It’s actually obvious and might fall under the *“Duh!”* heading for some, but it only recently sunk in on me that the ** Born Rule** is really just another case of

**the**. The connection is in the way the coefficients of a quantum superposition, when squared, must sum to unity (one).

*Pythagorean*theoremFor that matter, Special Relativity, which is entirely geometric, is yet another example of the Pythagorean theorem, but that’s another story. (One I’ve already told. See: SR #X6: Moving at Light Speed)

The obvious connection is the geometry behind how a quantum state projects onto the basis eigenvectors axes.