I got up this morning, looked out the window, and it looks dank and dark and grey and all other kinds of unpleasant. As I put on my backup extra sweather, Pin said, triumphantly, to me, "This is what Beijing usually looks like."

...

Getting off the plane last week, I saw that the visibility isn't great, that pollution is heavy, that smog is dense, and that I can't see any sky. Pin assured me that it was the norm.

And for four days straight after that, the weather just got better and better. Every morning I woke up to pleasant blue skies with more-or-less clear air. It might have been a tad chilly, but just the look of the beautiful sunshine warmed me up from the inside out. I really didn't mind just going around in a T-shirt and a light jacket.

Today, however, just a cursory glance out the window demanded that I take a scorching shower to get the chill out of my bones.

...

We are housed at Zhong Guan Yuan (Middle Gate Garden?!) just outside of the Peking University East Gate. Most of the people living there are temporary visitors to Peking University (especially Foreigners). On the first floor live a couple of Americans. There are rather many foreign students/visitors at Peking U. Walking through campus I can always spot Caucasian faces every couple of minutes. This is far more than I could say for National Taiwan University. (The density is comparable or more than that at TianMu, Taipei.)

...

So in the central courtyard of Zhong Guan Yuan, they have some bizarre looking exercise equipments, one of which you hold on with your hands and swing your lower body every which way. In the mornings, you see people doing Tai Chi in the courtyard, and there's even a stone/concrete ping pong table. Yesterday we discovered that the row of small houses next to the courtyard is actually still in use, and there's a small eatery. The food there isn't terribly good, but it is the most convenient way for us to get breakfast. Yesterday Pin and I shared a steamer of buns (he also had Tofu Brains, which I don't quite know how to translate properly...) and I had a Chinese egg-pancake this morning. The buns were quite delicious with some vinegar, but the pancake was a bit salty.

On the same topic, food, Pin bought something best described as "pineapple on a stick" from a street vendor. The way they husk a pineapple is quite impressive: they first shave off the outer skin with a knife. Now the seeds goes a bit deeper into the meet, so they have this tool that looks more like something from a sculptors toolbox: it is basically a half-pipe with a sharp front edge. Since the "eyes" on the pineapple are arranged in a stacked-diamond pattern, they use the tool to spiral down the sides, cutting grooves about half-inch deep, removing the seeds and at the same time keeping still half of the meat. So now the pineapple looks like a giant thumb screw. The vendor then sticks four skewers into the core, hack off the top (of the pineapple), and quarters the fruit. Now you have a wedge of pineapple on a stick with a sprial pattern on the outside (you don't eat the core on the inside anyway, at least I don't). And the pineapple is quite sweet too. If the sky clears up (wouldn't want too much dusty smog on my slice) I might go buy another one and take a picture.

...

Klainerman is interested in the Newman-Penrose formalism now. As far as I know, it is a way of picking a canonical frame consisting of two real null vectors and two complex space vectors at every space-time event. So now I am reading about spinors (yet another of those things that a year ago I would not have thought that I need to know, and on hindsight really should have learned it many moons ago). At least I am making steady progress. I'll write more about it when I get more familiar with the formalism.