i don't agree with all the conservation of energy stuff. you are simply shifting the matter to another time. in fact it happens all the time. see when you stared reading this your matter was say 10 seconds ago. the universe didn't end did it? anyway if you are really interested in this stuff, my physics prof. from a couple semesters ago is actually theorizing about this type of stuff. it's all about taychons.

http://physics.gmu.edu/%7Ee-physics/bob/n.htm
http://physics.gmu.edu/%7Ee-physics/bob/t.htm