…say that I am unable to produce an elementary explanation. It has been worked out from complicated quantum field theory and relativity by Professor Pauli. It was proved that this must be so. That is, one kind has to be one way and the other has to be…

…up, not because they're magnetically interacting, but for some other reason. It has to do with the quantum mechanics and the Pauli exclusion principle and whatnot. Ordinarily, two electrons cannot be in the same place in the same state. I mean, always they…

…that maybe the conservation law worked only statistically on the average for large scale But it turns out that Fermi, I mean Pauli, suggested no, that the fact that the energy doesn't check out is because there's something else coming out, which we now…