What Happened During the Philadelphia Experiment?

USS Eldridge ship.
USS Eldridge ship.

What Was the Philadelphia Experiment?

The Philadelphia Experiment is a supposed military experiment conducted by the United States (US) Navy on October 28, 1943, in Philadelphia, Pennsylvania. It is claimed that during the experiment the military managed to make the USS Eldridge, a US Navy destroyer escort, invisible to enemy devices. The tale of the Philadelphia Experiment emerged in 1955 through a letter sent to American astronomer and writer Morris K. Jessup. The story is believed to be a hoax, and the US Navy maintains it has never performed such an experiment. Additionally, details of the tale contradict well-established facts about the USS Eldridge. The US Navy also claims that the alleged story does not conform to the laws of physics.

Alleged Details of the Experiment

According to several accounts, the US Navy funded a group of unspecified scientists who believed that they could render an object invisible by bending light over it using large electrical generators, which would be very useful to the military. Unfortunately, there is no reliable, attributable account of what happened that day, but most theories suggest that all equipment necessary for the experiment was installed in the USS Eldridge at the Philadelphia Naval Shipyard. The experiment began during the summer of 1943, and one of the tests resulted in the ship becoming almost invisible, with witnesses claiming to have seen a green fog in its place. Most of the sailors aboard the vessel complained of nausea after the experiment, and when the ship reappeared, some of its sailors had been embedded in the ship’s metal structure, while others became mentally unstable.

The US Navy repeated the experiment on October 28 after altering the equipment. During the second experiment, the ship disappeared from the Philadelphia Naval Shipyard and reappeared 200 miles away in Norfolk, Virginia. The vessel was supposedly seen by crew aboard the SS Andrew Furuseth, before vanishing and appearing in the shipyard in Philadelphia. Some claim that the USS Eldridge traveled through time. There are many versions of the tale describing what happened to the sailors, including severe side effects. For example, some sailors were physically fused to the ship’s bulkheads, while others suffered various mental disorders. Some crew members vanished, while others were re-materialized inside-out. It is also alleged that the remaining sailors were brainwashed to help keep the experiment a secret.

Origin of the Story

The story originated from Morris K. Jessup, who had published a book about unidentified flying objects (UFOs), after receiving two letters from Carlos Miguel Allende in 1955, who claimed to have seen a secret Second World War experiment conducted at the Philadelphia Naval Shipyard. Allende explained that the US Navy rendered destroyer escort USS Eldridge invisible before it was teleported to New York. Allende believed the vessel was teleported to another dimension where it encountered aliens and was transported through time. Jessup dismissed Miguel’s tale and labeled him as a "crackpot." The Philadelphia Experiment was also featured in the book Invisible Horizons: True Mysteries of the Sea, written by Vincent Gaddis in 1963. The story was popularized by Berlitz Charles, who wrote a book on the topic in 1979. The tale was adapted into a movie The Philadelphia Experiment, which was directed by Raffill Stewart in 1984. The version of the story portrayed in the film was supported in 1990 by Bielek Alfred, a self-proclaimed survivor of the Philadelphia Experiment.


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