Wrinkles: From the Sea to Mathematics

[摘要] The mathematical meaning of wrinkle and its real-life meaning are very similar, particularly when the word is used todescribe features on the surface of the sea. Luckily, I was educated in sailing before learning advanced mathematics so Ispent a lot of time looking at wrinkles on the sea. After a long,windless period, it is delightful to observe their birth and theforms they take. Long after learning to sail, I read that theseforms bear great similarity to those predicted by R. Thom’ssingularity theory (see [15]). On one occasion, wrinkles appeared and grew so abruptly that they clearly announced astrong event; at the same time, the on-board radio issued galewarnings for the forthcoming night. Soon the fog cleared, allowing us to see an enormous cumulonimbus cloud, with itswhite anvil thousands of metres high, indicating the presenceof fantastic thermodynamic machinery. Fortunately, this experience concluded safely.