Near the end of my first semester at college, I was aimlessly looking through the early volumes of National Geographic (because that’s what bored college students do…right?), and I came across a lost speech of Alexander Graham Bell announcing his new invention he called the photophone, and asking for funding from the national science board. This invention was basically a wireless telephone, using the energy in light to transport sound waves rather than wires. He considered it to be his greatest invention, but the world wouldn’t listen because it was simply much too ahead of its time and too close to his recent telephone invention. The idea, however, would later pave the way for cellphones and fiber optics.
While the board blew him off, Bell’s friend and colleague Charles Sumner Tainter did listen, and he helped Bell many times in his refinement of the photophone. While experimenting with the various light wave lengths and colors to determine which wave on the spectrum carried sound best, Tainter discovered that the light waves at the end of the violet spectrum carried sound so well that it could be heard through an inch of rubber. Tainter continued this observation to create his own invention which he labelled the radiophone. If you are interested, you can read the rest here.