Keith Devlin
speaker
76 appearances
2 recordings
1 series
first heard Dec 2011
last heard Apr 2012
Keith Devlin’s voice in public audio — every appearance, attributed to the second.
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Appearances
The measure of the size of the revolution that followed Leonardo's publication of Libero Bacci is precisely that what had once been impossible became completely taken for granted today.
and regarded as just, well, duh, of course we can do arithmetic.
Yeah, the one person who wouldn't be surprised would have been Leonardo himself, because he really had nothing to do with the Dan thing.
Every now and then he would throw in a whimsical problem just to sort of lighten the load, and one of the whimsical problems was a problem about a fictitious rabbit population, and you have to figure out how many rabbits there are in this population after they've been breeding for a year.
Now, that problem wasn't original to him.
Then in the 19th century, a French mathematician who's looking through Leonardo's work sees this sequence in Liber Abaci, knows that this sequence has interesting properties to do with the way flowers and plants grow and that kind of thing, and he gives it a name, the Fibonacci sequence.
That's the only connection between Leonardo and the Fibonacci sequence, I'm afraid.
It's impossible for us to realise the beginning of the 13th century, nobody in Europe had ever seen that kind of thing before.
It really was the first comprehensive, actually the first coverage at all, of modern, what we now call Hindu-Arabic arithmetic, the kind of arithmetic that we all learn when we're in the elementary school.
Yeah, in fact, modern arithmetic, including counting with the ten digits from zero through nine, all the algorithms, all of the methods we learn at school, that had been invented by Indian mathematicians in about the first six or seven centuries of the current era.
Then the Arabic-speaking traders in the Muslim world who were trading between North Africa and Europe and the Orient, they discovered these methods and they started using them in their trade.
And then some of their scholars started developing them.
And one of the offshoots was what we now call algebra.
And so for several hundred years, it was those traders that were sort of developing it and using it.
And it was in North Africa when Leonardo, who was a teenager, who had gone over to join his father, who was a customs official in Bougia in North Africa,
Leonardo sees these traders in the coffee shops using this incredible method and he recognizes at once this can change the world if I can package this and make it accessible to ordinary people then anyone can do their own arithmetic
and suddenly anyone can set up in business.
Roman numerals are fine for adding and subtracting, but that's not very useful when you're working out volumes of things that you want to buy.
And so you need multiplication and division, and Roman numerals are hopeless for that.
So when people did calculations, they did one of two things.
Showing 21–40 of 76 · page 2 of 4
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