"QED" by Richard Feynman
Review by Borodutch
"QED" made me appreciate light in new ways and finally got me on the track to understanding that mysterious wave function in quantum physics. Feynman was a masterful teacher, and if you want your children to be interested in theoretical physics, this is the book to read! The author catches your attention and turns on your natural curiosity to eleven.
Richard explains everyday processes like reflections and diffraction mirrors in a way that classical physics cannot—because they don't follow the rules of classical physics! For instance, do you know why a sheet of glass reflects some light and lets the rest pass through? It's a simple question, yet the answer blew my mind.
Additionally, I finally understand that the duality of light being both a particle and a wave is virtually a lie. It's a particle, but a quantum one! And quantum particles follow the wave-like properties of probability. In short, many properties of a quantum particle have regions of probability (including interaction with other particles). This probability follows the wave function, which allows the probabilities to interfere as if the particles were waves.
Now, this opens up a Pandora's box of questions. Sure, classical waves interact physically; hence the interference—but probability waves appear to interact with each other without any respect for time! How does adding a second reflective surface for the glass affect how many photons bounce off the first pane? The first reflective surface already happened; the second should not have affected it!
It is all described by the QED theory, and even a layperson can understand how Feynman explains it. It is all probabilities and non-determinism (at least for now) until we measure it.
Still, I can't wrap my head around the fact that particles freely go backward in time (these are called anti-particles) simply because the math allows it. I would brush it off if not for the fact that we've been capturing and maintaining anti-particles stably for decades now.
Read QED, you'll love it.