Everything is made of atoms.

Thus we can get the correct answer for the probability of partial reflection by imagining (falsely) that all reflection comes from only the front and back surfaces. In this intuitively easy analysis, the 'front surface' and 'back surface' arrows are mathematical constructions that give us the right answer, whereas .... a more accurate representation of what is really going on: partial reflection is the scattering of light by electrons inside the glass.

The problem of creating something new, but which is consistent with everything which has been seen before, is one of extreme difficulty.

Scientific knowledge is an enabling power to do either good or bad — but it does not carry instructions on how to use it.

No man is rich who is unsatisfied, but who wants nothing possess his heart's desire.

The whole question of imagination in science is often misunderstood by people in other disciplines. ... They overlook the fact that whatever we are allowed to imagine in science must be consistent with everything else we know.

All we know so far is what doesn't work.