Archive for September, 2011

Alexander G. Bell’s Photophone

Wednesday, September 28th, 2011

Of all of Alexander Graham Bell’s inventions, the one that initially comes to mind is the telephone.  It was a groundbreaking invention that made communication between cities and even states possible.  What few know is that Bell was also working on another invention, one that would make coast-to-coast information transmission possible, wirelessly.  This invention used nothing but the light produced by the sun to transfer voice from a transmitter to a receiver.  The photophone, as it became known, would redirect sunlight against a hair thin mirror, which vibrated as the sound waves from your voice hit against the back of it.  As this was happening, the waves of light were then transferred across the air to the receiver, which of course had to be in direct line of the transmitter.  Bell and his assistant Charles Sumner Tainter viewed this new invention as greater than the telephone.  Their invention would enable the transmission of information without the need for running miles of numerous cables through lakes and across rough terrain.  This also became the precursor to modern day fiber-optic communications.

The first call with the photophone was made on April 1, 1880, from the roof of the Franklin School in Washington, D.C. to Bell’s laboratory window, which was roughly seven hundred feet away. After the successful transmission of sound, Bell was thrilled.  He sent his father a letter stating, “I have heard articulate speech produced by sunlight!  I have heard a ray of the sun laugh and cough and sing!”  He was so proud in fact that he wanted to name his second daughter after the invention.  Bell had hoped that the photophone would negate telephone lines and make ship to shore communication possible.  Unfortunately for Bell and Tainter, the euphoria would be short lived.

Bell and Tainter had invented an apparatus ahead of its time, where people still used candles to light houses and relied primarily on horses for work and transportation.  In 1880, some people still viewed cabled phones with a sort of primitive skepticism.  People were skeptical of such technology and along with that, the duo had to fight against environmental forces as well.  Much like light from the sun, when fog, snow, and rain move in very little light can penetrate the density of the obstructions.  Unlike its modern counterparts like fiber-optic cable, it was unshielded, leaving it completely at the mercy of the weather.  Bell Laboratories continued to try and improve on the photophone long after its invention, hoping to produce one with enough power to negate the weather forces and become a reliable form of communication.  Regrettably, this never came true.



Bell, Alexander G. “On the Production and Reproduction of Sound by Light.” The American Journal of Science 20 (1880): 305-324.

Bell, Alexander G. 1880. Apparatus For Signaling and Communicating, Called “Photophone”. U.S. Patent 235,199, Filed August 28, 1880, and Issued December 7, 1880.

Bell, Alexander G. 1880. Photophone-Transmitter. U.S. Patent 235,496, Filed September 25, 1880, and Issued December 14, 1880.

Bruce, Robert V. Bell: Alexander Bell and the Conquest of Solitude, New York: Cornell University Press, 1990.

Carson, Mary K. Alexander Graham Bell: Giving Voice To The World, New York: Sterling Publishing, 2007.

Better Late Than Never?

Sunday, September 18th, 2011

So, while winding down my weekend of crazy children and weddings, I remembered that I hadn’t posted my blog yet! For the upcoming solo project, I’ve decided to discuss the uses and barriers of using the Photophone, first used by Alexander G. Bell on April, 1880.  The photophone uses sunlight, then, with a thin mirror which flexes as the sound waves from your voice hit the back of it, it transmits the light waves to a receiver which then reconvert the light waves to sound waves.  This is considered the first wireless telephone call and a precursor to modern fiberoptics, which use light to transmit information in much the same fashion.

My only barrier to information at this point is the fact that the photophone was a short lived project.  Fog, clouds, and snow all played a part in disrupting the signal from the photophone, and since cabled telephones became all the rage just a few years later, little was written about the device.  I have found the four patents filed for the photophone, along with some era specific illustrations demonstrating the use of the photophone. There are also a few secondary sources in the form of scholarly books available on google books. I do feel comfortable that with the number of sources I have, I should be able to produce a 500 word project without a hitch.

Hey Folks

Thursday, September 1st, 2011

My name is Anthony Hahn and I’m a senior pre-law history major who transfered from ODU last year. I moved back here to my home on Lake Anna where my parents have lived for 14 years after the birth of my son, Koen, who is now 15 months old. I have full custody of him currently and I work full time at Best Buy along with this so I stay busy.

Most of you will recognize me as the guy who rides his longboard to class. I also ride BMX and snowboard when in season. My newest toy at the moment is my new seadoo xp jet ski. Obviously I also have a love for technology. Ive worked at Best Buy for 5 years now, and am currently typing this blog on my HP Touchpad which is rooted and in the next day or so will be running android OS 2.2. My phone of choice is the iPhone 4, jailbroken, and running windows os7. Quite the contradiction.

With this, it is easy to see why I’m taking History of the Information Age. I love technology, and would appreciate learning more about the origins of how technology evolved exponentially along with the spread of information.  Hopefully we all have fun this semester and build some awesome friendships.