A model should be as simple as it can be but no simpler
Watch the stars, and from them learn.
I hate all the loathsome nonsense that goes with patriotism.
The more success the quantum theory has, the sillier it looks
Student: Dr. Einstein, Aren't these the same questions as last year's [physics] final exam? Dr. Einstein: Yes; But this year the answers are different.
Galileo had already made a significant beginning toward a knowledge of the law of motion. He discovered the law of inertia and the law of bodies falling freely in the gravitational field of the earth.