Just start my QM1 course,and our textbook is "Quantum Physics-of atoms,molecules,solids, nuclei,and particles" by Robert Eisberg and Robert Resnick.(adsbygoogle = window.adsbygoogle || []).push({});

Here are 2 of the questions bothering me recently:

1. In Compton's scattering experiment, if the photon's wavelength doesn't change in scattering, we say it belongs to Rayleigh's scattering. My question is, if a photon just passes thru the slab and doesn't change wavelength, does it belong to Rayleigh's scattering? The book mentioned implicitly it doesn't, but why?

2.In Dirac's consideration about relativistic energy of electrons,

[tex]E = \pm \sqrt {m_0^2{c^4} + {p^2}{c^2}} [/tex]

and he said the negative energy levels are fully occupied, but since momentum p is arbitrary, the energy levels should be continuous, is that right?

If so, we need infinite many electrons to occupy them, but if there are infinite many, the global version of charge conservation won't make sense any more, it would be weird to me.

Thanks in advance.

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# Two basic questions.

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