Basdevant:Why do physics? Laurent Schwartz, the man I admired most, liked the question:
what’s the use of doing mathematics? “It’s very simple,” he said,
mathematicians study

spaces, negligible sets, and representable
functors. One must certainly do mathematics. Because mathematics
allows to do physics. Physics allows to make refrigerators. Refrigerators
allow to keep lobsters, and lobsters are useful for mathematicians
who can eat them and therefore be in a good mood to do

spaces,
negligible sets, and representable functors. It is obviously useful to do
mathematics.
Why do physics? I’ve often thought about that question.