From what astrologists know, particles were created after Big Bang from energy.
For more information, read The Brief History of Time from Stephen Hawking.
When a particle pair drop into black hole, the positive energy will turn into negative energy and vice-versa due to the strong gravity force of black hole. Thus, the negative energy drop into the black hole and decrease the energy of the black hole. According to E=mc^2, the mass of black hole...