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I am just an enthusiast. Don't feel too bad if my unprofessional comments make you angry.

Thursday, January 25, 2007

A new space war

Last week China showed off her military power by shooting down an old Chinese satellite using a ballistic missile. I don’t think it is too difficult in the 21 century. All the reports I read from Chinese media cheer this event, and believe this test gives China tremendous political leverage to bargain with the US. However, the hawks in DC might very much appreciate Chinese government. A recent Wired article (Fanning Fears of a Space War) cited Hank Cooper, a former director of the Strategic Defense Initiative: "I hope the Chinese test will be a wake up call to people. I'd like to see us begin a serious anti-satellite program."

It is premature to see how practical this Chinese prototype missile will be in wartime, or how much risk China will take to destroy a US satellite. The US is still many decades ahead of China in space technology. The ripple generated by the missile might be favorable to China as they hoped. Maybe not.

Thursday, January 18, 2007

Give aliens more time to find us

OK. In my earlier blog, I found an article says that we are highly likely the only advance civilization in the galaxy, otherwise we had been conquered by aliens. A new arXiv article says Aliens need a lot more time to find us (original paper). The author made an assumption that the alien spaceships travel at 1/10 of the speed of light. Each ship is capable of launching up to eight probes. It will take 10,000,000,000 years (3/4 the age of the universe) to explore just 0.4% of the galaxy. So be patient. Let's look at the sky waiting for our little green friends with no hurry. However, I have to say that assumption underestimates the alien technology, without challenging our known physical principles (e.g., speed of light, time machine…). How about the spaceships travel at 20%, or 99.9% of light speed? What if each ship can carry 32 or ten thousand probes, each sends off radio signals or more nanobots?

Friday, November 03, 2006

Build astronomical observatories on the Moon?

What can be the moon good for us? Of course it is beautiful. I also like to visit tidal pools by seashores during low tide. Serious scientists is thinking about doing serious science on the moon, and politicians might be considering how to justify Bush's space policy of a moon base. I enjoy the out-of-the-world debate whether we should use moon for a massive observatory on Physics Today. There are so many unthinkable issues that common people like me won't dream of on the moon. How do you think? Can you justify an observatory on the moon?

Tuesday, October 31, 2006

China: We don't censor the Internet.

A Chinese official said in an international conference: We don't censor the Internet. (CNET News.com) Wow, what a bold statement! So they are censoring without feeling censorship? It is always hard to understand Chinese wisdom.

Saturday, September 23, 2006

Poincaré conjecture #2

Following up the story of the Poincaré conjecture, I read the info of another math genius 31-year-old Terence Tao, a Fields Medalist of 2006. He got his Ph.D. at the age of 20 from Princeton, promoted to full professor at the age of 24 at UCLA, has written 80+ journal papers. To common people like me, he became famous because of the Fields Medal. Truely amazing!

Then, how do I know Fields Medal? That is because Grigory Perelman, the mathematician who outperformed other geniuses by proving Poincaré conjecture, refused the medal and dramatically walked away from the math community. Sometimes awards make people famous, occasionally a person makes an award famous.

Thursday, September 21, 2006

Very complicated Poincaré conjecture

What does math have anything to do with drama? We can find the answer by reading the very intensive, dramatic article in New Yorker “MANIFOLD DESTINY”. The story talks about the political struggle in the mathematic community to fight the credit of proving the century-old math problem Poincaré conjecture. Similar to the fairy tale Cinderella, there is a Cinderella-type pure heart, Russian mathematic genius Grigori Perelman. Of course, there is also the stepmother (prominent mathematician Shing-Tung Yau 丘成桐) who fought to rob away the handsome prince (Fields Medal, the Nobel Prize for mathematicians) for the ugly stepsisters (Yau’s disciples).

This New Yorker article is written by Sylvia Nasar, the author of A Beautiful Mind, the story of Nobel laureate John Nash. I guess Nasar is writing another novel about the life of Perelman, which I am sure is more fascinating than Nash's. (Just read of a few news reports: Russian may have solved great math mystery, 7/1/2004; Meet the cleverest man in the world (who's going to say no to a $1m prize) 8/16/2006; World's top maths genius jobless and living with mother, 8/20/2006. Actually, the titles tell the story well.)

Note that Yau has accused New Yorker of defamation on Sep. 20 (see his campaign website). Some mathematicians interviewed by Nasar condemned her distortion of their statements. Sounds like MANIFOLD DESTINY was made too dramatic.Many people defend Yau by attacking each of Nasar's accusation. However, the disturbing review process of Yau's disciples' research paper that claimed to completely solve the problem is still unanswered. I am deeply troubled by this because Yau had been my hero for decades. Apparently all mathematicians are smart in some ways, and crazy in other ways.

Image: New Yorker Issue of 2006-08-28.

Monday, September 11, 2006

Wikipedia vs. China's censors

The Observer interviewed Jimmy Wales, the founder of Wikipedia, on the Chinese censorship on Wikipedia (see Wikipedia defies China's censors). Wales told The Observer: “We're really unclear why we would be [banned] … We have internal rules about neutrality and deleting personal attacks and things like this. We're far from being a haven for dissidents or a protest site.”

Obviously there is something Mr. Wales (and most Americans) don't understand: The Chinese government sometimes is the one violates neutrality or attacks individuals. How can Wales expect the Chinese government accepting the rules of Wikipedia?