Читать книгу The Number Mysteries: A Mathematical Odyssey through Everyday Life - Marcus Sautoy du - Страница 25

Rice is not the only food associated with exploiting the power of doubling to create large numbers. Dragon noodles, or la mian noodles, are traditionally made by stretching the dough between your arms and then folding it back again to double the length. Each time you stretch the dough, the noodle becomes longer and thinner, but you need to work quickly because the dough dries out quickly, disintegrating into a noodly mess.

Cooks across Asia have competed for the accolade of doubling the noodle length the most times, and in 2001 the Taiwanese cook Chang Hun-yu managed to double his dough 14 times in two minutes. The noodle he ended up with was so thin that it could be passed through the eye of a needle. Such is the power of doubling that the noodle would have stretched from Mr Chang’s restaurant in the centre of the Taipei to the outskirts of the city, and when it was cut there were a total of 16,384 noodles.

This is the power of doubling, and it can very quickly lead to very big numbers. For example, if it were possible for Chang Hunyu to have carried on and doubled his noodle 46 times, the noodle would be the thickness of an atom and would be long enough to reach from Taipei to the outer reaches of our solar system. Doubling the noodle 90 times would get you from one side of the observable universe to the other. To get a sense of how big the current record prime number is, you would need to double the noodle 43,112,609 times and then take one noodle away to get the record prime discovered in 2008.