Some questions in the Theory Development forum seem to be revolving around the topic of formulating electromagnetism as a geometrical theory along the same lines as gravity in General Relativity. (I couldn't post this in that forum for some reason.) This was apparently done 50 years ago but not widely known by a man named Burkhard Heim. Remarkably, this theory is the only one which seems to reproduce the mass spectra of the known subatomic particles from first principles, and no he was not a crank. His theory is not widely known because he was severely handicapped and did much of his (mostly unpublished) work in seclusion. A good overview is at: http://en.wikipedia.org/wiki/Heim_theory For the conveneince of the forum goers, I have collected together some of the papers referenced in the overview. These papers are good background for the Heim Theory but are somewhat speculative and geared toward the possible application of Heim theory to exotic propulsion systems. http://www.ar.tech.new.net/Heim/DroscherHauserJuly2002.pdf http://www.ar.tech.new.net/Heim/DroscherHauserJuly2003.pdf http://www.ar.tech.new.net/Heim/DroscherHauserJuly2004.pdf http://www.ar.tech.new.net/Heim/HQT2005.pdf Keep an open mind and let's hear some feedback from the experts on the forum.