"Everything should be made as simple as possible, but not simpler."

-Albert Einstein

"Electromagnetic Archimedes' principle and Coulomb's law in charged media,"
Revised: May 11, 2011, v1: April 12, 2011.

"Elementary derivation of time-induced gravitational mass
and potential energy,"
May 15, 2010.

"Gravitational force near a rotating black hole,"
February 26, 2010.

"Archimedes' principle and a hollow, fluid-filled sphere,"
January 18, 2010.

"Gradient operator in general coordinates,"
December 27, 2009.

"Archimedes' principle and gravitational levitation,"
June 01, 2009.

"Time-dependent electric field outside a charged sphere,"
January 26, 2009.