: Lorentz used electromagnetic relativity to predict relativistic mass in 1899, and it was experimentally confirmed a couple of years later. Poincare used E=mc2 for radiation in 1900. So I think that electromagnetic aspects of relativity do relate to physical mass. They also relate to various frames of reference, as electromagnetic experiments were done at different times of the year to test different frames of reference in the Earth's orbit. Gravity and electromagnetism are separate forces, and I guess it is fair to say that relativistic aspects had to be tested separately. [[User:RSchlafly|RSchlafly]] 00:04, 22 August 2011 (EDT) | : Lorentz used electromagnetic relativity to predict relativistic mass in 1899, and it was experimentally confirmed a couple of years later. Poincare used E=mc2 for radiation in 1900. So I think that electromagnetic aspects of relativity do relate to physical mass. They also relate to various frames of reference, as electromagnetic experiments were done at different times of the year to test different frames of reference in the Earth's orbit. Gravity and electromagnetism are separate forces, and I guess it is fair to say that relativistic aspects had to be tested separately. [[User:RSchlafly|RSchlafly]] 00:04, 22 August 2011 (EDT) |