What I particularly liked about physics was the tight logic. That you could look at something, and if you figured it out correctly, thought about it carefully, you could be pretty sure. “Yes, this is right,” or something else isn’t right. Lots of new things to explore, but they were explored through logic, experimentation, but experimentation based on certain logical ideas. So it was the firmness and the definiteness which one could decide what really is right, I think, that attracted me. Plus the fact that it was dealing with what I thought were important ideas. Mathematics appealed to me, and I enjoyed mathematics, but I preferred to do something that involved the real world around me. Real objects, like physics. Even though that also involved mathematics, it was dealing with a sort of real life a little bit more, I felt, than mathematics.