Mathematics anecdotes

Mathematics anecdotes

On this day, Lorenz wanted to know more about the follow-up changes of a certain record. He re entered the meteorological data at a certain time into the computer, so that the computer could calculate more follow-up results. At that time, the computer's processing of data was not fast enough. Before the results came out, it was enough for him to have a cup of coffee and chat with friends, However, he was stunned. Compared with the original information, the initial data was almost the same. The later, the greater the difference between the data, just like two different pieces of information. The problem is not the computer. The problem is that the difference between the data he entered is 0.000127, and these tiny differences make a huge difference. So it is impossible to accurately predict the weather in the long run
Han Soldiers
Han Xin's command of troops is also known as the Chinese remainder theorem. It is said that Liu Bang, the great ancestor of the Han Dynasty, asked how many soldiers Han Xin was in charge of. Han Xin replied that there were more than one soldier in a line of three, two soldiers in a line of five, four soldiers in a line of seven, and six soldiers in a line of 13 Liu Bang was at a loss and didn't know the number
Let's first consider the following questions: suppose that the number of soldiers is less than 10000, and there are three soldiers in each of the five, nine, 13, and 17 soldiers?
First, we find the least common multiple 9945 of 5, 9, 13 and 17 (Note: because 5, 9, 13 and 17 are reciprocal integers, the least common multiple is the product of these numbers), then add 3 to get 9948
There is an ancient Chinese mathematical book "Sunzi Suanjing" which has a similar question: "there are things today. I don't know how many they are. Three or three numbers, two or five numbers, three or seven numbers, and two numbers. How about the geometry of things?"
And he said, "Twenty three."
Shu said, "if there are three or three numbers left in two, set them at one hundred and forty, five or five numbers left in three, sixty-three, seven or seven numbers left in two, set them at thirty, and get 233. If there are three or three numbers left in one, set them at seventy, five or five numbers left in one, set them at twenty-one, and seven or seven numbers left in one, set them at fifteen."