The Philadelphia Experiment

By Stuart Slade and Tony DiGiulian
Updated 14 February 2000

Background Note

About once every six months, someone asks about the infamous "Philadelphia Experiment."  There's always a mention of how they read a book or saw the movie of that name about this mysterious US Navy test in 1943 where a destroyer escort off Philadelphia vanished and then reappeared near Norfolk, Virginia.  The descriptions usually include such horrific items such as crewmembers rematerializing half inside the deck and walls of the ship or that they were all discharged as being mentally unstable.  The story goes on that the USN had discovered the secret of time travel or teleportation but has then kept it under wraps for almost sixty years.

I do not expect the following article to stop such questions, but hopefully it will save me the effort of having to keep from shaking my head at just how gullible people are.

First of all, I suggest a look at the Official US Navy Explanation of this alleged incident:

Naval Historical Center Faq #21-1

And a look at some of the people involved in promoting this story:

Skeptic's Dictionary - Philadelphia Experiment

Any questions?  Of course, these could just be part of the "massive cover-up."  So, let's take a little reality check here.

Assuming that you've read one of these books, did you happen to notice the lack of first person interviews with any of the crew members of the Eldridge?  There are only stories that most if not all of the crew - that is, those that survived the terrible incident - were discharged from the Navy as being mentally unstable and unfit for further service.

OK, now think about that.  The Eldridge carried about 200 men.  After fifty-seven years, the authors were unable to find a single one of these people to interview?  How likely is that?  Show me a first person interview with a former crewmember who says "yes, I was transported to Norfolk and then back to Philadelphia" and maybe I'll start taking this story seriously.  And, I certainly don't mean the stories like "a friend of a brother of a former crewman" sort of psuedo-eyewitness accounts that seem to be accepted as gospel by the authors.

Could the real reason why there aren't any first-person stories on this alleged incident simply be that it just didn't happen?  Don't believe me?  Would you believe a real first person account that flatly denies that it ever happened?

"In March of 1999 fifteen members of the crew of the USS Eldridge held a reunion in Atlantic City.  They were a bit bewildered about why of all the ships in the U.S. Navy the Eldridge was chosen for this rumor.  Some were getting tired of being asked about it.  All denied anything like what was in the Allende story or the Moore/Berlitz book ever actually happened.  Quipped former crew member Ed Tempary, as he gave his comrades a smile, 'The only part of the book I think is true is the part about the crew being a little crazy.'"

The above is taken from this website:

Philadelphia Experiment

Just another member of the cover-up, I suppose .

So, you tell me, are these former crewmembers in on the conspiracy?  After over fifty years, are they still holding onto the dark, mysterious secret of time travel?  Or, are they just ordinary sailors who wish this whole nonsense would just go away?

The real staying power of this story is that it is extremely difficult to prove that something didn't happen.  For example:

Can you prove to me beyond a shadow of a doubt that Hillary Clinton didn't sneak in your room last night while you were asleep and then stared at you for hours?  Why not?  Doesn't the fact that you can't prove that she wasn't there say that she could have have been there without your knowledge?  And, who says that she did it without your knowledge?   Isn't true that you are conspiring with the government to hide the fact that Hillary Clinton stared at you?  In fact, why don't you just show me your proof that you're not on the government payroll yourself as a paid member of the conspiracy to hide Hillary Clinton's whereabouts from the taxpayers.  And, while you're at it, just where were you on the day when Cort Cobain committed his alleged suicide?  Oh, really?  How about giving us the names of the witnesses to your whereabouts so that they can be added to the list of co-conspirators?

See how easy it is?

My friend Stuart Slade has a much more prosaic explanation for this story:

The experiments that gave rise to the ludicrous stories about the "Philadelphia Experiment" were possibly concerned with optical camouflage using a technology known as counterlighting.

In 1941 aircraft were beginning to be used extensively for ASW work.  They hit a problem.  Because the aircraft being used were relatively low performance, alert lookouts on submarines could spot the aircraft before the aircraft could get close enough to launch an effective attack.  This was unfortunate, not from an operational reality point of view (the sub was being forced down so it could no longer track the convoy) but from an aircrew morale point of view.  All they saw was the subs getting away.

So a whole series of experiments were performed to try and improve the chance of the aircraft getting close enough.  One of these involved a trick known as counterlighting.  An aircraft is seen as a dark block on a bright background.  In fact, what the observer sees is the shadows on the underside of the aircraft contrasting with the bright sky.  So, somebody realized, if we can use floodlights to illuminate those shadow areas, the aircraft should be much less visible.

This was tried out and proved highly successful.  The aircraft equipped with counterlighting arrays were almost invisible.  However, the arrays consumed large amounts of electrical power and their drag slowed the aircraft right down and put fuel consumption up.  This made the idea impractical.  The solution was to use higher performance aircraft (Avengers and Wildcats in place of Swordfish and Liberators in place of Sunderlands) and adopt a new paint scheme copied from seagulls (light grey upper surfaces, gloss white belly).  These had the effects required.

For all its disadvantages, counterlighting worked well.  This inspired people to find applications where the power and drag problems weren't critical.  Somebody came up with the idea of using it on ships - particularly on the Arctic Convoy runs.  So one destroyer escort was equipped with counterlighting equipment and its effects evaluated.

The ship was at sea in normal conditions and being tracked visually and by radar.  When the counterlighting floodlights were turned on, those ships that were positioned so the target ship was silhouetted against the bright horizon saw it "apparently" vanish to re-appear when the lights were switched off.  Since the ship was under way at the time, this made it look as if she had moved from one spot to another.  Its important to note that at no time did the aircraft tracking the ship visually, ships tracking her by radar or those ships not in the correct aspect to her lose contact with her.  The experiments showed that counterlighting worked but only in comparatively narrow conditions and it wasn't really a practical technique.  It was more or less abandoned (although I have heard that it may have been used by some merchant ships).  Note that some of the effects ascribed to the "Philadelphia Experiment" (which was actually held in the West Indies and did not involve the Eldridge) are exactly those one would expect to get from staring straight at a brilliant light.

Other bits of history have become associated with the story.  One is degaussing, a technique applied to nearly all warships in WW2.  In this, the hull of the ship is "wiped" with a high-tension cable that reverses the magnetic field in the hull.  This doesn't make the ship "invisible" it flips the mine fuze the wrong way.  The effect of a degaussing fades quite quickly so the process has to be repeated regularly.  Later many ships had a degaussing cable fitted permanently to them.

Ships based in Philadelphia often used to go to Norfolk to bomb up.  This was routine and was an astonishingly quick turn-around.  This was helped by using a thing called the Inter-coastal waterway.

The bits of bodies etc.? Ships were coming back to Philadelphia after taking bad combat damage.  In some cases the inside of those ships (that had taken bomb or torpedo hits) looked like a butchers shop.  Again, somebody heard horror stories about what ships damaged in combat look like and added it in.

Counterlighting has reappeared a couple of times since WW2.  Its interesting now because its possible to formulate some composites so they glow when an electrical charge is put across them.  This means we can overcome the power consumption and drag problems.  It also means that this technology has drifted back into the black world.  None the less, its WW2 incarnations are well-documented.


On 15 January 1951 the USS Eldridge DE-173 was transferred under the Mutual Defense Assistance program to Greece, with whom she served as destroyer escort Leon (D-54).

The Leon was decommed by the Greek Navy in 1991 but she was retained as a training hulk.  I don't know if she was eventually scrapped or not.

The Greek sailors were rather amused at the occasional visitor who showed up to examine the ship for evidence of the alleged experiment and were reportedly not above having a few laughs at their expense.  As I cannot verify the accuracy of these stories - although I do not doubt that something of this nature did occur - I do not include them in this essay.


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