Did you know that you can get good estimates for the value of PI by just looking at your own files? It’s all down to number theory and the ratio of relatively prime pairs of numbers to non-prime pairs. (A number x is relatively prime with respect to y if x and y have no common factors. For example, 10 and 21 are relatively prime, even though neither of them is prime.) See this neat page for more details, and Real Code. (The same guy’s site includes a very good description of his PhD research; I’d like to write something similar about mine.)
Some “war on terrorism” links:
- The Onion is generally a pretty good source of satire. This issue is from 26 September, and is very good, including headlines like US vows to defeat whoever it is we’re at war with and God angrily clarifies “Don’t kill” rule. More recently, this piece makes the civil liberties argument very well (though perhaps laying it on a bit thick).
Boston Globe finds evidence that private
security firms, the airlines and the FAA were all getting a bit
cosy about security responsibilities at Logan Airport before 11
September. For example, on the possible forms of security
“We didn’t want everyone testing us without knowing what to look for exactly,” Bibbey, the Logan manager for Globe Aviation Services, said in an interview. “We don’t need people improvising test pieces to purposely make people fail.”
- The LA Times on the Arab TV channel Al Jazeera, and how it is providing a valuable service.
- Finally, a discussion from the Washington Post about civilian casualties as a result of bombing Afghanistan.