Are electrons particles, or are they waves? In some sense, the answer is – it depends. It depends on how you choose to look at it. Here’s a nice video that gives a sense of how quantum mechanics developed, from Bohr’s model of the atom, to the Heisenberg uncertainty principle, to Schrödinger’s equation.

The second video is a demonstration of the uncertainty principle using a laser, an adjustable slit, and a projection screen.

Below is a picture with Bohr, Heisenberg, Schrödinger, Plank, Einstein and a few other famous scientists from the 1927 Solvay conference.