The description of right lines and circles, upon which geometry is founded, belongs to mechanics. Geometry does not teach us to draw these lines, but requires them to be drawn.
Isaac NewtonAbsolute, true and mathematical time, of itself, and from its own nature flows equably without relation to anything external.
Isaac NewtonDo not the Rays which differ in Refrangibility differ also in Flexibity; and are they not by their different Inflexions separated from one another, so as after separation to make the Colours in the three Fringes above described? And after what manner are they inflected to make those Fringes?
Isaac Newton