Hawking radiation is a theoretical prediction made by physicist Stephen Hawking in 1974. It suggests that black holes are not completely black, but instead emit a form of radiation due to quantum effects near the event horizon.
The process of Hawking radiation involves the creation of particle-antiparticle pairs near the event horizon of a black hole. According to quantum mechanics, particles can momentarily appear in a vacuum as virtual particles, which quickly annihilate each other and disappear. However, in the vicinity of a black hole, if one of these virtual particles falls into the black hole while the other escapes, it is said to have undergone a process known as "tunneling" or "Hawking radiation."
The energy required to create the virtual particle pair comes from the gravitational field near the black hole. This means that the black hole loses a small amount of mass and energy, while the escaping particle contributes to the observed radiation. The process effectively extracts energy from the black hole, causing it to gradually shrink and lose mass over time.
It's important to note that the mass lost by the black hole through Hawking radiation is incredibly small. For astrophysical black holes, such as those formed from stellar collapse, the rate of mass loss is minuscule, and it would take an extremely long time for a black hole to significantly decrease in mass through this process.
So, while one of the virtual particles may fall into the black hole and contribute to its mass, the other escaping particle carries away energy from the black hole, resulting in a net loss of mass over time. This process of particle creation and energy loss near the black hole's event horizon is what gives rise to Hawking radiation.