To decide upon the answer is not scientific. In order to make progress, one must leave the door to the unknown ajar ajar only.
Richard P. FeynmanAlthough it is uncertain, it is necessary to make science useful. Science is only useful if it tells you about some experiment that has not been done; it is not good if it only tells you what just went on.
Richard P. FeynmanStrange! I don't understand how it is that we can write mathematical expressions and calculate what the thing is going to do without being able to picture it.
Richard P. Feynman