Velu
We've all been told that the colors of the rainbow correspond to different wavelengths of visible light - red, orange, yellow, green, blue, and violet. Where's pink in that list?...
Suppose you have a ball covered entirely with hair and you're trying to comb the hair so that it lies flat everywhere along the surface. If the ball were a donut, or it existed in two...
To make a laser, all you need to do is give a big collection of atoms enough energy so they're excited and ready to emit light. Once one of them spontaneously emits a photon, it'll...
