871. Einstein's famous equation E=mc2 says that mass is directly proportional to energy. Does this mean that an object that is suspended overhead has more mass than an object located at ground level? — ST, Denver, CO
Yes, the mass/energy of a suspended object is greater than the mass/energy of that same object at ground level. The extreme example of this result comes with lowering an object slowly toward the surface of a black hole—as the object descends, its mass/energy diminishes until it reaches zero at the surface of the black hole.