Alexander Graham Bell invented a way to talk on a beam of sunlight. The year was 1880, and he called his strange device the photophone.
While Bell’s telephone had to have wires connecting one caller with another, his photophone needed no such wires. It transmitted sound through the air on a beam of light using vibrating mirrors.
The vibrating mirrors changed sound waves to light waves and then back to sound waves again. Bell was very proud of his invention. He thought it his finest work, much better than the telephone or phonograph.
But the whole world was in love with the telephone, and Bell’s photophone was too big, and at the time it didn’t always work the way it should. Bell wrote, “I have heard a ray of sun laugh and cough and sing,” but nobody was interested.
It would be almost 100 years before the world was ready to think seriously about talking on a beam of light, and that would be brought about by the invention of the laser beam.
