Mathematics is like childhood diseases. The younger you get it, the better.

- Arnold Sommerfeld

Thermodynamics is a funny subject. The first time you go through it, you don't understand it at all. The second time you go through it, you think you…

- Arnold Sommerfeld

If you want to be a physicist, you must do three things-first, study mathematics, second, study more mathematics, and third, do the same.

- Arnold Sommerfeld