[Prof_Sai]

You don't want to be converting matter to energy. The conversion factor involves the speed of light squared, so a human sized mass will explode large cities off of the Earth. You have to put the mass somewhere. Information inherent to the subject must either be retained or intelligently paired down. You can't shrink atoms, period.

Also, you'd be using pounds or at least cubic feet. A "foot of mass" doesn't really mean anything unless you define the other two dimensions.