It was never physically dangerous except when I nearly fell off a horse, but it was physically arduous - especially when you were working late at night. ↗
The real exertion in the case of an opera singer lies not so much in her singing as in her acting of a role, for nearly every modern opera makes great dramatic and physical demands. ↗
To have any doubt in your body is the biggest weakness an athlete can have. There are times when I physically can't get myself to go for a skill because I'm thinking, 'My knee hurts really bad.' ↗
In 1947 I defended my thesis on nuclear physics, and in 1948 I was included in a group of research scientists whose task was to develop nuclear weapons. ↗