" The luminosity below me seemed confined directly to the area to be lighted; there was no diffusion of light upward or beyond the limits the lamps were designed to light. This was effected, I was told, by lamps designed upon principles resulting from ages of investigation of the properties of light waves and the laws governing them which permit Barsoomian scientists to confine and control light as we confine and control matter. The light waves leave the lamp, pass along a prescribed circuit and return to the lamp. There is no waste nor, strange this seemed to me, are there any dense shadows when lights are properly installed and adjusted, for the waves in passing around objects to return to the lamp, illuminate all sides of them. The "

― Edgar Rice Burroughs , The John Carter of Mars Collection (7 Novels/Bonus Audiobook Links)