用数学解释你对于爱丽丝梦游仙境的疑惑

JACKI LYDEN, host:

This is WEEKEND EDITION from NPR News. Im Jackie Lyden.

The film "Alice in Wonderland" continues to rule the box office. The story has been popular ever since 1865, the year the world first met Alice, the Dodo, the Cheshire Cat and, of course, the Mad Hatter.

(Soundbite of film, "Alice in Wonderland")

Mr. JOHNNY DEPP (Actor): (as Mad Hatter) Well, as you can see, we're still having tea.

(Soundbite of dishware and utensils)

Mr. DEPP: (as the Mad Hatter) And that's only because, Alice, I've spent a long time waiting for your return. You're terribly late you know? Naughty.

LYDEN: That was a scene from Tim Burton's "Alice in Wonderland," the version of the story in which an older but may be not wiser Alice has returned by way of the rabbit hole, getting on to the fractious day.

But there may be more to the story than talking, time-keeping rabbits and smoking caterpillars. Lewis Carroll whose real name was Charles Dodgson, was a mathematician at Christ College, Oxford, he actually ferried the real Alice Little and her sisters down the River Thames, while telling them the story.

Mathematicians say that "Alice in Wonderland" is full of algebraic lessons. And to explain, we're joined by - now, wait, wait. Just maybe I should ask, who are you?

(Soundbite of laughter)

Professor KEITH DEVLIN (Stanford University): Oh, what an introduction. Hi, Jackie. Keith Devlin from Stanford here.

LUDDEN: Keith, have you been drinking something to make you tall or small?

Prof. DEVLIN: No, the interesting thing about radio is that no one can see what we look like. So they have to imagine that I've got a very long neck and a very short body.

LYDEN: First thing, Keith, the riddle the Mad Hatter asks Alice, "Why is a raven like a writing desk?"

Prof. DEVLIN: Yeah, that particular scene and lots of other scenes in "Alice in Wonderland" were a reflection on the increasing abstraction that was going on in mathematics in the mid 19th century.

Dodgson himself was a very conservative, traditional mathematician, and he didn't like what was going on. To him, algebra was all about numbers. Whereas what happened in the 19th century, was people were developing all kinds of bizarre new algebras. Algebras where X times Y is not equal to Y times X.

And in fact, really, why is a raven like a writing desk? What he's trying to say is the new mathematics that he didn't like, lots of things that every common-sense person would say are different, in this new mathematics they turned out to be the same.

LYDEN: So were you tired a bit of Tim Burton's new "Alice in Wonderland" film and the scene where Alice encounters the Mad Hatter and the Dormouse still their tea party, and the Mad Hatter and the March Hare?

But I understand, underneath, tea is for time and that math underlies the madness.

Prof. DEVLIN: Yeah, because one of the big developments that were going on at that time - that Dodgson or Lewis Carroll was satirizing - was work by an Irish mathematician called William Hamilton, who developed a new arithmetic called quaternions. And the quaternions were numbers, not to deal with counting things, but to deal with understanding rotations.

Back in Victorian times, when Hamilton himself was doing this work, he tried to understand his new arithmetic in physical terms. And he said one of the four terms that was involved in these numbers had to be time. And when you look at what was going on at the Mad Hatter's tea party, time was missing.

And so when you take time out of the...

LYDEN: Time, the character was missing.

Prof. DEVLIN: Time, the character was missing. And what Hamilton said was if you take this time parameter out of his new numbers, then the numbers would just keep rotating around. They won't go anywhere and it was just like the characters rotating round and round the tea party, round and round the table.

And, in fact, when the Hatter and the Hare tried to squeeze the Dormouse into the teapot, they're trying to somehow get away from this complexity throw away another of the parameters, if you like so that life can resume as normal.

So instead of trying to reintroduce time, what Dodgson is saying is let's just go back to the familiar old geometry that we've had since Euclid for 2,000 years.

LYDEN: Keith, this may come as a surprise to us. But it seems like mathematicians have always known how much Carroll has been bound up in this.

Prof. DEVLIN: Oh, well, because we knew that Carroll was actually a mathematician, we've always suspected that and we've seen some mathematics in it. Last year, in fact, a scholar in Oxford called Melanie Bayley wrote a complete dissertation analyzing "Alice in Wonderland," and she identified a number of mathematical allusions in the story. Most of us have sort of glossed over them when we try to look for the mathematics in the story.

LYDEN: Interesting to think that another fairy tale that Dodgson apparently wrote that didnt have all the math underneath as a base was really dull, sentimental and nobody cared and we dont even know the name of it.

Prof. DEVLIN: That's right. And in fact, the very first version of "Alice in Wonderland" story that he wrote for the real Alice, almost certainly what he did was said, here's this cute story that I've written for this real Alice. I'm going to take that and I'm going to use it to do this wicked satire of what I think are these crazy, stupid developments in mathematics that are getting us away from the real, solid mathematics that I've loved all my life.

LYDEN: Keith Devlin is a professor at Stanford University and WEEKEND EDITION's math guy.

Keith, off with your headphones.

(Soundbite of laughter)

Prof. DEVLIN: Thanks, Jackie.