At AllTheScience, we're committed to delivering accurate, trustworthy information. Our expert-authored content is rigorously fact-checked and sourced from credible authorities. Discover how we uphold the highest standards in providing you with reliable knowledge.

Learn more...

What is the Philadelphia Experiment?

G. Melanson
G. Melanson

Also known as “Project Rainbow,” the Philadelphia Experiment was allegedly conducted by the U.S. Navy in 1943, as part of the military’s initiative to render one of their ships invisible. The incident is said to have occurred at Philadelphia, Pennsylvania’s Naval Shipyard on the USS Eldridge in front of witnesses who claim that the ship was invisible for a brief period. The U.S. Navy, however, denies that the experiment occurred.

There are various contradictory reports surrounding the Philadelphia Experiment which lend skepticism to the story and cause many to believe the accounts are a hoax. The most widely-told version of events is that test phases of the experiment first occurred during the summer of 1943 when the USS Eldridge first achieved partial invisibility. On 28 October 1943, the ship not only achieved complete invisibility, according to reports, but also teleported to Norfolk, Virginia’s Naval Base before reappearing at its original location in Philadelphia.

Woman with hand on her hip
Woman with hand on her hip

The crew of the USS Eldridge are said to have suffered severe psychological and physical problems as a result of the experiment, while others reportedly vanished altogether. One of the conspiracy theories regarding what happened to the crew is that they were brainwashed by military officials in order to forget the traumas of the incident.

Skeptics of the Philadelphia Experiment point out the lack of credibility in some of the alleged witnesses themselves. One eye-witness account given by a purported witness and USS Eldridge crew member, Alfred Bielek, was eventually debunked by a team of investigators who were able to confirm that Bielek was not aboard or near the ship at the time of the experiment.

As well, inconsistencies in the time line of events have also caused skepticism about The Philadelphia Experiment. In 1999, a Philadelphia newspaper reported that some veterans of the USS Eldridge claim the ship never even docked in Philadelphia. World War II documents seem to testify to this as well; they place the ship in the Bahamas at the time of the October incident.

The Philadelphia Experiment has captured the attention of both the literary world and Hollywood. It has inspired the 1978 novel,Thin Air, as well as the most recognized source of information on the incident, The Philadelphia Experiment: Project Invisibility in 1979. In 1984, the story made it to the big screen in The Philadelphia Experiment, and returned in 1993 with Philadelphia Experiment II. The Philadelphia Experiment has also been the subject of small screen shows that tackle conspiracy theories such as Unsolved Mysteries and The X-Files.

Discussion Comments


Spaceship! Possible. Biblical accounts of extras in the sky.


For some reason, this article makes me think of Star Trek and how only the bad guys were able to "cloak" their ships to make them undetectable. (Although it seems like the Enterprise could always find a way to detect a cloaked ship if they just wanted to badly enough!)

Wasn't it something about a treaty the Federation had signed that kept them from developing cloaking technology? One wonders why they would agree to sign something that so obviously kept one hand tied behind their backs. But then, if I remember right, they *did* develop a cloaked ship (the Defiant) during the Deep Space Nine years. We always called that one "Star Stay" because you can hardly call it a "trek" if you stay on a space station!


When I clicked on this, I assumed the Philadelphia Experiment wold be something boring! Wow! I wouldn't put it past DARPA to work on something like this. Really, if you think about it, the military isn't doing its job if it isn't pursuing every avenue, no matter how silly! (Although these days, surely it is far more important to be invisible to radar and other technological means.)

Post your comments
Forgot password?
    • Woman with hand on her hip
      Woman with hand on her hip