Let’s say it already, from the beginning (especially for the purists of the original authors of the inventors, if there is such a thing): six years before Gray and Bell developed it, the Italian Antonio Meucci already had the invention of the telephone. What Alexander Graham Bell did , actually, was imagine a more organic infrastructure for such an invention.
Be that as it may, in addition to this invention, the photophone is more fascinating: it is actually a kind of light telephone .
The light phone
The photophone consisted of a mirror that reflects sunlight, mounted on a support that vibrates with the voice, so that the reflected light is received by a parabolic mirror and concentrated on a selenium cell that translates the signal into audible sound in a telephone receiver, as explained by Santiago Álvarez in his book On women, men and molecules :
Thus, the inventor of the telephone was also a forerunner of the optical transmission of signals, which today we call photonics.
The photophone was patented on December 18, 1880 , but the quality of communication remained poor and the investigation was not continued by Bell. Still, shortly before his death, he told a reporter that the photophone was "the best invention [that I have] made, bigger than the telephone.
Later this invention served as the basis for the development of communications using fiber optics and lasers.
Understanding the phenomenon of light reflection is another story. The extrusion theory advocated by Euclid and Ptolemy, among others, maintained that light comes out of the observer’s eyes. On the contrary, the theory of intrusion (light enters through the eyes) was defended by Aristotle and rescued by Avicenna in the 10th century.
If you are still a bit angry with the fact that Bell is unfairly credited with the invention of the telephone (or even the photophone), then perhaps you should watch the following video, where it is exposed that the idea of Author has something religious or romantic as well as the idea of Inventor; And, given the structure of the history of innovation in the world, we should begin to give less romantic importance to inventors or discoverers, and more to the ecosystems where such inventions and discoveries occur: