A few notes on quantum field theory

Contradiction often means integration at a higher level.

The introduction to the field in the class I took last term starts with a problem to solve. After introducing several tricks, we come to a seem-to-be-the-right answer, only then discovered that some part of the answer is infinite. Then we are introduced the concept of "renormalization", which modified the initial question to cancel out the bad parts of the answer (pretty much out of nowhere). Plus there are multiples ways to do this. So we will get different answers. It was kind of fishy, I used to think. A problem is not solvable, so we change the problem itself to make it solvable.

Then, after a while, I started to discover that the task is not to solve that particular problem, but to find the solvable problems in a family of similar problems. Why didn't they just say this in the beginning?

Now the real mystery is.....why does quantum electrodynamics perform so well? There are many ways of renormalization, and each of them will give slightly different answers. Do we just pick one using experimentally measured values? I haven't got to that part in lecture, so I guess I'll find it out before the end of the school year.

Passage

Before reading my comments below, please go to http://hcsoftware.sourceforge.net/passage/ and download the game to play. You don't need to install anything, and the game only lasts 5 minutes. Control: 4 arrow keys to move, and q to quit.






(Mouse-select the text to read)

The first time I played it I went straight down to explore the maze, found quite some treasure boxes, and received some points. After a while, I noticed that the hair of the protagonist starts to decrease, and only then did I notice the real nature of the game. I tried to go forward, but soon the character becomes a tomb. Time's up.

Then I tried a second time. This time I went right almost all the time, and also got married. With the wife, a lot of places that were accessible, weren't anymore. The family has become an obstacle from time to time. So I can not go much down anymore, and I kept moving forward. After a while, the wife died, and the main character died shortly after. The score is much less this time, but who cares. No matter how much it is, 5 minutes later, the score lost its meaning.

This is a new category of game, a lot different than traditional games. It is more of a poetic experience than a gaming experience. And afterward, the game makes you think about several basic questions of life. One can either go down by itself and look for treasure, or go right to advance forward for a smooth life. Or anything in between. However, no matter what the choice is, the time limit is the same.

Russian

I have been studying Russian by myself for a while now. My goal is to master major languages and go traveling some day.... the very reason I picked Russian first is that I know somebody who studied Russian in university. It's more fun this way. Imagine a few years later when I'm trying to learn Thai or Arab. There won't be anybody I know good enough around. Well, things will straighten itself out, I believe.

Back to Russian. This time I went back home, met her, and learned an astonishing news: she is really going to get married. Now it's kind of awkward. Should I continue to learn the language? Should I stop? Either way doesn't seem quite right to me. Should I switch to another language and come back later? Hmm.

It's been a while....

I've been lazy again with updating my blog ^^" How have you been doing?

I went back home, stayed for two weeks. After adjusting the jet lag, I came back to do it again. Now my sleep is not regular. Sometimes I just can't sleep at night. I don't know why, but my heart just kept pounding, no matter how I tried to relax. It's really frustrating and disturbing. So I'm posting this blog in an attempt to switch gears.

This new term I picked up a couple new courses. One of them is introduction to computer graphics research. It's goal is to introduce the students to recent literature in computer graphics. Yesterday, no, actually the day before yesterday already, we introduced seam carving as a way to change the aspect ratio of the image while keeping the content less distorted than old ways of resizing. And the homework is, of course, to implement it. I haven't code for centuries, but it feels okay yesterday when I wrote the bulk of the program. All that's left is some user interface cosmetics. I should be able to survive....but the term is going to be fun. I have to take some more random courses before settling down in a research group :p Afterward it is even a question whether I am allowed to take physics classes. So, some neuroscience classes next term?

All other classes are regular physics classes which you would expect a lot of first-year graduate students to take, nothing special about me taking them.

I wish that I can learn a lot this term. This is what counts in the end.