A final "electromagnetic" consideration of the molecular matter contained within a gravity field is that such matter holds less entropic energy compared to free molecules of hydrogen gas in space.  Thus if  molecule of hydrogen is absorbed into a gravitational body it loses 
"time energy" in the forms of a) various atomic and molecular motions, and b)  entropy.  But more critically it can also be recognized that when a new object joins a larger mass body in space the larger entity must transfer a very slight quantity of its own time-energy to the new mass.   That preciously-unrecognized energy transfer, and its inverse capacity,  will eventually be central to future space travel.