> From: "Jones Beene" > Hydrogen seems to be uniquely placed in having these overlapping > traits: > > 1) a resonance point that is easy to achieve spatially, since the > 21 cm wavelength is a size which fits in nicely with many existing > lab items and tubes.
I'm having a real problem understanding this. The 21 cm hydrogen line is caused by the hyperfine structure of the 1s level of the hydrogen atom. This splitting of the 1s level is due to the interaction of the nuclear spin and the electron spin. When these spins are parallel the hydrogen atom is in a slightly higher energy state and spin flipping results in the emission of a 5.9 x10^-6 eV photon. In your OPines on molecular hydrogen nuclear spins, are you saying that flipping the electron spin can change the molecular spin? My head is spinning.
