Thomas Edison seated in his laboratory, c. 1904. (Photo: Library of Congress/LC-USZ62-55339)

In the late 1920s, not long before his death, Thomas Edison reportedly gathered with other scientists in a secret laboratory to record the voices and presence of the dead. They used “speakers, generators, and other experimental equipment,” Modern Mechanix magazine alleged after the fact, in October of 1933.

The magazine article describes Edison’s machine, in which a “tiny pencil of light, coming from a powerful lamp, bored through the darkness and struck the active surface,” which could detect the smallest particle. These particles would be proof of the afterlife, physical bits of human personality left in the atmosphere, waiting to be discovered. Unfortunately, after “tense hours” spent watching the delicate instruments, nothing happened; which was, the magazine adds, why no one had heard of this experiment before.

Full disclosure: that specific account might have been a spooky fantasy for the magazine’s October issue. But, while it’s unclear if that exact scene occurred, there’s ample proof that Edison was interested in speaking to the dead using technology. In 1920, the inventor shocked the public when he told 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.”

Edison, who was known for having hundreds of patents of inventions and creating an efficient version of the light bulb, added that this new invention would not function by “any occult, mystifying, mysterious, or weird means, employed by so–called “mediums”, but by scientific methods. I am engaged in the construction of one such apparatus now, and I hope to be able to finish it before very many months pass.”

An image from a seance held by medium William Hope, c. 1920. (Photo: Public Domain)

Edison’s idea became known as a “spirit phone”, and caused a media storm. For years many historians believed the invention to be a joke or a hoax; no blueprints or prototypes of a spirit phone could be found. But while he may not have actually contacted the dead, there is evidence he experimented with the idea. In 2015 the French journalist Philippe Baudouin found a rare version of Edison’s diary in a thrift store in France.

This version includes a chapter that was not printed in the widely known 1948 English edition, called the Diary and Sundry Observations of Thomas Alva Edison. This missing chapter was dedicated to his theory of the spirit world, and how it might be possible to contact it. Baudouin re-published the French edition as Le Royaume de l’au-delà.

A century ago, however, the wider world was somewhat less receptive to the revelation that the great inventor was working on a spirit phone. The resulting media circus was summed up in an editorial note in American Medicine, which said “the press have failed to deal with proper dignity and respect an announcement from the great man who has produced so many modern miracles.”

As magazines regurgitated the story, Edison’s somewhat pragmatic approach to the spirit world morphed into evidence that he was (or soon could be) regularly chatting with ghosts. A French cartoon from the time depicted a depressed husband being pestered by his mother-in-law beyond the grave via Edison’s spirit phone.

An illustration of Alexander Graham Bell and Clarence J Blake’s ear phonautograph. (Photo: Internet Archive/Public Domain)

That a well-respected scientist who greatly influenced modern technology could try to contact spirits might seem unlikely to the public now. But when Edison spoke of his idea in 1920, spiritualists were still going strong in the United States—some even called themselves “phone-voyants,” and claimed that they could harness the electric signals in conventional phones to interpret spirits.

For many, the spirit phone’s unbelievable promise invoked technologies like the telegraph and air flight, which were both seen as impossible until proven otherwise. The public was, for example, aghast at Edison’s phonograph when it was new in 1877, an invention many felt “could turn the ancient dream of immortality into reality, in an attempt to cheat death,” Baudouin notes in the documentary Thomas Edison & the Realms Beyond.

At the time, communicating with spirits didn’t seem much more impossible than harnessing electricity. Other similarly eerie ideas appeared during this time too. Thomas Watson, the well-regarded assistant of telephone inventor Alexander Graham Bell, also dabbled in the idea of a spirit phone; while an invention by Bell and ear specialist Clarence J. Blake, the “ear phonautograph,” recorded sounds using a stylus attached to a human ear and skull.

During Edison’s lifetime, science and technology advanced at a rapid clip, giving us the gas-powered car and the theory of relativity. These unexpected advancements seemed endless, and the possibility of a physical spirit seemed plausible. Edison mused to American Magazine that scientists studying electricity would probably be the first people to review his device. “It would cause a tremendous sensation if successful,” he said. Yet if his device failed, he added, our belief in the spirit world would wane significantly.

A photograph of Edison from a 1920 issue of Scientific American, which included an interview “regarding his attempt to communicate with the next world.” (Photo: Public Domain)

Speaking to loved ones beyond the grave may have appealed to the public, but for Edison this was a matter of strict science. Edison believed that life was indestructible, and that the “quantity could never be increased or decreased.” He theorized that like our bodies, our personalities have a physical form, made of tiny “entities” similar to our current view of atoms. He thought these entities might exist after humans passed away—a personality-based residue of loose memories and thoughts, containing part of who a person was during life.

If these particles existed, he reasoned, they could collect together in the ether around us. Possibly they could be amplified by his device like a human voice could be amplified and recorded by a phonograph.

According to Baudouin, Thomas Edison wrote plans and theories for these devices, though whether he actually built and tested one, and to what extent, is still unknown. He never named the machine, and referred to it as a “valve,” which was highly sensitive to vibration. Later sketches of Edison’s spirit phone by magazines depicted phonograph-like parts, including a fluted horn containing an electrode, thought by some to have been dipped in the conductive potassium permanganate. This horn was attached to a wooden box containing a microphone, which was would pick up the vibrations of these entities because of its extreme sensitivity.

Edison’s idea became mixed in with occult studies in short order. Literary Digest’s circulation analysis for 1921 included “Edison’s Spirit Phone” in its list of articles on psychology, along with “Dreams”, “Mind Reading”, and “Why People Laugh.” Edison wasn’t keen on this grouping, though. In his interview with American Magazine, Edison criticizes the unscientific qualities of a psychic medium’s methods, which he called crude and childish. Some people, he said, “permit themselves to become, in a sense, hypnotized into thinking that their imaginings are actualities.”

From an article in Modern Mechanix magazine, about Edison’s experiments to “lure spirits from beyond the grave”. (Photo: Public Domain)

Since Edison’s death in 1931, ghost-communicating hopefuls have been looking for blueprints to build and test the spirit phone; or at least to approximate it. In 1941, researchers tried to replicate the spirit phone and call the inventor up, after they believed they were instructed to do so by Edison’s spirit via a medium. “Alas, the contraption did not seem to successfully transmit any life units,” Stephan Palmié writes in the anthology Spirited Things.

People still want to use technology for detecting and communicating with ghosts, though the preferred gadgets have evolved into electronic voice phenomena (EVP) recorders and geophones. Some cost-minded ghost hunters use ghost-detecting apps, converting their smartphones into portable spirit phones. In 2002, the late Frank Sumption claimed ghosts could speak, just as spiritualists hoped for with Edison’s invention, using a special radio called Frank’s Box; spirits tune in, directing the frequencies to form words from the world beyond.

Although a finished spirit phone never joined his many patents, Edison at least achieved the first half of his goal, which was “to give the scientific investigator—or for that matter, the unscientific—an apparatus which, like the compass of the seaman, will put their investigations upon a scientific basis,” as he wrote in his published diary.

While we don’t know if Edison was correct in his theory that our personalities inhabit physical “entities”, nor if he could hear them on his spirit phone, at least the inventor’s idea of using technology to speak beyond the grave lives on.