OT - Physics Question on Anti-Matter

[Suicide Junkie]

Renegade 13 said:

That's not entirely true. Blackholes represent a massive amount of potential gravitational energy that I'm sure could (eventually) be harnessed by mankind. However, physicists believe that blackholes do "decay" slowly over time, losing mass, so it is possible that even blackholes would eventually all disappear, though that would take hundreds of billions or trillions of years.

How is it not true?
How do you plan to get anything out of said hole without reducing the hole's mass-energy?

Just because there is a lot of mass there dosen't mean it is infinite in any way. Where "a lot" is only a handful of stellar masses in many cases.