Just as a poet often has license from the rules of grammar and pronunciation, we should like to ask for 'physicists' license from the rules of mathematics in order to express what we wish to say in as simple a manner as possible.
Richard P. FeynmanWe are not to tell nature what sheโs gotta be... She's always got better imagination than we have.
Richard P. FeynmanThe shell game that we play ... is technically called 'renormalization'. But no matter how clever the word, it is still what I would call a dippy process! Having to resort to such hocus-pocus has prevented us from proving that the theory of quantum electrodynamics is mathematically self-consistent. It's surprising that the theory still hasn't been proved self-consistent one way or the other by now; I suspect that renormalization is not mathematically legitimate.
Richard P. FeynmanThere is a computer disease that anybody who works with computers knows about. It's a very serious disease and it interferes completely with the work. The trouble with computers is that you 'play' with them!
Richard P. Feynman