Hawking Radiation

unstablestar  asked:

Can black holes die? if not, then is it possible for black holes to continue merging and expanding until all matter in the universe is pulled into one big massive black hole? if black holes can die then what happens with the matter that has been pulled in by the gravitational force? would a white hole then be produced after the black hole dies?

Black holes can, in fact, die! The way they die, however, is theoretical and not proven, but it’s possible and it’s called Hawking radiation. To summarize // oversimplify (because it’s really complicated), according to quantum physics we know that particle-antiparticle pairs pop in and out of existence all the time, and usually annihilate each other almost immediately. They are able to come into existence by “borrowing” energy from the universe, and when they annihilate they “return” that energy back.

Now, what if a particle-antiparticle pair comes into being right at the edge of a black hole’s event horizon, and one particle falls in and the other escapes? Well, now you’ve just “created” one particle that’s entered the universe, and one particle that’s entered the black hole (and can’t escape). Since these two particles can’t annihilate, they can’t “return” their borrowed energy to the universe. However, you can’t just spontaneously create energy; it has to come from somewhere. That somewhere is, you guessed it, the black hole. So, the amount of energy in the black hole decreases by the amount of energy required to create the particle-antiparticle pair. Since mass and energy are equivalent (e=mc2), the mass of the black hole decreases ever so slightly - the mass of an electron, positron, or other subatomic particle. 

This process takes billions of years, and it will be another several billion years before we’re able to see black holes finish evaporating. This process is expected to be faster the smaller the black hole is - once a black hole is small enough, this process happens faster and faster, until the black hole gives off lots and lots of radiation and “explodes” (think: gamma rays, really bright, as bright or brighter than a supernova), and no longer exists. While this isn’t proven and is entirely theoretical, it’s pretty cool that black holes, the killers of the universe from which nothing should be able to escape, are slowly losing mass over billions and trillions of years, one subatomic mass at a time.


Ask Ethan: What Happens When A Black Hole’s Singularity Evaporates?

“What happens when a black hole has lost enough energy due to hawking radiation that its energy density no longer supports a singularity with an event horizon? Put another way, what happens when a black hole ceases to be a black hole due to hawking radiation?”

One of the most puzzling things about Black Holes is that if you wait around long enough, they’ll evaporate completely. The curved spacetime outside of the event horizon still undergoes quantum effects, and when you combine General Relativity and quantum field theory in exactly that fashion, you get a blackbody spectrum of thermal radiation out. Given enough time, a black hole will decay away completely. But what will that entail? Will an event horizon cease to exist, exposing a former black hole’s core? Will it persist right until the final moment, indicative of a true singularity? And how hot and energetic will that final evaporative state be?

Incredibly, even without a quantum theory of gravity, we can predict the answers! Find out on this week’s Ask Ethan.

Simulating a black hole

40 years ago Stephen Hawking predicted that black holes emit a special kind of radiation. Consequently black holes are theoratically able to shrink and even vanish. This radiation arises when virtual particles (pairs of particles developing because of quantum fluctuations inside the vacuum; usually they nearly instantly destroy each other) are near the event horizon. Then the virtual particle pair gets divided: one disappears in the black hole (and its quantum mechanical information) and the other one becomes real. Thus the black hole radiates but unfortunately this radiation is so low that astronomical observations are nearly impossible.
Therefore scientists have to simulate black holes to get empirical evidence. The physicist Jeff Steinhauer of the Technion, the University of Technology of Haifa in Israel exactly did this. He realized an idea of physicist Bill Unruh with an acoustical event horizon. He uses a fog made of rubidium atoms which is only slightly above the absolute zero. Because they are trapped inside an electromagnetic field these atoms become a Bose-Einstein Condensate. Inside of this condensate the acoustic velocity is only a half millimeter per second. With the help of accelerating some above this speed an artificial event horizon is created. The low temperatures lead to quantum fluctuations: pairs of phonons develop. In the simulation these pairs also get divided: one gets caught by the supersonic event horizon; the other one becomes some kind of Hawking radiation.
It is still not sure if this experiment really simulates black holes. According to Ulf Leonhardt it does not proof for sure that the two phonons are entangled. Thus it is not sure if the pairs arised out of one fluctuation. Leonhardt even doubts that the fog of atoms is a real Bose-Einstein Condensate. Leonard Susskind thinks this experiment does not reveal the mysteries of black holes: for instance it does not explain the information paradox, because acoustic black holes do not destroy information.

In this dream, I was reading about a discovery that in significantly large systems of language (long sentences, long books, printings, the internet), there was a mathematically describable probability that adverbs would be randomly switched as an apparent “accident”.

I loved this, and was explaining it to someone else, along with the idea that has been discussed in real life that populations are surveyed and studied, as systems of knowledge become more certain, that the old formulas cease to apply and behavior in those systems becomes random. A kind of Heisenberg Uncertainty of Everything. This was similar, but in my mind I think I was comparing it to Hawking radiation? AH! NO! This is what that was.

I was discussing this article over coffee with Z, and explaining why I believed this strange equation was true, not because I liked it but because it seems to be how the world works. Then I started talking about how the duality between reason and dialectical thought was rooted in the same paradoxical dualism that makes the universe indescribable by a Unified Field Theory (screw you Higgs Boson).

What we call negation is what is described by probabilities in the sciences. The concept of time is nullified by the constant presence of the totality, and the dialectic follows from the structure hidden below in the mathematics. And the absolute negative acts as a kind of Hawking radiation from the void of thought. A mysterious energy that allows us to sense singularities-in-thought.

Earlier in the dream, someone from The Music Box asked me to evaluate some scripts. 


Ask Ethan: Do Black Holes Grow Faster Than They Evaporate?

“Wondering why black holes wouldn’t be growing faster than they can evaporate due to [Hawking] radiation. If particle pairs are erupting everywhere in space, including inside [black hole] event horizons, and not all of them are annihilating one another shortly thereafter, why doesn’t a [black hole] slowly swell due to surviving particles that don’t get annihilated?”

So, you’ve got a black hole in the Universe, and you want to know what happens next. The space around it is curved due to the presence of the central mass, with greater curvature occurring closer to the center. There’s an event horizon, a location from which light cannot escape. And there’s the quantum nature of the Universe, which means that the zero-point-energy of empty space has a positive value: it’s greater than zero. Put them together, and you get some interesting consequences. One of these is Hawking radiation, where radiation is created and moves away from the black hole’s center. It occurs at a specific rate that’s dependent on the black hole’s mass. But another is black hole growth from the mass and energy that falls through the event horizon, causing that black hole to grow. At the present time, realistic black holes are all growing faster than they’re decaying, but that won’t be the case for always.

Eventually, all black holes will decay away. Come find out the story on when evaporation will win out on this week’s Ask Ethan!

for @antcommander

Hawke’s hands are so much larger than his own. He presses fingertip against fingertip, softly moving to his palm. Tracing the lines which web, all the little cracks in skin, circling every bump and bone. A smile quirks on his lips when he sees Hawke’s fingers twitch with the feeling, even as he sleeps. His breathing even and calm, eyes closed and peaceful in dreaming. Fenris lies beside him, hand drifting over hand, as the fire begins to ebb down low.

Soft warm light, flickering over the both of them. Fenris traces the line of Hawke’s nose, the worrisome line of his mouth. A thumb drifting over lips, a feel he knows too well and not well enough. He moves through his beard, follows his jaw to the shell of his ears. Through coal colored hair, and back down again. Over shoulder to collarbone, to the well in the middle, broad chest and sturdy ribs, the heart that beats underneath.

He feels it underneath his palm, that steady rhythm, a peaceful song. He closes his eyes, feels the heat that radiates from Hawke. His eyes open again when a hand slips over his own. “What are you doing?” He asks, voice hoarse from sleep, his eyes barely able to remain open. Fenris shakes his head, pulls at the hair on Hawke’s chest. Hawke swats his hand away with a yelp. Fenris falls back into the bed, long white hair splaying out over the pillow.

“You are like a big, hairy bear,” Fenris says.

“And you are a small, handsome elf,” Hawke tells him with a smile. Fenris lets out a huff, crossing his arms, turning his face away from Hawke. It hides the slight shade of red that blossoms on his cheeks. Hawke tells him often - how handsome, how kind, how sweet… He never knows how to respond.

“I am of average size for an elf.” Hawke laughs, rolling over to drape an arm over Fenris’s chest, burying his head into the crook of his neck.

“Tell what you were doing,” Hawke murmurs, pressing a kiss to his neck.

“I was,” Fenris pauses, mulling it over, “memorizing.” Hawke shifts, raising himself up, hands pressing into the mattress. He leans over Fenris, until he finds the eyes that will not meet his own. Even without seeing it properly in the low light, he knows the blush that troubles Fenris’s cheeks.

“Does that mean I get to do the same?” Hawke leans back, moving to kneel at the end of the bed. Fenris doesn’t protest as Hawke pulls down the blanket, simply moving to lean against the headboard, watching as Hawke moves. The first touch is light against his ankle. Fingertips that come to rest against skin, feeling the heat of Hawke’s palm. His thumb moves in slow, affectionate, circles. Hawke smiles up at Fenris as he begins to move.

He keeps his thumb on the line of bone, drifting upwards. He takes care not to trace markings, lyrium chains, and shows his appreciation for all that Fenris is. Hawke glances up from his work often, to see the yes in Fenris’s expression, the way he bites at his bottom lip. He circles around Fenris’s knee, and ever upwards. A hand kneads against his thigh, teasing touches that never quite go where Fenris wants him to. Hawke smiles at Fenris’s intake of breath when his touch get near, then shifts to his hips.

He trails a finger over hipbones, and splays a hand over Fenris’s belly. He appreciates the hard muscle he feels, satisfaction in knowing that it’s not just muscle now – Hawke’s cooking has seen to that. Strong hands over ribs, a squeezing that isn’t tight, until Hawke cups his face in his hands.

Hawke leans forward, brushes lips over Fenris’s. A light kiss but deepening still, Fenris is lost when Hawke pulls away. Eyes half-lidded, a hand on Hawke’s arm. More than his human heat, more than the fire, there’s a burning of warmth in Hawke’s eyes - a fondness that Fenris melts underneath. “I know all of you,” Hawke says as he tucks a lock of hair behind pointed ears, “I love every inch.”


Hawking radiation   


A form of radiation believed to emanate from black holes, emerging from the region just beyond the black hole’s event horizon (from which no radiation can emerge). Pairs of virtual particles and anti-particles, created naturally in the vacuum fluctuation near the black hole, are split apart, one particle falling into the black hole and the other radiating away. The energy lost to such radiated particles is believed to come from the mass of the black hole.

Date a girl who is a 2D projection on the surface of a black hole that can only be detected through hawking radiation, and the only way you can communicate with her is by throwing messages through the black hole. She was all in awe and reverence at first, talking to a higher being, but she’s realized you’re just a huge dork like she is.

I’ve posted about it before, my brain being a goddamn nightmare, and it’s gotten to the point where I can’t even sleep at night because my brain is just “What about this? Would this make an experiment? Let’s think about the physics of black holes!! Let’s find a way to test string theory!! If you add these 18 equations together you can figure out this problem!! The data from lab today! Let’s think about the best way to analyze it to visualize the results!! Let’s learn about tachyons!!! Let’s read every scientific mumbling about Hawking radiation!!” And oh my god I can’t sleep. The only way I can sleep is to somehow inebriate myself with alcohol or nicotine or pot to get my brain to SHUT UP. I’m missing classes because my brain won’t let me go to fucking sleep. I’m up at 4am with my big ass whiteboard deriving black hole physics. I’m sitting on my floor smoking a cigarette with 13 academic papers sprawled out around me trying to connect the dots like a lunatic. I WANT TO SLEEP

Quantum bounce could make black holes explode

If space-time is granular, it could reverse gravitational collapse and turn it into expansion.

Black holes might end their lives by transforming into their exact opposite — ‘white holes’ that explosively pour all the material they ever swallowed into space, say two physicists. The suggestion, based on a speculative quantum theory of gravity, could solve a long-standing conundrum about whether black holes destroy information.

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willygowild  asked:

Is it possible, or even merely,..Plausible, that black holes, "theoretically", might perhaps be more akin to, say, a super-massive quantum? They DO have a "life cycle" so to speak. If Occam's razor is more or less, universally given to prove factual,..When a caterpillar transform into moth/butterfly,..The caterpillar, did NOT die,..It simply moved to another state of being,. And merely, became, something else. Far grander than its lowly crawling beginnings.So, what do you think?

I’m not sure what you mean by ‘super-massive quantum’ BHs. So, forgive me if I misinterpreted your question. Here’s what I know:

Quantum mechanical black holes may have formed in the early stages of the universe. We call these primordial black holes (PBHs). What’s really interesting about primordial black holes is that they are not the result of collapsing stars. According to general relativity, the key ingredient is basically a region of high density matter – like the quark soup, add some intense energy density fluctuation to that region of space (inflation) and you get an increased amount of matter within a Schwarzschild radius, and voilà, a miniature event horizon is born. Of course, PBHs could span an enormous mass range; those formed in the Planck epoch would have the tiny Planck mass (10^−5g),  and those formed 1 second after the Big Bang would be as large as 10^5 solar masses - like the ones thought to reside in the center of galaxies. These PBHs may still be with us today because the rate at which a black hole evaporates (Hawking radiation) is inversely proportional to its mass; a small black hole evaporates rapidly, and a massive black hole, therefore, evaporates slowly.  The smaller ones that have evaporated left some clues behind; they produced a huge amount of radiation which affected and delayed the onset of nuclei formation (nucleosynthesis), we know this because we measured the abundance of those nuclei. There is a possibility that the observed baryon asymmetry was generated by the evaporation of PBHs. The ones that are still evaporating are actually plausible dark matter candidates, they are a bit different from the typical dark matter candidates, of course, because they are not elementary particles like the weakly interacting massive particles (WIMPs), rather massive astrophysical compact halo objects (MACHOs). The other interesting thing is that we don’t really know the end result of evaporating black holes, maybe they shrink to the Planck scale and circle around the universe as Planck-mass relics.

A black hole is a shadow on the universe. (Like an x-ray shadow.) (Like the solar wind, as gravity.)

We are falling in a fourth-dimensional way. Falling, not progressing. Time is space. We’re feeling a queer gravity in a direction that we can’t acknowledge, like a sheet of gold as time rushes up at us, easier soaking the empty areas and getting caught on the massive areas. (Like the way magnetic fields look in space, or space looks when you reach the speed of causality.)

The slope of our own mass etches out our manifested acceleration as time rolls away up behind us like a hill we’re tobogganing down. We can’t move in that same direction so it pushes us in the ways we know, with added friction. Friction is the sign that we can’t go back in time and trying such will get us hurt.

Gravity is where the speed of causality takes longer to compute and you can overload it past a critical amount of information. These holes could have a flatter universe on the inside as the outer shell processes falling toward the singularity one ever-changing layer at a time, with awareness of space accounting for the perception of time.

I am liking more and more the idea that the multiverse is random universes’ black holes and we’re fractalising crystals of knots of wrinkles of stuff. Each of our black holes could present an unreachable universe separated by unfathomably warped time. We are a black hole to a higher dimension. The cosmic background radiation is the imprint of the star that’s still dying outside of us, or the resulting shape of our ball of 4d mass having its own equivalent of Hawking radiation and dappling.

We’re heading toward a 4d singularity and that is where time will stretch out space infinitely. But that would mean we come back out the other side, being lensed back together (going backwards).

So think of that any time you make a bad memory or take a poop. After you die you’re going to wait a long while before doing it again.

Black Hole

Black holes, the weirdest thing in the space.  When you look at the black hole you are looking at event horizon {as the event horizon is the black part of black hole}, it is impossible to cross event horizon even light can not escape the event horizon, so anything which tries to crosses the event horizon needs to be travel faster than the speed of light which is impossible as light also can’t escape the event horizon. As the event horizon is the black part of a black hole. So what is the center of the black hole? Singularity a singularity is infinitely dense it means all its mass is contrasted to the single point where there is no surface or no volume. If an object is size of black hole and if the black hole will suck that object so there will be no black hole remaining. So what will happen if you able to get in the black hole? For you time will get slower {as you will travel too fast} so you can see the future of the universe, but we are not quite sure what will happen. It could be possible that you could die but we don’t know, but what do we know is about hawking radiation, as all the black hole in the universe will die one day or another because of empty space, as in empty space virtual practicals came into existence and annihilate each other. When this process happens at the edge of a black hole then practical which is inside of the black hole will get inside the black hole and the outside particle will be deflected to the outside, so the black hole is losing the energy but this process is very slow. So we can say that black hole will die someday.


Ask Ethan #103: Have We Solved The Black Hole Information Paradox?

“How is Hawking’s theory of black holes storing information on the shell of an event horizon different than what Susskind said decades ago about black holes storing information on the shell of an event horizon? Did Hawking just pull a Steve Jobs and proclaim something new that Android figured out years before? Or is this actually new stuff?”

Stephen Hawking is claiming that the black hole information paradox has now been resolved, with the information encoded on the event horizon and then onto the outgoing radiation via a new mechanism that he’ll detail in a paper due out next month, along with collaborators Malcom Perry and Andrew Strominger. Only, that’s not really what’s happening here. While he does have a new idea and there is a paper coming out, its contents do not solve the information paradox, but merely provide a hypothesis as to how it may be solved in the future.

nittany-tiger  asked:

Pinkie has a space-time singularity in her name? Does it have an event horizon then? Does it emit some cuddly and cute form of Hawking Radiation?

For some reason this felt like a lecture, so I thought a chalk-board type picture would be appropriate.

“Specifically a hug is optimal” can probably be appended to most of my comics and still make sense.

anonymous asked:

Could you explain hawking radiation? I don't completely understand how it depletes the mass of a black hole and radiates since there is equal parts matter and anti-matter and what doesent fall in finds another matter/anti-matter particle to anialate with.

Sure! Basically, it comes back to the odd nature of virtual particles. As you might know, pairs of virtual particles are constantly being created and destroyed in empty space as a result of the uncertainty principle. A black hole has the ability to turn one of these virtual particles into an actual, observable particle, which is then emitted as Hawking radiation. The other particle is still virtual, so is allowed to have a “negative energy”, which then decreases the mass of the black hole.

This “negative energy” is only allowed because it’s a virtual particle, and can’t be observed directly. It’s simply an intermediate step that the universe will always shield from prying eyes. Thanks for asking!

Why black holes are too heavy?

Black hole are formed due to the explosion of a big star in a supernova it happens when a star runs out of fuel. A star like our sun will not become a black hole as it is too small to become black hole, it will become white dwarf {if you don’t about this you should check my previous blog on ‘stars can die’ like will be down} but what will happen if we crush an object its end limit, lets find it out;

What happens when we crush an object to its end limit? If we find a way to crush all the mass of Boeing A380 to its end limit it will become a black hole with the radius of 3.386 to the power -22 which is very very small, this black hole will last about 1 second or so due to the Hawking radiation. Let’s imagine what will happen if we crush our planet to a black hole, what will be the size of our earth? Hmm, it will be the size of a coin but nothing will happen to its gravitational field {as black hole doesn’t affect gravitational field}. So if our sun became a black hole it will have the radius of about 3km which is very small compared to our sun. The smallest black hole like XTE J1650500 has the radius of about 12km and has mass of 10 suns. The biggest black hole which is in the middle of our galaxy has the radius of about 12,700,000km and has mass of 4,300,000 suns inside of it. S50014+81 is the biggest black hole in the universe it is 236.7 billion kilometres big and has mass of about 40 billion suns which is incredible.

Scientists make waves with black hole research: Water bath simulation

Scientists at the University of Nottingham have made a significant leap forward in understanding the workings of one of the mysteries of the universe. They have successfully simulated the conditions around black holes using a specially designed water bath.

Their findings shed new light on the physics of black holes with the first laboratory evidence of the phenomenon known as the superradiance, achieved using water and a generator to create waves.

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