In the color lines of a spectrograph and what seems to be an area with a certain color, zooming in shows that this color is delicately split in half by a black vertical hairline, on one side it’s the emission of photons of color by a hydrogen atom with a spin up electron, on the other it seems to be the same color but it’s a spin down electron.
Whenever I hear that gap mentioned, 1/137 is invoked, but I’m not sure precisely what that means, and I’m visualizing that the color of the spectral emission can be divided or deconstructed into a total of 137 vertical lines, and the one in the middle is black.
Maybe it represents 1/137 of a photon’s wavelength at a certain color?
I’m getting to the edge of what I know, but emission and absorbtion lines so represent a irreducible step: an electron moving from one energy state to another inside an atom. That irreducibility is where the “quantum” in quantum mechanics comes from. It’s also how physicists figured how how electrons in an atom are grouped into shells and subshells.