Table of Contents
Can a black hole revert to a neutron star?
No it can’t. Anna is right that mostly a BH can’t loose energy or equivalently mass. But it can for some conditions as Anna wrote, like the Hawking radiation and when two BHs merge, the combined mass will be less than the sum of the two because they loose energy to gravitational radiation.
Can black holes turn back into stars?
No. A black hole is characterised by the formation of an event horizon. Matter which travels past an event horizon cannot return to the space outside the event horizon, to do so would require the matter to travel faster than light, and so would require infinite energy.
Do neutron stars have Hawking radiation?
It is likely that they are, at least in principle. You don’t _have_ to have an event horizon to have Hawking radiation (it’s a distributed process, out to maybe 20 Schwartzchild radii), so neutron stars will have Hawking radiation, and thus will decay too, VERY slowly. See The black hole quantum atmosphere.
Is Hawking radiation correct?
It is absolutely fitting that the way black holes decay, via Hawking radiation, bears his name. But the flawed analogy he put forth in his most famous book, A Brief History of Time, is not correct. Hawking radiation is not the emission of particles and antiparticles from the event horizon.
Is Hawking radiation real?
Hawking radiation has never been observed, but if it exists the information lost when objects enter a black hole might be carried out of the black hole via this light. If black holes emit light, then they have to have a thermal temperature.
How does Hawking radiation come from a black hole?
My understanding is that Hawking radiation isn’t really radiated from a black hole, but rather occurs when a particle anti-particle pair spontaneously pop into existence, and before they can annihilate each other, the antiparticle gets sucked into the black hole while the particle escapes.
What happens when a black hole loses mass?
This results in the black hole losing energy, and thus mass. Smaller primordial black holes can emit more energy than they absorb, which results in them losing net mass. Larger black holes, such as those that are one solar mass, absorb more cosmic radiation than they emit through Hawking radiation.
Do black holes gain energy from the CMB?
Black holes above this mass will be cooler than the CMB incident upon them, so will gather mass-energy from it. Black holes below it will lose energy due to Hawking radiation faster than they gain it from the CMB, so will head towards a catastrophic, runaway “pop.”
What is the mass of a black hole in K?
So, black holes have a temperature. It has a particular formula that is inversely proportional to the mass of the black hole. If you set that temperature equal to the current temperature of the Cosmic Microwave Background (CMB) that is 2.725 K, then you get a mass of about 4.503 X 10^22 kg, or a little over half the mass of the Moon.