak scale and the Planck seems to be a very different problem - it is the hierarchy problem that is harder to solve but some mechanisms of SUSY breaking effectively propose an analogous solution.

Too little time.

Dinner

I just returned from the dinner in the Society of Fellows which was fun, after a long time of having no such dinners. Andy Strominger confirmed my hypothesis that he is the center of the Universe if the metric is defined by the collaboration distance that we recently discussed on this blog. Several years ago, he was actually the #2 but it is more or less guaranteed that he became the #1.

Most of the debates were dedicated to various questions that were asked to David Elmer - who studies ancient Greek literature. Frank Wilczek asked many things about the existence of Homer and David, together with Frank, Bert Halperin, and perhaps me, did the best to evaluate the probability that Homer existed as a function of the chronological diversity of the contemporary texts in his epoch. If you didn't follow the details of the previous sentence, it does not matter because most of us did not follow them either.

At any rate, David did a very good job - although he finally admitted that he had to sweat a lot because of all these questions. David also asked a question to Frank Wilczek: What are you working on now because we're not interested in all this past nonsense that you did to be awarded by the Nobel prize. OK, the wording was a bit different. ;-) Would you expect such a focus on the most up-to-date issues from a classicist? Miracles occur in this world.

We also discussed the scenarios in which our civilization would be completely destroyed, much like the civization of the dinosaurs. The main question was whether any traces would be left for the future civilizations composed of robots or new kinds of birds. :-)

After Andy Strominger explained his profound consternation by the fact that we had not been able to analyze the civilization of native Americans who lived in Northern America as recently as 800 years ago, Frank Wilczek hypothesized that no future historian would be able to learn that on Monday, March 13th, 2005 AD, Frank Wilczek was sitting at the end of the table in Eliot House, Harvard University, next to Bert Halperin on his left side (followed by your humble correspondent) and David Elmer on his right side, and they were discussing ancient Greek music and history.

Of course, Bert Halperin knew better. He conjectured that the future historians were going to learn about this dinner anyway because there would be a distorted report about this event at The Reference Frame. The historians wouldn't have a better source so they would have to rely on this blog and analyze what can be trusted and what cannot be trusted. However, Bert Halperin has conjectured that there are so many blogs that the historians could not find the information anyway. Has he tried to find information about Wilczek and poems, for example? ;-)

Alison Farmer explained that we had made no interview because I apparently asked some completely crazy questions about the quark gluon plasma while her research is mostly about Saturn's rings (I really had to confuse her with someone else during my internet search) while Franziska Michor is in Japan and did not attend.

#### 1 comment:

1. Wilczek's joke about the eye reminds me of something I have been puzzled for a long time. Which there doesn't seem to be a good answer.

The question is related to the photosynthesis capability of life forms. All life forms on earth has to rely on biomass energy, and all biomass energy, including the fossil fuels we burn, ultimately came from solar energy, via photosynthesis.

The problem is, before life forms evolve to have the photosynthesis capability, what happened? A life form needs to have energy input to be able to survive and evolve. But without photosynthesis, where did the energy come from? So how did life manage to survive and evolve, in the dark ages prior to photosynthesis?

Of course, primitive life forms might be able to acquire energy from certain chemical reactions. For example, methane oxidation. But then the problem is there was NO free oxygen, prior to the occurance of photosynthesis. It's all suffocating carbon dioxide. And as the earth is formed from a cloud of extremely hot primordial soup, all materials would have to settle down into chemical componds of the lowest possible chemical energy. So there really shouldn't be any more chemical energy remaining to be utilized when life first occured.

Which brings in the possibility that photosynthesis may not have been evolved natively on earth, but instead be seeded from life forms carries onto earth by meterites.