In 1955, writer and astronomer Morris K. Jessup received two letters from a man named Carlos Miguel Allende, who claimed to have witnessed military time travel.
In the correspondences, Allende described a supposed secret experiment at the Philadelphia Naval Shipyard, in which the Navy used a variation of Albert Einstein’s unified field theory to render the destroyer escort USS Eldridge (DE-173) invisible. He wrote that the ship teleported through time and another dimension sometime around October 1943 in what is now known as “The Philadelphia Experiment.”
While Jessup wrote off Allende’s claims as the ramblings of a crazy person, he was unwittingly drawn into the bizarre story again when two years later, the Office of Naval Research (ONR) in Washington, D.C. got in touch with him.
Somebody had sent them a copy of Jessup’s book, “The Case for the UFO.” It had been filled with annotations referencing Allende’s earlier claims, leading Jessup to assume he was behind it. The ONR ended up funding a printing of 100 copies of the annotated version, known as the Varo edition, which helped spread the story of the alleged experiment.
Different versions of the story have circulated ever since. One of the most common claims is that researchers believed uniting the fields of electromagnetism and gravity into a single field to bend light around an object would make it invisible.
Supposedly, the Navy thought this would gives their ships an advantage over submarines by keeping them hidden from sight during World War II, so they began testing on the USS Eldridge in 1943.