### „We can deduce, often, from one part of physics like the law of gravitation, a principle which turns out to be much more valid than the derivation.“

— Richard Feynman American theoretical physicist 1918 - 1988

Context: Now we have a problem. We can deduce, often, from one part of physics like the law of gravitation, a principle which turns out to be much more valid than the derivation. This doesn't happen in mathematics, that the theorems come out in places where they're not supposed to be!
chapter 2, “ The Relation of Mathematics to Physics http://www.youtube.com/watch?v=M9ZYEb0Vf8U” referring to the law of conservation of angular momentum