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paul h
For years I have proposed the idea that the size of an event horizon is Dependant on the observers location. This I feel is due to the effects of gravity on time. To sum it up: the further away the observer, the larger the event horizon appears, and the close observer may not find on at all. much like chasing a rainbow. will toss this out to you and see what you have to say about it. Some that I have proposed this to say that it is very possible and then ask for me to prove it. I can't. I must say that I do not have the math skills to explain it with a formula. what do you guys think?
Ron
Hi Paul,
I don't understand your confuse of General Relativity with Special Relativity.
The laws of the universe are the same no matter the observer. Special Relativity gives us a way to ensure this (IE: Lorentz Transform. This is just a factor to ensure that we agree on all the laws of the universe.)
Black holes have been predicted over the years (from Einstein to Hawking) and they certainly have an effect on the universe around them (ever seen an active black hole? This is no illusion.)
I respectfully ask you differentiate the difference between Special an general Relativity. Special can give illusion to effects of the universe, but the Lorentz Transform allows us to see that the laws of the universe are the same no matter where.
Does this give you more to work with?
Peace,
Ron
paul h
>Does this give you more to work with?

It only makes it worse.

>The laws of the universe are the same no matter the observer

I read alot of theories that give different scenarios for different observers
paul h
Let me try that a different way.
the laws are the same but, the data would change with location giving a different result.
Ron
Hi Paul,
That is the entire purpose for the Lorentz Transform. It allows us to compensate for relativistic effects to prove that the laws of the universe are invarient.
Later,
Ron
Sapo
QUOTE (paul h+Sep 20 2007, 04:50 PM)
For years I have proposed the idea that the size of an event horizon is Dependant on the observers location. This I feel is due to the effects of gravity on time.  To sum it up: the further away the observer, the larger the event horizon appears, and the close observer may not find on at all. much like chasing a rainbow.  will toss this out to you and see what you have to say about it. Some that I have proposed this to say that it is very possible and then ask for me to prove it.  I can't.  I must say that I do not have the math skills to explain it with a formula. what do you guys think?


I may wish that I hadn't presumed, here, but reading the question over, I _think_ this may help:

Oh, this is tough for me to express, but I'll try.

The observer is assumed to be a point-like entity, just as mathematical points are 1-dimensional.

The frames of reference of the observer and the observed system may differ. (You are at a safe distance from the wonderful things happening a few light-years away)

Gravity does not act upon time, the curvature of space has time-like consequences.

So, skipping some steps, and back to what I think your question is, it seems that your proposed point of view would be inside looking out, very unlike Mr. Leary's predicament. laugh.gif
Sapo
I did presume, but I digress.

Consider being inside an event horizon. At a sufficiently large radius, a volume of space within might be flat enough for you to survive, and be a non-pointlike observer. This is purely metaphysical, and as such, not suitable for this forum.

There might be a study question, though. Google:

Arthur Stanley Eddington, for the number of protons calculated to be in the universe (in his time, if Hoyle has a say)

C.S. Lewis, for his understanding of collapsed dimensions. (The Narnia Chronicles, and The Perelandra Trilogy)

No more digression tonight, thanks.
paul h
For any point ever made there will be a dissenting opinion. With that said.
I understand that Einstein (and perhaps Hawkins) said that time slows with higher gravity. I know that was debated, some say debunked. (I don't know) If this has been debunked then all of my proposal is for naught. If true, then what I am saying can be explained like this: A distant observer (say here on earth) looks at a black hole somewhere across the universe and notes that as the particles circleing the hole "fall" into it at some distance from the center. The gravity becomes so strong that the light can't escape (or be seen) This is the outter region of the event horizion. This is what they taught us in school anyway. I think that the particles continue at there set velocity but, due to the slowing of time they are seen to the distant observer to exceed the speed of light, (an illusion). The speed of light ~186,000 miles per second. If the second is now longer (at the particle's location) the distance observer would see the particles disperse into blackness.
The close observer would be in the same time reference as the particle and to him the speed of light is the same and if close enough he may not even see the particle disperse. Thus a different diameter of the event horizon, depending on the observer's location. Yes the same constant for the speed of light at any location. No I am not proposing some metaphysical, Timothy Leary thing. Just an observed illusion like a rainbow that appears to move with the observer's location. My problem is in not being able to confirm the perceived change to time with gravity. As I said at the top, If this has not been debunked, by now there should be formulas to show the change on time at a given weakness or strength of a gravity region. Back in grade school (long time ago) we were told about experiments with two atomic clocks, one here on earth and the other sent into orbit. when they were reunited there was a difference.
Sapo
I think that the particle near the event horizon would not 'disperse' from the point of view of the distant observer. As the particle moves closer to the event horizon, the space through which it moves is more tightly curved. Therefore, the distant observer sees the particle's light red-shifted, and the particle appears to fall more slowly toward the event horizon, ad infinitum.

There is a link to an excellent lecture on black holes that AlphaNumeric posted,

O, well, I have to mangle the URL, please add your own "http colon whack whack" to:
forum.physorg.com/index.php?showtopic=17647&st=0&#entry255807

Professor Perry is quite understandable.
paul h
QUOTE (Sapo+Sep 21 2007, 03:39 PM)
I think that the particle near the event horizon would not 'disperse' from the point of view of the distant observer. As the particle moves closer to the event horizon, the space through which it moves is more tightly curved. Therefore, the distant observer sees the particle's light red-shifted, and the particle appears to fall more slowly toward the event horizon, ad infinitum.

There is a link to an excellent lecture on black holes that AlphaNumeric posted,

O, well, I have to mangle the URL, please add your own "http colon whack whack" to:
forum.physorg.com/index.php?showtopic=17647&st=0&#entry255807

Professor Perry is quite understandable.

I thought that the light moving out of the strong gravity well would be red shifted and the light moving into it would be blue shifted
Do I have this back-wards?
I have a bit of a grip on the difference between Gravitational time dilation and speed induced time dilation now adding red shift and any number of combined effects of all three can lead to a real hard time grasping the concepts correctly. I have read some debate about the idea that to the distant observer the two (gravity time dilation and speed induced time dilation) almost negating each other.
Sapo
No, you have it. It's just that you appear to be switching the point of view of the observer and the particle going down the rabbit hole.

If you think of acceleration, not speed, then gravity and acceleration are _not_ different, and will not add further to your confusion. wink.gif

And, Ron, thanks for the vote. I'll try to live up to your expectations...
paul h
Let me chew on that for a while. I'm sure I will have a question, just not so sure how to phrase it yet.
Ron
Hi Paul, Sapo,
Paul, you have to understand that even though time slows down 'to the observer' it's own time has not changed as far as it can tell. Yes, Garavitational time dilation is a (argued by some) well documented fact. I'll find an article that I saw recently that uses a binary system to show that time dilation and the Shapiro Effect were measured to an amazing accuracy.
Do not despair if it gives you problems. Very few people understand relativity completely (especially when your trying to combine Special and General).
I make a plea for Alphanumeric, Rpenner, or/and Euler to jump in. They are very well versed in these things. (Black holes arewhat Alphanumeric is schooling for.)
Peace all,
Ron
paul h
QUOTE (Ron+Sep 21 2007, 09:50 PM)
Hi Paul, Sapo,
Paul, you have to understand that even though time slows down 'to the observer' it's own time has not changed as far as it can tell. Yes, Garavitational time dilation is a (argued by some) well documented fact. I'll find an article that I saw recently that uses a binary system to show that time dilation and the Shapiro Effect were measured to an amazing accuracy.
Do not despair if it gives you problems. Very few people understand relativity completely (especially when your trying to combine Special and General).
I make a plea for Alphanumeric, Rpenner, or/and Euler to jump in. They are very well versed in these things. (Black holes arewhat Alphanumeric is schooling for.)
Peace all,
Ron

Ron,
Thanks.
I did download the lectures posted above and gained some in site (very little, its the math thing). It would take me 10+ years to teach myself the math but, Perry said that the horizon occurs independent of the gravitational Field. That this is the boundary where things can only go in. I kinda knew this but that somehow helped me understand what Sapo was saying about the red shift. Just outside there would be particles going in and away (correct?) Still I have been talking about (for a better word) "after" the photon went past (inside) the boundary. I still don't see why the distant observer would not see this happen at a greater distance from singularity than the close observer would. I think that Sapo is talking just outside the boundary. Sapo, could you please clarify. Ron, you said >that even though time slows down 'to the observer' it's own time has not changed. Are you talking about the distant observer?
alokmohan
There are two horizons.Absolute horizon and apparent horizon.
paul h
QUOTE (alokmohan+Sep 22 2007, 05:11 AM)
There are two horizons.Absolute horizon and apparent horizon.

Two? Please explain. It sounds like I may be thinking about your "apparent" horizon.
Ron
Hi Paul,
Yeah, distant as in not in the influence of the gravitational field.
I'll find some references, but right off 'try' reading "elegant Universe" by Brian Green. He writes with little or no math and describes GR and SR very well (before going into string theory, which I'm having a tough time with!). Also, if you can find it, John Gribbon wrote "In Search of the Big Bang" many years ago, but he does a fantastic job explaining both GR an SR.
Peace,
Ron
yor_on
Paul, as far as i know you will not change your frame of time by observing another frame, like a 'black hole'. A black hole is supposed to be observable due to its 'Hawking radiation' and of course it's gravitational effects on other light sources primarily. Light will bend around it, as it will create a 'hole' in space, but that is a geometric effect of spacetime and has nothing to do with photons being attracted or repulsed by its gravity.

So if you looked at it from afar you would have great difficulties seeing it, and when coming near it you would notice strange things happening to the 'light' around it. Depending on its size i would expect the event horizon to cover a smaller or a larger part of your view. On the other hand no one knows what a black hole is, it is supposed to be a place where all laws for our universe has broken down, so a larger black hole doesn't necessary imply a greater event horizon even though one would expect it to be so. But i think i can see your idea a little. Like that black hole compressing itself so hard that we won't be able to find it if we would get nearer? And the time and therefore light too?

You must understand that your time is personal and therefore invariant as far as you are involved, no matter :) if you are standing still or accelerating. So even if a black hole may have a very different timeframe as compared to yours it will not place objects further away (in time or space) But i agree that it strikes me too as blasphemy :) And if you fell down into that black hole i would expect time to behave 'as usual' for you. It would be the 'outside' of the event horizon that started to accelerate, not you slowing down, as seen consciously from your view point.

That is how i understand it at least :)

paul h
yor_on,

>So if you looked at it from afar you would have great difficulties seeing it,
I was thinking that outside and up to the event horizon would much more visible to any (far or close) observer than you have stated, as for seeing the hole well that would be hard to see, if I understand it at all. Hum. (food for thought on my part).
>as far as i know you will not change your frame of time by observing another frame
True, but would you be able to even see some thing in another frame? You are not the only one to say this here. But I fail to see how I gave the impression that I think my time will change. As you said >~i would expect time to behave 'as usual' for you. Yes no matter where I am, my time is my time. However what I am trying to convey is that if I see something that is in the same time frame that I am in (close observer) it will be visible to me and if I see something that moves into an altered time, from my prospective it will disappear. It's disappearance occurs at the instance when it goes down the proverbial rabbit hole. Or in other words the reason the hole is black to an observer is because of the time dilation. For the close observer there would be no dilation difference between the observer and the photon and would therefore appear to still be outside of the horizon. Thus giving the illusion that the horizon appears to have a different size depending on ones proximity to it.
Now I have to say that I am not trying to just keep restating the same thing over and over regardless of how you guys try to explain it to me but, rephrasing it helps me make sure that I have not been misunderstood. As is often the case. I don't always say what I mean. Sorry if this makes me sound like a hard headed ol jackass.
Sapo
QUOTE (Ron+Sep 22 2007, 07:55 AM)
Also, if you can find it, John Gribbon wrote "In Search of the Big Bang" many years ago, but he does a fantastic job explaining both GR an SR.
Peace,
Ron

You are putting a date on me and you, hm? I remember reading that, also many years ago. It was better than pie.
Zephir1
QUOTE (paul h+Sep 20 2007, 11:50 PM)
...the size of an event horizon is dependent on the observers location...

Yes, you're right. By AWT most of black hole behaves like dark stars formed by neutrinos, so that the event horizon is equivalent to physical surface of such star. Nevertheless, the high density of vacuum near such star makes the size of such star illusory, it will grow as you approach to such star, because the close neighborhood of such star behaves like optical lens. In close proximity the dark star would appear like pretty giant object, suppose you'll use the light wave for size measurement, not the mechanical measure, which will expand too. So we can say, the size of dark star will depend on the method used in near proximity, the methods based on mechanical measures will always give the lower results, then the optical ones.

We should realize, the true black hole wouldn't have the event horizon at all from close proximity, so you could see the interior of black hole directly, suppose you wouldn't dissolve in the vacuum near black hole, where its density is comparable with the density of interior of atom nuclei. The expansion of the matter detected recently by pair of ukrainian scientists can be interpreted as a gradualy accelerated fall of our universe generation through throat of giant dark hole or dark brane.

http: // forum.physorg.com/index.php?showtopic=123
yor_on
Paul i see you a little better now :)
"if I see something that is in the same time frame that I am in (close observer) it will be visible to me and if I see something that moves into an altered time, from my prospective it will disappear. "

Time is a concept that springs from spacetime, as you say it seem to be containing many different 'timeflows' but there is one 'goldstandard' and that is spacetime in itself. We are inhabitants of that spacetime, and no matter where the observer goes nothing 'disappears' . What happens with different accelerated frames is not that they drop out of sight. Take for example a spaceship accelerating to a star (ok planet then :)

You standing on the planet with a strong telescope watching it. Your brother goes in that ship. Due to its acceleration he will 'lose' time as compared with you, but that doesn't mean that at some time his spaceship 'blips out' while you are watching it. In fact, to you that ship will just continue normally and you will notice no strange behaviour from it (well there are some phenomena as length contraction etc, but that good a telescope has nobody :) you will see it turn and come back, and land. At no time will it disappear from sight but if your idea worked then it should have, don't you agree? Still he will be younger than you would expect him to be.

The way i think about that is that time is a property of spacetime, even though we see it as a linear force ticking away for us all at the same rate that is only because we ( roughly :) exist in the same time frame. Your brother didn't for a 'short while' :) But as i said it still gives me a major headache as it proves that time can and will move at 'different rates' around us, without us ever noticing any strangeness, as we all will have, at all times 'the same' ratio of flow,that means that your 'inner clock' will tick at the same rate as everything else in your 'frame'..

So time is very stable as seen from each and every one of us, but when compared to other frames extremely changeable and all at the same 'time' ::)) So how can this be, maybe because time doesn't exist? At least it can't be as we perceive it 'normally'. and yes we are allowed to watch all other time frames and perceive them even though they don't flow at our rate. Time is a enigma to me :) It do control us and the universe and without it nothing would be. Compare that to taking away one of the other three dimensions f ex width. There would still be a universe containing two dimensions plus time, yes, it would seem to disappear when viewed from certain angles but if we viewed it from another we would be able to see it again (while viewing it from our three dimensional 'reality' plus time. ) But if we let it have those three dimensions but no time, would we be able to view it then?

Do i make sense :)
And as always, there might be other views of it out here :)
Sapo
yor_on,

I worry that too much Islay malt whiskey has distorted my perceptions of space-time, not angels distorting yours.

biggrin.gif You said it very well, and you probably didn't need a driveby.
yor_on
Hey, why didn't you share man, i love islay malt. Half a botle and then of to bed, and no hangovers ever. Awwh now you got me thirsty :)

Awh SH** Angels? Was it :)
paul h
QUOTE (Zephir1+Sep 22 2007, 10:26 PM)
Yes, you're right. By AWT most of black hole behaves like dark stars formed by neutrinos, so that the event horizon is equivalent to physical surface of such star. Nevertheless, the high density of vacuum near such star makes the size of such star illusory, it will grow as you approach to such star, because the close neighborhood of such star behaves like optical lens. In close proximity the dark star would appear like pretty giant object, suppose you'll use the light wave for size measurement, not the mechanical measure, which will expand too. So we can say, the size of dark star will depend on the method used in near proximity, the methods based on mechanical measures will always give the lower results, then the optical ones.

We should realize, the true black hole wouldn't have the event horizon at all from close proximity, so you could see the interior of black hole directly, suppose you wouldn't dissolve in the vacuum near black hole, where its density is comparable with the density of interior of atom nuclei. The expansion of the matter detected recently by pair of ukrainian scientists can be interpreted as a gradualy accelerated fall of our universe generation through throat of giant dark hole or dark brane.

http: // forum.physorg.com/index.php?showtopic=123

>We should realize, the true black hole wouldn't have the event horizon at all from close proximity,

As this is what I have been trying to confirm with this thread I should just be happy with your post but,
I seem to read between your lines when you say "The True" black hole.
If you want to do some splaining, please do.
paul h
you_on,
>Do i make sense smile.gif
Yes, (discussing time can give anyone a headache)
So I may have a (somewhat) proper understanding of the event horizon but, I came to with all the wrong reasoning.
Sapo
QUOTE (yor_on+Sep 22 2007, 07:17 PM)
Hey, why didn't you share man, i love islay malt. Half a botle and then of to bed, and no hangovers ever. Awwh now you got me thirsty smile.gif

My deepest apologies, and here's a good dram for you. And another?

yor_on
And you think that that will help me keep it sober, huh.
Throw me the bottle :)

Well Paul wellcome to the club migraine, the shade is never on :)
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