The FBI grabbed and sealed papers left by Nikola Tesla subsequent to his death in 1943. Later that year, a rumored “Philadelphia Experiment” is said to have occurred. This coincidence suggests perhaps use of Tesla “ether physics” in the Philadelphia Experiment and consequent bizarre side-effects. (Background: Our Friend, The Ether (Part 8), Ersjdamoo’s Blog entry of October 25, 2013.)
However generally speaking, proponents of the Philadelphia Experiment believe the theories of Albert Einstein, especially his “Unified Field Theory”, played a major role in the alleged 1943 experiment.
Morris K. Jessup (image above, hopefully), an astronomer and mathematician, received some strange letters from one Carlos Allende (alias Carl Allen, image below, hopefully). These communications were received by Jessup consequent to the publication of his book, The Case for the UFO, in 1955. Allende alleged that a 1925-1927 version of Einstein’s Unified Field Theory had been closer to the truth than thought. Einstein had retracted the 1925-1927 version not because of the mathematics so much but more because of his concern for the “Humantics.” Einstein circa 1927 had apparently been horrified to realize what the power of his Unified Field Theory might unleash. 
Later, in 1943, under the stress of wartime, the U.S. Navy had acted as sorcerer’s apprentice when it resurrected the buried 1925-1927 Unified Field Theory for its Philadelphia Experiment, leading to uncanny and disastrous results. 
The Ether had once been the “unified field.” Through The Ether traveled the electro-magnetic waves and the force of gravity as well. But then a wrong interpretation of the Michelson-Morley experiment undermined belief in The Ether. Later, in 1905, Albert Einstein’s Special Theory of Relativity seemed to deliver the coup de grâce to The Ether. But Einstein, like the Prodigal Son, returned to a version of The Ether in 1918. In that year Einstein published, “Dialogue concerning Accusations against Relativity Theory”:
The Critic: So how is life now for that sick man of theoretical physics, the ether, which most of you had declared irrevocably dead?
The Relativist: He has had a changing destiny, and it is impossible to say that he is dead now. Before [Hendrick] Lorentz he existed as an all penetrating fluid, as a gaseous fluid or in other very different forms of existence, changing from author to author. With Lorentz he became rigid and impersonated a system of coordinates ‘at rest,’ that is to say a privileged state of motion in the Universe. 
(The Ether could not help chiming in at this point. “It is just as I have said! It is the ‘scientists’ themselves who are ‘relative’!”)
The Ether of Einstein’s General Theory of Relativity (1916) was his “new ether.” This “new ether” was only a “gravitational ether.” Unlike the “previous” Ether, the “new ether” considered the electro-magnetic field to be “something in the space-time continuum.” Thus came the problem of a possible “unified field” which might account for both gravity and electro-magnetism, something which the “previous” Ether had handled perfectly well. 
The “scientists” were “relative.” They were like the restless disciple whose mind could never be satisfied. The master had said, “The world rests on an elephant.” But the restless disciple had wanted to know, “On what does the elephant rest?” This line of questioning soon continued ad infinitum. (Background: Our Friend, The Ether (Part 7), Ersjdamoo’s Blog entry of October 23, 2013.)
At any rate, the restless disciple Albert Einstein had found when he declared The Ether to be “not necessary” that there began to be problems. And so, a “new ether” was introduced. But the “new ether” as yet had not “unified” the gravity force and the electro-magnetic field. And so Einstein began struggling to find a “unified field theory” which could contain both gravity and electro-magnetism.
It is claimed by proponents of a “Philadelphia Experiment” that Einstein had completed a version of his “Unified Field Theory” in the years 1925-1927.  This is corroborated by a second source. In 1925, “Einstein was convinced that he had found a final and satisfying solution to the problem.” The official version is that Einstein “abandoned” this solution but years later “returned” to it.  However the version told by “Philadelphia Experiment” proponents is that Einstein had in fact solved the problem but suppressed this due to “Humantics.” Later, circa 1940, because Einstein detested the Nazis, the “Unified Field Theory” is said to have been quietly revived. 
By 1943, Albert Einstein was working for the U.S. Navy as a scientific consultant, it is claimed. In July 1943, Dr. Vannevar Bush appointed Einstein to a shadowy committee.  (That name, Vannevar Bush, will be familiar to some as head of “Majestic 12”, also called “MAJIC 12.” I personally connect the Manhattan Project to the “MAJIC 12” – i.e., MA(hattan) ProJECt = MAJEC = MAJIC.)
We know now about the Manhattan Project and the atomic bomb. But what other secret projects might “Majestic 12” have been overseeing? A “Project Rainbow” perhaps (i.e., “Philadelphia Experiment”)? And what role might The Ether have played?
——- Sources ——-
 The Philadelphia Experiment, by William L. Moore (with Charles Berlitz). New York: Fawcett Crest, 1979.
 Einstein and the Ether, by Ludwik Kostro. Montreal: Apeiron, 2000