Evening Republican, Volume 18, Number 77, Rensselaer, Jasper County, 31 March 1914 — LIGHT THAT PRODUCES SOUND [ARTICLE]

LIGHT THAT PRODUCES SOUND

Statement Sounds Incredible, but Experiment Will Speedily Demonstrate It to Be a Fact. It seems incredible that a beam of light sould be made to produce sound, but such a thing can be done. A ray of sunlight is thrown through a lens on a glass vessel containing lampblack, colored silk or worsted, or any like substance. A disk having slits or openings cut In It Is made to revolve swiftly in this beam of light, so as to "cut it up,” thus causing alternate flashes of light and shadow. When one places his ear to the glass vessel he hears strange sounds so long as the flashing beam falls upon the vessel. A still more extraordinary effect Is produced when the beam of sunlight is made to pass through a prism, so as to produce what Is called the solar spectrum. The disk is turned and the colored light of the rainbow is made to break through it Now, if the ear be placed to the vessel containing the silk or other material, as the colored lights of the spectrum fall upon it sounds will be given by the different parts of the spectrum and there wijl be silence tn other parts. For example, if the vessel contains red worsted and the green light flashes, upon IL loud sounds will be • heard when the red and the blue parts of the

rainbow fall upon the vessel. Other colors produce no sounds at all. Green silk gives out sound best in a red light Every kind of material gives more or less sound In different cblors and no sound kt all in others.—Harper’s Weekly.