And so our kind of imagination is quite a difficult game. One has to have the imagination to think of something that has never been seen before, never been heard of before. At the same time the thoughts are restricted in a strait jacket, so to speak, limited by the conditions that come from our knowledge of the way nature really is. The problem of creating something which is new, but which is consistent with everything which has been seen before, is one of extreme difficulty.

Richard Feynman (1918-1988) American physicist

The Feynman Lectures on Physics, Vol. 2, ch. 20 “Solutions of Maxwell’s Equations in Free Space,” sec. 20–3 “Scientific Imagination” (1964)
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