Sunday, May 21, 2006

paradigms in large number construction

You have fifteen seconds. Using standard math notation, English words, or both, name a single whole number—not an infinity—on a blank index card. Be precise enough for any reasonable modern mathematician to determine exactly what number you’ve named, by consulting only your card and, if necessary, the published literature.

So starts this article on big numbers by scott aaronson. The previous test, being conducted on school students tends to bring up solutions using many 9's. However, in the science of big numbers who wins is who is able to deal with the strongest mathematical paradigm, not who writes faster. Read the link for an account on the history of exponentials, multiple exponentials, Ackerman's function and Busy Beavers.

As is pointed out by the author, there is a large correspondence between the status of science in each era, and the progress in our capacity to name big numbers. As you progress through the article it becomes clear how new concepts such as recursion and computability have to be developed to name bigger and bigger numbers.

The article ends with a reference to a study which appeared 1999 in Science in which a group of Neuropsychologists developed an experiment to associate language with our capacity to compute and predict (ie, our capacity to make approaximated computations). The authors of the study, cited below, conclude that different parts of the brain are used when doing precise computations and approximations. Interestingly, when doing a precise computation the part of the brain that is used is the same part that deals with language. Why? Because computation depends on the capacity to manipulate symbols, be it mathematical symbols or linguistic symbols. On the other hand, they argue that approximations are done using a mental image of a "number line". It's an interesting point. However I don't understand some parts of their methodology, particularly when they claim that a larger percentage of the test individuals correctly solved computation problems stated in the language in which they learned to solve them, rather than in a different tongue. I'm not sure what they mean and why this happens. It should not be difficult to translate a mathematical problem, and trying to solve it using an unknown symbol system is something that I can't even imagine... I guess I have to read the original source :)

Here's the reference for this paper:

S. Dehaene and E. Spelke and P. Pinel and R. Stanescu and S. Tsivkin, "Sources of Mathematical Thinking: Behavioral and Brain-Imaging Evidence," Science, vol. 284, no. 5416, May 7, 1999, pp. 970- 974.

Tuesday, May 16, 2006

old salon article revisited

This weekend, while reading on the physical views of a certain Tom van Flanders (on which I came casually while cruising through wikipedia), I came across this article on salon which discusses recent controversies on the procedures used by einstein to develop his theory of general relativity. The article is not very technical nor detailed, but it's interesting and written in an entertaining way. In the end the author looks more biased towards support the standard viewpoint (ie, Einstein did not cheat) but I won't restart this discussion here (lack of detailed knowledge on my side, and also lack of comments here ;) sorry).

on a personal note, it's rather strange that I repost links to articles on my blog. it's mostly a way to increase traffic so not sure if I should continue with that...
fins aviat - see you

Thursday, May 11, 2006

俳句のスピーチ

As expected I spent most of last week preparing my short speech on haikus which I delivered at yesterday's class. I've noticed that my japanese has not improved much as of late. That worries me, I should definitively spend some more time into readings and increasing my vocabulary. Anyway, before the speech gets lost forever I'll post it here :)

The speech was accompanied with the famous basho hokku 'the old pond' and a haiku by Masaoka Shiki that I found on this nice page of virginia.edu dedicated to the works of Shiki.

---

俳句は日本の最も短い詩です。 俳句は短詩の1つの種類です。
俳句は定型詩で、五・七・五の韻律があります。
それは短歌と同じです。短歌は歌う詩です。
でも、俳句はそんなに定型ですから歌えません。

俳句の知識が濃いです。それに、時々助詞もありません。
だから、読者が自分で解釈をしなければなりません。

俳句は所について説明をしますが、感情を表わす言葉は全然ありません。
俳人の目的は読者が自分の感情を経験することです。

それに、俳句には季節についての言葉が含まれていなければならない。
この言葉は季語と言い、俳句に大切です。

少しい例を挙げます:
春の季語: 蛙、蛍、桜 …
秋の季語: 天の川、名月…
夏の季語: 蝉、トンボ、夕涼み…
冬の季語: 雪、元日…

俳句の元は俳諧の連歌です。この詩は俳人のグループの書きことでした。
俳諧には五・七・五と七・七の韻律を連ねます。
まずの五・七・五の詩の節が発句と言いました。
この詩は最も大切な連歌の分です。
だから、普通もっと経験がある俳人はその発句を書きました。

正岡子規は19 世紀の終わりに俳諧の連歌から発句を離しまして、
発句は俳句と言われるようになりました。
だから、芭蕉の俳句と言うのは正しくないです。
芭蕉や蕪村や森竹は発句をかきました。
子規の時代の俳人は俳句を書きます。