X rays can go through solids.
Radio waves can go through solids.
And both of these are on either side of visible light in the spectrum. Why can’t visible light go through solids?
In: Physics
It’s stranger for light, radio waves, etc. to get _stopped_ by matter than to pass right through it. There are some materials that are opaque to X-rays (lead, your bones), and some materials that are transparent to visible light (diamonds, glass). But the _default _ reaction electromagnetic radiation has when encountering matter is to pass right through it… _unless_ it hits an atom with an electron that can absorb exactly the frequency of the radiation. Then, instead, the photon is absorbed, exciting the electron, and then re-emitted when the electron de-excites.
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