The Philadelphia Experiment
A navy destroyer is said to have been made invisible and moved to another port in a secret wartime test.
What was reported
The story says that in October 1943, the US Navy destroyer escort USS Eldridge was made invisible in a secret experiment at the Philadelphia shipyard, vanished in a green fog, appeared briefly in Norfolk, Virginia, and returned, leaving its crew changed.
It began in 1955 and 1956 with letters to the UFO author Morris Jessup from a man calling himself Carlos Allende, and later inspired books and a 1984 film.
Explanations offered
The US Navy says no such experiment took place. Historians think the story may have grown from real wartime work on degaussing, which made ships harder for magnetic mines to detect, in that sense 'invisible'. The letter writer later gave conflicting accounts.
- When
- Said to be October 1943
- Where
- Philadelphia Naval Shipyard, Pennsylvania, USA
- Witnesses
- None confirmed
- Status
- Hoax
Famous cases are real, widely reported events. Each file sets out what witnesses said and the explanations that have been offered, without taking a side.