Who likes short shorts?

Sveraci

Just got back from the gala opening of the Sverak (no diacritics, I’m afraid) festival at the Riverside Studios. With a personal appearance by Sveraks junior and senior. “Empties” was an enjoyable enough gentle comedy of the typical Czech form. More thoughts (yeah, right) as they occur to me.

Before I go to bed,

congratulations to Obama! That is all. Good night.

Alla!

Miserable failure

No, not my life in general, but my efforts to avoid the US election. I tried, but at 12.30am I made the fatal error of just checking the BBC site. And the first two states were close to declaring. I knew I would be drawn in, even thought I have not read a single article about the election or candidates since their nominations were confirmed. So I lay here another hour or so as various states turned red or blue (Pennsylvania was the last I remember), then fell into a fevered sleep, subconciously picking up the results as the BBC coverage played on my Mac. Then I woke up at 5.42 – Obama had won. But I have been unable to get back to sleep since. My own stupid fault.

On second thoughts

and having listened to the whole of the Nightmares on Wax album, it is a little disappointing – as if they had discovered the rock guitar setting on their sequencers – many of the tracks stray into sub-Prince/later Massive Attack territory, but the last two tracks provided a joyful end to proceedings for me at least. I am now onto Wax On, a compilation of tracks from their record label – full of head-nodding hiphop from around the globe (I cannot imagine that Hungarian lends itself to ill rhymes, but I shall persevere – maybe the two Gelka tracks are purely instrumental). Or alternatively in English;)

I am consciously avoiding the US election coverage – as much as I loathe the circus of UK General Election, the constituencies are mercifully small, and the UK is only in one timezone, so a result is relatively quick in coming (even if it is at 3am or so). The US one drags interminably, especially if recounts are required.

In the meantime, more maths:

If you have five people in a room and each person shakes hands with every other person exactly once, how many total handshakes happen?

This week

is a mixed bag – two Czech films over the weekend, plus a fireworks display. And, of course, rushing to finish everything at work before I leave for 2 weeks holiday. Anyways, the following are currently floating my boat:

Surely you’re joking Mr Feynman
Thought so
Lagos jump
The anticipation of Red Desert (although it will have to wait a couple of weeks).

In the meantime, though, an anecdote from the above book:

“A Japanese man came into the restaurant. I had seen him before, wandering around; he was trying to sell abacuses. He started to talk to the waiters, and challenged them: He said he could add numbers faster than any of them could do.

The waiters didn’t want to lose face, so they said, “Yeah, yeah. Why don’t you go over and challenge the customer over there?”

The man came over. I protested, “But I don’t speak Portuguese well!”

The waiters laughed. “The numbers are easy,” they said.

They brought me a paper and pencil.

The man asked a waiter to call out some numbers to add. He beat me hollow, because while I was writing the numbers down, he was already adding them as he went along.

I suggested that the waiter write down two identical lists of numbers and hand them to us at the same time. It didn’t make much difference. He still beat me by quite a bit.

However, the man got a little bit excited: he wanted to prove himself some more. “Multiplicação!” he said.

Somebody wrote down a problem. He beat me again, but not by much, because I’m pretty good at products.

The man then made a mistake: he proposed we go on to division. What he didn’t realize was, the harder the problem, the better chance I had.

We both did a long division problem. It was a tie.

The bothered the hell out of the Japanese man, because he was apparently well trained on the abacus, and here he was almost beaten by this customer in a restaurant.

“Raios cubicos!” he says with a vengeance. Cube roots! He wants to do cube roots by arithmetic. It’s hard to find a more difficult fundamental problem in arithmetic. It must have been his topnotch exercise in abacus-land.

He writes down a number on some paper— any old number— and I still remember it: 1729.03. He starts working on it, mumbling and grumbling: “Mmmmmmagmmmmbrrr”— he’s working like a demon! He’s poring away, doing this cube root.

Meanwhile I’m just sitting there.

One of the waiters says, “What are you doing?”.

I point to my head. “Thinking!” I say. I write down 12 on the paper. After a little while I’ve got 12.002.

The man with the abacus wipes the sweat off his forehead: “Twelve!” he says.

“Oh, no!” I say. “More digits! More digits!” I know that in taking a cube root by arithmetic, each new digit is even more work that the one before. It’s a hard job.

He buries himself again, grunting “Rrrrgrrrrmmmmmm …,” while I add on two more digits. He finally lifts his head to say, “12.01!”

The waiter are all excited and happy. They tell the man, “Look! He does it only by thinking, and you need an abacus! He’s got more digits!”

He was completely washed out, and left, humiliated. The waiters congratulated each other.

How did the customer beat the abacus?

The number was 1729.03. I happened to know that a cubic foot contains 1728 cubic inches, so the answer is a tiny bit more than 12. The excess, 1.03 is only one part in nearly 2000, and I had learned in calculus that for small fractions, the cube root’s excess is one-third of the number’s excess. So all I had to do is find the fraction 1/1728, and multiply by 4 (divide by 3 and multiply by 12). So I was able to pull out a whole lot of digits that way.

A few weeks later, the man came into the cocktail lounge of the hotel I was staying at. He recognized me and came over. “Tell me,” he said, “how were you able to do that cube-root problem so fast?”

I started to explain that it was an approximate method, and had to do with the percentage of error. “Suppose you had given me 28. Now the cube root of 27 is 3 …”

He picks up his abacus: zzzzzzzzzzzzzzz— “Oh yes,” he says.

I realized something: he doesn’t know numbers. With the abacus, you don’t have to memorize a lot of arithmetic combinations; all you have to do is to learn to push the little beads up and down. You don’t have to memorize 9+7=16; you just know that when you add 9, you push a ten’s bead up and pull a one’s bead down. So we’re slower at basic arithmetic, but we know numbers.

Furthermore, the whole idea of an approximate method was beyond him, even though a cubic root often cannot be computed exactly by any method. So I never could teach him how I did cube roots or explain how lucky I was that he happened to choose 1729.03.”