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How Hawking Radiation Works



The name Stephen Hawking will forever be associated with a brilliant and inspirational scientist who helped come up with theories and explanations for some of the strangest mysteries in physics. One such theory, known as Hawking Radiation, could shed light on objects that frighten and fascinate us: black holes. Here’s what Hawking Radiation is and how it is theorized to work.



1. According to Hawking, black holes aren’t actually black.
The first and most essential thing to understand about Hawking Radiation is that it asserts that black holes, the objects we think of as sucking in all matter around them and letting nothing escape, actually do emit something—black body radiation.

2. The theory states that particle-antiparticle pairs are created at a black hole’s event horizon.
Quantum theory states that every particle has an antiparticle that acts as its opposite. These two usually annihilate one another, but in the case of Hawking radiation, they don’t. Instead, one falls into the black hole’s gravity, and the other is able to escape. That emitted particle has energy in the form of radiation, thus it appears that the black hole is emitting radiation instead of just absorbing it.



3. If this is the case, black holes lose mass.
While one particle is absorbed by the black hole, the other one escapes. This means the black hole is losing energy, and if it’s losing energy it’s losing mass. Therefore, black holes shouldn’t continue on forever. At some point they will lose all of their mass and, according to the theory, wink out of existence.
 
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rod

Oct 22, 2019
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Looks like black holes cannot escape the 2nd law of Thermodynamics - increasing entropy, black holes will die. A book I enjoy is 'Black Holes & Time Warps', Einstein's Outrageous Legacy by Kip S. Thorne, 1994. Always a good read still :)
 
Dec 28, 2019
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My own view is this. Yes, black holes lose mass via Hawking radiation. But (I'm guessing) the mass they GAIN from sucking in interstellar gas and even planets and stars way exceeds the mass they lose via Hawking radiation. Thus the only time Hawking radiation will account for net mass loss by black holes is in the far far distant future after all the stars, planets and gas in the universe have been sucked up by black holes....
 
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Reactions: rod

rod

Oct 22, 2019
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My own view is this. Yes, black holes lose mass via Hawking radiation. But (I'm guessing) the mass they GAIN from sucking in interstellar gas and even planets and stars way exceeds the mass the lose via Hawking radiation. Thus the only time Hawking radiation will account for net mass loss by black holes is in the far far distant future after all the stars, planets and gas in the universe have been sucked up by black holes....
This suggest that at the end, the 2nd Law wins out - heat death.
 


The name Stephen Hawking will forever be associated with a brilliant and inspirational scientist who helped come up with theories and explanations for some of the strangest mysteries in physics. One such theory, known as Hawking Radiation, could shed light on objects that frighten and fascinate us: black holes. Here’s what Hawking Radiation is and how it is theorized to work.



1. According to Hawking, black holes aren’t actually black.
The first and most essential thing to understand about Hawking Radiation is that it asserts that black holes, the objects we think of as sucking in all matter around them and letting nothing escape, actually do emit something—black body radiation.

2. The theory states that particle-antiparticle pairs are created at a black hole’s event horizon.
Quantum theory states that every particle has an antiparticle that acts as its opposite. These two usually annihilate one another, but in the case of Hawking radiation, they don’t. Instead, one falls into the black hole’s gravity, and the other is able to escape. That emitted particle has energy in the form of radiation, thus it appears that the black hole is emitting radiation instead of just absorbing it.



3. If this is the case, black holes lose mass.
While one particle is absorbed by the black hole, the other one escapes. This means the black hole is losing energy, and if it’s losing energy it’s losing mass. Therefore, black holes shouldn’t continue on forever. At some point they will lose all of their mass and, according to the theory, wink out of existence.
SaraRayne, If one particle falls into the black hole won't that increase its mass? The other particle that gets emitted is from the outside of the event horizon, not from the black hole itself. It looks to me like the black hole is extracting matter from space (quantum field/foam/fluctuations, aether, vacuum energy, dark energy or whatever) and getting bigger, not smaller! I don't understand! Please help.

Take a look at my book SaraRayne. With all the extra topics, my book is more than just a universe theory, so hopefully, provides a picture of existence which is complete, whole, (except for the minute details of every particle etc) and self-sufficient, requiring no creation or evolution and needs no beginning or end. With much of it based on solid scientific principles and good reasoning.
 
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rod

Oct 22, 2019
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My comment. Kip S. Thorne book, Black Holes & Time Warps, Einstein Outrageous Legacy has quite a bit to say about black holes evaporating, Hawking radiation, thus the 2nd law wins out. The accelerated universe expansion rate (i.e. Type Ia SN) leads to eventual heat death. Quantum gravity is the new math here. The death of the black hole can take 1E+70 years or more but in the end, death comes to the black hole and eventually the universe. It seems modern science using present processes and laws - cannot explain the origin of the universe but does understand, the universe will die in the distant future. This indicates that the universe did not create itself :) The use of quantum gravity still remains largely untested and unverified as operating throughout the universe like observations of gravity in binary star systems (e.g. Sirius A and B) or exoplanet studies and Kepler's planetary laws.
 

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