The Real Philadelphia Experiment

Did a US Navy warship completely disappear in 1943?

by Brian Dunning

Filed under Conspiracies, Paranormal, Urban Legends

Skeptoid #16
December 24, 2006
Podcast transcript | Listen | Subscribe
Also available in Russian

Today we're going to pull a giant switch on the wall and activate powerful generators, which will create a mysterious force field around us and cause us all to disappear. For we're going to discuss the perennially silly "Philadelphia Experiment."

The story goes that in October of 1943, at the Philadelphia Naval Shipyard, an experiment was conducted aboard a US Navy Cannon-class destroyer escort called the USS Eldridge, number DE-173. The experiment involved the creation of a force field which rendered the ship invisible both to the eye and to radar. The experiment was witnessed by hundreds, possibly thousands, of sailors both ashore and on other ships nearby. Unfortunately, there were severe side effects to the crew on board ship. Some were found materialized inside the metal of the ship, others were never seen again, and still others were driven insane or plagued for years by mysterious cases of phasing in and out of existence. In typical Navy fashion, everything has been denied.

None of the above ever actually happened. What follows, did actually happen.

The secret of the mysterious experiment and its terrible aftermath was kept for 12 years, until one day when Morris Jessup, the author of a book about UFO's, was unexpectedly summoned to the US Navy's Office of Naval Research. The ONR had received, in the mail, a copy of Jessup's UFO book, filled with handwritten annotations. The notes were all in the same handwriting, but in three characters, in three colors of ink. The notes revealed all the details of the Philadelphia Experiment, and the ONR wanted to know if Jessup knew anything about who might have written these notes and sent the book to them.

Jessup recognized the crazy handwriting immediately. He had received a series of letters from a man calling himself Carlos Allende, who claimed to have witnessed the experiment from aboard a merchant marine ship nearby, the SS Andrew Furuseth. Jessup had dismissed Allende as a crackpot — among Allende's claims was that Albert Einstein had personally spent several weeks mentoring him on subjects such as invisibility and faster-than-light travel. Several copies of the annotated book were produced, and the rest is history: The Philadelphia Experiment story became part of the fabric of pop culture.

Robert Goerman, a researcher of the paranormal and a friend of mine, noticed that the return address of Allende's original mailing to the ONR came from his own home town, New Kensington, Pennsylvania. He had spent some time putting together the history of the Philadelphia Experiment story and in 1979, found to his great surprise that Carlos Allende, whose real name was Carl Allen, was the son of a close family friend. Over time, Goerman filled in the blanks and presented the complete case in magazine articles and on television shows such as History's Mysteries, Unsolved Mysteries, and The Unexplained — three show titles which by themselves lend far too much credence to Carl Allen's stories. Carl Allen was something of the dark horse of the family, a creative and imaginative loner, notorious for annotating anything and everything in the house, and sending bizarre writings and claims to everyone in the family for any occasion. Goerman also assembled all of the facts of the USS Eldridge: little things, like the ship was nowhere near Philadelphia when the experiment happened, the ship had detailed corroborated records for the normal duties that it was in fact performing at the time, and that nobody who had ever been a crewman on board the ship knew anything about any experiment. The Eldridge had been launched only two months before the experiment, and you'd think that if it was hosting Albert Einstein and the most amazing experiment in history, somebody would have known about it. Without exception, every single fact that Carl Allen presented as evidence of the Philadelphia Experiment has been easily proven to be a complete fabrication.

And therein lies the problem. The trouble with discussing government conspiracies is that the believers generally refuse to accept the factual evidence, because it becomes part of the conspiracy. It's a bit like having a debate about Creationism: believers simply say "God did it" and it's a matter of faith, not of evidence or fact. If the government is trying to cover something up, every falsified claim becomes evidence for the conspiracy. In summary, there is no amount of evidence that can be compiled that will be accepted by a conspiracy theorist. In the conspiracy theorist's mind, evidence against is actually evidence for.

Among this schizophrenic evidence is the US Navy's reply to the Philadelphia Experiment story, which is available online at As you might surmise, it simply says that they have no idea what this guy could be talking about, here's where both ships were and what they were doing at the time, and here are the statements from their officers. It's an entertaining report, but predictable.

Interestingly, there are some question marks left standing about the Philadelphia Experiment. As you might expect, two or three veterans of the Eldridge and the USS Engstrom, which was once moored alongside the Eldrige in 1943, have claimed to be a guy whom Allende saw disappear in a bar or who have found themselves transported across dimensions. It should be noted that such claims were made well after the Philadelphia Experiment became a pop-culture phenomenon, and in more than one case it turned out that these guys were not actually veterans at all. A more interesting question comes from the very genesis of the story, when the Navy ONR first summoned Morris Jessup to their office to talk about the strangely annotated book. If there was nothing in those annotations of genuine interest to them, why did they call?

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Who knows. Goerman suggested that these ONR officers did this on their own time out of personal intrigue, or that some of the allusions in the annotations were similar to actual Navy research and the ONR was simply being responsible at following every lead. Conspiracy theorists maintain that this proves Allen's annotations must have been true. Whatever the truth, I happen to love that this story has this annoying little footnote that can't be easily explained away. I love a good mystery and I remember a streak of disappointment when Goerman's debunking of the case was laid out before me — like most people I'd done no thorough research of my own and only knew what the average moviegoer knows about the Philadelphia Experiment. Intellectually I know the story is silly, but I still love that little loose end. Carl Allen may have been a prankster, but I thank him for making the century just that little bit more interesting.

Brian Dunning

© 2006 Skeptoid Media Copyright information

References & Further Reading

Barnes, M., Houpt, F., Schelm, G. "Al Bielek finally debunked." Al Bielek Debunked. Golf Sierra, 18 Jun. 2003. Web. 12 Oct. 2009. <>

Broderick, James F., Miller, Darren W. Web of Conspiracy: A Guide to Conspiracy Theory Sites on the Internet. Medford, N.J.: CyberAge Books, 2008. 175-188.

Carroll, R. "Philadelphia Experiment." The Skeptic's Dictionary. Robert T. Carroll, 15 Feb. 2011. Web. 15 Sep. 2015. <>

Goerman, Robert A. "Alias Carlos Allende: The Mystery Man Behind the Philadelphia Experiment." FATE Magazine. 2 Oct. 1980, Volume 33, Number 10.

Knight, Peter. Conspiracy Theories in American History: An Encyclopedia. Santa Barbara, California: ABC-CLIO, Inc., 2003. 583-585.

Vallee, Jacques F. "Anatomy of a Hoax: The Philadelphia Experiment Fifty Years Later." Journal of Scientific Exploration. 1 Oct. 1994, 8: 47-71.

Reference this article:
Dunning, B. "The Real Philadelphia Experiment." Skeptoid Podcast. Skeptoid Media, 24 Dec 2006. Web. 4 Oct 2015. <>


10 most recent comments | Show all 126 comments

This expt also appeared in Readers Digest Many years ago under true stories

Savvy, Asia
August 9, 2013 1:18am

Yep, Readers digest has a lot more to answer for.

I was quite happy to read this publication when I was young. Thankfully it has probably been one of the initiators of my stoicism over the decades.

It was a read for the train or bus to work or school and left about as much impression as the regular events on these regular trips..Things you'd gladly avoid for a good natter.

Madime Dantefer, Greenacres by the sea Oz
August 13, 2013 6:46pm

Was it Tesla that discovered a certain vibration could cause earthquakes or make a building collapse? is this a fallacy or truth? one other ?. Has anyone checked out the rectangle on google maps that is blacked out. was this done on purpose? it was said to be hiding planet X from us non governmental people. i know the backed out triangle is there but the question is why?

Valerie Holden, just a little left of between a Rok & a hard spot.
October 15, 2013 2:19am

this a real story

raghav, london munsi party school
October 31, 2013 7:48am

If it was true then it would now be declassified as 50 years has passed . I've not seen any leaked document's either. I don't believe there was a experiment.

tony, south africa
November 24, 2013 11:33am

Interesting - The book 'The P.E and the Nazi Bell' gave some interesting info on the boat's weights and log sheets that have been altered.
I have also spoken to a family member of a South African navel off. that was part of a back-up team on the radar checking of the P.E. and this off. had related some of what was monitored by South Africa at the time.It sounded like he knew of what he was talking.

Coen, South Africa
May 23, 2014 3:20am

The saying goes, where there's smoke, there's fire. I bet no one ever thought back then that an atomic bomb could be created & wipe away a country, but it happened. Surely you don't believe everything the Govt says, do you? They experimented on our own Soldiers by putting them in harms way while they conducted atom bomb experiments; they gave Black men LSD drugs without their knowledge, experimented on kids in orphanages & SO much more! Yes, OUR GOVT did & does those things & they are very secretive, don't expect them to tell the truth....EVER!

Ginger, Vegas
May 25, 2014 8:19am

Except there are plenty of examples of "smoke" without fire.

Chad H., here, there, everywhere
September 3, 2014 8:44pm

Inside thick layers of codswallop, there is a kernel of truth to this story - the degaussing of ships during the World War 2.

In 1939 the Germans dropped a new type of sea mine into the seas around Britain which soon started to cause losses to commercial shipping and warships. This was the magnetic mine which exploded when the steel hull of a ship distorted the local magnetic field. The mine lay on the seafloor, so conventional mine sweepers could not find it.

Starting in 1940, countermeasure were used by British Empire ships. After Pearl Harbour, Britain shared this technology with the US.

Every 3 months or so, ships had their magnetic fields adjusted by dragging huge electrical coils carrying 2,000 Amps around the hull. During this process the crew were ordered out of the ship for safety. Usually an officer would read out an official explanation of what was being done. I have seen documents that used the phrase "this will make the ship invisible to mines".

At the time the sailors understood "invisible" to be a metaphor, but if you have no understanding of the historical context or the technology, and a bias towards constructing weird theories, you could easily misconstrue this.

But why would some dingbat idea get so popular? Especially in the US, the world leader in science and technology? And why so many dingbat ideas and why do they all seem to originate in the US?

Search Wikipedia for Degaussing

John Faulkner, Sydney, Australia
March 31, 2015 7:57pm

I'm not sure if the story is true, but I own a ac/dc meter that was on board the ship at the time of the experiment. So far it hasn't disappeared and I will be quite upset if it does. It works fine and would have gone well with the rest of the test equipment used during the experiment for it is a very hi freq, low volt meter, Hmm, you never know......

Step, Budd Lake, NJ
May 4, 2015 10:15am

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