Identical Particles in Quantum Mechanics
The concepts of identical particles and indistinguishability are fundamental to quantum mechanics, and, therefore, also to quantum computing. I find group theory has helped me to understand identical particles much better.
In this era of lost privacy, the concept of indistinguishability is rapidly becoming very foreign to young kids weaned on the Internet. It may soon become impossible for us old timers to explain it to them. An example of indistinguishability for posterity: These blank avatars are either (1)University Academics, (2) Dishonest politicians, or (3) Used Car salesmen. Johnny, can you tell me which is which? You can’t? Well, that’s the point.