Etheric force

Etheric force is a term Thomas Edison coined to describe a phenomenon later understood as high frequency electromagnetic waves—effectively, radio. Edison believed it was the mysterious force that some believed pervaded the ether.

At the end of 1875, Edison and his assistants were experimenting with the Acoustic Telegraph when they noticed that a rapidly vibrating spark gap produced a spark in an adjacent relay.^[1] Subsequent investigation showed that the phenomenon could be made to occur at a distance of several feet without interconnecting cables. Edison, with this small amount of evidence, announced that it was "a true unknown force",^[2] since he believed that the spark transmitted electricity without carrying any charge.^[3] Edison concluded that this discovery had the potential to cheapen telegraphic communication and to allow transatlantic cables to be laid without insulation. He was also interested in finding new forces as a means for providing scientific explanations for spiritualist, occult and other allegedly supernatural phenomena following his disenchantment with Helena Blavatsky's Theosophy.

Edison's apparatus consisted of a spark gap vibrating at a high frequency powered by batteries and connected to tin foil sheet about 12 by 8 inches, effectively acting as an antenna. A similar tin foil sheet, connected to ground was located at about eight feet away with two more similar, un-grounded tin foil sheets between. Sparks could be seen at the "receiver" sheets. Effectively, Edison had observed wireless transmission and was later to regret that he had not pursued it.^[1]

Edison's last laboratory notebook entry on etheric force in 1875, which shows his experimental apparatus, can be seen at the Edison Papers at Rutgers School of Arts and Sciences.^[4]