At least in the first Superman movie, Superman's X-ray vision could see through female character Lois Lane's clothing to see the color of her underwear.
The rays must permit Superman, but not Earthling standing in line with the reflected rays, to see through normally opaque surfaces.
But first, before we get into the meat of the paper, lets see what others around the InterWebs have said about Superman's amazing seeing through underwear powers.
The mechanics of the X-ray vision vary wildly. Sign up using Facebook. Of course, as Winter Toad points out, Silver Age Kryptonians could transmute materials with their X-ray vision, which is inconsistent with the behavior of ordinary X-rays.
Fresnel zone plate pattern. Human vision has evolved to make use of several physical properties of 'visible' light: You can, in fact, make zone plates for use with x-rays.
Processing that intake is another story, but Superman is often shown to filter out the noise of the entire planet Earth and hear a single cry for help, or focus his visual acuity down to microscopic levels. And even reflection is complicated by the fact that typical x-ray wavelengths are comparable to the spacing between atoms. Twelfth Twelfth 22k 1 33 92. There are two ways how vision might work When any electromagnetic wave passes through any material some amount energy in the wavelength corresponding to the characteristics of the material will be absorbed this how spectrometer works so when multiple materials of different types are arranged in layers they absorb some wavelength corresponding to their matrial and the resulting waves will interfere with each other and are diffracted or reflected thus masking the signal of the inner layer thus making it opaque.
So how does Superman do it! In evolutionary point predators hunting for prey might develop such vision to hunt for prey that hides among solids. The pattern of diffracted beams lets you deduce the crystal structure and spacing for whatever target you're looking at.
So his "super hearing" and "x-ray vision" might instead be due to some Just like we can look through foggy glasses, Superman can see. A scientific study of Superman's flight. Also, x-ray optics are very different to light optics.