> Except that under some theories the net energy in our universe is actually zero. Antimatter+matter = nothing. So the concept of unlimited energy can be accept

> Except that under some theories the net energy in our universe is actually zero. Antimatter+matter = nothing. So the concept of unlimited energy can be acceptable under the rubric that energy in one area is mirrored by anti-energy in another. No, anti-matter still has positive energy. It's the gravitational potential energy that balances out all of the other energy to leave a total of zero - every particle's energy is cancelled by its negative potential energy of its gravitational field.