CMI Lecture Notes and Articles
My friend pointed out that the Clay Mathematics Institute has released books in PDF format, and are available on the CMI Lecture Notes and Articles page.
There are some interesting books, such as
- Ricci Flow and the Poincaré Conjecture
John Morgan and Gang Tian - Mirror Symmetry
Cumrun Vafa and Eric Zaslow - Strings and Geometry
Michael Douglas, Jerome Gauntlett, Mark Gross
They are all wonderful books. The Mirror Symmetry book, which I often use as a reference, is the most complete literature survey I have found on the subject; it is nearly a 1000 pages! Thanks to the PDF version, now I can just grab my laptop and move around the world with all the heavy books right next to me!
post mini-project
I have been busy lately, working on my mini-project writing a review article on D-branes, homological algebra, and category theory. I have posted the review on my homepage, but if you want to learn it seriously I recommend reading Aspinwall, D-Branes on Calabi-Yau Manifolds. I had to compress the 132-page-long lecture notes and also Witten’s Mirror Manifolds and Topological Field Theory in just 15 pages for my essay, so I couldn’t build up homological mirror symmetry from scratch.
I also gave a talk on this subject for the Part III return conference in Cambridge, which was held for theoretical physicists that did Part III last year. It was nice to see all my friends again. Here is a cute teaser by Flip for the fifth Part III return conference. I was initially planning to blog about the conference, but I decided against it. Mostly because I didn’t understand most of the talks, except for Cyril’s talk on spin geometry.
Since all of the dust has settled down, I will (attempt to) start blogging regularly. I can’t promise anything now, but I am hoping to write about generalized complex geometry. There is one problem, though, I have to learn it beforehand! So patience and silence might be needed.
T. D. Lee and C. N. Yang
T. D. Lee and C. N. Yang received a Nobel Prize in Physics for their theory in weak force interactions between elementary particles. They predicted that weak interaction between elementary particles do not have parity symmetry (P). This was confirmed in a famous experiment by Chien-Shiung Wu. There is an interesting episode on this experiment.
Pauli and Schwinger had formulated CPT theorem before people learned that in weak interactions, actually P is not conserved. (Even though P is not conserved in weak interaction, CPT theorem is not violated in the end. – I don’t know how to show this, but I know it is well-known (to others).) Before Pauli knew the results of the experiment of Wu, he wrote to Weisskopf in a letter dated January 17, 1957[1]:
[...] I do not believe the Lord is a left-hander, and I am ready to bet a very high sum that the experiment will give symmetric angular distribution of the electrons. [...]
Georges M. Temmer was on a laboratory tour in western Europe at that time, and Pauli asked him what was the latest news from the States. Temmer said that parity is no longer assumed to be “conserved”. Pauli replied with great surprise “that’s total nonsense”. Temmer said “I assure you that the experiment says not”. Pauli curtly, “then it must be repeated!”. [2]
After knowing the results of the experiment, Pauli wrote to Weisskopf in January 27, 1957.
[...] Now the first shock is over and I began to pull myself together. [...] It is good that I did not make a bet. I can afford making a fool out of myself, but cannot afford loosing money. [1, and re-translated by my friend]
But stories around weak interaction does not end on Pauli. T. D. Lee and C. N. Yang are also well known to have been in bad relationship for a long time.
It was when C. N. Yang was in Princeton. T. D. Lee came from Chicago and visited him and had a private conversation in his office. After a few minutes, people in the hallway could hear both of them shouting at each other, and T. D. Lee burst out of Yang’s office and slammed the door behind. Unfortunately, nobody around could understand Chinese, and the reason of quarrel has been a mystery since. People guess it was about who, among them, first proposed the idea of parity non-conservation for weak interaction.
There is another episode. It happened when Yang was visiting Malaysia for a conference. The Malaysian press were interested at the Nobel Laureate, and asked “what do you regret most in your life?”. Yang said, “the fact that I selected T. D. Lee”. [3]
Sources
[1] Tung-Mow Yan, Professor C. N. Yang’s Impact on Physics
[2] David R Lide, A Century of Excellence in Measurements, Standards, and Technology
[3] ExtraD, C. N. Yang and T. D. Lee (Korean)
