UV, X Rays, and Gamma Rays

When we get to wavelengths shorter than the visible spectrum, and even in the visible spectrum, we begin to run into problems with Maxwell’s theory of light.
These problems were first clearly displayed by Max Planck who in 1900 developed a theory that explained the blackbody spectrum of radiation. The problem with Planck’s theory of blackbody radiation is that it could not be derived from Maxwell’s theory of light and Newtonian mechanics. His theory involved arbitrary assumptions that would not be understood for another 23 years, until after the development of quantum mechanics.
Despite the failure of Newton’s and Maxwell’s theories to explain all the details, the electromagnetic spectrum continues right on up into the shorter wavelengths of ultraviolet (UV) light, then to x rays and finally to γ rays. Ultraviolet light is most familiar from the effect it has on us, causing tanning, sunburns, and skin cancer depending on the intensity and duration of the dose. The ozone layer in the upper atmosphere, as long as it lasts, is important because it filters out much of the ultraviolet light emitted by the sun.

X rays are famous for their ability to penetrate flesh and produce photographs of bones. These rays are usually emitted by the tightly bound electrons on the inside of large atoms, and also by nuclear reactions. The highest frequency radiation, γ rays, are emitted by the smallest objects—nuclei and elementary particles.