Ciro Santilli @cirosantilli 40

A gene that got duplicated withing the same species. The copies may diverge in function from the original.

Important example: hox genes.

Kind of a synonym for hydrogen emission spectrum not very clear if fine structure is considered by this term or not.

A line set for hydrogen spectral line.

Formula discovered in 1885, was it the first set to have an empirical formula?

Approximation to Huygens-Fresnel principle.

Like the special orthogonal group is to the orthogonal group, $SO(m,n)$ is the subset of $O(m,n)$ with determinant equal to exactly 1.

The fact that this foundation has a bunch of paid, closed, certification courses makes Ciro Santilli not respect them at all. They should be making open access content instead!

One single universal wavefunction, and every possible outcomes happens in some alternate universe. Does feel a bit sad and superfluous, but also does give some sense to perceived "wave function collapse".