## Saturday, March 23, 2013

### Srinivasa Ramanujan

Today, I would like to tell a story about an Indian mathematician named Srinivasa Ramanujan. He was born in 1887 and died in 1920. Even though he had such a short life, he is said to have been one of the best math minds of all time.

Because of the poverty in Southern India at the time, his math education was restricted to two books: Plane Trigonometry by S.L. Loney and Synopsis of Elementary Results in Pure Mathematics by G.S. Carr. As a young boy, Ramanujan read and interpreted the information in these books, and began to rediscover numerous mathematical concepts.

He ended up sending some of his discoveries to three British mathematicians. Two of them thought his work was disorganized and his ideas were unrealistic and far-fetched. The third one, G.H. Hardy, was skeptical, but  realized that even though the work was sloppy, it was ingenious. He invited Ramanujan to come study with him in England.

Despite Ramanujan's religious beliefs and mother's wishes, he ended up traveling to England. Since he had never been out of India, he hated the European lifestyle. Because of his discomfort, he ended up getting extremely sick, resulting in his early death.

Even though this story is pretty sad, there is a more well-known, amusing story from his life. When Ramanujan was in England, Hardy went to visit him in the hospital. When he got there, Hardy had mentioned that the number on the taxi he rode in was 1729. "Rather a dull number, wouldn't you say?" he said.

Ramanujan smiled, and responded, "No, Hardy, not at all. 1729 is a fascinating number! It is the smallest number that can be expressed as the sum of two cubes in two different ways."

If you were to add together 23 and 33, you would get 35. However, you cannot find two other cubes to add together to get this.

However, Ramanujan noticed the number 1729 could be derived with two different pairs of cubes.

103 + 93 = 1000 + 729 = 1729
123 + 13 = 1728 + 1 = 1729

I thought this was an interesting little fact, and a fascinating backstory to go with it.