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What particles does a black hole emit when it evaporates itself?

What particles does a black hole emit when it evaporates itself?


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Due to Hawking Radiation, after a very long time, a black hole will eventually disappear.

But where does this "evaporation" go? What is this made of?


Although black holes are widely believed to emit Hawking radiation, it should be stressed that it has not actually been observed (yet?). The Hawking radiation should consist of electromagnetic radiation/waves that have a near-perfect black body spectrum, which is at a temperature that is inversely proportional to the mass of the black hole - the smaller the black hole, the higher the temperature.

The radiation is caused because "vacuum" is not empty when considered in quantum mechanics. Particle/anti=particle pairs are created for brief moments of time, before they annihilate again. Close to the event horizon of a black hole, it is possible that one particles from a virtual particle pair travels within the event horizon of the black hole and cannot escape to annihilate with its anti-particle. In principle, these particle/anti-particle pairs could be any types of particle, but in practice they are more likely to be the lightest particles. The lightest charged particles are electron/positron pairs, since these need to "borrow" less energy from the vacuum to be created. I do not think it is essential for one of the pair to disappear, since "Unruh radiation", a close relation of Hawking radiation should also be seen whenever there is acceleration with respect to the vacuum.

To stay out of the black hole event horizon the particles must be accelerating. Accelerating charged particles locally emit electromagnetic radiation, which is then gravitationally redshifted when seen by an observer a long way from the black hole. It turns out that to be in a thermal equilibrium, the radiation must have a blackbody spectrum form.

The temperatures and amount of radiation emitted are very small for stellar-sized black holes. The temperature of a non-rotating Schwarzschild black hole is given by $$ T = frac{6.2 imes 10^{-8}}{M} K,$$ where the mass $M$ is in solar maases.

The power emitted by a black hole as Hawking radiation is $$ P = frac{9 imes 10^{-29}}{M^2} W$$


What are the final particles emitted from an evaporating black hole?

Hawking radiation predicts that black holes can slowly evaporate through the effective emission of a particle. This particle is a real particle, as in, it is not a black hole itself. I'll write this (a bit tongue-in-cheek) as follows, with $A$ being the emitted particle, and black hole prime being the black hole with slightly reduced mass.

There is every reason to think this continues until the black hole stops being a black hole. So we are left with a radiated particle and something else. We don't know much about this process, but I think we can still limit it to a 2-product decay.

What could the something else, $B$, be? I don't know much about it, but I know that it is:

It might be more realistic to ask what other conditions should we impose on B? I realize this is probably an unsolved problem. Also, won't $A$ be really highly energetic? How energetic? Actually, what is $A$ to begin with?


Answers and Replies

The whole "particle pair" description of Hawking Radiation is a hueristic and is NOT to be taken as what actually happens (although it almost always is, incorrectly, in pop-sci presentations). Hawking said that the particle pair heuristic was the only thing he could come up with to describe in English what really can only be described in the math.

Again, it is NOT what actually happens so all your questions are based on incorrect descriptions you have read about Hawking Radiation.

Annihilation of matter and antimatter particles.

It has negative energy because it is already in and there is no way out.

The potential energy is negative.

For the general limits of the particle explanation see phinds' post.

I think I've found a different approach for a simple explanation:


We know that the entropy of a system is a measure for the number of possible microscopic configurations for a given macroscopic parameters of the system.

Since we don’t know what is going on inside the event horizon, then the black hole (for an outside observer) is basically a ball with mass M and radius R.

One can calculate (don’t ask me how) the entropy for this ball, and it depends only on the macroscopic parameter M.

Once can now calculate the temperature of the black hole from the derivative of the entropy.

Now that we know the temperature of this ball, one would expect it, like any other body, to radiate a black body radiation according to its temperature.

One can explain that this radiation actually comes from quantum fluctuations of the electromagnetic field around the zero mean value. These fluctuations happen near the event horizon.

The negative energy fluctuations gets sucked in the black hole (reducing its energy hence the mass) but the positive energy fluctuations escape as black body radiation.

The only thing I'm missing is an intuitive explanation why the negative fluctuations are sucked in.

No, we would not expect this. If nothing can escape from inside the EH, including EM radiation, why would you "expect" radiation? Black holes are not LIKE other black bodies.

Prior to Hawking, it was assumed that BH's did NOT radiate, not that they did radiate.

Plutonium radiates alpha particles. A plutonium atom does this on average 48000 years (half life 24k). Are you comfortable with that?

The quantum physicists claim that "the alpha particle tunnels out of the quantum well". Should we picture particles with pick axes digging out of a well? Physicists also say that the particles are lost (uncertain about either position and momentum) and periodically find themselves outside of the well. Stepping outside the well is something like jumping a fence, if the outside is a lower energy (like a cliff beyond a safety fence) the particle suddenly has a lot of energy. It is worthwhile being very skeptical of the description. Quantum mechanics is entirely based on mathematics. The English language that is used to describe the conclusions drawn by quantum mechanics is mostly fiction, however, the conclusions can be tested by experiment.

The Hawking radiation is inverse proportional to the black hole's mass. The radius of the event horizon is proportional to the mass. Larger mass means the event horizon is further away from most of the mass. That lowers the frequency/probability that any particle will "find itself" near the event horizon.

Lean a fence against a brick wall and then jump over it. You should hit the wall and land back inside the fence. When you measure yourself you find that you are still inside the same fence and on the same floor. There is no mass change. If Hawking is correct then virtual matter/antimatter pairs are popping up everywhere. It is only at the event horizon of a black hole that some matter/antimatter pairs separate. Maybe imagine a tidal force pulling apart the virtual pair. Small black holes have a lot of tidal force and can pull apart things that are otherwise tightly bound.


What happens to its stuff when black hole vanishes?

Physicists have argued strenuously that it was not possible that all quantum information could remain hidden within
the black hole when it shrunk to minute sizes. Simulated view of a black hole in front of the Large Magellanic Cloud. Image credit: Alain r/Wikimedia Commons

For all their extraordinary power, black holes are not immortal.

They have a life cycle just like we do. Forty years ago Stephen Hawking, the world’s foremost expert on black holes, announced that they evaporate and shrink because they emit radiation.

But if a black hole evaporates and shrinks, what happens to everything it devoured during its lifetime?

Most mathematical calculations have suggested that the information and everything else inside the black hole simply vanishes, a conclusion that raised more questions than it has answered.

Chris Adami is professor of physics and astronomy at Michigan State University. Adami said:

The issue was never laid to rest because Hawking’s calculation was not able to capture the effect that the radiation, called Hawking radiation, has on the black hole itself. Physicists assumed that the black hole would shrink in time as the Hawking radiation carries away the black hole’s mass, but no one could verify this through mathematical calculations.

A calculation of the black hole’s evaporation seemed impossible, unless a full theory of quantum gravity that unites Einstein’s general relativity with the framework of quantum field theory could be found.

Adami’s new paper, published March 8, 2016 in Physical Review Letters, changes that premise.

Adami and colleague Kamil Bradler of the University of Ottawa have developed a new theory that allows them to follow a black hole’s life over time. What they find is striking: Whatever quantum mysteries were hiding behind the black hole event horizon—the invisible boundary of a black hole—slowly leak back out during the later stages of the black hole’s evaporation.

With this finding, a major black hole physics problem is avoided. Physicists have argued strenuously that it was not possible that all quantum information could remain hidden within the black hole when it shrunk to minute sizes.

It turns out that to show that black holes do not destroy information forever as they evaporate, Adami and Bradler did not have to create the elusive theory of quantum gravity. Instead, they used Hawking’s own theory, but with a twist.

To understand how a black hole would interact directly with the Hawking radiation it generates, Adami and Bradler used a set of sophisticated mathematical tools and high-performance computers to evolve the black holes over sufficiently long times until they were able to find quantum information outside of the black holes. Adami said:

To perform this calculation, we had to guess how a black hole interacts with the Hawking radiation field that surrounds it.This is because there currently is no theory of quantum gravity that could suggest such an interaction. However, it appears we made a well-educated guess because our model is equivalent to Hawking’s theory in the limit of fixed, unchanging black holes.

While our model is just that—a model—we were able to show that any quantum interaction between black holes and Hawking radiation is very likely to have the same properties as our model.

The theory was able to reproduce a feature long searched for in black hole physics, the so-called “Page curves,” named after University of Alberta physicist Don Page. His model predicted the curves that show the quantum information first entering, then exiting the black hole. Adams and Bradler’s calculation is the first that yielded curves just like those Page had anticipated.

But much work remains to be done. In principle, the team’s guess should follow from the yet-to-be-discovered fundamental unified theory of quantum gravity. But in the absence of that theory, the success of Adami and Bradler’s theory may give hints as to just how such a theory—one that goes beyond Hawking’s—could be constructed.

In the new era of gravitational wave observatories that the LIGO discovery just ushered in, such a theory may even one day be tested.


When a star explodes at the end of its life, it leaves a dense, stable, "ball" (from the simultaneous implosion). Depending on density of the final "ball", it is ether a black dwarf (destiny of our sun), a neutron star, or a black hole as Rebound said.

Light essentially curves around any very massive bodies (incl. the sun). A black hole is a mass that will have light spiral inwards.

We're in computing but we have a classmate that says that when a star collapses, all the material in it fuses together under such power, that it creates one giant super stable atom, and the actual black hole isn't a hole at all.

hey guys .. a black hole is nothing but a compressed mass , and a hole means absense mass of a particular area of a substances . i don't see absense off mass in a black hole
and it is called a hole , because in a hole everything just falls and is very hard (nearly immpossible in this case) to remove it

and rebound . can you pls tell me that if black holes leak then do they leak the leaked matter which is at a greater velocity of light .

hey guys .. a black hole is nothing but a compressed mass , and a hole means absense mass of a particular area of a substances . i don't see absense off mass in a black hole
and it is called a hole , because in a hole everything just falls and is very hard (nearly immpossible in this case) to remove it

and rebound . can you pls tell me that if black holes leak then do they leak the leaked matter which is at a greater velocity of light .

Black holes do not "leak matter", but under the correct conditions it's theorized that they would emit Hawking radiation. For the rest. yeeeeaaaahhh. I think we're pretty clear on what GR says a black hole is, and what it may be in other frameworks as well. I should add that the MASS isn't compressed, it just exists within a given region as a result of matter having collapsed at a prior point in time. A black hole is a region more than anything else a region having a specific mass within (what appears to be) a given volume that vanishes to 0 at the singularity, if that is indeed what happens.

Finally. where do you get faster than light out of all this? Are you talking about polar jets, and relativistic beaming which makes them APPEAR to be "faster than light" to some observers. but is NOT EXCEEDING c? That radiation comes from the poles of the accretion disk OUTSIDE of the event horizon, just to be clear.


Video: How do black holes evaporate?

Artist's illustration of black holes.

Nothing lasts forever, not even black holes. According to Stephen Hawking, black holes will evaporate over vast periods of time. But how, exactly, does this happen?

The actor Stephen Hawking is best known for his cameo appearances in Futurama and Star Trek, you might surprised to learn that he's also a theoretical astrophysicist. Is there anything that guy can't do?

One of the most fascinating theories he came up with is that black holes, the universe's swiffer, can actually evaporate over vast periods of time.

Quantum theory suggests there are virtual particles popping in and out of existence all the time. When this happens, a particle and its antiparticle appear, and then they recombine and disappear again.

When this takes place near an event horizon, strange things can happen. Instead of the two particles existing for a moment and then annihilating each other, one particle can fall into the black hole, and the other particle can fly off into space. Over vast periods of time, the theory says that this trickle of escaping particles causes the black hole to evaporate.

Wait, if these virtual particles are falling into the black hole, shouldn't that make it grow more massive? How does that cause it to evaporate? If I add pebbles to a rock pile, doesn't my rock pile just get bigger?

It comes down to perspective. From an outside observer watching the black hole's event horizon, it appears as if there's a glow of radiation coming from the black hole. If that was all that was happening, it would violate the law of thermodynamics, as energy can neither be created nor destroyed. Since the black hole is now emitting energy, it needs to have given up a little bit of its mass to provide it.

Let's try another way to think about this. A black hole has a temperature. The more massive it is, the lower its temperature, although it's still not zero.

From now and until far off into the future, the temperature of the largest black holes will be colder than the background temperature of the universe itself. Light from the cosmic microwave background radiation will fall in, increasing its mass.

Now, fast forward to when the background temperature of the universe drops below even the coolest black holes. Then they'll slowly radiate heat away, which must come from the black hole converting its mass into energy.

The rate that this happens depends on the mass. For stellar mass black holes, it might take 10^67 years to evaporate completely.

Viewed in visible light, Markarian 739 resembles a smiling face. Inside are two supermassive black holes, separated by about 11,000 light-years. The galaxy is 425 million light-years away from Earth. Credit: Sloan Digital Sky Survey

For the big daddy supermassive ones at the cores of galaxies, you're looking at 10^100. That's a one, followed by 100 zero years. That's huge number, but just like any gigantic and finite number, it's still less than infinity. So over an incomprehensible amount of time, even the longest living objects in the universe – our mighty black holes – will fade away into energy.

One last thing, the Large Hadron Collider might be capable of generating microscopic black holes, which would last for a fraction of a second and disappear in a burst of Hawking radiation. If they find them, then Hawking might want to the acting on hold and focus on physics.

Nothing is eternal, not even black holes. Over the longest time frames we're pretty sure they'll evaporate away into nothing. The only way to find out is to sit back and watch, well maybe it's not the only way.

The LHC. Credit: CERN

Black hole evaporation

Mass/Energy are interchangable, But photons have mo mass, if you converted the universe's mass into energy, I would presume there would be no mass, no gravity. Maybe this relates to the early universe before the higgs particles existed??

It is thought that photons have no rest mass.

They do posses relativistic mass. That's how Solar sails work--through pressure generated by the momentum of photons slamming into the sail material.

the math is fairly simple too. Energy = (momentum)© (rest mass)

Since Photons probably have zero rest mass the equation is just Energy = (momentum)©

So it can't really be said that photons have no mass, only that they have no 'rest mass' and since photons don't exist with zero velocity. the statement is rendered mute anyway.

I think it is wrong to talk about virtual particles in the same sense as one refers to matter and antimatter.

When an atom of matter meets an identical atom of antimatter they annihilate each other and what is left is energy in the form of radiation. the total energy contained in both atoms still exists in the universe, just in another form.

When Virtual partners interact, they cease to exist in our universe..they leave nothing behind.

A particle and antiparticle meeting are like two semis hitting each other head on with such force that they are both vaporized.

When a Virtual pair meet it is like they fall through a trap door and vanish from our Universe without a trace.

Pesse (. even CSI Miami couldn't find evidence of their prior existence.) mist

Photons transfer monentium, But I don't think that means they exhibit mass. You can look at many examples in the electronics world where electro-magnetic fields transfer energy, but to the best of knowledge there isn't a mass transfer.

Look at a power transformer, where current flow in the primary uses electro-magnetic fields to induce currents in the secondary.

Also look at radio transmission between transmit and recieve antennas.

So how do photons transfer momentium? If movement of charged particles generates photons, I can see how the resulting photon when it's captured would apply a recoil force. Like if you took 2 speakers facing each other, applying power to one, which generates air pressure waves, and using the second one as a detector. The air that the wave exists in has mass in this case, but I don't know if I'd say the wave itself has any mass. I suspect something similar happens with photons.

It's still my opinion that virtual particles, while they exist are normal in every way, that means when they annhilate they have to emit gamma's (or whatever form of energy that particle/anti-particle becomes). Now I agree that we don't seem to see these gamma's, maybe they are the source of energy that's borrowed to become the virtual particle in the first place?

I could also see that the original energy comes from some leakage from one of the collasped dimensions, and maybe the energy leaks out the same way.

#52 Dane B

#53 Qkslvr

Qkslvr - By 50/50 I meant the absorption rate across the event horizon of particle vs. antiparticle should be even, one type of particle should not be absorbed more frequently that the other.

#54 Pess

Photons transfer monentium, But I don't think that means they exhibit mass. You can look at many examples in the electronics world where electro-magnetic fields transfer energy, but to the best of knowledge there isn't a mass transfer.

But mass and energy are the same thing. You can't say that a photon can transfer energy but not mass.

That's like saying you were hit by a Ford Bronco but not hit by a car. E=MC^2 is the basis of modern physics.

So if a photon transfers energy to something you can plug the amount into the formula above and compute the mass transferred.

Pesse (Time for a bedtime story below) Mist

#55 Pess

Once upon a time there existed nothing. No vacume, no space and no time.

In this time before time a point of energy emerged. Essentially all the energy in the Universe we know today erupted from a single singularity.

Lots of guesses, no one knows why and even Heisenberg is uncertain.

As the singularity expanded from a single point it created a space/time fabric in its wake.

Just after the first clock measured the first interval of time the Universe was dominated by gravitational energy which radiated, permeated, rebounded and was the dominant energy . big bully on the block.

If we ask Professor Heisenberg he will tell us, in no uncertain manner, that at any given time the fabric of our universe can have localized increases in energy without violating conservation of energy as long as this 'spontaneous' fluctuation doesn't hang around longer than quantum mechanics will allow.

Now we can call this localized increase in energy anything we want..say lets call it 'Virtual Energy'. "Hey Virt!"

Now Virt can't overstay his welcome because it's against the law! Them Conservation of mass & Energy police are not to be trifled with!

But the laws have a loophole. If you can come up with a huge amount of energy from some nice resident of the Universe, our illegal alien 'Virt', can get a green card and stay around! (maybe get a job as an apprentice Sun maker or something).

In the early years, well before the cuckoo clock chirped its first second, there was no mass or particles in the Universe. just all this intense gravitational energy bouncing around inside the tiny Universe as it poured off of the singularity which, for all intents and purposes, was the Mother-of-all Black Holes.

So when Virt and his buddies came visiting our Universe they found, with all that intense gravitational energy abounding around, that they could absorb that energy and become the Real Particles that Uncle Geppetto said they could be.

Since the energy for their stay came from a source already in the Universe, no laws were violated.

Eventually enough of Virt & his friends got to stick around to form all the matter in the Universe!

Now descendants of Virt still come to visit all the time but unless they visit near an extremely powerful energy source. say an Event Horizon or Pulsar. they are not invited to stick around.


Milky Way’s Black Hole Is Shooting Particle Jets

A torrent of energetic particles appears to be spewing from the center of our Milky Way Galaxy, coming from the gigantic black hole that lies at its heart, according to a new study.

Such jets are common throughout the universe, and most supermassive black holes are thought to produce them. When matter falls into these behemoths, some material also is accelerated away, usually in two straight beams that fly out along the black hole&rsquos spin axis.

The Milky Way&rsquos giant black hole, called Sagittarius A* (pronounced &ldquoSagittarius A-star&rdquo) has long been theorized to have jets, but evidence was inconclusive. Now researchers have combined x-ray photographs of the galaxy&rsquos center from NASA&rsquos Chandra space telescope with radio data from the Very Large Array (VLA) observatory in New Mexico to offer the best support yet for the idea of jets from Sagittarius A*. The x-ray photos show a wispy bright line of gas that is emitting x-ray light to one side of the black hole&mdashperhaps indicating the jet itself&mdashand the radio observations highlight a wall of gas that scientists think is a shock front created where the jet is slamming into a cloud, snow-plowing the gas into a clump.

In a paper accepted for publication in The Astrophysical Journal, Zhiyuan Li of Nanjing University in China, Mark Morris of the University of California, Los Angeles, and Frederick Baganoff of the Massachusetts Institute of Technology show these features share a &ldquostriking spatial relationship,&rdquo the researchers wrote. &ldquoThere are many pieces of this story that fit nicely,&rdquo Morris says. &ldquoIt&rsquos not a slam dunk, but to my mind it&rsquos stronger evidence than anyone has seen so far.&rdquo

The jet is so hard to find in part because it is relatively faint&mdashthe Milky Way&rsquos black hole just is not eating enough to produce really robust jets, researchers say. Furthermore, the center of the galaxy is shrouded in so much gas and dust that nothing is easy to see there from our perspective on Earth. &ldquoThere&rsquos basically all the gunk between us and the galactic center, plus a big screen of plasma that is sort of like bathroom shower glass, serving to smear out images because of electron scattering,&rdquo says astronomer Sera Markoff of the University of Amsterdam, who was not involved in the new study. For example, scientists have detected a weak jet emanating from the black hole at the center of the nearby galaxy M81, but models suggest that if the same jet projected from the Milky Way&rsquos core, we wouldn&rsquot be able to see it. The new study supports the idea that jets may become visible only when they hit something. &ldquoMaybe the shock excites and accelerates particles in the jet,&rdquo causing the beam to light up, Markoff says.

Jets arise because the black hole is spinning. As matter falls into the black hole, the matter&rsquos magnetic field gets twisted and amplified by the black hole&rsquos spin, and this pumped-up magnetic field launches material outward in the form of jets. If the signals from Chandra and the VLA really are a jet, its direction would reveal the spin axis of the Sagittarius A* black hole. &ldquoLo and behold, the spin axis appears to be the same as the galaxy,&rdquo Morris says. &ldquoThat&rsquos so satisfying, because that&rsquos what you would expect if the black hole has never undergone a major disturbance.&rdquo

Some previous studies, however, suggested the jets pointed in a different direction. The new study is well thought out and &ldquowill be a benchmark against future claims of jet orientations,&rdquo says astronomer Heino Falcke of Radboud University Nijmegen in the Netherlands, who has also argued for a jet at the galactic center, and recently found that theoretical models favor one. &ldquoIs it a smoking gun now? Well, there is smoke, but until we find the bullet and the pistol, we can't really convict anyone for sure.&rdquo

An opportunity to test some of these ideas should arrive soon from a cloud of gas that is circling the drain of our central black hole. This cloud, called G2, has been on astronomers&rsquo radar for awhile, and predictions vary about what its future holds. In the next couple of years most scientists think the strong gravitational tides near the black hole should rip the cloud to shreds, and some of these scraps should fall in, potentially causing the jet to flare brighter. &ldquoEverybody&rsquos watching,&rdquo Morris says.

ABOUT THE AUTHOR(S)

Clara Moskowitzis Scientific American's senior editor covering space and physics. She has a bachelor's degree in astronomy and physics from Wesleyan University and a graduate degree in science journalism from the University of California, Santa Cruz.


Black holes are basically neutron stars with such a gravitational force that even light cannot escape from it.

A black hole is a mathematical solution. A neutron star over the critical mass gets so dense that it forms larger and larger time dilation relative to the outside universe thus we get to see what happens on short time scales.

But what causes it to emit radiation

Note that classical general relativity does not predict Hawking radiation. So the answer has to be a quantum effect. So recall that we see things that happen in short time scales?

So things would have to emit radiation in short time scales and if they normally interact with other things in a short time scale it must balance out but the asymmetry and the geometry of the set up makes it not balance out.

Another completely different way to look at it is through the equivalence principle and conclude that an accelerating particle detector clicks more often than one moving at a steady velocity, the Unruh effect. And this just means that what looks like a vacuum in one frame does not look like a vacuum to another frame accelerating relative to the first.

The reason black holes emit radiation is because virtual particles are popping into existence and popping out of existence throughout space including at the event horizon of a black hole. When they pop into existence they pop into existence in pairs that then annihilate within a fraction of a fraction of a second. When a pair of virtual particles pop into existence near a black hole one may fall into the black hole while the other escapes and is unable to annihilate with its twin and so it becomes a real particle that carries away energy that was originally in the black hole.

Why is it that black holes emit Hawking radiation?

We don't actually know that they do. Hawking radiation remains a hypothesis. It's been around for so long that people rather take it for granted, but there's no actual evidence for Hawking radiation. And when you read the "given" explanation, it doesn't seem to make sense. See Wikipedia:

"This radiation does not come directly from the black hole itself, but rather is a result of virtual particles being 'boosted' by the black hole's gravitation into becoming real particles".

But see anna's answer here: virtual particles exist only in the mathematics of the model. They are abstract things, not something that can be boosted into reality. That's a fairy tale. So is this:

"An alternative view of the process is that vacuum fluctuations cause a particle-antiparticle pair to appear close to the event horizon of a black hole. One of the pair falls into the black hole while the other escapes. In order to preserve total energy, the particle that fell into the black hole must have had a negative energy (with respect to an observer far away from the black hole)."

Electrons and positrons do not pop into existence, and neither has negative energy. We know of no negative energy-particles. That's another fairy tale. One that totally ignores gravitational time dilation.

Black holes are basically neutron stars with such a gravitational force that even light cannot escape from it. But what causes it to emit Hawking radiation?

They aren't neutron stars, but nevermind. We have good evidence that black holes exist, for example there's something very small and very massive in the centre of our galaxy. And general relativity is one of the best-tested theories we've got. And general relativity features a variation in the "coordinate" speed of light. The light doesn't escape a black hole because the coordinate speed of light at the event horizon is zero. Hawking radiation totally ignores this.


Longevity

And the lifespan of an evaporating black hole? A complicated question, relating to the speed that material falls in and the size of a black hole at any given point. The material falling in is what supplies the energy for Hawking radiation to occur in the first place and so the more it falls in the faster the evaporation occurs. Yes, the radiation does occur at a minimal level just by having the black hole move, but it would take 10 71 years for a solar mass black hole to disappear. Material falling in does cause the mass to grow but eventually the black hole clears its area of space and then evaporation wins out (Siegel 05 Dec.).

But a very subtle but major issue arises when we talk about a lifespan of black holes. What happens to everything the black hole accumulated? Information cannot be lost, according to quantum physics, so what actually happens? To fully understand that, scientists need quantum gravity to deal with both relativity and quantum mechanics, but scientists at the University of Ottawa and MSU have run a simulation to try and parse something together. Chris Adami and Kamil Bradler set up a simulation that looked at the latter stages of a black holes life, and it showed that the information contained in the black hole was slowly released as the black hole evaporated via Hawking radiation. Their model correlated well with the anticipated Page curves which predict how information enters and leaves a system, so that give the model some credence (Ward).

And the very end of a black holes life would be spectacular. After evaporating for countless years, the last second arrives. Evaporation has taken all but 228 metric tons of the black hole, whose event horizon is now 3.4*10 -22 meters in size. This is roughly 2.05*10 22 Joules of energy here, and the final second sees that evaporated into space as the singularity is removed and space-time at that location is restored. Lots of light will befall the region and then…nothingness. Such is the ironic end to an evaporating black hole: no one ever knows it was there (Siegel).


Watch the video: TIMELAPSE OF THE FUTURE: A Journey to the End of Time 4K (November 2022).