By the 1920s, Thomas Edison’s legacy was secured. The American inventor had forever changed the world by introducing the phonograph, the motion picture camera, and the first practical incandescent light bulb. If he had decided to retire that year, his reputation as one of the greatest geniuses of the past two centuries would still be strong today. But he had plans for a new invention, and it was his most ambitious yet—a “spirit phone” that could be used to contact the dead.

Instead of merely fame, fortune, or scientific advancement, one of Edison’s biggest motivations for the new machine was the chance to best a rival one last time. That rival's name? Nikola Tesla.

Tesla and Edison: Old Adversaries

The friction between Edison and Tesla made for one of history’s greatest rivalries. Their relationship went back to 1882, when Edison was a successful scientist and businessman and Tesla a promising young engineer working for the Continental Edison Company in Paris. Tesla eventually moved to the business’s American location on a good recommendation from his supervisor, but Edison wasn't as confident in the new transfer, calling his ideas “splendid” but “utterly impractical.”

As the two men advanced in their careers, the differences between them became more apparent. While Thomas Edison was a tireless experimenter, Tesla preferred figuring out his inventions on paper before picking up any tools. Tesla was a slave to cleanliness, and Edison, in Tesla's words: "lived in utter disregard of the most elementary rules of hygiene."

The conflict came to a head with the “War of Currents.” Tesla’s versatile alternating current (AC) eventually won out over Edison’s safer but limited direct current (DC), marking Tesla’s biggest victory over his former employer.

Though they would likely never admit it, the two men shared several similarities. Both were eccentric, egotistical, and obsessive workers. They also both dabbled in using technology to talk to ghosts.

When Tesla “Positively Terrified” Himself

Around the turn of the 20th century, when electricity was first being used to light rooms at the flip of a switch and make images move onscreen, the idea of using technology to contact spirits didn't seem that absurd. Tesla considered this possibility while experimenting with a crystal radio powered by electromagnetic waves in 1901. The signals he picked up one night were so unnerving that his scientific mind couldn't help but think of ghosts. He wrote in his diary, "My first observations positively terrified me, as there was present in them something mysterious, not to say supernatural, and I was alone in my laboratory at night."

In 1918, he wrote of similar sounds he heard after tinkering with another radio, but he was careful not to automatically attribute them to otherworldly sources. "The sounds I am listening to every night at first appear to be human voices conversing back and forth in a language I cannot understand,” he wrote. “I find it difficult to imagine that I am actually hearing real voices from people not of this planet. There must be a more simple explanation that has so far eluded me.”

There was a simple explanation: The type of radio he used is capable of picking up very low frequency radio signals from unseen sources like electrical storms, atmospheric disturbances, and household electronics. Translated to audio, the signals can sound like the uncanny chatter of disembodied voices.

Edison's Scientific Séance

When Edison learned that Tesla thought his inventions might be used to get in touch with another plane, he wanted in on the action. Though a notable agnostic and critic of the séance-holding mediums that were popular at the time, he became intrigued by the idea of forces existing beyond our world. In 1920, he told The American Magazine, “I have been at work for some time building an apparatus to see if it is possible for personalities which have left this Earth to communicate with us.” Others later referred to this device as his "spirit phone."

Like all of his experiments, this one was rooted in science. Edison pulled from the work of Albert Einstein, particularly his theories of quantum entanglement and special relativity. Edison’s thinking went like this: If it’s possible to convert mass to energy, then maybe the spirits of living people become coherent units of energy when their bodies stop working. And if entangled particles can affect each other across great distances, as the quantum entanglement theory states, then maybe there’s a way for those energy bundles to interact with our physical world.

According to the authors of Edison vs. Tesla: The Battle Over Their Last Invention, Edison put a prototype of his spirit phone invention to the test in 1920. He invited both mediums and scientists to come over and observe a mysterious experiment. They saw a projector-like machine, set out on a workbench, that emitted a thin beam of light onto a photoelectric cell. The illuminated cell was meant to detect the presence of forces and objects moving through the beam—even those invisible to the naked eye. If a being from another world were to attend the gathering and pass through the light, a meter hooked up to the photoelectric cell would let them know, Edison explained.

If his guests showed up that day expecting scientific evidence of ghosts, they were disappointed. Hours passed and the needle on the meter remained still—even the mediums in attendance had to admit there was nothing supernatural going on. But the inventor wasn’t discouraged. Though some skeptics have called Edison's dabbling in the supernatural a hoax, an entry recovered from his personal diary suggests his pursuits were genuine. He continued working on his so-called “spirit phone” throughout the 1920s.

Poor Connection

Edison died in 1931 without producing any evidence of spirits more convincing than the sounds picked up by Tesla’s radio decades earlier. But the quest to transmit a message from the other side using technology wasn’t quite over. In his earthly state, Edison had made plans to continue his work after death. He made a pact with his engineer William Walter Dinwiddie that whoever died first would try to make contact with the other. Dinwiddie passed away in 1920, about a decade before Edison, and as far as we know, that marked the end of any correspondence between the two men.

Though Dinwiddie wasn't around to receive a ghostly message from Edison when he died, others took up his mantle. A group of researchers claimed the inventor reached out to them during a séance in 1941. Edison's spirit allegedly shared the plans for building the spirit phone he had spent the last decade of his life working on. The group followed the entity’s instructions, but when assembled, the machine was no more effective at communing with the dead than the ones Edison had built while he was alive. An essay in the anthology Spirited Things recounting the attempt notes, “Alas, the contraption did not seem to successfully transmit any life units.”

Source: https://www.mentalfloss.com/article/602456/thomas-edison-nikola-tesla-spirit-phone

David Wilson’s Morse code messages

One of the earliest reports of phantom phone calls dates back to the early twentieth century, when a London solicitor, David Wilson, received bizarre messages on a machine he had made himself from a wireless telegraph. Devised to use the Morse code system, Wilson’s communication machine first received strange messages in 1913 when used by his friend. The signals were delivered in Morse as audible beeps. Astonishingly, the device continued to relay messages even after the receiving wire had been disconnected. 4

With the help of a second witness, Wilson translated each message as they came through. The telephonic messages the machine received appeared to be meaningful. In January 1915, this was received:

“Great difficulty, await message, five days, six evening.”

Similar instructional phrases like, “wait until next Tuesday”, also came through.5 However, despite waiting, nothing ever happened that illuminated on the messages’ meanings. Confused as to why he was receiving such messages without any input, the solicitor invited researchers to inspect his machine and try to explain the source of the Morse code. No explanation, and no source of the signal, could be found. After publishing his experiments, David Wilson and his Morse communmassications disappeared from the records. 6

The case of David Wilson inspired others to ponder on the possibility of electronic communications being delivered from beyond the grave. Some took the idea further, purposefully constructing machines to aid in interdimensional communication.

Francis Grierson’s “psycho-phone”

From 1920 to 1921, the English-born psychic medium and composer Francis Grierson (who gave demonstrations under his stage name, Jesse Shepard) claimed to have had detailed conversations with spirits on the other side by means of a “psycho-phone”. Far from speaking with any old ordinary Joe, Grierson published transcripts of conversations with Thomas Jefferson, Abraham Lincoln and Benjamin Franklin. The conversations were extensive and intelligent, and – by deviating from contemporary popular opinions – seemed to suggest insight and opinion unconstrained by the time in which they were received. 7

“The psycho-phonic waves, by which the messages were imparted, are as definite as those received by wireless methods.” – Francis Grierson8

As unbelievable as Grierson’s reports may seem, he was far from alone in his claims. Telephonic communication experiments were something of a trend in the 1920s.

F.R. Melton’s “psychic telephone”

With the help of his eldest son, British psychical researcher F.R. Melton designed and built a psychic telephone in an attempt to converse with the dead. He even published a pamphlet in 1921, titled A Psychic Telephone: Its Construction, the Laws and Conditions that Govern Its Use, which described, in detail, the different components of the machine. As well as containing expected elements, including a transmitter, receiver and a battery, Melton’s design included a balloon at the centre which was filled with the breath of a psychic medium. 9

Thomas Edison’s spirit phone

In 1920, during an interview for Scientific American, inventor Thomas Edison discussed his plans to construct a similar machine.

“I do claim that it is possible to construct an apparatus which will be so delicate that if there are personalities in another existence or sphere who wish to get in touch with us in this existence or sphere, this apparatus will at least give them a better opportunity to express themselves than tilting tables and raps and Ouija boards and mediums and other crude methods now purported to be the only means of communication.”10

When Edison died in 1931, the fate of this invention was unknown. Some records suggest that he did indeed build a spirit phone, but that it had failed to produce results. Whatever the case may be, no blueprints for any such apparatus designed by Edison are known to exist. 11

In modern times, one can see the use of so-called Ghost Boxes, EVP recorders, and other electronic communication based “ghost hunting” devices, as a continuation of the ideas proposed by inventors like Melton and Edison.

Source: http://www.paranormalscholar.com/telephone-calls-from-the-dead/