Black holes may not exist!

[OnlyMe]

Wait a minute, paddoboy, if their existence is irrefutable why spend this money to study them? From the first paragraph of your reference:

...They are now believed to reside at the heart of most galaxies...

The first page lists a couple dozen authors. Perhaps you should drop each of them a note informing them that their "beliefs" are irrelevant because existence of black holes and event horizons is irrefutable. Stephen Hawking might like to hear about your opinion as well.

RJ, it seems pretty clear that the "believed to exist" part of the above, refers to "most galaxies", not any galaxy or all galaxies.

While it is reasonable to debate the character, nature and composition of whatever lies within an even horizon, even what is actually happening at an event horizon, in a general sense both black holes and events horizons exist... Perhaps even at the center of "most" galaxies.

Repeatedly there have been links to the obseverved orbital paths of stars around an unseen mass at the center of our own galaxy, posted in this thread... Since the stars are observed and what they orbit is not, the lable black hole fits.

The rest of most of these discussions involves too many fundamental a priori assumptions, to be more than conceptual debates. Until we have a fundamental quantum theory of gravitation that stands up, debating the reality of what it is that we cannot see that acts like a massive black hole, is really just speculation. We don't even have a sound and settled description of what mass is, or the mechanism(s) from which inertia emerges, and both would seem fundamental requirements for any complete understanding of the mechanism(s) leading to gravitation. Heck, we don't even have a clear universal understanding of what empty space is!

Some of these discussions become very difficult, precisely because they wind up trying to explain a portion of physics that requires agreement of both GR and QM . . . and we just don't have that down, as of yet.

 

[Farsight]

Farside, can you link to where Einstein agree’s with you that the event horizon has physical significance...

Yes. See the history section of the wiki Schwarzschild metric article where you can read this:

"However, perhaps due to the obscurity of the journals in which the papers of Lemaître and Synge were published their conclusions went unnoticed, with many of the major players in the field including Einstein believing that singularity at the Schwarzschild radius was physical.[9]"

...and it takes forever to get there? You have been suggesting that nothing reaches the horizon because it takes forever to get there, or if it did get there it would be ‘stopped’ because of infinite time dilation.

Yes, but remember what I said about the hailstone. You don't cross the event horizon. It crosses you.

You make the point of saying Einstein is on your side?

Yes.

Einstein, according to these two sources, thought matter couldn’t collapse down to the required densities to form singularity because of the speed they would acquire in their orbit, not because of your reason of taking forever. Your wiki link, use the reference number 9 to see where that info came from. Your find It comes from ‘The Explanding Worlds of General Relativity‘. This is from that book….View attachment 6865 Look for the book on google books, page 239. And this is Kevin Brown making the same point… Falling Into and Hovering Near A Black Hole

Have a look at the paper:

http://www.jstor.org/discover/10.2307/1968902?uid=3739256&uid=2&uid=4&sid=21103500421513

See this:

"This means the clock kept at this place would go at the rate zero. Further it is easy to show that both light rays and material particles take an infinitely long time (as measured in "coordinate time") to reach the point r = u /2 ..."

Einstein's paper featured orbits rather than matter falling straight down as per a collapsing star. I can't explain why he didn't cover the latter.

 

[Farsight]

I have intentionally been avoiding the discussion of Hawking Radiation because I feel that GR suffices in disproving black holes. That being said micro black holes are theorized as being formed all the time and everywhere so you damn well better hope that Hawking Radiation takes care of them!

They aren't being formed all the time, RJ. That article is speculative woo. As is Hawking radiation. I mean, have you ever actually looked at the given explanation? Virtual particles are field quanta, they aren't real particles. The gravitational time dilation is totally ignored. There are no negative energy particles. The whole thing is hogwash.

Undefined: your post noted. Drop an electron into a black hole and it goes faster and faster and faster while the coordinate speed of light is getting lower and lower and lower.

 

[nimbus]

Have a look at the paper:

http://www.jstor.org/discover/10.2307/1968902?uid=3739256&uid=2&uid=4&sid=21103500421513

See this:

"This means the clock kept at this place would go at the rate zero. Further it is easy to show that both light rays and material particles take an infinitely long time (as measured in "coordinate time") to reach the point r = u /2 ..."

Einstein's paper featured orbits rather than matter falling straight down as per a collapsing star. I can't explain why he didn't cover the latter.

my bold

People have been telling you that 'infinitely long time' is coordinate time. Not the infaller's frame.

 

[RJBeery]

my bold

People have been telling you that 'infinitely long time' is coordinate time. Not the infaller's frame.

Other than the infaller...is there a frame external to the event horizon which doesn't calculate such an infinitely long time? I believe the answer is no.

 

[przyk]

Other than the infaller...is there a frame external to the event horizon which doesn't calculate such an infinitely long time? I believe the answer is no.

Can you explain what you mean by "frame"? Are you sure you actually understand what you're asking for?

Likewise, can you explain what you meant by a "self-referential observer" in [POST=3160275]post #264[/POST]?

 

[RJBeery]

Can you explain what you mean by "frame"? Are you sure you actually understand what you're asking for?

Forget frame, let's go with observers. Are there any observers external to the event horizon who would claim that the infaller would take a finite amount of time to pass it?

Likewise, can you explain what you meant by a "self-referential observer" in [POST=3160275]post #264[/POST]?

I'm trying to be careful in my rewording on this. I'm bothered by the fact that the black hole analysis presumes its existence.

 

[brucep]

my bold

People have been telling you that 'infinitely long time' is coordinate time. Not the infaller's frame.

Farsight cites the Einstein paper to refute himself. Adding new depth to the term ignorance.

 

[przyk]

Forget frame, let's go with observers. Are there any observers external to the event horizon who would claim that the infaller would take a finite amount of time to pass it?

This is just shifting the problem. What criteria would an external observer use to make such a claim? In what way do you propose an external observer should take a distant event (the infaller crossing the horizon) and assign it a particular time on their own clock, finite or not? Most importantly, why should an external observer even need or want to do this in the first place? This is why I ask if you're sure you understand what you're asking for: GR doesn't come with built-in definitions about how to do any of this.

I'm trying to be careful in my rewording on this. I'm bothered by the fact that the black hole analysis presumes its existence.

I'm not seeing where the problem is. The Schwarzschild geometry is a vacuum solution of the Einstein field equation. That makes it a prediction of general relativity and, if you accept GR, a perfectly valid curved spacetime that we could live in (well, if we were all massless test particles, that is). If it weren't for the gravitational singularity, there'd be nothing really remarkable about it. If I told you that the spacetime we live in was the Schwarzschild geometry, you would know everything there is to know about the geometry of spacetime, and you could use the theory to predict what you'd experience if you were or fell into the black hole, or if you stayed out of it. That's good enough for most of us (it's in principle no different from any other solution GR or any other theory we use could spit out). For some reason, this doesn't seem to be satisfactory to you, yet you never really seem to be able to articulate why, or why it's only when you were confronted with black holes that "existence" suddenly became an issue for you.

 

[Russ_Watters]

Forget frame, let's go with observers. Are there any observers external to the event horizon who would claim that the infaller would take a finite amount of time to pass it?

From the math of GR alone, no, but clearly from the subject article in this thread it is an active area of research, which includes trying to reconcile GR with QM. So at this point, the answer has to be "unknown".

Just to be clear here, you're talking about the event horizon predicted by GR at the Schwarzchild Radius, not your hypothesized R=0 event horizon, right?

I'm trying to be careful in my rewording on this. I'm bothered by the fact that the black hole analysis presumes its existence.

Ahh, so you did recognize the potential validity of some of the objections and rather than deal with them are trying to reboot?!

 

[Farsight]

my bold

People have been telling you that 'infinitely long time' is coordinate time. Not the infaller's frame.

The infaller's frame comes to a grinding halt. His clock stops, and so does he. He doesn't see his clock ticking normally. He doesn't see anything.

I'm surprised there's anybody here who still doesn't get this. Look, imagine you've got an observer who is travelling through space at the speed of light. We all know that you can't actually travel at the speed of light, but this is another situation where time dilation goes infinite, so go with the flow. Does this observer see his clock ticking normally? No. He doesn't see anything. Ever. He's a popsicle. It's the same for the observer at the event horizon. And he doesn't fall through it, because the coordinate speed of light is zero there. And he can't go faster than light.

 

[James R]

Farsight:

The infaller's frame comes to a grinding halt. His clock stops, and so does he. He doesn't see his clock ticking normally. He doesn't see anything.

No. Proper time never comes to a halt.

I'm surprised there's anybody here who still doesn't get this.

You mean you haven't considered that everybody here gets it except you.

Look, imagine you've got an observer who is travelling through space at the speed of light. We all know that you can't actually travel at the speed of light, but this is another situation where time dilation goes infinite, so go with the flow.

You're better off considering something that can actually happen, like an observer travelling at 99.999999% of the speed of light or something.

Does this observer see his clock ticking normally? No.

Yes.

He doesn't see anything. Ever. He's a popsicle. It's the same for the observer at the event horizon.

I don't know what you mean by that.

And he doesn't fall through it, because the coordinate speed of light is zero there. And he can't go faster than light.

Right. According to a distant observer, he never falls through the event horizon.

But you're mixing frames - a common error.

In his own proper frame, a traveller has no problem crossing the event horizon of a black hole (apart from possible tidal force, which can be made negligible for a large hole).

Travelling observers, by the way, never see the clocks they carry with them ticking slower or faster than normal. Those clocks are at rest relative to the observer carrying them, so they must be seen to tick at the "rest" rate.

This is basic relativity. I'm somewhat surprised that you, as someone who regularly posts in these kinds of threads, doesn't have a basic understanding of relativity. How long have you been posting about such topics?

 

[Russ_Watters]

The infaller's frame comes to a grinding halt. His clock stops, and so does he. He doesn't see his clock ticking normally. He doesn't see anything.

I'm surprised there's anybody here who still doesn't get this. Look, imagine you've got an observer who is travelling through space at the speed of light. We all know that you can't actually travel at the speed of light, but this is another situation where time dilation goes infinite, so go with the flow. Does this observer see his clock ticking normally? No. He doesn't see anything. Ever. He's a popsicle. It's the same for the observer at the event horizon. And he doesn't fall through it, because the coordinate speed of light is zero there. And he can't go faster than light.

Farsight, you are violating BOTH postulates of SR with that. The first postulate tells us no one ever sees their clock as anything but normal. And the second says all observers measure light to be C, so no observer can ever be traveling at C.

Your contradiction about the speed of light (knowing you can't reach bit, but selecting it anyway) also implies you don't understand calculus and the nature of infinity.

[Edit:beaten]

 

[Farsight]

No. Proper time never comes to a halt.

Yes it does. That's the thing that people just aren't getting here. Proper time is merely some regular cyclic local motion "clocked up" on your clock. When your clock stops, that's the end of your proper time. You don't see your clock ticking normally because you're "stopped" too. You don't see anything. Ever.

You mean you haven't considered that everybody here gets it except you.

I get it. Einstein got it. Wheeler didn't. Nor did Kruskal.

You're better off considering something that can actually happen, like an observer travelling at 99.999999% of the speed of light or something.

That was an illustration to try to get it through to nimbus. If you are subject to infinite time dilation, your clock is stopped and you are stopped, you don't see it ticking normally, you don't see anything, ever.

Yes.

No. We'll all wait a billion years. Has James seen his clock tick yet? No. Let's wait another billion years. Has James seen his clock tick yet? No. The answer is always no.

I don't know what you mean by that.

Somebody who is a popsicle is somebody who is frozen. It ties in with the frozen-star black hole interpretation. At the event horizon gravitational time dilation is infinite so you, the infalling observer, are frozen. And again: your clock is stopped and you are stopped, you don't see it ticking normally, you don't see anything, ever.

Right. According to a distant observer, he never falls through the event horizon.

He doesn't see himself fall through the event horizon either. Ever.

But you're mixing frames - a common error. In his own proper frame, a traveller has no problem crossing the event horizon of a black hole (apart from possible tidal force, which can be made negligible for a large hole). Travelling observers, by the way, never see the clocks they carry with them ticking slower or faster than normal. Those clocks are at rest relative to the observer carrying them, so they must be seen to tick at the "rest" rate. This is basic relativity. I'm somewhat surprised that you, as someone who regularly posts in these kinds of threads, doesn't have a basic understanding of relativity. How long have you been posting about such topics?

Eight years. And I'm the one who does understand it. The clock is "at rest" relative to the observer carrying it. But when gravitational time dilation goes infinite, the clock is stopped, and so is the observer. And a stopped observer does not see a stopped clock tick at the normal rate. He doesn't see anything. It's very simple James.

 

[Farsight]

Farsight, you are violating BOTH postulates of SR with that. The first postulate tells us no one ever sees their clock as anything but normal. And the second says all observers measure light to be C, so no observer can ever be traveling at C.

Einstein violated his own SR postulate. Look:

1911: “If we call the velocity of light at the origin of coordinates c₀, then the velocity of light c at a place with the gravitation potential Φ will be given by the relation c = c₀(1 + Φ/c²)”.

1912: “On the other hand I am of the view that the principle of the constancy of the velocity of light can be maintained only insofar as one restricts oneself to spatio-temporal regions of constant gravitational potential”.

1913: “I arrived at the result that the velocity of light is not to be regarded as independent of the gravitational potential. Thus the principle of the constancy of the velocity of light is incompatible with the equivalence hypothesis”.

1915: “the writer of these lines is of the opinion that the theory of relativity is still in need of generalization, in the sense that the principle of the constancy of the velocity of light is to be abandoned”.

1916: “In the second place our result shows that, according to the general theory of relativity, the law of the constancy of the velocity of light in vacuo, which constitutes one of the two fundamental assumptions in the special theory of relativity and to which we have already frequently referred, cannot claim any unlimited validity. A curvature of rays of light can only take place when the velocity of propagation of light varies with position”.

Your contradiction about the speed of light (knowing you can't reach it, but selecting it anyway) also implies you don't understand calculus and the nature of infinity.

I understand it. Put your observer in a freezer and ask yourself if he measures the speed of light to be c. The answer is no. He doesn't measure anything, he doesn't see anything. Gravitational time dilation goes infinite at the event horizon. So at the event horizon your observer is effectively frozen. Ask yourself if he measures the speed of light to be c. The answer is no. He doesn't measure anything, he doesn't see anything. Do you get it yet?

 

[RJBeery]

Farsight, even though we disagree on the details, this is an area that I agree with you on. Making the claim that an observer's proper time does not dilate is irrelevant. To use a computer analogy:

Computers make calculations via their internal clock, which determines how many individual actions the computer can perform per second. For example, a 1-Gigahertz CPU can process 1,000,000,000 atomic* actions per second. You can overclock a computer, allowing it to perform more calculations per second; you can also underclock it. Either way, a "conscious computer" would be oblivious to its clock speed. It only knows how many actions it has performed, not how many actions per second it is performing. Now, if one were to underclock the computer to 0 Hz (by disabling the clock), the computer would be none the wiser. You could disable the processing clock for a decade, then re-engage it, and the computer would continue its last operation as if nothing happened, claiming that its world experience was smooth and continuous (unless of course it was processing the image of a human clock on the wall )

Extending this, if you disabled the processing clock forever the "conscious computer" would be effectively frozen for eternity without realizing it.

*atomic in this case means that the action cannot be broken down into additional steps; it's the computer-equivalent to a quantum of action in physics

 

[Farsight]

Farsight, even though we disagree on the details, this is an area that I agree with you on. Making the claim that an observer's proper time does not dilate is irrelevant. To use a computer analogy:

Computers make calculations via their internal clock, which determines how many individual actions the computer can perform per second. For example, a 1-Gigahertz CPU can process 1,000,000,000 atomic* actions per second. You can overclock a computer, allowing it to perform more calculations per second; you can also underclock it. Either way, a "conscious computer" would be oblivious to its clock speed. It only knows how many actions it has performed, not how many actions per second it is performing. Now, if one were to underclock the computer to 0 Hz (by disabling the clock), the computer would be none the wiser. You could disable the processing clock for a decade, then re-engage it, and the computer would continue its last operation as if nothing happened, claiming that its world experience was smooth and continuous (unless of course it was processing the image of a human clock on the wall )

Extending this, if you disabled the processing clock forever the "conscious computer" would be effectively frozen for eternity without realizing it.

Good stuff, RJ. The computer that's frozen for eternity doesn't measure everything going tickedy-boo as usual. It doesn't measure anything. Ever.

Hoorah. At least somebody gets it.

 

[Russ_Watters]

Does the effect happen suddenly or gradually an where is he when it happens?

 

[paddoboy]

I understand it. Put your observer in a freezer and ask yourself if he measures the speed of light to be c. The answer is no. He doesn't measure anything, he doesn't see anything. Gravitational time dilation goes infinite at the event horizon. So at the event horizon your observer is effectively frozen. Ask yourself if he measures the speed of light to be c. The answer is no. He doesn't measure anything, he doesn't see anything. Do you get it yet?

Which observer sees anything frozen in time? Certainly not any clock or observer doing the approaching, and crossing of the EH....In that local FoR, everything appears as normal in that same local frame [Ignoring any possible tidal gravitational effects]
Certainly not any observer in a distant FoR watching another intrepid ship mate approach the EH. In any distant FoR, all that is observed is a gradual redshift to infinity as the intrepid one approaches the EH, but is never quite seen reaching it...so again no freezing/stopping of time.

 

[Russ_Watters]

A Brief History of Time, page 89+ discusses this issue in detail. A quick quote:

"He would not, in fact, feel anything special as he reached the critical radius, and could pass the point of no return without noticing it."