:::::I don't understand why you call what I wrote as being "arbitrary" KonradG. The frame of reference is an absolute one, i.e., relative to the center of mass of the two objects being separated. Since the gravity of a human is negligible, its influence can be ignored. Lifting a weight upwards one meter against Earth's gravity is simply an issue of adding potential energy into an object by increasing its separation from the center of the Earth from, for instance, 6,366,197 meters to 6,366,198 meters. Also, I don’t think I'm missing the key point that what I wrote is directly and explicitly supported by Dr. Paul Marmet, who wrote exactly what we're talking about in 1.3: Mass-Energy Conservation at a Microscopic Scale. This is but one section from a single page from a comprehensive treatise on Einstein’s equations titled Einstein's Theory of Relativity versus Classical Mechanics. The only way that Sbharris has been able to deal with this is to simply declare that the Ph.D is incorrect. Hey, life’s simple when you deal with problems that way. I don't know why I bothered to contact the researcher who participated in the APOLLO laser ranging experiment that looked for small violations of Einstein’s Strong Equivalence Principle (SEP); Sbharris declared that guy to be incorrect too!