To answer the question of the fate of black holes, one has to compare the loss of mass due to Hawking radiation to the increase in mass due to accretion. This demonstrates that for known black holes – and more generally for the real-world black holes of today – accretion is always dominant.
If you want to know how much mass a black hole loses each time due to Hawking radiation, you are looking at its radiative strength. This gives (using the famous equation E = mc2) Directly the amount of mass lost each time. Hawking radiation has a black body spectrum. The Hawking temperature decreases linearly with the hole block. If one also takes into account that the spherical surface of the event horizon is proportional to the square of the mass, then it can be seen that the rate of mass loss decreases quadratically with mass. Thus the service life increases with the third power of the block.
Even if one neglects the processes of accretion, the age of a very massive black hole with more than 10 billion solar masses is80– times the age of the universe, 13.8 billion years. For the huge number 1080 To illustrate, one can imagine that this is the number of atoms in the observable universe.
The smallest black holes, which can be created in astrophysics through the collapse of matter, will likely have about three solar masses. They will be around 10 “only”55Age of the universe time. In one global era, it could lose nearly 100 hydrogen atoms. In contrast, they could accumulate up to about 1,000 billion tons of matter per second. So even these “small” holes can only grow realistically.
One can now wonder if there are any black holes completely evaporating within a single universe. However, these must be so small that they cannot be caused by material breakdown. Astrophysicists believe that “primordial” black holes with roughly mountain masses formed shortly after the Big Bang. Such virtual things could really evaporate in the age of the world. Because the radiation temperature rises when the mass decreases, the energy released in the final stage of evaporation will be so high that the radiation expresses itself as a flash of gamma rays. This provides the possibility to experimental demonstration of Hawking radiation – if any.