Berkeley is one of the mathematical capitals of the world. Besides the University of California - Berkeley math department, one of the strongest of the world, it hosts the Mathematical Sciences Research Institute, a math research institute at the highest level. This means the density of mathematicians per square mile is incredibly high here, and it makes that all mathematicians in the world come here in peregrination every few years, be it for a conference, a special program for MSRI, or a visit, or whatever.
Besides, Berkeley is one of the most liberal cities in the US, it had many years a mayor of the Communist Party (unthinkable in the rest of the country). In Berkeley you can see many people on bikes, and bikes are admitted in public transportation, including buses, which have a special rack for them. You can also see many hippies, people with long beards and ragged look. I guess weather helps, because here they have here a Mediterranean climate, like in Catalunya. I feel at home :-)
MSRI is on a hill in Berkeley, and it enjoys a breathtaking view of the San Francisco Bay. I am putting here a small picture I took with the iphone, before a panoramic view I hope I can take before I leave. This is the central bay, at the far end you can see the (small) Golden Gate Bridge over the entrance of the Bay, and the Pacific Ocean behind it. The piece of land right to the left of the bridge is San Francisco. I plan to go there tomorrow, so expect more pictures in a few days.
