True Crime/Paranormal/Conspiracy Theories Part VII (Wattys2025)

The Philadelphia Experiment

The Philadelphia Experiment was an alleged event claimed to have been witnessed by an ex-merchant mariner named Carl M. Allen at the United States Navy's Philadelphia Naval Shipyard in Philadelphia, Pennsylvania, United States, sometime around October 28, 1943. Allen described an experiment where the U.S. Navy attempted to make a destroyer escort, the USS Eldridge, disappear and the bizarre results that followed.

The story surfaced in late 1955 when Allen sent a book full of hand-written annotations referring to the experiment to a U.S. Navy research organization and, a little later, a series of letters making further claims to a UFO book writer. Allen's account of the event is widely understood to be a hoax. Several different—and sometimes contradictory—versions of the alleged experiment have circulated over the years in paranormal literature and popular movies. The U.S. Navy maintains that no such experiment was ever conducted, that the details of the story contradict well-established facts about USS Eldridge, and that the physics the experiment is claimed to be based on are non-existent.

Origins of the story

The story of a "Philadelphia Experiment" originated in late 1955 when Carl M. Allen sent an anonymous package marked "Happy Easter" containing a copy of Morris K. Jessup's book The Case for the UFO: Unidentified Flying Objects to the U.S. Office of Naval Research. The book was filled with handwritten notes in its margins, written with three different shades of blue ink, appearing to detail a debate among three individuals, only one of whom is given a name: "Jemi". They commented on Jessup's ideas about the propulsion for flying saucers, discussed alien races, and expressed concern that Jessup was too close to discovering their technology.

The commenters referred to each other as "Gypsies", and discussed two different types of "people" living in outer space. Their text contained non-standard use of capitalization and punctuation, and detailed a lengthy discussion of the merits of various elements of Jessup's assumptions in the book. There were oblique references to the Philadelphia Experiment (one commenter reassures his fellow annotators who have highlighted a certain theory which Jessup advanced).

Shortly thereafter (January 1956) Allen began sending a series of letters to Jessup, using his given name as well as "Carlos Miguel Allende". The first known letter warned Jessup not to investigate the levitation of unidentified flying objects. Allen put forward a story of dangerous science based on alleged unpublished theories by Albert Einstein. He further claimed a scientist named Franklin Reno put these theories into practice at the Philadelphia Naval Shipyard in October 1943.

Allen claimed to have witnessed this experiment while serving aboard the SS Andrew Furuseth. In Allen's account, a destroyer escort was successfully made invisible, but the ship inexplicably teleported to Norfolk, Virginia, for several minutes, and then reappeared in the Philadelphia yard. The ship's crew was supposed to have suffered various side effects, including insanity, intangibility, and being "frozen" in place. When Jessup wrote back requesting more information to corroborate his story, Allen said his memory would have to be recovered and referred Jessup to what seems to be a non-existent Philadelphia newspaper article that Allen claimed covered the incident.

In 1957, Jessup was invited to the Office of Naval Research where he was shown the annotated copy of his book. Jessup noticed the handwriting of the annotations resembled the letters he received from Allen.  (Twelve years later, Allen would say that he authored all of the annotations in order "to scare the hell out of Jessup".)

Two officers at ONR, Captain Sidney Sherby and Commander George W. Hoover, took a personal interest in the matter.  Hoover later explained that his duties as Special Projects Officer required him to investigate many publications and that he ultimately found nothing of substance to the alleged invisibility experiment.  Hoover discussed the annotations with Austin N. Stanton, president of Varo Manufacturing Corporation of Garland, Texas, during meetings about Varo's contract work for ONR.