- As per quantum physics, space everywhere is filled with fluctuating fields. Even the space just outside the black hole’s event horizon (surface beyond which there is no return) has tiny fluctuating fields.
- The quantum fluctuations can lead to creation of particles from the quantum fields (more on it below). It’s happening all around us but such particles exist only for a very short period of time and get annihilated.
- When such particles are created just at the surface of black holes, it may happen that one particle falls into the blackhole, while the other falls outside the black hole. The one that falls into the black hole doesn’t return, while the one that falls outside the blackhole is emitted as “Hawking radiation”
- In case of Hawking radiation, there is a net creation of particles (that don’t annihilate). The energy for creation of such particles must come from somewhere. It comes from the blackholes itself (technical version of this phenomenon in FAQs below). It means that as the Hawking radiation is emitted, blackholes lose a part of their energy. If you wait long enough, black holes lose all their energy and evaporate!
- Negligible threat of blackhole catastrophe in CERN’s Large Hadron Collider (LHC): There is a theoretical possibility of creation of tiny black holes in LHC. But we don’t need to worry about them because they evaporate in a short time, due to Hawking radiation
- Holographic principle: Holographic principle says that our 3D world may just be a projection of the information on the 2D surface at the outer edge of the cosmos, just like holograms where we see a 3D object on a 2D surface. The physics of holographic principle will be a topic of another post but just note that Hawking’s radiation led to the formulation of holographic principle. Holographic principle was also part of the famous Big Bang Theory TV series.
black hole the mass of our Sun would take 10⁶⁷ years to evaporate; the one at the Milky Way’s center would require 10⁸⁷ years, and the most massive ones in the Universe could take up to 10¹⁰⁰ years!