Can Black Holes initiate matter creation?

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Offline LeeE

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Can Black Holes initiate matter creation?
« on: 06/08/2008 19:26:24 »
It seems to me that a photon intersecting the event horizon of a black hole at a perfect tangent should go into orbit around it, at the radius of the event horizon.  If there should happen to be two suitable photons in such orbits, and they eventually collide, it could result in the creation of a matter/anti-matter pair where, unless the two particles were perfectly aligned along the event horizon, one would fall into the BH while the other could escape it.

At first thought, it might seem that the number of photons hitting the event horizon at a perfect tangent would be vanishingly small but if you think of the photons as a wave front it then seems inevitable.  Every wave front that passes over a BH should result in a 'ring' of photons going in to orbit around it (or alternatively, at least one photon being captured in orbit).

As the BH is floating in space, and surrounded by stars, it therefore seems that it should have quite a lot of photons orbiting it, in it's event horizon, and in view of this, matter/anti-matter producing collisions should be quite common.

If we then say that the BH has a charge, it seems to me that if the particle (of the pair) that is created outside the event horizon has the opposite charge to the BH, it'll be even more likely to escape.  If this process actually occurs, a side effect would be to reduce the charge of the BH.

There's also the issue of time dilation at the event horizon and how this might affect the energy of the photons, but I haven't thought about that very much yet.
...And its claws are as big as cups, and for some reason it's got a tremendous fear of stamps! And Mrs Doyle was telling me it's got magnets on its tail, so if you're made out of metal it can attach itself to you! And instead of a mouth it's got four arses!

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Offline LeeE

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Can Black Holes initiate matter creation?
« Reply #1 on: 08/08/2008 00:09:08 »
Aw come on folks - does any of this seem plausible?
...And its claws are as big as cups, and for some reason it's got a tremendous fear of stamps! And Mrs Doyle was telling me it's got magnets on its tail, so if you're made out of metal it can attach itself to you! And instead of a mouth it's got four arses!

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Offline JP

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« Reply #2 on: 08/08/2008 04:09:16 »
I'm not sure how this works with photons coming in from the outside, but this sounds similar to Hawking radiation, where the black hole loses mass by sucking in only 1/2 of a particle/antiparticle pair, while the other particle escapes.  The difference here is that you have energy being injected to create the particle/antiparticle, where Hawking radiation is based on virtual particles created from the vacuum. 

I'm not quite sure if I buy that the opposite-charge to the black hole will get sucked in.  Since electromagnetism can't escape a black hole (it sucks light back in), electromagnetic forces shouldn't be able to pull things into a black hole from outside.

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Offline DoctorBeaver

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Can Black Holes initiate matter creation?
« Reply #3 on: 08/08/2008 09:27:19 »
I agree with jpetrucelli (for what little my agreement is worth [:(] ). As EM cannot escape the black hole, how can it attract an oppositely-charged particle from outside? I'd have thought that the probablitity is that you would get equal amounts of positively & negatively charged particles being sucked in, thus maintaining the BH's overall charge.
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Offline graham.d

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« Reply #4 on: 08/08/2008 10:44:02 »
The Event Horizon of a BH is not a tangible surface. It is a surface defined such that the energy required to move from that surface to infinity is infinite. If you approach a black hole this surface shrinks, and crossing the EH (as viewed from a long way off) could occur without you being aware of it. There would be visual spacial distortions and extreme tidal forces but nothing specific to the EH itself.

The idea of a photon approaching the EH needs a clearer definition; for instance, as seen by a distant observer. In this case I don't believe it is possible to have a particle (at least a classical particle) approach such a surface (as seen from said distant observer) exactly tangentially unless emitted from a source close to the EH. The particle would have a very high energy indeed at this point but I cannot think of any trajectory that could take such a particle exactly to this surface, as Lee alludes to. The idea that this very high enery particle may be a photon and then would behave differently because of considering it as a wave may have some validity, but I would guess this would also apply to particles with finite rest mass too, because they would have their probability amplitude waves giving uncertainty to their position and trajectory.

The matter - anti-matter creation is right. With all the high energy photons about you should get plenty of electron-positron pair creation. I think you are right that, over time, any charge on the BH will then be neutralised. I think this could happen because of spontaneous electron-hole pair creation too. This is interesting because this would mean, for a charged BH, a reduction in the total energy of the BH (wouldn't it?) and so its mass decreasing. This is not unlike Hawking radiation but of a different form. It begs the question of where the mass of a body is "contained" - is it within the body or in its gravitational field, or in both? For an electron it is certainly the case that its mass is considered to be partly within its electrical field.

BTW I don't think it is correct that because EM radiation cannot escape a BH that it cannot be charged and have an electric field. I think the mathematical arguments are rather complex but can be seen by analogy: a BH has a gravitational field but cannot produce Gravitational waves.


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Offline LeeE

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« Reply #5 on: 09/08/2008 14:30:36 »
Thanks for the comments folks.  It seemed as though it might be plausible and I wanted to run it by some people who would have a clue.

I thought it was interesting that there might be another particle creation process going on, in addition to Hawking Radiation.  Presumably, if particles created by Hawking Radiation can escape the BH then particles created by photon collision could escape too.  I'm also wondering if particles created by photon collision could potentially be much more energetic than particles created by Hawking Radiation.

The main significance of referring to the Event Horizon is that I believe that it's the orbital radius where the orbital velocity is 'c', so any orbiting photons would have to be in that exact orbit, making collisions inevitable.  Particles with mass though, could have any orbit outside the EH.  As to the possibility of long-distance photons intersecting the EH radius at an exact tangent - if you consider photons from a star passing by the BH, some of them will fall into it and some will just be diverted, or lensed.  The possible range of paths therefore must include one that results in a perfect tangent intersection, or so it seems to me.

I wasn't sure about BH charges but apparently they are a valid property, and as they can't be detected from inside (in so far as any test results couldn't be communicated back to the outside) it seems that the charge must be detectable outside the BH.  I'm not at all sure how much repulsive effect the BH charge would have over similarly charged particles, but as before, if Hawking Radiation particles can escape a BH then a repulsive charge can only accelerate the escaping particles.  I'm not sure what the effect would be of reducing any charge on the BH - there does seem to be a potential energy aspect to it though, which is interesting (but then this process is about supplying external energy anyway).

Thanks again for your comments and thoughts.
...And its claws are as big as cups, and for some reason it's got a tremendous fear of stamps! And Mrs Doyle was telling me it's got magnets on its tail, so if you're made out of metal it can attach itself to you! And instead of a mouth it's got four arses!

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Offline Alan McDougall

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Can Black Holes initiate matter creation?
« Reply #6 on: 09/08/2008 16:48:06 »
Well my take on this is that there is no such thing as creation. Everything that exists has always existed only changing form and state is an everlasting cycle
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lyner

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Can Black Holes initiate matter creation?
« Reply #7 on: 09/08/2008 17:18:55 »
I think your understanding of the word 'creation' is at variance with that of the other people posting here.

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Offline LeeE

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« Reply #8 on: 12/08/2008 00:05:43 »
After a bit more thought...

Arguments against:

Re the charge issue - I can't think of any mechanism whereby the charge of the BH could influence which one of the matter/anti-matter particle pair is created inside the EH and which one is created outside it, so the likelyhood of oppositely charged particles falling in to the BH is likely to be balanced by the number of similarly charged particles falling in to it.

Re photons being captured in an orbit where the orbital velocity is 'c' - this only works if the photon has a zero-sized cross-section, which then doesn't work with the inverse-square law (it's an area law), so if a photon has a non-zero sized cross-section, part of it must be inside the EH (if it is centered on the EH radius) and part must be outside.  Dunno what happens to photons straddling the EH - perhaps they have to split [???]

However, there does still seem to be the possibility of matter/anti-matter pair creation due to lensing.  If one thinks of the double-slit experiment, the distance between the two slits isn't critical and this is analogous to photons being lensed around the periphery of the BH cross-section, so lensing still seems likely to result in photon collision.  Collisions closer to the BH should have more energy (due to time dilation effects), and therefore would be more likely to produce matter/anti-matter pairs, but as the photons focus further away from the BH they should lose energy.

Thanks again for the comments.
...And its claws are as big as cups, and for some reason it's got a tremendous fear of stamps! And Mrs Doyle was telling me it's got magnets on its tail, so if you're made out of metal it can attach itself to you! And instead of a mouth it's got four arses!

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Offline graham.d

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Can Black Holes initiate matter creation?
« Reply #9 on: 12/08/2008 11:40:24 »
Lee, you did not address the issue I raised about what the EH is. It is not a tangible surface and its position (radius) depends from where it is viewed. The normal definition is as viewed from infinity (practically, a long way off). To a particle or photon (or observer) nearby, the EH will have a smaller radius and, when approached, will recede completely. You probably should just consider how a particle or photon would behave as viewed from infinity. The particle cannot have fallen from infinity. If it had then it would have infinite energy at the observed EH. This would be interesting as this particle would also then add an infinite mass to the BH. So assuming the accretion is from local sources, anything approaching the EH (even if some way off) will have insufficient energy to escape whatever the trajectory. If they get close they can only fall in. Anything else with similar energy that is to escape will have a hyperbolic trajectory some distance away from the EH.

I think that anything that could be in orbit at exactly the EH (as defined above) would have to have infinite energy.

I believe that your first assumption that a charged BH will gradually become neutral is a fair one. I don't think it needs any postulates about where the matter-anti-matter pair are created. It is sufficient to note that a charged BH will be more attractive to oppositely charged matter than to similarly charged matter. This would make a difference over sufficient time and the charge would eventually be neutralised.

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Offline Alan McDougall

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« Reply #10 on: 12/08/2008 13:13:20 »
I do not think anything new is ever created out of nothing, Everything that exists has always existed, just changing form in the constant cyclic process of cosmic evolution.

Or everything in its fundamental essence is energy

Regards

Alan
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Offline LeeE

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« Reply #11 on: 12/08/2008 13:17:43 »
Hi Graham.d

The main significance of referring to the Event Horizon is that I believe that it's the orbital radius where the orbital velocity is 'c'...

Perhaps I should not have referred to the Event Horizon at all and instead referred only to the orbital radius where the orbital velocity is 'c'.  It just seemed quicker and easier to say 'EH'.

I agree that to an object approaching it, the EH will appear to recede but is this not due to time dilation effects?  i.e. as the body drops down the gravitational gradient it's local rate of time slows, so it will seem to take longer to reach it.  There is a difference though, between particles with mass and massless particles falling into the BH (and I was only considering massless photons) - the particles with mass will accelerate but the zero mass particles won't(can't).  Instead, their frequency increases, so I would agree that if a photon could orbit a BH at the EH it's energy would indeed be infinite (infinite frequency in zero time, so the energy should be infinity^2  [;D]).

Re the charge issue:  We have gravity playing off against opposing charges and although the EM force is much stronger than the Gravity force I wouldn't want to bet that the opposing charge force is stronger than the gravitational force in the case of BHs.
...And its claws are as big as cups, and for some reason it's got a tremendous fear of stamps! And Mrs Doyle was telling me it's got magnets on its tail, so if you're made out of metal it can attach itself to you! And instead of a mouth it's got four arses!

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Offline LeeE

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« Reply #12 on: 12/08/2008 13:19:56 »
Alan - it's as though you're debating whether tea exists or not, while we're discussing how to make it and whether we should put the milk in first.
...And its claws are as big as cups, and for some reason it's got a tremendous fear of stamps! And Mrs Doyle was telling me it's got magnets on its tail, so if you're made out of metal it can attach itself to you! And instead of a mouth it's got four arses!

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Offline graham.d

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« Reply #13 on: 12/08/2008 13:44:47 »
Milk first, definately :-)

Lee, I think the issue about the EH is not just an observational one or to do with time dilation. Even classically the radius of an EH can be defined as the point at which you need infinite energy to escape to infinity. The radius to get to somewhere closer than infinity is a smaller radius.

I just had an interesting thought about this but have no time right now. Get back later.

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Offline graham.d

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« Reply #14 on: 12/08/2008 15:22:30 »
I did not have time to consider this earlier, but it is an interesting thought experiment...

I was thinking about two cases: one where you were a long way from a BH where you could define and measure the EH and another where you were much closer to the BH so that the EH that you perceive would be smaller. With some initial vector you could, in both cases, plot a course which would allow you to free fall and get back to the same position. Neither case can involve crossing the position of the EH that you perceive from your initial position. By definition this would be impossible. However, it is possible that, from the nearer start position, that you could pass below the proper EH (as seen from infinity) but above the one viewed from your starting position. Such an elliptical orbit would be perfectly OK (as long as you did not hit anything). What is interesting is that it would mean that even from your starting position you do not have enough energy to escape to infinity. The energy you have is only the same energy that you would have when you passed below the proper EH so you cannot escape to infinity. So why is this the case when you start from a position well outside the proper EH.

I think the answer to this paradox may lie in the fact that the initial position is not a stable one unless from a position of orbit and therefore having considerable kinetic energy to start with. To fall towards the BH in an elliptical orbit you have to shed a lot of this kinetic energy; this would have to be enough to mean that you could no longer escape to infinity. What do you think?

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Offline DoctorBeaver

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« Reply #15 on: 13/08/2008 10:19:06 »
Milk first, definately :-)


By God, you're a MIF (Milk In First). DeBrett's would have you ostracised if they found out!
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Offline Alan McDougall

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« Reply #16 on: 13/08/2008 11:59:42 »
LeeE,




1)
Quote
Alan - it's as though you're debating whether tea exists or not, while we're discussing how to make it and whether we should put the milk in first.

2)
Quote
I thought it was interesting that there might be another particle creation process going on, in addition to Hawking Radiation.  Presumably, if particles created by Hawking Radiation can escape the BH then particles created by photon collision could escape too.  I'm also wondering if particles created by photon collision could potentially be much more energetic than particles created by Hawking Radiation

 1)No you don't understand where I am coming from in this debate. You cant make your particle hypothetical tea unless the energy that makes up tea exists in some other form before you attempt this combination on the fundamental scale.

2) In quote 2) you talk about particle creation when there is no such thing. Particles have always existed in some prior form and in the ultimate prime form "pure uncreated energy"

The colossal forces in a black hole of course combine fundamental particles into newer particle, just like you tea, made from tea, milk and sugar. These elements if you like exist before this combination, into your nice maelstroms of cosmic tea.

Therefore the term "created is not really true but there is nothing wrong with it in this debate. Everything is created from something else and at the end we have to abandon the term created, with EXISTED that is my point.

I think when we use the term "Created" we should acknowledge that we mean put together of formed. Existence is that which always was and uncreated prime something I call primorial energy

Regards

Alan

The Truth remains the Truth regardless of our beliefs or opinions the Truth is always the Truth even if we know it or do not know it (The Truth remains the Truth)

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Offline graham.d

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« Reply #17 on: 13/08/2008 14:01:30 »
Quote
By God, you're a MIF (Milk In First). DeBrett's would have you ostracised if they found out!

I'm a scientist and engineer. It saves having to stir it!

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Offline Alan McDougall

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« Reply #18 on: 13/08/2008 17:01:12 »
graham

Quote
I'm a scientist and engineer. It saves having to stir it!

And so am I.
 
 
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Offline graham.d

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« Reply #19 on: 13/08/2008 17:05:26 »
And a MIF man too I trust?

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Offline Alan McDougall

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« Reply #20 on: 13/08/2008 17:48:33 »
Graham

Quote
Milk first, definately :-)

A scientist and engineer that "definitely" can not spell!!
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Offline LeeE

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« Reply #21 on: 13/08/2008 19:50:50 »
Hi Graham.d,

That's an interesting idea.  The problem I have with it is that the true radius of the EH is absolute and not dependent on the observer.

Also, I'm not sure that an observer sees the EH getting smaller or whether it just seems to be further away in relation to their locally perceived speed.  If it were to appear to get smaller as they approach it, it would eventually appear to have zero size and then any path not directly through it would miss it.

Perhaps we should go back to an observer directly approaching a BH - this observer would never actually experience reaching the EH because of the time dilation factor - the last instant before they crossed the EH would seem to take forever, but to a distant observer, they're irretrievably gone - do we agree on that?

Speaking of which, I have to scoot now too.  I'll check back in later though.
...And its claws are as big as cups, and for some reason it's got a tremendous fear of stamps! And Mrs Doyle was telling me it's got magnets on its tail, so if you're made out of metal it can attach itself to you! And instead of a mouth it's got four arses!

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Offline syhprum

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« Reply #22 on: 13/08/2008 20:04:11 »
"Definitely" is definitely the most frequently misspelt word on message boards even those that have built in spell checkers
syhprum

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Offline LeeE

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« Reply #23 on: 15/08/2008 00:39:43 »
Comment overheard just before the Big Bang:  "Better late than never"

This [the elliptical orbit that dips below the EH as seen by a distant observer but not by the local observer, who sees themselves as remaining outside the EH] seems like a good paradox.  It hints towards an absolute space-time-frame, which can only be seen by an observer who is  infinitely far away, which is impossible - nice  [;D]
...And its claws are as big as cups, and for some reason it's got a tremendous fear of stamps! And Mrs Doyle was telling me it's got magnets on its tail, so if you're made out of metal it can attach itself to you! And instead of a mouth it's got four arses!

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Offline graham.d

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« Reply #24 on: 15/08/2008 13:37:38 »
I never spellcheck my posts and just write them straight in to the quick reply box. I definItely will get spellings wrong occasionally. I'm quite good by average science/engineering standards though :-)

Lee, thanks for taking the time to think about this. Interesting isn't it? The problem is I lack the knowledge (and the time) to do a proper mathematical treatment using General Relativity. There is definitely a limit as to how far you can understand these things by just reasoning.

I am not sure about whether time dilation plays a role or not here. If you take the fall from a large distance straight into a black hole then, as far as you are concerned, the black hole EH (that you observe) will get smaller as you get closer. Just before you get to the position where the theoretical EH would be (as viewed from infinity) the universe would seem a small place (in the direction of you travel) because of the Lorentz contraction. When you get to the theoretical EH the universe would have got to zero size in the direction of travel and the centre of the BH (a naked singularity??) and the EH are coincident. I suppose if the distance you fall into the BH from is not infinitely far off and/or you are not really in free fall to the BH because of all the other gravity fields around, your speed will not be so high as to Lorentz contract the universe and BH so much. Still, the perceived EH must always recede from you. I imagine that it is possible that the distance from the perceived EH to the singularity gets could converge to zero when you actually hit it. Not that this matters as the gravitational forces would have long since turned you into a pulp of fundamental particles long before.

There may be an issue though with how the mass of the BH increases with your relative velocity which may change this view and also solve the paradox. As you get close to the theoretical EH (in free fall from infinity OR IF IN ORBIT) the mass of the BH will rise as you perceive it because it is moving at great speed relative to you. This would mean that the EH would also not shrink in the way I suggested. What do you think?

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Offline Alan McDougall

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« Reply #25 on: 15/08/2008 15:36:38 »
Graham,

I was just kidding! who does not make spelling mistakes especially myself who also constantly makes key errors. I think the internet jargon for this is "Fat Fingered'

Thomas Jefferson a notorious mispeller said anyone can spell correctly, it takes talent and creativity to misspell words like he did.

It just goes to show that you have a colourful creative mind, I meant no offence

Regards

Alan
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Offline graham.d

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« Reply #26 on: 15/08/2008 15:45:46 »
He he. No offence taken. Good grief, my skin is a bit thicker than that :-)

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Offline LeeE

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« Reply #27 on: 16/08/2008 14:08:12 »
I think that time dilation is a very important factor because it will affect all of your local energy calculations.  For example, if you're orbiting a BH at the radius where the rate of time due to gravity induced time dilation is 0.5, you will perceive yourself completing an orbit in half the time that an infinitely distant observer would measure, and thus seem to be traveling twice as fast, which then has implications for your perceived orbital distance i.e. you'd see yourself orbiting more closely.  The distant observer, on the other hand, will just see an apparent mass increase and foreshortening.

I don't think that the distance from which the object falls is necessarily the most important factor here, and neither by inference is it's speed.  There's nothing to stop us from accelerating, or decelerating the 'falling' object by using a rocket booster or retro thrust.  Using retro thrust to slow the falling object would allow the object to be traveling much slower than it's free-fall speed as it approaches the BH, and given sufficient thrust the object could be held stationary above the BH.  The length contraction and mass increase factors would then be zero i.e. unchanged, but the gravitational time dilation factor would still be present and would affect your calculations regarding how much fuel you perceive you're burning to maintain your stationary position.

That's an interesting point regarding how a closely orbiting body would see the BH, or rather the EH, as it would have to be orbiting outside the EH.  If your local rotation period is equal to the orbital period, so that you're always facing the BH, it, as a point source, wouldn't be appearing to move at all.  But then you can't see the BH itself, only the EH, which as you pointed out earlier, isn't an actual surface.  However, if you should see other objects falling in to the BH as you orbit around it, you'd see the length contraction and mass effects upon them.  Once again though, the events you'd see would appear to happen more quickly because less time has passed for you.

What I'm wondering now is how would relativistic orbital speed time dilation factors combine with gravitational time dilation factors?
...And its claws are as big as cups, and for some reason it's got a tremendous fear of stamps! And Mrs Doyle was telling me it's got magnets on its tail, so if you're made out of metal it can attach itself to you! And instead of a mouth it's got four arses!

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Offline graham.d

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« Reply #28 on: 16/08/2008 20:44:25 »
I was discounting time dilation effects as I was only considering the view of the person falling and not that of any other view from a distant place and/or different frame. The  reason for considering just a free falling object was to avoid the difficulty of adding the extra complication of other specific "events" like an acceleration. You are quite right that you could slow down using rocket motors (for example). You could suspend your fall into the BH for a period of time, as long as you were outside the theoretical EH, and even accelerate away with sufficient fuel available. It would be valid to consider what the BH would look like from such a viewpoint. There would be no relative motion with respect to the BH but there would be the huge gravitational field and that you would be a long way down the gravitational well.

The orbital situation gives both velocity and a gravitational time dilation with respect to distant objects. These will add so that your clocks will run slow when seen by a distant observer. From your perspective the universe outside will be blueshifted because you are in a gravity well, but you are moving with respect to distant objects (they are moving relative to you) so their clocks should run slow. The two effects are in opposition but there is no reason why they should cancel. At least, I don't think so.

Is there anyone out there who fancies doing the maths for these situations? :-) I expect some of these may not have solutions except via simulation.

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Offline LeeE

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Can Black Holes initiate matter creation?
« Reply #29 on: 17/08/2008 15:17:46 »
I think the problem with only considering the point of view an observer falling in to a BH is that from their point of view they can never reach the EH.  From such a point of view, nothing can fall in to a BH, which seems to be false.

I have to say seems to be because there's the issue of the rate of time becoming zero at the EH, and physics as we understand it cannot explain how anything can happen in zero time i.e. if the rate of time at the EH is zero, how can anything move below the EH when there is no time for anything to happen?

I can't see any reason for the gravitational and speed time dilation effects to cancel - for this to happen you'd need to be able to accelerate time, which can't be done - the fastest rate of time is 1, which can only actually occur in no gravitational field and at zero velocity, and which can only apply to the hypothetical infinitely distant observer.

I thought I'd have a look at some of the numbers so I've done a simple spreadsheet to calc the Schwarzschild Radius (Rs), the rate of gravitational time dilation at the Rs, Rs+1m & Rs+10m, the orbital velocity at Rs, Rs+1m and Rs+10m, and the time dilation factors at those orbital speeds, for a range of masses, for a circular orbit around a non-rotating spherical mass.  Assuming I've done it all correctly, it shows that the rate of time at the Rs is zero, but that the orbital velocity is well below 'c' (I'd assumed that it was 'c', without ever actually working it out - doh!).

www.spatial.plus.com/Gravitational_Time_Dilation.xls

It was created using OpenOffice.org under Linux, so I'm happy to assert that it's virus free, but anyone downloading this spreadsheet should virus check it for their own peace of mind.  I'd appreciate it if someone can verify it's correct - I make no guarantees.
...And its claws are as big as cups, and for some reason it's got a tremendous fear of stamps! And Mrs Doyle was telling me it's got magnets on its tail, so if you're made out of metal it can attach itself to you! And instead of a mouth it's got four arses!

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Offline graham.d

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Can Black Holes initiate matter creation?
« Reply #30 on: 17/08/2008 19:08:12 »
Your equations are right I think but your conclusion that an observer falling into a BH never reaches (or crosses) an EH is not correct. To a distant observer an object cannot be seen to cross an EH, but to an observer who is actually falling in, this is not the case. His local space will be distorted but, if the BH were big enough, this distortion can be small enough that tidal effects may be negligible. He could cross the EH without even noticing. Although he may see a distorted universe if he looked out of a window. His "Proper Time" ticks would go to zero at the EH, as they would for anyone who approached the speed of light for example, but this relates to how his measured time passes with respect to other observers in different frames and not to how he sees the world locally. The meaning is more that he would see a distant observer's clock running very quickly and, ultimately, infinitely fast as the EH was crossed.

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Offline LeeE

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Can Black Holes initiate matter creation?
« Reply #31 on: 17/08/2008 22:49:26 »
I'm afraid I still can't see how an observer who is inside the EH can experience any time passing because the time rate becomes zero at the Schwarzschild Radius, which isn't dependent upon the observer.  Although the spatial distortion of space-time might be a practical problem to our falling observer, I don't think we really need to consider it as a relevant factor here.

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The meaning is more that he would see a distant observer's clock running very quickly and, ultimately, infinitely fast as the EH was crossed.

I agree with this totally, but the converse of the [falling] observer seeing the distant observer's clock running infinitely fast at the point where he crosses the EH is that his clock has stopped - no time passes for him from that point onwards, and he is effectively frozen in time.  He cannot make any observations, or do anything, or experience anything inside the EH because there is no time for him to do it within.  So yes, he would not notice that he had crossed the EH, but he'd not notice anything else either.

Heh  [:D] - I think that all this talk of orbits has left us going around in circles and we really need some more informed input.
...And its claws are as big as cups, and for some reason it's got a tremendous fear of stamps! And Mrs Doyle was telling me it's got magnets on its tail, so if you're made out of metal it can attach itself to you! And instead of a mouth it's got four arses!

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Offline graham.d

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Can Black Holes initiate matter creation?
« Reply #32 on: 18/08/2008 08:57:06 »
I think it is to do with the multiple definitions of time. What the observer at an EH would experience is all of his local environment's "proper" time slowing. He would continue to breathe and his heart would continue to beat in a normal way. A distant observer would see his bodily movements slowing to a standstill.

Googling shows a good summary:

http://cass.ucsd.edu/public/tutorial/GR.html

In particular:

http://casa.colorado.edu/~ajsh/singularity.html

All the other pages are a good read though and cover much of our discussion, including to some extent, your original question! It seems photons will orbit at 1.5R (R= Schwartzchild radius) and not at R.

There is quite a lot on the web - not all of it well informed - but I think this site is very good.

 

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Offline LeeE

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Can Black Holes initiate matter creation?
« Reply #33 on: 18/08/2008 19:05:19 »
Thanks for the links - I'll have a look at those.  When I worked out the orbital velocity for the Schwartzchild Radius it was < 'c' and the orbital radius where the velocity = 'c' was inside the Rs/EH, not outside it.
...And its claws are as big as cups, and for some reason it's got a tremendous fear of stamps! And Mrs Doyle was telling me it's got magnets on its tail, so if you're made out of metal it can attach itself to you! And instead of a mouth it's got four arses!

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Offline Gabe2k2

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Can Black Holes initiate matter creation?
« Reply #34 on: 11/09/2008 02:19:05 »
As I talked about in the forum thread

Is a black hole a point!

 The understanding of black holes is very wrong and simply put yes black holes are very creative perhaps every galaxy, Every solar system Every star is created by a body which resembles a black hole.

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Offline Alan McDougall

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Can Black Holes initiate matter creation?
« Reply #35 on: 11/09/2008 03:20:46 »
Lee,

The changing or creation of matter from energy is a fascinating topic and is this not what they are attempting at the CERN Large Hadron (Proton) collide

Taking the energy from the collision of the protons to form mass/matter a reverse to nuclear Fusion in some sense

Alan
The Truth remains the Truth regardless of our beliefs or opinions the Truth is always the Truth even if we know it or do not know it (The Truth remains the Truth)

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Offline LeeE

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Can Black Holes initiate matter creation?
« Reply #36 on: 12/09/2008 15:24:53 »
I wasn't thinking in terms of a BH creating matter or energy, just that they may provide a location where the conversion of photons to matter via collisions might be very high.

Specifically, I was thinking about the possibility of trapping many photons in a common orbit around a BH where collisions would then become very common, but once I worked it out it turns out that the orbital radius where the orbital velocity is equal to 'c' is less than the Schwarzchild radius, and therefore inside the Event Horizon, so the whole idea is wrong and I'm reminded to check things first instead of relying upon mistaken assumptions  [:I]
...And its claws are as big as cups, and for some reason it's got a tremendous fear of stamps! And Mrs Doyle was telling me it's got magnets on its tail, so if you're made out of metal it can attach itself to you! And instead of a mouth it's got four arses!