We are fond of saying things are symmetric, but what does that really mean? Intuitively we have a sense of symmetry as a kind of mirroring. Suppose we draw a vertical line through the middle of a ...

If you want to fully describe how the Universe works at a fundamental level, you have to look at it in two different — and incompatible — ways. To describe the particles and their electromagnetic and ...

To most people, “symmetry” means the bilateral symmetry exhibited by, say, a butterfly, or the human face. That is, if you take a picture of a butterfly and draw a straight line down the middle of the ...