feeding a black hole (APOD 27 Jun 2008)
feeding a black hole (APOD 27 Jun 2008)
http://antwrp.gsfc.nasa.gov/apod/ap080627.html
I am guessing the beast can swallow the entire galaxy, eventually. Not impossible to imagine if you accept as fact the entire mass of the universe ( as we know it, or not ) was liberated in the Big bang and lit/seen for the first time.
I am guessing the beast can swallow the entire galaxy, eventually. Not impossible to imagine if you accept as fact the entire mass of the universe ( as we know it, or not ) was liberated in the Big bang and lit/seen for the first time.
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Re: feeding a black hole (APOD 27 Jun 2008)
Hm, imagine a black hole...
Who knows what happens inside that event horizon? Within the event horizon perhaps a whole new set of physics governs space-time.
From inside, the event horizon might encompass an entire universe. What would that look like?
Perhaps the moment of black hole creation is the "big bang birth" of a whole new universe, seemingly infinite to those inside.
Imagine universes within universes.
Food for thought.
-Noel
Who knows what happens inside that event horizon? Within the event horizon perhaps a whole new set of physics governs space-time.
From inside, the event horizon might encompass an entire universe. What would that look like?
Perhaps the moment of black hole creation is the "big bang birth" of a whole new universe, seemingly infinite to those inside.
Imagine universes within universes.
Food for thought.
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Hello NoelC,
One would think that at some point in the approach to a BH gravitational lensing of nearly everything from the opposite direction could be expected. Strange elongations and arcings of matter and light maybe.
But the question to me is this: would the BH appear to be a ball of light at the Event Horizon as electrons are stripped from their atoms and give off photons or other EM energy? Would Dark Matter be revealed or clump up into visible objects of some sort close to the EH? And , finally, (as a more whimsical idea) other than infrared wavelengths, does light escape from a BC? (Black Cloth)
One would think that at some point in the approach to a BH gravitational lensing of nearly everything from the opposite direction could be expected. Strange elongations and arcings of matter and light maybe.
But the question to me is this: would the BH appear to be a ball of light at the Event Horizon as electrons are stripped from their atoms and give off photons or other EM energy? Would Dark Matter be revealed or clump up into visible objects of some sort close to the EH? And , finally, (as a more whimsical idea) other than infrared wavelengths, does light escape from a BC? (Black Cloth)
"Everything matters.....So may the facts be with you"-astrolabe
Re: feeding a black hole (APOD 27 Jun 2008)
In the late seventies and early eighties of last century there was a quest for the 'missing mass'. This was spawned by the idea that a black hole does not necessarily has to be small. So is it possible that a black hole with the size of the then known universe (15 Gly) would exist? How much mass is needed for such a black hole? Well, if one estimates all mass in the universe and consider the size of the universe, one can calculate the average density. That was two orders of magnitude too small to account for a black hole of the size of the universe.NoelC wrote: From inside, the event horizon might encompass an entire universe. What would that look like?
Dark matter was not yet fully accepted, there was some idea of halos of invisible (radiation producing) matter around galaxies. But the halos were too small to account for the 'missing mass'. Neutrinos may have mass was the next argument. Recently it was proven that all three types of neutrinos have a rest mass. Their masses are not yet known, just the differences between the squares of their masses. Nevertheless: there is still 'missing mass'. If Dark matter accounts for the 'missing mass', we -maybe arrogant to say "we" in stead of all beings in this universe- might be living inside a black hole. Thanks to e.g. APOD we know how that looks. And if the universe known to us is a black hole, other universes can not be excluded. Of course, this is all a lot of speculation and has little to do with the APOD of M81.
The moment of big bang remained in these days (1970-1980) a large mystery to me. How is it possible for a point to explode, when it is a black hole? Nowadays there is consensus that the big bang was not localized at one mathematical point. That point would have been the ultimate black hole and would have excluded the existence of the universe itself. Nevertheless your suggestion is congruent with mine: "We might be living inside a black hole".NoelC wrote:Perhaps the moment of black hole creation is the "big bang birth" of a whole new universe, seemingly infinite to those inside.
Regards,
Henk
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Re: feeding a black hole (APOD 27 Jun 2008)
According to the Asterisk rules it is OK to write about subjects related to Astronomy, just preferred to keep to the APOD... this slightly off-APOD writing is sometimes more enjoyable as I have learned much from these readings... Thank you and everyone at Asterisk for that!henk21cm wrote: ... And if the universe known to us is a black hole, other universes can not be excluded. Of course, this is all a lot of speculation and has little to do with the APOD of M81.
You have said a mouthfull here... more fun food for thought... This astronomical thinking is very intriguing for someone like me... my capacity is to think on this scale is in simpler terms such that includes my wondering if black holes could eject matter??? As you mentioned, how can a black hole explode??? I cannot fathom matter "disappearing" into a hole without somewhere else to go. So an exploding black hole makes sense to me. I wonder if the black hole menu winds up on someone else's plate... say another part of the universe.henk21cm wrote:The moment of big bang remained in these days (1970-1980) a large mystery to me. How is it possible for a point to explode, when it is a black hole? Nowadays there is consensus that the big bang was not localized at one mathematical point. That point would have been the ultimate black hole and would have excluded the existence of the universe itself.
The propagation of multiple "universes" from black holes is interesting. If I understand what's been said so far, there aren't any indications of a super massive black hole in the universe and if black holes are restricted to inside a galaxy, it seems it would be a disappointing universe on the other side of the black hole size wise. But then, I suppose what you don't know won't be missed.NoelC wrote:Perhaps the moment of black hole creation is the "big bang birth" of a whole new universe, seemingly infinite to those inside.
From our vantage point... there usually has to be an origin and an end... we are born and we die and there are numerous examples of this cycle in our physical realm.
Science is all about uncovering truth, not all about speculation though... right? Sometimes even scientists seem to loose the distinction. Darwinism is proof of that. We have to make the distinction from theory to truth in order to maintain the allocation and propagation of truth about our existence and the universe around us. But it is great fun to speculate about our origin and the beginning of the universe. And we do sooo like to believe we have answers.
The image of M81 and the indication of multiple black holes is new and intriguing for me... I previously thought that black holes were singular to a given galaxy.
Re: feeding a black hole (APOD 27 Jun 2008)
G'day Ed,
Since mass bends the fabric and since the mass does not decrease, there is no way out. Anything fallen into the black hole will remain there untill a new 'Einstein' is born and proves the former Einstein was wrong. Current theories predict that noting will come out. Somethimes it looks like mass is escaping the black hole. Near the polar axis of the black hole some mass does not fall in. It is a combination of the good old well flow and superheating of gasses.
What happens inside the black hole, is pure speculation. From the point of view of the scientific method, any theory is wrong, since there is no experimental method conceivable to falsify the theory. Why? Information what happens inside the black hole, can never be acquired. From a philosophical perspective a black hole is very unsatisfactory. It is like having a conversation in Cobol with a virus: there is no reaction. Anything can happen inside and that 'everything' withdraws itself from our observation.
Massive black holes are usually in the center of a galaxy. It was either the condensation nucleus for the formation of the 'droplet of stars' in a galaxy or it changed the orbits of the galaxy so that stars rotate around it. Lighter black holes (1=100 sun masses) are expected to be more common in a galaxy. Any heavy OBese star will end with the nuclear synthesis of Fe and beyond and from that point it is the end of the exothermal fusion reactions. Radiation pressure stops and the star implodes under its own gravity. It might form a neutron star or a black hole. What strikes me more is that our galaxy and others are not teeming with black holes.
General relativity explains that mass deforms the spacetime fabric. From Euclidian space in absense of mass, mass changes the fabric into curved Riemann space. Make a circle with your thumb and index finger. Put a handkerchief over it and put a marble on it. It sinks into the circle: the 2D equivalent of curved space. A light beam follows the fabric and since the fabric is bent, the light beam itself is bent. The heavier you make this marble -from foam, to plastic to glass to steel- the deeper it sinks through the circle and the more curved your spacetime fabric will be. Our sun creates a very moderate curvature, light straight along the outer layers of the chromosphere is bent over just an arc second. Sirius A is heavier and denser and bends space more. AFAIK 6 arc seconds. Neutron stars are very compact and bend space much more. If you increase the density at constant radius the fabric get so curved, that all paths for light beams along the object just go inwards to the object, light will not escape. A black hole is born.emc wrote:my capacity is to think on this scale is in simpler terms such that includes my wondering if black holes could eject matter??? [...] I cannot fathom matter "disappearing" into a hole without somewhere else to go.
Since mass bends the fabric and since the mass does not decrease, there is no way out. Anything fallen into the black hole will remain there untill a new 'Einstein' is born and proves the former Einstein was wrong. Current theories predict that noting will come out. Somethimes it looks like mass is escaping the black hole. Near the polar axis of the black hole some mass does not fall in. It is a combination of the good old well flow and superheating of gasses.
What happens inside the black hole, is pure speculation. From the point of view of the scientific method, any theory is wrong, since there is no experimental method conceivable to falsify the theory. Why? Information what happens inside the black hole, can never be acquired. From a philosophical perspective a black hole is very unsatisfactory. It is like having a conversation in Cobol with a virus: there is no reaction. Anything can happen inside and that 'everything' withdraws itself from our observation.
We need a new 'Einstein' to explain exploding black holes. A black hole will disappear if its density decreases and so unstretches the spacetime fabric. When we see a black hole disappear, we know that the enigma what happens inside is broken. We do not gain any knowledge from it: since the black hole has disappeared, space has restored itself to 'normality'.emc wrote:So an exploding black hole makes sense to me.
Early -right after their discovery- suggestions were that quasars could be 'the other end of the drain' of a black hole. This idea was not generally accepted and nowadays quasars in its current explanation of early galaxies are part of the 'common astronomical dinner table'.emc wrote:I wonder if the black hole menu winds up on someone else's plate... say another part of the universe. [...] I previously thought that black holes were singular to a given galaxy.
Massive black holes are usually in the center of a galaxy. It was either the condensation nucleus for the formation of the 'droplet of stars' in a galaxy or it changed the orbits of the galaxy so that stars rotate around it. Lighter black holes (1=100 sun masses) are expected to be more common in a galaxy. Any heavy OBese star will end with the nuclear synthesis of Fe and beyond and from that point it is the end of the exothermal fusion reactions. Radiation pressure stops and the star implodes under its own gravity. It might form a neutron star or a black hole. What strikes me more is that our galaxy and others are not teeming with black holes.
Regards,
Henk
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Re: feeding a black hole (APOD 27 Jun 2008)
Hi Henk, Thank you for writing and sharing!
) Unfortunately, a vanishing black hole doesn’t register with my intellect either. I thought, from my very limited physics studies, that there is never more or less of anything, just different states and compositions. I am way behind I expect.
Is this in reference to Einstein's general relativity theory and how you expect matter to behave in regard?
Thank you! It is commendable to be so frank and honest.henk21cm wrote:What happens inside the black hole, is pure speculation. From the point of view of the scientific method, any theory is wrong, since there is no experimental method conceivable to falsify the theory. Why? Information what happens inside the black hole, can never be acquired. From a philosophical perspective a black hole is very unsatisfactory.
Have we (the proverbial we) actually seen a black hole disappear? Did you witness this in your work? This is even more fascinating. (If we had that new ‘Einstein’ to solve stellar travel we would have solved our garbage dump resource problem.henk21cm wrote:A black hole will disappear if its density decreases and so unstretches the spacetime fabric.
![Wink :wink:](./images/smilies/icon_wink.gif)
henk21cm wrote:What strikes me more is that our galaxy and others are not teeming with black holes.
Is this in reference to Einstein's general relativity theory and how you expect matter to behave in regard?
I was always under the impression that GR gave a fairly decent description of what goes on inside an event horizon, as long as it stays away from the singularity itself (where those pesky infinities crop up)?
I think the difference (again, in GR) between a universe and a black hole is that the universe has a singularity in its past (ie. everything inexorably moves away from the singularity), while a black hole has its singularity in the future (ie. everything is doomed to fall into the singularity).
I think the difference (again, in GR) between a universe and a black hole is that the universe has a singularity in its past (ie. everything inexorably moves away from the singularity), while a black hole has its singularity in the future (ie. everything is doomed to fall into the singularity).
Don't just stand there, get that other dog!
Re: feeding a black hole (APOD 27 Jun 2008)
I don't believe we have . . . yet.emc wrote: . . . Have we (the proverbial we) actually seen a black hole disappear? . . .
However, in response to questions (lawsuits, even) about the safety of the CERN LHC near Geneva, it is asserted by physicists that the possible creation of microscopic black holes is benign because they would rapidly disappear due to Hawking radiation, and thus pose no danger.
To me this explanation flies in the face of the definition I was taught of a black hole (a mass of such great density that nothing, not even radiation, can escape its gravity well). I've tried to read and understand the wiki article on Hawking radiation (http://en.wikipedia.org/wiki/Hawking_radiation), but I just can't reconcile what it says with what I understand a black hole to be.
Like many, many things I read about here on APOD, this, too, is a puzzlement.
![Confused :?](./images/smilies/icon_confused.gif)
![Embarassed :oops:](./images/smilies/icon_redface.gif)
Re: feeding a black hole (APOD 27 Jun 2008)
G'day Ed, Qev and Pete,
Regarding the 'deficit' in black holes, well, one could expect more. Not all stars are so 'OBese' that the evolve into a black hole of a few sun masses. There are lots and lots of ordinary F G K stars. Statistics about OB stars are not very precise, since countings are biased. OB stars don't live very long, the ones you see, are relatively young. So although they aren't very numerous, at least a milli percent or so must be an O or B star. If only a few of these evolve into a black hole, there must be a lot of black holes, since their remains are here to stay. By a process which i do not understand (Hawking radiation, welcome to the club Pete) they seem to be able to evapourate. What i read about it, is that it relies on seemingly thermodynamical processes, like radiative heat transfer, between the black hole and the cosmic background radiation. Yet we know that radiative heat is a form of electromagnetic radiation and so it is subjected to the deformed fabric of spacetime. "How could a black hole emit radiation and at the same time be a black hole"? Similar as to "How can you witness on earth a solar eclips when it is full moon"?
Well prof. Hawking figured out that, although the process is generally explained by thermodynamics, it is a quantum mechanical (QM) problem. One of the basics of QM are the Heisenberger uncertainty relations. Energy and time can not be measured very accuratedly at the same moment. Momentum and location are another pair of these -literally- not commutating properties. Werners uncertainty relations are very real: and results can be seen in the macroscopic world. They prevent Helium to become a solid at atmospheric pressures, even at 0 K. Nevertheless i have some second thoughts on radiating Black Holes. If mass deforms space, so distances become smaller etc, it must have influence on the QM properties like the spread of wave functions as well. Hawking radiation has never been observed, it is a theoretical concept. There must be some confidence in it, NASA has launched recently a satellite to investigate trails of Hawking radiation and usually NASA does not launch satellites without a good reason.
Never read about it. That would have been stunning news. BTW, i'm not an astronomer of profession, i'm JAA (Just An Amateur).emc wrote:Have we (the proverbial we) actually seen a black hole disappear?
Regarding the 'deficit' in black holes, well, one could expect more. Not all stars are so 'OBese' that the evolve into a black hole of a few sun masses. There are lots and lots of ordinary F G K stars. Statistics about OB stars are not very precise, since countings are biased. OB stars don't live very long, the ones you see, are relatively young. So although they aren't very numerous, at least a milli percent or so must be an O or B star. If only a few of these evolve into a black hole, there must be a lot of black holes, since their remains are here to stay. By a process which i do not understand (Hawking radiation, welcome to the club Pete) they seem to be able to evapourate. What i read about it, is that it relies on seemingly thermodynamical processes, like radiative heat transfer, between the black hole and the cosmic background radiation. Yet we know that radiative heat is a form of electromagnetic radiation and so it is subjected to the deformed fabric of spacetime. "How could a black hole emit radiation and at the same time be a black hole"? Similar as to "How can you witness on earth a solar eclips when it is full moon"?
Well prof. Hawking figured out that, although the process is generally explained by thermodynamics, it is a quantum mechanical (QM) problem. One of the basics of QM are the Heisenberger uncertainty relations. Energy and time can not be measured very accuratedly at the same moment. Momentum and location are another pair of these -literally- not commutating properties. Werners uncertainty relations are very real: and results can be seen in the macroscopic world. They prevent Helium to become a solid at atmospheric pressures, even at 0 K. Nevertheless i have some second thoughts on radiating Black Holes. If mass deforms space, so distances become smaller etc, it must have influence on the QM properties like the spread of wave functions as well. Hawking radiation has never been observed, it is a theoretical concept. There must be some confidence in it, NASA has launched recently a satellite to investigate trails of Hawking radiation and usually NASA does not launch satellites without a good reason.
Right Qev, i admit, i'm not sure. I had the impression that what happens inside the event horizon, is not described by general relativity. But i do not have a reference. Impression. If i'm wrong, do correct me, i'm JAA.Qev wrote:I was always under the impression that GR gave a fairly decent description of what goes on inside an event horizon, as long as it stays away from the singularity itself (where those pesky infinities crop up)?
Regards,
Henk
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hi Qev, iampete, and Henk,
I read the Hawking radiation article in wiki which helps clarify how a black hole might disappear... According to Dr. Hawkings theory, black holes will lose mass through evaporation. And if the BH evaporates more than it gains... they disappear. But that is not really disappearing if the matter has evaporated. Maybe the theory is telling us that black holes contribute to dark matter??? I didn't see that outlined in the article, it just seems to makes sense. Of course, a disappearing black hole is just theory and remains to be seen.
It is all very hard to 'swallow', first there is the black hole... how can an object so relatively small carry so much mass that it "eats" anything within reach. And then, how can something that "eats" light emit anything??? Definitely a puzzlement of astronomical proportions.![Confused :?](./images/smilies/icon_confused.gif)
I read the Hawking radiation article in wiki which helps clarify how a black hole might disappear... According to Dr. Hawkings theory, black holes will lose mass through evaporation. And if the BH evaporates more than it gains... they disappear. But that is not really disappearing if the matter has evaporated. Maybe the theory is telling us that black holes contribute to dark matter??? I didn't see that outlined in the article, it just seems to makes sense. Of course, a disappearing black hole is just theory and remains to be seen.
It is all very hard to 'swallow', first there is the black hole... how can an object so relatively small carry so much mass that it "eats" anything within reach. And then, how can something that "eats" light emit anything??? Definitely a puzzlement of astronomical proportions.
![Confused :?](./images/smilies/icon_confused.gif)
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I understand from reading ancient Scripture that God transcends time and space... maybe this is true of black hole emissions??? Say the emissions wind up somewhere else in the universe??? (Just a little brain tickle)BMAONE23 wrote:If [black hole] evaporation is basically matter changing state, and the gravity of a BH is strong enough to trap light, then how could matter either disappear (cease to be) or escape the gravity well???
![Wink :wink:](./images/smilies/icon_wink.gif)
I still think black hole... dark matter... black/dark... makes sense to me.
![Wink :wink:](./images/smilies/icon_wink.gif)
![Question :?:](./images/smilies/icon_question.gif)
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G'day folks,
Energy can be converted into a pair of particles: a normal particle and its anti-particle. The momentum of these two particles are opposite, since momentum must be conserved. Half of the energy is in the normal particle, half of the energy is in the anti-particle. Hawkings theory, as far as i understand (AFAIU) it, states that such a generation of a particle pair near the event horizon, will cause one particle to fall deeper into the black hole, the other to fly away from it, by a process called tunneling. Tunneling is a consequence of the wave functions of particles. The location of a particle is expressed in a probability density function, a function of the position.
The Hawking evapouration states that the black hole looses energy. It radiates. When a body radiates, it must either loose mass (like the stars) or cool down. The temperature of a black hole is inversely proportional to its mass. The formula for the black body temparature of a black hole with the mass of our sun is 77 nK. For a black hole with the size of the earth the black body temparature is 20 mK. So when a black hole cools down, AFAIU it must gain mass. Hey! that is in contradition with the energy, since it lost energy. Now i'm lost.
never mind, "Paint it black"!
Evaporation is more a semantical inaccuracy than a physical state. Gouvernmental organisations have budgets for a year. If they do not spend their budget during that year, "the money evaporates at December 31st". Nevertheless i never saw a cooking pan with money evapourating. It is just semantics. The process is rather complicated, that is not a new statement in this discussion. Its a case of fiddling with theories. A unified theory for gravity and quantum mechanics is AFAIK not yet found. Maybe in the N-dimensional string theory? If you treat gravity and QM as two independent theories, you will end up with evapourating black holes.BMAONE23 wrote:Never understood BH evaporation myself. If evaporation is basically matter changing state, and the gravity of a BH is strong enough to trap light, then how could matter either disappear (cease to be) or escape the gravity well???
Energy can be converted into a pair of particles: a normal particle and its anti-particle. The momentum of these two particles are opposite, since momentum must be conserved. Half of the energy is in the normal particle, half of the energy is in the anti-particle. Hawkings theory, as far as i understand (AFAIU) it, states that such a generation of a particle pair near the event horizon, will cause one particle to fall deeper into the black hole, the other to fly away from it, by a process called tunneling. Tunneling is a consequence of the wave functions of particles. The location of a particle is expressed in a probability density function, a function of the position.
The Hawking evapouration states that the black hole looses energy. It radiates. When a body radiates, it must either loose mass (like the stars) or cool down. The temperature of a black hole is inversely proportional to its mass. The formula for the black body temparature of a black hole with the mass of our sun is 77 nK. For a black hole with the size of the earth the black body temparature is 20 mK. So when a black hole cools down, AFAIU it must gain mass. Hey! that is in contradition with the energy, since it lost energy. Now i'm lost.
black hole... dark matter... dark magic... black smith...emc wrote:I still think black hole... dark matter... black/dark... makes sense to me.
never mind, "Paint it black"!
Regards,
Henk
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Henk
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Hello Henk21cm,
Cuold it be that as a BH evaporates energy the radiation draws heat with it and at the QM level the voids allow the cooler remaining mass to become ever denser in it's less-energetic state and the BH shrinks to a smaller diameter? If so then bursts could happen as each new stage of greater density heats up and repeats the cycle until the BH is gone or it accretes new material. This process might also be "stageless" and occur at a reasonably steady rate until the BH just withers away.
If at the center of a galaxy, the accretion disk may be countering the ability of a BH to radiate in all directions and so only jets can occur.
If anyone can speculate with absolutely no facts at all...it's me, dreamin' away about things of which I know sooooooo little!![Sad :(](./images/smilies/icon_sad.gif)
Cuold it be that as a BH evaporates energy the radiation draws heat with it and at the QM level the voids allow the cooler remaining mass to become ever denser in it's less-energetic state and the BH shrinks to a smaller diameter? If so then bursts could happen as each new stage of greater density heats up and repeats the cycle until the BH is gone or it accretes new material. This process might also be "stageless" and occur at a reasonably steady rate until the BH just withers away.
If at the center of a galaxy, the accretion disk may be countering the ability of a BH to radiate in all directions and so only jets can occur.
If anyone can speculate with absolutely no facts at all...it's me, dreamin' away about things of which I know sooooooo little!
![Sad :(](./images/smilies/icon_sad.gif)
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My (meager) understanding of Hawking radiation causing the eventual evaporation of black holes includes a time frame that's extremely extended. In other words, "eventual" in this context is on timescales that are nearly impossible for us to quantify, and even difficult to imagine.
To put it in perspective, imagine viewing the universe on a timescale such that you would see an impossibly brief flash of light - like that emitted from a camera flash - representing the tens or hundreds of billions of years of existence the bright universe we now see. Now imagine that brief flash followed by eons of black hole existence in which they slooooowwly evaporate, one particle at a time.
On a possibly unrelated thought, it is interesting that the universe in which we live is dominated almost completely by matter particles, with very little antimatter to be found.
Is it possible Hawking radiation over some long past period has been responsible for the emission of matter particles in greater quantities than antimatter particles?
Just more food for thought.
-Noel
To put it in perspective, imagine viewing the universe on a timescale such that you would see an impossibly brief flash of light - like that emitted from a camera flash - representing the tens or hundreds of billions of years of existence the bright universe we now see. Now imagine that brief flash followed by eons of black hole existence in which they slooooowwly evaporate, one particle at a time.
On a possibly unrelated thought, it is interesting that the universe in which we live is dominated almost completely by matter particles, with very little antimatter to be found.
Is it possible Hawking radiation over some long past period has been responsible for the emission of matter particles in greater quantities than antimatter particles?
Just more food for thought.
-Noel
Possible. The point is that the temperature of a black hole is more or less a statistical concept. The mother of all thermometers is a gas thermometer. It registers pressure as function of temperature. Pressure is the collision of particles to the wall or to a piston, mercury, i.e. a solid or liquid. These collisions have a distinct character, if our sensors were very accurate and our electronics very fast, we could register separate collisions. They are not ideal, and so we register statistical properties like a time average. First law of thermodynamcs is that when there is an unbalance in temperature, thermodynamics takes care of that and levels the difference: "When a system of two body with different temperatures is brought in contact, in the asymptotic state both temperatures will be the same". It does not state how much time is needed. Hawking radiation assumes that the cosmic back ground is one system, a black hole is the other. Large black holes have a low temperature -the wiki on this subject comes up with a formula, however the way they arrive at that result is subject of more intense study to me- and so the black hole receives radiation and thus heat from the cosmic background. A black hole with little mass is hotter than teh cosmic background and will radiate heat to the cosmic background.astrolabe wrote:Cuold it be that as a BH evaporates energy the radiation draws heat with it and at the QM level the voids allow the cooler remaining mass to become ever denser in it's less-energetic state and the BH shrinks to a smaller diameter?
They have even found out how much power is radiated. That is relatively low and so the 'normal' black holes of 10 sun masses looses heat so slowly, that it will 'never' fully evapourate. Never in the meaning of time comparable to the current livetime of the universe. Note: i can not reproduce the result, i miss the underlaying knowledge and must assume that it is valid. From a philosofical point of view, that is very dangerous: believe what other people have said. Always try to prove it or let someone else do that.
In todays national science magazine an article is written about Pierre Auger, which died in 1993. Auger was doing work on super energetic particles entering the earth atmosphere. When you accellerate an electron in a potential difference of 1V, it energy increases by 1 eV. Auger was doing research on particles with more than 1E19 eV, so more than 1 J. Some theories speculate that these higly energetic particles are miniature black holes, which evapourated. The Hawking radition predicts that low mass black holes evapourate rather fast: 1E-20 s or shorter. Most likely noticeble as gamma ray burts. NASA's latest satelite is looking for these micro gamma ray bursts.
astrolabe wrote:If at the center of a galaxy, the accretion disk may be countering the ability of a BH to radiate in all directions and so only jets can occur.
That is a realy nice explanation for those pesky jets. When i was writing down the arguments about the cosmic back ground, i was thinking: "how about the tremendous heat of the accretion disk, that outshines the cosmic back ground completely".
As long as we realize that we know nothing and as long as we do not behave complacent and as longs as we open our minds to new thoughts, human race is not doomed. For me the Asteriks forum is a way to learn more about the wonders of the universe. During the (nearly) half year that i participate in the debate, i came into contact with more 40 new ideas.apodman wrote: If anyone can speculate with absolutely no facts at all...it's me, dreamin' away about things of which I know sooooooo little!
The unbalance between matter and antimatter is one of the largest enigmas of the current universe. Even the cleverest researchers do not have an answer for that question, so do not expect an aswer from me. Your remark sparked a thought. Since the charge of anti particles is opposite of that of the 'normal' particle, magnetic fieldlines may be the answer. In a pair creation near the event horizon the anti particle might be bent to the 'left', into the black hole, the 'normal' particle to the right, beyond the event horizon. The assumption is that QM does not obey the rules of gravity.NoelC wrote:On a possibly unrelated thought, it is interesting that the universe in which we live is dominated almost completely by matter particles, with very little antimatter to be found. Is it possible Hawking radiation over some long past period has been responsible for the emission of matter particles in greater quantities than antimatter particles?
Nay, that is nonsense. In that way the universe would have been populated with protons and positrons. The electron would have been a oddity.
Regards,
Henk
21 cm: the universal wavelength of hydrogen
Henk
21 cm: the universal wavelength of hydrogen
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The inversion operator
Would you prefer a universe populated with electrons and anti-protons? You know, for me, that would simplify a lot. If our universe is within a black hole, no expansion of the spacetime fabric is needed to explain the red shift. The closer a galaxy gets to the event horizon, the more gravity it feels, the slower the pace of time, the more red the light emitted. Unfortunatedly this theory was slashed into many pieces. It is not in agreement with the data. Which data, i do not know.NoelC wrote:Unless we're "inside" the black holeNoel
Why unfortunatedly? It is a very simple theory. Maybe too simple. After a few publications it's over, dried out.
Regards,
Henk
21 cm: the universal wavelength of hydrogen
Henk
21 cm: the universal wavelength of hydrogen
Are Black Holes , Hot or Cold ?
"Evaporation is more a semantical inaccuracy than a physical state." Henk
Here's how my understanding goes, and it begins with the Hawking idea that space and time trade properties upon crossing the event horizon: Space becomes 'time like' and time becomes 'space like', in that as one moves over distance, one moves to a different 'time'; and if one stays in the same place time is a non moving constant. As the escape velocity at the event horizon is the speed of light, on the black hole's side of the event horizon one has to go faster than light in order to move away from the 'center', therefore space has a 'time likeness' to its nature, in that one cannot move in a certain direction -outward- for that as being likened to backwards in time on this side of the event horizon.
I am proposing that 'energy' and 'inertia' also swap properties, like 'time' and 'space' have traded properties. Energy on this side of the event horizon is the great communicator of information. It goes throughout the universe and carries all kinds of information via its various wavelengths that have differing abilities to permeate different mediums with impunity. Inertia is somewhat stuck in being limited mainly to protonic matter to exhibit its greatest effects, and it has no 'field' of influence beyond those protons. It is not like gravity in attracting things, it is not like light in carrying information billions of years of distance, it only carries a potential energy quality for a rotating object with protonic mass to the limit of the radius of that protonic mass. On the black hole's side of the event horizon I'm seeing inertia becoming the great communicator and Energy (the radiative state of the electro magnetic spectrum) being stuck and unable to move, like inertia is stuck here. Because the protonic density is very great inside the event horizon, Inertia is very prevalent throughout that space and in communication with itself between protons. In this way Inertia becomes the great communicator of what is happening inside the event horizon. Whereas Energy is constrained by the faster than light speed necessary due to the strength of gravity, it cannot profusely pervade all over the place at its will, like it does on this side of the event horizon.
Inertia is the one to transmit information out of a black hole, and thusly this is how a black hole would evaporate, by information leakage of inertial events happening inside it. For example, more mass could not be ingested by the black hole until the requisite inertia information is passed to the outside environment, as a way of maintaining a 'conservation of information lost principle', so that there is a balance, and information cannot be 'permanently lost' via a one way path. Black hole total inertial quanta would be communicated to the surrounding mass field before a certain amount of mass would be able to cross the event horizon; and this limit of information communication is what might be preventing matter from being ingested from the accretion disk any faster than it is, and also why the jets form. They are the infalling matter that is arriving too fast to be accommodated by the inertia information communication exchange, and so are 'rejected' from assimilation, and as they have to go somewhere, and as they are being accelerated towards the event horizon, their path of least resistance is out from the poles.
Admittedly this is a difficult subject to launch into in the moment of doing other things, so pardon my inability to say it as well as i might, I'm working on it!
Here's how my understanding goes, and it begins with the Hawking idea that space and time trade properties upon crossing the event horizon: Space becomes 'time like' and time becomes 'space like', in that as one moves over distance, one moves to a different 'time'; and if one stays in the same place time is a non moving constant. As the escape velocity at the event horizon is the speed of light, on the black hole's side of the event horizon one has to go faster than light in order to move away from the 'center', therefore space has a 'time likeness' to its nature, in that one cannot move in a certain direction -outward- for that as being likened to backwards in time on this side of the event horizon.
I am proposing that 'energy' and 'inertia' also swap properties, like 'time' and 'space' have traded properties. Energy on this side of the event horizon is the great communicator of information. It goes throughout the universe and carries all kinds of information via its various wavelengths that have differing abilities to permeate different mediums with impunity. Inertia is somewhat stuck in being limited mainly to protonic matter to exhibit its greatest effects, and it has no 'field' of influence beyond those protons. It is not like gravity in attracting things, it is not like light in carrying information billions of years of distance, it only carries a potential energy quality for a rotating object with protonic mass to the limit of the radius of that protonic mass. On the black hole's side of the event horizon I'm seeing inertia becoming the great communicator and Energy (the radiative state of the electro magnetic spectrum) being stuck and unable to move, like inertia is stuck here. Because the protonic density is very great inside the event horizon, Inertia is very prevalent throughout that space and in communication with itself between protons. In this way Inertia becomes the great communicator of what is happening inside the event horizon. Whereas Energy is constrained by the faster than light speed necessary due to the strength of gravity, it cannot profusely pervade all over the place at its will, like it does on this side of the event horizon.
Inertia is the one to transmit information out of a black hole, and thusly this is how a black hole would evaporate, by information leakage of inertial events happening inside it. For example, more mass could not be ingested by the black hole until the requisite inertia information is passed to the outside environment, as a way of maintaining a 'conservation of information lost principle', so that there is a balance, and information cannot be 'permanently lost' via a one way path. Black hole total inertial quanta would be communicated to the surrounding mass field before a certain amount of mass would be able to cross the event horizon; and this limit of information communication is what might be preventing matter from being ingested from the accretion disk any faster than it is, and also why the jets form. They are the infalling matter that is arriving too fast to be accommodated by the inertia information communication exchange, and so are 'rejected' from assimilation, and as they have to go somewhere, and as they are being accelerated towards the event horizon, their path of least resistance is out from the poles.
Admittedly this is a difficult subject to launch into in the moment of doing other things, so pardon my inability to say it as well as i might, I'm working on it!
Re: Are Black Holes , Hot or Cold ?
I'm trying to understand what you mean, since it is not entirely clear to me, even after reading your explanation half a dozen times. Maybe my response is an oversimplification. I notice pairs of properties. Time and place. These might follow from the Lorentz invariance, where √(r²-c²t²) is a dominant term in describing the relation between position and time. Next pair you introduce is Energy and Inertia. Since i sometimes mix inertia up with coefficient of inertia, by inertia i hope you mean the product of mass and velocity? Quantum mechanics has similar pairs of parameters. Location and inertia, Energy and time. They are important due to the uncertainty principle.kovil wrote: Here's how my understanding goes, and it begins with the Hawking idea that space and time trade properties upon crossing the event horizon: Space becomes 'time like' and time becomes 'space like',
Now i get the impression (did i mix them up, since you mention rotating objects?) you mean inertia as in "the moment of inertia of a rotating object" or maybe the amount of ratation? In either case, where i have second thoughts on your explanation is that due to the dense nature of the barionic mass inside the event horizon, there are numerous interations between particles. In these interactions inertia of the individual particles can change. When two particles collide, inertia is being transfered from one particle to the other. This might lead to equipartition of inertia as in gasses: every particle has the same amount of inertia. Inertia as a means of transferring information would in that case be rather ineffective, after a number of collisions the information is lost. Where the information came from and what it was, can no longer be determined, like in the early stages of the universe, when light was interacting with the dense and hot universe.kovil wrote:It {inertia} is not like gravity in attracting things, it is not like light in carrying information billions of years of distance, it only carries a potential energy quality for a rotating object with protonic mass to the limit of the radius of that protonic mass. On the black hole's side of the event horizon I'm seeing inertia becoming the great communicator and Energy (the radiative state of the electro magnetic spectrum) being stuck and unable to move, like inertia is stuck here.
In your explanation inertia is being transferred beyond the event horizon, into the 'normal' universe. For that it needs a 'carrier', a messenger. It must be a massless carier, since gravity forbids barionic matter to travel from within the event horizon to the outside, other than maybe by means of QM tunneling processes. Not even photons, massless particles in a state of rest, can cross the event horizon. The argument, i.e. gravity, you are using that forbids light to travel perpendicular to the event horizon, towards the event horizon, prevents barionic particles to do the same. The only option barionic matter has is to fall deeper into the well. So where i have difficulties in following you explanation is how inertia leaks into the normal world.kovil wrote:Inertia is the one to transmit information out of a black hole, and thusly this is how a black hole would evaporate, by information leakage of inertial events happening inside it.
kovil wrote:For example, more mass could not be ingested by the black hole until the requisite inertia information is passed to the outside environment, as a way of maintaining a 'conservation of information lost principle', so that there is a balance, and information cannot be 'permanently lost' via a one way path.
kovil, is the "conservation of information" a well known theorem, like the conservation of inertia, conservation of energy, conservation of charge? It is unfamiliar to me, -that NOT being a standard .... ..- every day i loose information.
This argument is an explanation for the 'pesky' jets. But i'm still missing the evapourization, which it all started. I hope that, in spite of my reaction, you will enjoy this simulating discussion as much as i do.kovil wrote:Black hole total inertial quanta would be communicated to the surrounding mass field before a certain amount of mass would be able to cross the event horizon; and this limit of information communication is what might be preventing matter from being ingested from the accretion disk any faster than it is, and also why the jets form.
Regards,
Henk
21 cm: the universal wavelength of hydrogen
Henk
21 cm: the universal wavelength of hydrogen