On this day in 1877, Thomas Edison patented the phonograph. Phonographs were among the first devices to both record and play audio recordings. Phonographs record audio using needles, which use sound waves to create etches into a foil-covered cylinder. As the cylinder rotates, a second needle runs along these etches and plays the recorded audio.
Did you know that Nikola Tesla, inventor of the Tesla Coil, also invented the AC (alternating current) system that is still used to power our homes even today? It’s true! Considered eccentric by many, Tesla was a brilliant inventor, and was briefly employed by Thomas Edison as an electrical engineer. Tesla and Edison went their