The Philadelphia Experiment: Anatomy of a Twentieth-Century Hoax

The legend says that on October 28, 1943, the US Navy destroyer escort USS Eldridge was wrapped in a greenish fog at the Philadelphia Naval Shipyard, vanished, reappeared briefly in Norfolk, Virginia, and returned. Some sailors, the story goes, were embedded in the steel hull. Others lost their minds.

None of that happened. The Eldridge was not in Philadelphia on October 28, 1943. She was on her first shakedown cruise in the Bahamas, with a documented day-by-day war diary on microfilm at the US National Archives. The legend originates from a series of handwritten letters mailed in 1956 by a single merchant seaman named Carl M. Allen, almost all of whose claims have been falsified by surviving Navy records. The interesting story is not the “experiment” — there was no experiment. The interesting story is how one set of crank letters became, over four decades, a Hollywood film, a bestselling book, and a phrase that still gets tens of thousands of Google searches a month.

What the USS Eldridge Actually Did in 1943

The Eldridge was a Cannon-class destroyer escort, named for Lieutenant Commander John Eldridge Jr., killed in action in the Solomon Islands on November 2, 1942. She was launched on July 25, 1943, at Federal Shipbuilding and Dry Dock Co. in Newark, New Jersey, and commissioned on August 27, 1943, at the New York Navy Yard. Her first commanding officer was Lieutenant C. R. Hamilton, USNR.

According to her surviving war diary and deck logs — which the Naval History and Heritage Command holds on microfilm (file NRS-1978-26) — the Eldridge remained in New York and Long Island Sound from her commissioning until September 16, 1943, when she sailed for Bermuda for her shakedown cruise. She was in the Bermuda and Bahamas area, not at the Philadelphia Naval Shipyard, on October 28, 1943, the date of the supposed experiment.

Between January 4, 1944, and May 9, 1945, she made nine convoy voyages to Casablanca, Bizerte, and Oran in support of Allied operations in North Africa and Southern Europe. She transferred to the Pacific in late May 1945 and arrived off Okinawa on August 7, just before the Japanese surrender. She was placed in reserve on June 17, 1946, transferred to the Royal Hellenic Navy on January 15, 1951, under the Mutual Defense Assistance Act, renamed HS Leon (D54), and finally sold for scrap on November 11, 1999. A 1999 reunion of Eldridge veterans, reported in a Philadelphia newspaper at the time, confirmed that the ship had never made port in Philadelphia.

The Hoaxer: Carl M. Allen

Carl Meredith Allen was born in 1925, served briefly in the US Marines from July 1942 to May 1943, and spent most of the rest of his working life as a merchant seaman. He died in a Colorado nursing home in 1994. His existence was so obscure that for more than two decades after the hoax began, even researchers writing books about the Philadelphia Experiment did not know who he actually was. The journalist Robert Goerman finally identified and located him in 1980.

In early 1956, Allen mailed his first long letter to UFO researcher Morris K. Jessup, an astronomer and author of The Case for the UFO (Citadel Press, 1955). The first letter, postmarked Gainesville, Texas, arrived at Jessup’s desk on January 13, 1956. Allen wrote under the name “Carlos Miguel Allende,” claimed to have witnessed the Eldridge‘s disappearance from the deck of the merchant ship SS Andrew Furuseth, and asserted that he had been “personally tutored by Albert Einstein” in unified field theory. He used unusual capitalisation, eccentric spelling, and underlining throughout — features that Navy investigators would later use to identify his handwriting.

Jessup wrote back. Allen sent more letters. When Jessup pressed for evidence, Allen could not provide any. Jessup eventually concluded that Allen was, in his own words, a “crackpot,” and ended the correspondence.

The Annotated Book and the Office of Naval Research

In the summer of 1956, the Office of Naval Research in Washington, DC, received a manila envelope postmarked Seminole, Texas, marked “Happy Easter” on the outside. Inside was a paperback copy of Jessup’s The Case for the UFO with marginal annotations in three different colours of ink, supposedly representing three different annotators — “Mr. A.”, “Mr. B.”, and “Jemi” — discussing alien technology, government conspiracies, and the Philadelphia Experiment.

Two ONR officers, Captain Sidney Sherby and Commander George W. Hoover, took the package seriously enough to investigate. Working with the Varo Manufacturing Company of Garland, Texas, they produced an internal mimeographed edition — known as the “Varo edition” — that reproduced the annotated book together with the Allende letters Jessup had received. Only a small number of copies were printed. The Varo edition itself became a collector’s item among UFO researchers.

It was, however, all the work of one person. Handwriting analysis confirmed that the marginal annotations matched Allen’s letters to Jessup. In 1969, Allen himself admitted in a recorded interview that he had written all three “annotators,” demonstrating in person how he had simulated three different handwriting styles. He said his goal had been, in his words, to “scare the hell out of Jessup” away from continuing his research on Einstein’s unified field theory, which Allen had decided was dangerous. He later retracted the admission, but the handwriting evidence is independent of his confession.

Morris Jessup never recovered from the affair. He died by suicide in Florida in April 1959 — a tragedy conspiracy writers have since tried to weave into the legend, but for which there is no evidence beyond Jessup’s documented financial and personal difficulties at the time of his death.

The Book and the Movie

The hoax might have died in obscurity if not for two New York–based UFO writers, Charles Berlitz and William L. Moore, who in 1979 published The Philadelphia Experiment: Project Invisibility. The book was a paperback bestseller. It elaborated the story with additional, equally unsourced details: a code name (“Project Rainbow”), the involvement of Tesla and von Neumann, the supposed teleportation route from Philadelphia to Norfolk and back.

In 1984, director Stewart Raffill released the film The Philadelphia Experiment, a science-fiction time-travel feature loosely based on Berlitz and Moore. The destroyer escort used for filming was actually the museum ship USS Laffey (DD-724), not the long-since-scrapped Eldridge. A sequel followed in 1993. The franchise has since seeded countless other works of fiction — the audio drama ars PARADOXICA, the TV miniseries The Triangle, episodes of Doctor Who, and even an appearance in Marvel’s Loki series.

The Navy’s Documentary Response

By the late 1990s, the question had been asked of the US Navy so often that the Naval History and Heritage Command and the Office of Naval Research issued formal, sourced statements. Their official online reading-room entry lays out the contradictions one by one:

• The Eldridge‘s 1943 war diary and deck logs place her in New York, Bermuda, and the Bahamas — never Philadelphia.
• The SS Andrew Furuseth‘s movement-report cards (held by the Modern Military Branch of the National Archives) show that she was not in Norfolk on October 28, 1943. She had left Norfolk three days earlier, on October 25, with Convoy UGS-22, bound for Oran.
• William S. Dodge, the wartime master of the Andrew Furuseth, supplied a letter to the Navy’s archives explicitly denying that any unusual event was observed by his crew.
• The Office of Naval Research did not exist in 1943. It was created in 1946. The September 1996 ONR statement, signed by Public Affairs Officer Therese Hood, reads in part: “ONR has never conducted any investigations on invisibility, either in 1943 or at any other time.”
• Einstein was a part-time consultant to the Navy’s Bureau of Ordnance in 1943–44 on conventional explosives research, not unified field theory. He never completed a unified field theory at any point in his life.

What Was Probably Happening Instead

The Philadelphia Naval Shipyard in 1943 was, in fact, working on a real classified technology that made ships “invisible” — not to the human eye, but to magnetic mines and torpedoes. The technique was called degaussing (sometimes deperming): wrapping a ship’s hull in heavy electrical cabling, then running large currents through the cables to neutralise the ship’s magnetic signature. The technique had been developed by the Canadian naval officer Charles F. Goodeve while serving in the Royal Canadian Naval Volunteer Reserve, and by 1943 was in routine use across Allied navies.

Edward Dudgeon, who served aboard the USS Engstrom (which was dry-docked alongside the Eldridge‘s sister ships during the same period), recalled in later interviews that the equipment looked exactly like the kind of mysterious electrical rigging an outside observer might mistake for a “force field.” The greenish glow witnesses sometimes describe is plausibly St. Elmo’s fire — atmospheric plasma discharge in strong electric fields, which sailors have reported around masts and rigging for centuries.

And the supposed “teleportation” from Philadelphia to Norfolk and back? Naval vessels of the era routinely took the inland Chesapeake and Delaware Canal between the two ports, which dramatically shortened a journey that, by sea around the Delmarva Peninsula, would have taken much longer. A ship that “went to Norfolk and back” in a single day was not teleporting. It was using the canal.

What Most Accounts Get Wrong

Popular treatments of the Philadelphia Experiment usually concede that the story is “disputed” and then list the dramatic claims as if they were on a par with the documentary record. They are not. On one side: a man with no corroborating witnesses, no documentary evidence, no internally consistent timeline, and a 1969 confession that he authored the supposed third-party evidence. On the other side: the ship’s deck logs, the merchant captain’s letter, the ONR’s founding date, Einstein’s biography, and the Naval History and Heritage Command’s archive.

This is not a case of “we may never know.” It is a case of “we already know, and Carl Allen made it up.” The historically interesting question is not whether the experiment happened — it didn’t — but why a clumsy hoax from 1956 became one of the most durable American conspiracy theories of the twentieth century.

The honest answer is probably some combination of Cold War nuclear anxiety, postwar distrust of military secrecy, real (and real-sounding) classified wartime technology like degaussing, and the structural appeal of a story in which the government is hiding capabilities it does not actually have. Folklore prefers an interesting wrong answer to a boring right one.

Why It Still Matters

The Philadelphia Experiment is a useful case study in how a single unreliable source, given the right cultural moment and the right amplifiers, can produce a “history” that outlives every correction. Forty years after Allen admitted authorship of the supposed corroborating evidence, the legend is more visible than ever, embedded in films, novels, podcasts, video games, and superhero cinematic universes. The actual USS Eldridge — a working ship crewed by ordinary American sailors who escorted nine convoys to North Africa under genuine wartime danger — has been almost entirely erased by a story she had no part in.

That is its own piece of history, and worth remembering whenever a dramatic claim turns out to rest on the word of a single anonymous correspondent.

For more on the wartime era, see our pieces on women in the American founding and Black Americans in the Revolutionary War.

Frequently Asked Questions

Did the Philadelphia Experiment actually happen?

No. There is no surviving documentary evidence that the US Navy ever attempted to make a ship invisible or teleport one. The USS Eldridge‘s 1943 war diary and deck logs, held on microfilm by the Naval History and Heritage Command, place her in New York, Long Island Sound, Bermuda, and the Bahamas during the period of the supposed experiment, not at the Philadelphia Naval Shipyard. The Office of Naval Research, which allegedly ran the experiment, was not established until 1946.

Where did the story come from?

The story originated in a series of letters mailed in early 1956 by merchant seaman Carl Meredith Allen, writing under the pseudonym “Carlos Miguel Allende,” to UFO researcher Morris K. Jessup. Allen also anonymously sent the Office of Naval Research an annotated copy of Jessup’s book, The Case for the UFO, supposedly written in three different hands by three different people. Handwriting analysis later confirmed all three were Allen, and Allen himself admitted authorship in a 1969 interview.

Who was Morris K. Jessup?

Morris Ketchum Jessup (1900–1959) was an astronomer, mathematics teacher, and author of The Case for the UFO (1955) and its sequels. He briefly took Carl Allen’s letters seriously before concluding that Allen was a crackpot. The Office of Naval Research drew Jessup back into the affair when it received Allen’s annotated book in 1956. Jessup died by suicide in Florida in April 1959. Conspiracy theorists later attempted to link his death to the experiment, but there is no evidence supporting that connection.

What was the USS Eldridge actually doing in October 1943?

According to her war diary and deck log on file with the Naval History and Heritage Command, the Eldridge was conducting her first shakedown cruise in the Bermuda and Bahamas area. She had been commissioned only two months earlier, on August 27, 1943, at the New York Navy Yard. She began Mediterranean convoy duty in January 1944 and ultimately made nine voyages to Casablanca, Bizerte, and Oran before transferring to the Pacific in 1945.

What happened to the USS Eldridge?

After the war the Eldridge was placed in reserve on June 17, 1946. On January 15, 1951, she was transferred to the Royal Hellenic Navy under the Mutual Defense Assistance Act and renamed HS Leon (D54). She served Greece until decommissioning on November 5, 1992, and was sold for scrap on November 11, 1999, to V&J Scrapmetal Trading Ltd. of Piraeus.

Is there any real technology behind the legend?

Yes — but it has nothing to do with invisibility or teleportation. The Philadelphia Naval Shipyard in the 1940s was a major centre for degaussing, a real classified technique that wrapped a ship’s hull in electrical cables and used powerful currents to neutralise its magnetic signature so that magnetic mines and torpedoes could not detect it. The technique had been developed by Canadian naval officer Charles F. Goodeve and was in routine wartime use. Witnesses to actual degaussing operations would have seen unusual equipment, sparking arcs, and possibly St. Elmo’s fire — the documentary record suggests these are the most likely source of any genuine 1943 observations later folded into the legend.

Sources

1. US Naval History and Heritage Command — Philadelphia Experiment (official archive entry)
2. US Naval History and Heritage Command — USS Eldridge (DE-173) service history
3. US Office of Naval Research — 1996 statement on the Philadelphia Experiment (PDF)
4. American Heritage Center, University of Wyoming — Carlos Allende papers
5. Military.com — “The Truth Behind WWII’s Creepy Philadelphia Experiment”
6. The Revealer — David Halperin, “The Philadelphia Experiment”
7. Africa Check — “No, Philadelphia experiment that made entire ship vanish never happened”
8. War History Online — “About The Philadelphia Experiment: The Navy’s Biggest Hoax”
9. Robert A. Goerman, “Alias Carlos Allende: The Mystery Man Behind the Philadelphia Experiment,” FATE Magazine, October 1980
10. Jacques Vallée, “Anatomy of a Hoax: The Philadelphia Experiment Fifty Years Later,” Journal of Scientific Exploration, vol. 8, no. 1 (1994)
11. Charles Berlitz and William L. Moore, The Philadelphia Experiment: Project Invisibility (Grosset & Dunlap, 1979) — the principal popular source for the legend, treated here as a primary document for the hoax rather than a reliable history