Black holes

[DeiRenDopa]

I decided to take a closer look at Farsight's use of a particular diagram, in this thread.

Here's what I found (not 100% sure I got them all, but I don't think I've missed more than one or two, at most), in chronological order, oldest first:

I've provided ample evidence previously in the form of optical clocks and the Shapiro delay. As you know the coordinate speed of light varies in a non-inertial reference frame such as the room you're in, and we can simplfy the optical clocks to parallel-mirror light clocks thus:

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The evidence is patent. There is no evidence however for the sky-falling-in waterfall scenario which is not in accord with general relativity.

I'm the one who's skeptical here. I've offered evidence, you haven't. I've given the evidence of the Shapiro delay and optical clocks which demonstrate that the coordinate speed of light varies:

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And we have our evidence from sonar in a non-flowing ocean, plus Shapiro and optical clocks demonstrating this:

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No it doesn't. Remember the optical clocks losing synchronisation at different elevations, simplified to parallel-mirror light clocks:

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The lower clock goes slower because the light goes slower. That's real.

The metric doesn't tell me it varies. Experiment tells me that. It's as plain as the nose in front of my face. Experiments like the Shapiro delay. Experiments using super-accurate optical clocks which lose synchronisation when separated by only a foot of vertical elevation. They're optical clocks. They employ electromagnetic hyperfine transistions and electromagnetic waves. And we can simplify them to parallel-mirror light clocks, which we know will also lose synchronisation when at different elevations:

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Can you see the time flowing in these experiments

I'm looking at hard physical evidence that says the speed of light varies with gravitational potential regardless of any coordinate system. There is no coordinate system you can use to make the light traversing the lower parallel mirror get to the end before the light traversing the upper.

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Essentially optical clocks losing synchronisation when separated by a vertical elevation of only a foot. I've also mentioned the GPS clock adjustment and the Shapiro delay, but they're essentially the same thing. The optical clock uses aluminium rather than caesium, and a UV frequency rather than a microwave frequency, but it works along the same lines, and employs electromagnetic phenomena. When these move at a lower rate, the clock runs slower. We use the idealised parallel-mirror light clock extensively in relativity, see for example this instance, and we know that parallel-mirror light clocks would keep time with optical clocks at different elevations. So we know that this scenario applies:

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Think of the two light beams as racehorses.

Oh yeah? Have a try switching coordinates to make the lower light-clock tick faster than the upper:

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Then try switiching coordinates to make the lower light-clock tick:

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The speed of light c = √(1/ε₀μ₀) depends on the impedance of space. And it varies. We can see it varies in the Shapiro delay, and in those optical clocks which lose synchronisation, as would parallel-mirror light clocks:

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In a gravitational field the speed of light demonstrably varies. So the impedance of space must be varying too. It isn't constant either.

Where the light goes slower your second is bigger, and you use that bigger second on the slower light and hence measure the same speed. Even though you can look at parallel-mirror light clocks and see this going on:

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Just think of them as racehorses. They aren't going at the same speed.

That the speed of light varies, remember?

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Regarding the main point I'm trying to convey, if I showed you two parallel cables with a different impedance, you'd expect to see some variation in the A/C signal propagation time, which we might depict like this:

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If I replace the cables with light beams in say a smoke-filled chamber, and gave you a gedanken high-speed camera, you should be able to play back the film and see the light beams propagating in a similar fashion:

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I would hope that you would attribute this difference to vacuum impedance rather than "time flowing slower", and conclude that c = √(1/ε₀μ₀) is not an absolute constant.

You merely consider two parallel-mirror light clocks at different elevations, you're aware that GR predicts that these clocks do not stay synchronised, and then you draw yourself a picture showing one beam of light moving faster than the other. Like this:

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See above. One needs somewhat perverse reasoning to assert that the two light beams are moving at the same speed. If they were, the two clocks would remain synchronised, contrary to Einstein's GR prediction which has been verified repeatedly.

Wow guys, I've just read through to the end of the thread and frankly I'm amazed. You're showing the most awful groupthink here. You still can't see the obvious. Let's try it another way. Let's say we've got two trains on parallel tracks. They start off at the same time, and one reaches the end before the other. Like this:

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Which train is going faster? Easy. The top one.

Now repeat this with two light beams in parallel-mirror clocks:

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Which one's going faster?

It's that simple, it really is.

And at the event horizon c is zero! Hence the gravitational time dilation goes infinite at the event horizon. Take the lower clock down to the event horizon, and this is what you've got:

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And that reflects what we can see with our parallel-mirror light clocks losing synchronisation at different elevations, just like those super-accurate optical clocks.
…
you could devise an experiment with superhighspeed cameras and watch the two light beams making progress in a misted chamber:

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It's only constant because it's defined to be constant. If it was truly constant, optical clocks and parallel-mirror light clocks at different elevations would stay synchronised, and we'd then assert that indeed the speed of light is absolutely constant:

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The speed of light varies. Experiment tells you this. Einstein did too.

Tell me about those trains, sol, and the light beams going at the same speed:

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I can see that the speed of light varies with gravitational potential:

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These two light beams are not going at the same speed.

Tell me how two trains moving like this, or two light beams, are moving at the same speed.

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You won't.

I can see that the light goes slower where it's lower.

Speed is how fast something is moving. Even without choosing any coordinates or defining any units, one can point to the scientific evidence of optical clocks and parallel-mirror light clocks and say that one thing is moving faster than another. Your choice of coordinates does not alter this relationship, you cannot contrive gravitational time dilation to make the upper clock tick faster than the lower. Light does not curve away from a star, it curves towards it.

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Now look to that evidence. The speed of light varies. You can see it varies, just like Einstein said.

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You can conduct the experiment when you and your two-parallel-mirror light clocks are in free fall. At all times the lower clock is below the upper clock, so you continue to see that the light beam in the lower clock goes slower than the light beam in the upper clock:

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The evidence that supports Einstein is right there in optical clocks losing synchronisation at different elevations. You know they'll each stay synchronised with parallel-mirror light clocks at those elevations, so you know that parallel-mirror light clocks at different elevations lose synchronistion. We can represent that like this:

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Coupled with say the Shapiro delay, it's clear that the speed of light varies.

And still nobody will address the hard scientific evidence of the Shapiro delay and light clocks losing synchronisation at different elevations:

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Nobody will concede that this demonstrates with crystal clarity that the speed of light is not constant.

In a later post, or two, I'll go through at least some of this.

I expect to be able to point out several inconsistencies in how Farsight has used this diagram, as in, for example, how the same diagram is used to mean quite different things (without Farsight explaining, clearly, what those differences are).

Also, I will use this to show several examples of where, and how, Farsight fails to communicate well.

Not included here are the many responses to Farsight's posting of this diagram. By not including those, I will not be able - easily - to show how Farsight has - often - failed to modify (edit, amend) his message, to address (some) obvious failures of communication.

In the meantime, enjoy!

 

[ben m]

Visser also suggests his students look up http://www.crank.net

Awesome.

 

[W.D.Clinger]

Here are some more quotations from Matt Visser's notes on general relativity.

Everything that Visser says below has already been said within this thread, but it's even more fun to quote Visser now that Farsight is citing Visser as his authority.

There are still a few die-hard nutters out there who still to this day do not understand the Schwarzschild solution.

Warning: The fact that because of the coordinate freedom two quite different seeming metrics can really represent the same geometry is the source of considerable confusion — a lot of the nutters completely lose it on this point.

With respect to the Schwarzschild t coordinate becoming space-like inside the event horizon, Visser wrote:

Yet more of the nutters lose it at this point. The symbol “t” is just a label for a particular coordinate, a mnemonic label that is supposed to remind you that it is a “time” coordinate on a large piece of the manifold. But it is just a label, “t” does not have to be a “time” coordinate over the entire manifold, and in fact in the presence of a horizon the Schwarzschild “t” coordinate will not be a “time” coordinate inside the horizon.

 

[Farsight]

Oooh, Clinger is slinging mud. I like it when people who have no counterargument do that. It just makes them look stupid and vindictive and bitter. And yawn, Dopa is boring his imaginary audience to death again.

But not on other things. So why do you choose to believe Einstein completely on some issues, and ignore him completely on others? What makes the difference? Because it looks to me like the only difference is whether he says what you already believe. When he does, he becomes an authority to use like a talisman. When he doesn't, then you hide him away like Ruprecht.

It isn't a question of believing Einstein. It's a question of looking at the scientific evidence, and believing what you can see with your own eyes. Then when you see Einstein backing it up, you understand that there are some issues with the way modern GR is taught, and consequently with the way black holes are portrayed. For Dopa's benefit, what it all boils down to is that when parallel-mirror light clocks at different elevations lose synchronisation, it's because the speed of light at those two locations is not the same:

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Farsight, you fail to realize that Matt Visser's "gravastars" violate GR. He hypothesizes that GR breaks down, in some as-yet-unseen circumstance, due to an as-yet-undiscovered quantum effect, so that the deformed spacetime at high curvature generates a massive (or possibly negative-mass) "condensate"; once you're inventing arbitrary condensates, you can invent arbitrary equations-of-state for them, and one such choice generates gravastars. He is not supporting your wacky notion that current GR theory is wrong, misuses math, differs from Einstein's GR, etc.. I have no idea why you seemed to say he did. Lying? Delusion? Misunderstanding?

Ah mudslinging, how quaint. I didn't say that. He's into gravastars now, a development of frozen stars not Chicken Little. He's moved on from what he was saying 15 years ago, so sol's left with egg on his face.

None of those citations, of course, is to John Duffield. Nor do the people doing "careful skeptical analysis" cite John Duffield (who nonethelesss pretends to be the first person since 1916 to do careful skeptical analysis). Nor do people willing to try "radical proposals" cite John Duffield (who nonetheless pretends to be the first person since 1916 brave enough to do anything radical.)

What are you on about? I'm not pretending anything. The Tolman–Oppenheimer–Volkoff limit and the frozen stars date from 1939. See arXiv for papers on the varying speed of light, such as this.

 

[Ziggurat]

It isn't a question of believing Einstein.

Then there is no reason to cite Einstein. The theory is either accurate or not. Its predictions either match observations, or they don't. Who said what becomes irrelevant, if you're not interested in believing someone. So why do you keep quoting his words? And given that other words of Einstein directly refute some of your claims, why do you have no interest in proving Einstein wrong on those points?

It's a question of looking at the scientific evidence, and believing what you can see with your own eyes.

You skipped a rather critical step: you also need to understand what it is the theory predicts. If you don't understand the predictions of the theory, you have no way of testing the theory against observations.

And you clearly don't understand the predictions of the theory, because every single observation you've decided to test it against matches the predictions of the theory. But then, that's par for the course with internet cranks: they think standard physics is wrong and that they can disprove it, even though they don't even understand it.

For Dopa's benefit, what it all boils down to is that when parallel-mirror light clocks at different elevations lose synchronisation, it's because the speed of light at those two locations is not the same:

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No. This is absolutely critical: what you have is ONLY an observation of an effect. The observation does not tell us the cause. If you want to figure out a cause, you develop a theory of a possible cause. You determine what the different consequences (ie, predictions) of that theory are. You compare them with reality. If the predictions match observations, then the theory is accurate (not correct - we can never prove that). But ANY theory which predicts the observed results is accurate. Which, again, is the most we can ever say about any theory. An accurate theory provides a possible explanation of a cause, and if the theory is accurate enough under a wide enough range of conditions, then we conclude that this is likely the correct explanation. But we never, NEVER, actually know for sure.

So does this clock synchronization experiment demonstrate that standard MTW GR, as taught, is wrong? Well, obviously not, because that theory predicts exactly the loss of synchronization that you refer to. And not qualitatively either, but quantitatively. You keep referring to this experiment, but you will continue to fail with it, precisely because standard theory which you try to refute gives the exact same answer for the only actual observation you ever refer to. You still can't come to grips with this, and it's growing ever more pathetic.

 

[sol invictus]

He's into gravastars now, a development of frozen stars

So, you don't know what gravastars are. Shocking.

Gravastars don't have a horizon, Farsight. That's the whole point of them. So it's rather impossible for them to be "frozen stars" in your sense, because there's no point where any redshift goes to infinity.

not Chicken Little. He's moved on from what he was saying 15 years ago, so sol's left with egg on his face.

I'm left with egg on my face because Visser wrote a correct paper 15 years ago, rather than 1 year ago? Did the mathematics in it expire and become wrong during that time?

 

[Brian-M]

I'm not wrong. The earth is not sucking in the surrounding space.

But how do you know this? (And is anyone claiming that the earth is literally sucking in surrounding space?)

I haven't demonstrated that an analogy for fairies doesn't work mathematically. So what?

Now that's an analogy I'd like to read.

But seriously, mathematics is only means we have to precisely describe the behavior of the universe. Consequently, there are only two ways to demonstrate such a description wrong. Either by demonstrating the math to be flawed, or by presenting empirical evidence to the contrary.

Since you've admitted that you haven't been able to demonstrate that the math doesn't work, the only way you could possibly know that it's wrong is if you have empirical evidence.

Do you have any empirical evidence?

 

[Roboramma]

And yawn, Dopa is boring his imaginary audience to death again.

Just for clarity: I am neither imaginary nor bored.

 

[Farsight]

Then there is no reason to cite Einstein.

There's every reason to cite Einstein when people support pseudoscience assertions with "GR tells us".

The theory is either accurate or not. Its predictions either match observations, or they don't. Who said what becomes irrelevant, if you're not interested in believing someone. So why do you keep quoting his words?

As above.

And given that other words of Einstein directly refute some of your claims, why do you have no interest in proving Einstein wrong on those points?

Other words of Einstein don't "directly refute some of my claims". Don't believe Clinger when he makes that claim, he's just trying to distract you from the scientific evidence.

You skipped a rather critical step: you also need to understand what it is the theory predicts. If you don't understand the predictions of the theory, you have no way of testing the theory against observations.

I know what the theory predicts. I've already referred to The Confrontation between General Relativity and Experiment by Clifford M Will. Read it.

And you clearly don't understand the predictions of the theory, because every single observation you've decided to test it against matches the predictions of the theory.

Quite. And that includes the observation that the speed of light varies with gravitational potential. But it doesn't include any observation that space is falling inwards in a gravitational field.

But then, that's par for the course with internet cranks: they think standard physics is wrong and that they can disprove it, even though they don't even understand it.

I'm no crank. Cranks are the guys who say "Einstein was wrong". Now take a look at which side of the fence you're on. LOL, the irony!

No. This is absolutely critical: what you have is ONLY an observation of an effect. The observation does not tell us the cause. If you want to figure out a cause, you develop a theory of a possible cause. You determine what the different consequences (ie, predictions) of that theory are.

That's what Einstein did.

You compare them with reality. If the predictions match observations, then the theory is accurate (not correct - we can never prove that).

That's what Eddington and others did.

But ANY theory which predicts the observed results is accurate. Which, again, is the most we can ever say about any theory. An accurate theory provides a possible explanation of a cause, and if the theory is accurate enough under a wide enough range of conditions, then we conclude that this is likely the correct explanation. But we never, NEVER, actually know for sure.

Yes I know.

So does this clock synchronization experiment demonstrate that standard MTW GR, as taught, is wrong?

Yes. Standard MTW GR teaches you that the speed of light is constant, when you can see it isn't. Just like Einstein said.

Well, obviously not, because that theory predicts exactly the loss of synchronization that you refer to. And not qualitatively either, but quantitatively. You keep referring to this experiment, but you will continue to fail with it, precisely because standard theory which you try to refute gives the exact same answer for the only actual observation you ever refer to. You still can't come to grips with this, and it's growing ever more pathetic.

Irony isn't your strong suit, is it Zig? Why don't you tell everybody about your negative carpet again?

 

[Brian-M]

And yawn, Dopa is boring his imaginary audience to death again.

Just for clarity: I am neither imaginary nor bored.

But are you dead... again??

 

[Farsight]

But how do you know this? (And is anyone claiming that the earth is literally sucking in surrounding space?)

Because the universe is expanding, and the solar system isn't getting smaller. And yes they are.

But seriously, mathematics is only means we have to precisely describe the behavior of the universe. Consequently, there are only two ways to demonstrate such a description wrong. Either by demonstrating the math to be flawed, or by presenting empirical evidence to the contrary.

No problem with that. There's empirical evidence that the speed of light varies with gravitational potential, which means the maths of Kruskal-Szekeres coordinates is flawed. It isn't wrong as such, it's flawed in that it presents you with a description that does not match the behaviour of the universe.

Since you've admitted that you haven't been able to demonstrate that the math doesn't work, the only way you could possibly know that it's wrong is if you have empirical evidence. Do you have any empirical evidence?

Yes. I've given it repeatedly. The speed of light varies with gravitational potential just like Einstein said. But people who are convinced that it's absolutely constant absolutely refuse to accept it. If I arranged two parallel-mirror light clocks at different elevations, you know that they won't stay synchronised. You also know that there's no literal time flowing between the mirrors, just light moving. If we used say dust in space, you'd be able to see the light beams moving like this:

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Think of the light beams as racehorses. When one gets ahead of the other you say it's moving faster than the other. If somebody tried to tell you they were going at the same speed, you'd laugh at them. When they then tried to tell you that space was falling down, you'd tell them to stop wasting your time with fairytales.

 

[Farsight]

So, you don't know what gravastars are. Shocking.

I know what gravastars are. And I didn't say they were identical to frozen stars. So your feigned shock cuts no ice.

Gravastars don't have a horizon, Farsight. That's the whole point of them. So it's rather impossible for them to be "frozen stars" in your sense, because there's no point where any redshift goes to infinity.

Oh stop whining. We call all read about gravastars and see that this depiction is a better match with the original frozen-star black hole interpretation that your Chicken-Little fairytale.

I'm left with egg on my face because Visser wrote a correct paper 15 years ago, rather than 1 year ago? Did the mathematics in it expire and become wrong during that time?

No. You're left with egg on your face because the guy who wrote the paper you referred to is into gravastars now. He has abandoned your sky falling in, and left you high and dry.

 

[Brian-M]

Because the universe is expanding, and the solar system isn't getting smaller. And yes they are.

The universe is expanding because space is expanding. Is the solar system getting bigger? No. All that extra space has to be going somewhere. So why can't the earth be sucking in all that extra space?

(Okay, I'm not being completely serious with this question. But it is an interesting point. How do you know it's not the case?)

No problem with that. There's empirical evidence that the speed of light varies with gravitational potential, which means the maths of Kruskal-Szekeres coordinates is flawed. It isn't wrong as such, it's flawed in that it presents you with a description that does not match the behaviour of the universe.

But Kruskal-Szekeres coordinates show that time varies with gravitational force, resulting in the appearance of the speed of light varying with gravitational potential from the perspective of a distant observer.

In exactly what way does if fail to match the observed behavior of the universe? Where's the flaw?

Yes. I've given it repeatedly. The speed of light varies with gravitational potential just like Einstein said. But people who are convinced that it's absolutely constant absolutely refuse to accept it.

You don't know that the local speed of light varies with gravitational potential. Even you've admitted that there's no way to locally measure the speed of light that would show it to be traveling at a different speed.

But everyone here agrees that non-local light appears to the observer to travel at different speeds. Nobody disputes that.

The standard way of explaining this is that light appears to travel slower in areas of high gravity because time is passing at a slower rate in those areas. You're claiming that light actually does travel slower in areas of high gravity because... um... just because.

And your description of the effect of the slower speed of light is indistinguishable from what we regard as time traveling slower.

Since the observable behavior of the universe in your description is completely indistinguishable from the observable behavior of the universe in the standard description, what is your basis for claiming that the standard description is wrong?

You can't show us any math, and all empirical evidence supports both descriptions equally.

Plus your description completely fails to explain why light is traveling slower, while the standard description for why light appears to travel slower provides both an explanation and a complete mathematical outline.

If I arranged two parallel-mirror light clocks at different elevations, you know that they won't stay synchronised. You also know that there's no literal time flowing between the mirrors, just light moving.

It's statements like this that make me wonder exactly what kind of strange and bizarre concept of time lurks within your mind.

If we used say dust in space, you'd be able to see the light beams moving like this:

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Gee, thanks for the diagram. Somehow I didn't quite understand it the first five hundred times, but suddenly it now makes perfect sense.

Think of the light beams as racehorses. When one gets ahead of the other you say it's moving faster than the other. If somebody tried to tell you they were going at the same speed, you'd laugh at them.

Let's say that we're watching the race on a large TV screen, from an overhead camera. The horses are side by side, but one falls behind the other.

Now let's say that the track that the lagging horse is on has dips and rises in it that we can't see on the TV, because they're in a third dimension not visible on the 2D screen.

This would mean that the track the lagging horse is on has a longer distance in 3D space that isn't apparent in 2D space.

In this situation, the two horses could be traveling at the exact same speed and one would appear to be traveling slower because it's path is curved in a third dimension.

In relativity, time is represented by a fourth dimension. Light appears to be traveling slower because it's path is curved in a fourth dimension.

To quote Dr. Emmett Brown: You're just not thinking fourth dimensionally!

ETA: I know I've probably explained this quite poorly, but hopefully someone else will provide a clearer and more accurate explanation.

When they then tried to tell you that space was falling down, you'd tell them to stop wasting your time with fairytales.

Nobody's claiming that space is literally being sucked into a black hole or planet.

 

[sol invictus]

I know what gravastars are.

No, you've made it obvious that you don't.

Oh stop whining. We call all read about gravastars and see that this depiction is a better match with the original frozen-star black hole interpretation that your Chicken-Little fairytale.

Nonsense. Gravastars are not black holes. They don't have horizons or singularities. They are not vacuum solutions to GR. They are not described by the Schwarzschild solution at the would-be horizon. By contrast the river analogy is the Schwarzschild metric, it has a horizon, etc.

This entire thread has been devoted to your failure to understand the Schwarzschild horizon, which gravastars don't have. So follow Visser's advice.

No. You're left with egg on your face because the guy who wrote the paper you referred to is into gravastars now. He has abandoned your sky falling in, and left you high and dry.

This comment reveals something interesting about your psychology. To you, these ideas don't have any solidity or validity apart from that imparted to them by the people that espouse them, and the moment the author of one moves on to something else, the ideas he worked on previously go poof.

How postmodern of you, Farsight. And how completely inconsistent with your other habit of ignoring everything Einstein said except for one or two early quotes.

 

[sol invictus]

Nobody's claiming that space is literally being sucked into a black hole or planet.

Indeed, nobody has made that claim.

The facts are that a certain set of hydrodynamic equations describing a fluid flowing with a speed that increases as a function of distance until it reaches and then passes the speed of sound in that fluid are identical to those describing the spacetime near a black hole.

That's a fact. Does it mean space is a flowing fluid? No. For one thing, those fluid equations are an approximation that fail to describe real fluids perfectly. By contrast, as far as we know the equations of relativity don't break down in the analogous context.

In relativity, the local speed of light in any frame is always c. In other words there is no rest frame, there's no difference between moving and not moving. It might seem impossible for any fluid to have that characteristic (after all, moving through a fluid is different from being at rest with respect to the fluid - right?), but interestingly it turns out that sound propagating in the fluid does have that characteristic. You simply follow Einstein's careful procedure for defining Lorentz frames, but replacing light with sound. It works.

However, according to relativity all the laws of physics are invariant under changes of Lorentz frame - that's called "Lorentz invariance", and it's believed to be a fundamental principle. Here, only the equations describing sound and fluid propagation are invariant, and even that invariance gets broken at higher order (by interactions between sound waves, for example).

Nevertheless, the analogy is extremely useful, because our intuition about sound waves doesn't come from those small, higher order interactions.

 

[Farsight]

The universe is expanding because space is expanding. Is the solar system getting bigger? No. All that extra space has to be going somewhere. So why can't the earth be sucking in all that extra space?

The solar system isn't expanding because it's gravitationally bound. Ditto for a galaxy. The space surrounding the galaxies is expanding, but the galaxies themselves aren't. That's the "raisins in the cake" analogy. Note what Einstein said in his Leyden Address: a gravitational field is inhomogeneous space.

(Okay, I'm not being completely serious with this question. But it is an interesting point. How do you know it's not the case?)

Because if gravity did suck space in, the early universe would have contracted reather than expanded and I wouldn't be here.

But Kruskal-Szekeres coordinates show that time varies with gravitational force, resulting in the appearance of the speed of light varying with gravitational potential from the perspective of a distant observer.

They don't, they airbrush over the way the speed of light varies with gravitational potential. You don't need to be a distant observer to see this, you can do it within the confines of a room. What you can't see is time. Don't allow something you can't see to blind you to something you can.

In exactly what way does if fail to match the observed behavior of the universe? Where's the flaw?

In whether the mathematics provides a real solution. There's nothing wrong with the mathematics that tells you that the square root of 16 is either 4 or -4. But if you then assert that a carpet measuring -4m by -4m is something real, you've got a problem.

You don't know that the local speed of light varies with gravitational potential. Even you've admitted that there's no way to locally measure the speed of light that would show it to be traveling at a different speed.

I can. I can see that optical clocks lose synchronisation when separated by only a foot of vertical distance. From that I know that parallel-mirror light clocks will do the same. So I know that this is what's happening:

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But everyone here agrees that non-local light appears to the observer to travel at different speeds. Nobody disputes that.

There's no appears about it. One light beam is going faster than the other and that's that.

The standard way of explaining this is that light appears to travel slower in areas of high gravity because time is passing at a slower rate in those areas. You're claiming that light actually does travel slower in areas of high gravity because... um... just because.

Just because I can see it. There's no time passing in between the mirrors. You're claiming that light doesn't move slower because of something you can't see.

And your description of the effect of the slower speed of light is indistinguishable from what we regard as time traveling slower.

For some things yes, but when we start talking about time travel and black holes you start to see differences.

Since the observable behavior of the universe in your description is completely indistinguishable from the observable behavior of the universe in the standard description, what is your basis for claiming that the standard description is wrong?

I can see light moving. I can't see time passing.

You can't show us any math, and all empirical evidence supports both descriptions equally.

I've shown you the maths of the Lorentz interval and how SR time dilation is based on the motion of light and Pythagoras' theorem. The interval is invariant for the twins with their parallel-mirror light clocks because their two light paths are the same length. And the empirical evidence does not support the time passes slower description.

Plus your description completely fails to explain why light is traveling slower, while the standard description for why light appears to travel slower provides both an explanation and a complete mathematical outline.

I've told you why. The vacuum impedance of space Z0 = √(μ0/ε0) is increasing, and c = √(1/ε0μ0).

It's statements like this that make me wonder exactly what kind of strange and bizarre concept of time lurks within your mind.

The concept developed by Godel and Einstein in 1949. See A World Without Time: The Forgotten Legacy of Godel and Einstein. It isn't strange or bizarre, you can trace it back through Presentism to the ancient Greeks. It's just "time is change".

Gee, thanks for the diagram. Somehow I didn't quite understand it the first five hundred times, but suddenly it now makes perfect sense.

Chuckle. Shifting conviction is like shifting a tooth. I have to keep up the pressure. Take another look at that diagram, animate it in your mind. Wheee! See that time passing in there? Er no. Just light. Moving.

Let's say that we're watching the race on a large TV screen, from an overhead camera. The horses are side by side, but one falls behind the other.

Fine.

Now let's say that the track that the lagging horse is on has dips and rises in it that we can't see on the TV, because they're in a third dimension not visible on the 2D screen.

Why? The horses are side by side. Racetracks are flat. Just accept what you see. One horse lags behind the other. So the other horse is going faster.

This would mean that the track the lagging horse is on has a longer distance in 3D space that isn't apparent in 2D space.

You could make up anything to try to explain away the obvious. Don't.

In this situation, the two horses could be traveling at the exact same speed and one would appear to be traveling slower because it's path is curved in a third dimension.

It's two horses on a level track!

In relativity, time is represented by a fourth dimension. Light appears to be traveling slower because it's path is curved in a fourth dimension.

No. Light is travelling slower. It's path curves when it travels through a region of space where die Ausbreitungs-geschwindigkeit des Lichtes mit dem Orte variiert. That's what Einstein said. The speed of light varies with position. Oooh, I see somebody has altered the Google translate for that. Naughty. Try a different translator, such as this.

To quote Dr. Emmett Brown: You're just not thinking fourth dimensionally! ETA: I know I've probably explained this quite poorly, but hopefully someone else will provide a clearer and more accurate explanation.

They can't, Brian. I'm the one explaining it clearly and accurately. Think through what I've said. Think for yourself. It's really simple once it clicks. A bit like riding a bike.

ETA: Don't let sol or anybody else do your thinking for you. That includes me. Think for yourself.

 

[Farsight]

Nobody's claiming that space is literally being sucked into a black hole or planet.

Indeed, nobody has made that claim

Do your own research Brian. Read back through the thread, and check out google to see how many times this nonsense has been ladled out to a gullible public.

In relativity, the local speed of light in any frame is always c. In other words there is no rest frame, there's no difference between moving and not moving. It seems impossible for any fluid to have that characteristic, but it turns out that sound in the fluid does have that characteristic. You simply follow Einstein's procedure for defining Lorentz frames, but replacing light with sound.

Then you look at sonar, you note the refraction and curvature, you remember pair production and the wave nature of matter and say I am made of sound, and then you read what Robert Close said.

Who wants to talk about electromagnetism? But later. I'm off to paint the laundry room.

 

[DeiRenDopa]

That I may have failed to understand your ideas is entirely possible; after all, in ~five years' of posting, it would seem very few (if any) others do understand your ideas.

Most people in such a situation would take that as pretty strong evidence that either their ideas were incoherent, or their presentation style was flawed. Unfortunately, Farsight/Mr. Duffield does not appear to have reached the same conclusion, presenting the same ideas in the same way as far back as you care to google.

That's a pretty sound conclusion; as you note, using google you can find plenty of evidence that Farsight has no success in enabling/helping/facilitating/persuading/etc others of the validity of his ideas. Further, the approach he seems to use does not seem to have changed, in any significant way, over the past half-dozen (or more) years.

Does that mean he's fooling himself over obvious (in)validity of his ideas? Or that he's simply blind to just how total his failure to communicate is (objectively)? Or that he doesn't care, one way or the other? Or that his true (a word he himself likes to use) aim has nothing to do with the (apparent) content of his posts? I do not know.

This being so - and Farsight has, so far, been mute here - I got to wondering if I could show where he could have done a better job.

The regular lurkers to this thread may find this interesting, and may even be interested enough to comment.

You keep asserting that, but you seem to be incapable of providing any evidence.

I've provided ample evidence previously in the form of optical clocks and the Shapiro delay. As you know the coordinate speed of light varies in a non-inertial reference frame such as the room you're in, and we can simplfy the optical clocks to parallel-mirror light clocks thus:

|----------------|
|----------------|

The evidence is patent.

(some bold added)

That's the first use in this thread, by Farsight, of his signature diagram.

Given that he's been rabbiting on for years about this, and given that he could reasonably expect there to be new readers, how could he have presented this better?

Well, a link to "previously" would have helped.

As this is the first time, in this thread, he's introduced "the optical clocks to parallel-mirror light clocks thus", a small investment in time to carefully, and clearly, explain what an optical clock is, and what a parallel-mirror light clock is would surely have helped get readers onto the same page as he is.

Then comes the signature diagram.

And here Farsight really damages his image, and sets himself up for hard arguing.

If you present, or use, a diagram for the purpose of (or with the hope of!) communicating something clearly and succinctly, the book on how to communicate successfully says you should label it clearly, and make sure that all your intended audience gets it.

So, what does Farsight intend the two lines of text/symbols to represent? He doesn't say (certainly not clearly).

What do the four vertical lines/symbols stand for? Who knows? Farsight doesn't tell you.

What are the minus signs supposed to be? Silence.

The metric doesn't tell me it varies. Experiment tells me that. It's as plain as the nose in front of my face. Experiments like the Shapiro delay. Experiments using super-accurate optical clocks which lose synchronisation when separated by only a foot of vertical elevation. They're optical clocks. They employ electromagnetic hyperfine transistions and electromagnetic waves. And we can simplify them to parallel-mirror light clocks, which we know will also lose synchronisation when at different elevations:

|--------------|
|--------------|

Can you see the time flowing in these experiments, sol? No. You see light moving through space. That's all that's there. Learn to see what's there instead of

That's from the fifth use in this thread, by Farsight, of his signature diagram.

Here he at least explains what he means by "optical clocks" (albeit mostly with a link, and perhaps not the most helpful such link).

By inference, we, the readers, can conclude that the set of symbols on the second line is supposed to represent something - perhaps a parallel-light clock? perhaps a super-accurate optical clock? - at a different elevation than the same sort of thing as the set of symbols on the first line.

But which is which? Farsight doesn't say.

And if distance down the page/screen represents vertical distance, and distance across the page/screen horizontal distance, is it reasonable to also conclude that the two scales are comparable? Silence.

Still no word on what the two key symbols (vertical line, minus sign) are supposed to represent.

Essentially optical clocks losing synchronisation when separated by a vertical elevation of only a foot. I've also mentioned the GPS clock adjustment and the Shapiro delay, but they're essentially the same thing. The optical clock uses aluminium rather than caesium, and a UV frequency rather than a microwave frequency, but it works along the same lines, and employs electromagnetic phenomena. When these move at a lower rate, the clock runs slower. We use the idealised parallel-mirror light clock extensively in relativity, see for example this instance, and we know that parallel-mirror light clocks would keep time with optical clocks at different elevations. So we know that this scenario applies:

|----------------|
|----------------|

Think of the two light beams as racehorses.

(bold added)

In this, still later, use of his signature diagram, Farsight does, finally, explain the background. Does he do so clearly? Perhaps not, but looking into that would take me too far from what I want this post to be about.

However, there's still no explanation of the diagram itself; nothing on what he intends the symbols to represent, which clock (if indeed they are clocks) is at the higher elevation, what the scale is, and so on.

Worse, here he introduces an analogy ("Think of the two light beams as racehorses"), with no explanation! For example, what (or where) are "the two light beams"? If they're racehorses, where is the racecourse? The two lines of text/symbols can't be the racecourse, because they're at different elevations (so one may conclude, even though Farsight doesn't say), and racehorses on a racecourse run parallel on parallel tracks, at the same elevation!

And so on.

There's more of this, Farsight's use of his signature diagram in this thread; I intend to present it in later posts.

To close, let me stress that the reason why I think this is so important - for Farsight - is that a) he has failed, spectacularly, in communicating his idea, despite having posted it in various internet fora for many years; and b) his idea includes many pieces which seem, on first reading, to be the same as what you'd find in a decent popsci piece, or a good textbook, but which he interprets/explains/understands in a quite different way.

Of course, I may have made a big mistake here; I have assumed that Farsight - at some level - is genuinely interested in communicating his idea to others, in having more people (than just himself) truly understand this idea of his.

 

[DeiRenDopa]

Continuing my observations on Farsight's failure to communicate successfully, with regard to his signature diagram.

This is from the twelfth (yes, 12th!) post in which Farsight uses his signature diagram:

Regarding the main point I'm trying to convey, if I showed you two parallel cables with a different impedance, you'd expect to see some variation in the A/C signal propagation time, which we might depict like this:

|-----------------|
|-----------------|

If I replace the cables with light beams in say a smoke-filled chamber, and gave you a gedanken high-speed camera, you should be able to play back the film and see the light beams propagating in a similar fashion:

|-----------------|
|-----------------|

I would hope that you would attribute this difference to vacuum impedance rather than "time flowing slower", and conclude that c = √(1/ε₀μ₀) is not an absolute constant.

Perhaps for the first time, Farsight attempts to tie his diagram to what you might expect to observe, in an experiment ("If I replace the cables with light beams in say a smoke-filled chamber, and gave you a gedanken high-speed camera, ..."). That's good. Using the diagram so many times previously, without something like this? That's bad; you'd've flunked the homework assignment if you were in the Communications 101 class Farsight.

However, the presentation itself could have been much, much better.

For example, key to what Farsight has been trying (but failing) to convey is the importance of a difference in elevation ("separated by only a foot of vertical elevation", from the fifth post in which he uses this diagram). Yet this post doesn't even mention elevation, much less label (parts of) the lower diagram to show which light beam is at what elevation.

Worse, by not mentioning elevation, and by using an analogy ("two parallel cables with a different impedance"), Farsight implies elevation is not important. Even if Farsight had not had years of complete failure (i.e. zero success in communicating the validity of his idea), by this point in the thread he should have been fully aware of the fact that his audience* was simply not understanding him at all. So spelling out, clearly, what elevation has to do with the diagram would have been A Very Good Thing To Do.

Now Farsight has, many times in this thread, urged others to "think for yourself", to "do your own research". Doing so here would lead to questions such as:

Why would I expect to see the parallel light beams propagate like that?

Where are the light beams supposed to come from?

What are the vertical marks supposed to be?

Playing back the film gives me a video; how does the diagram capture what would be in the video (the diagram is a still image)?

And so on.

Farsight could have done a much better job of communicating his idea if he had anticipated some of these questions, and put the time and effort in to labeling, explaining, etc.

However, I think the biggest communications failure in this post concerns the Gedankenexperiment itself ("light beams in say a smoke-filled chamber, and gave you a gedanken high-speed camera, you should be able to play back the film and see the light beams propagating in ..."). From his years of interacting with others, Farsight certainly knows that a goodly number of his audience will 'smell a rat' in the way he's presented this Gedankenexperiment. For example, many in his audience will have learned that simultaneity, of remote events, is relative; that one's everyday intuitions are unreliable when it comes to grokking relativity; and that remote records (which is what the film from the gedanken high-speed camera is) need to be analyzed very carefully, to draw sound conclusions.

So how could Farsight have avoided serious miscommunication on this last point? Many ways; for example, he could have bent over backwards to explain the set up (e.g. where is the gedanken camera located? how is it triggered, to start the film rolling? how are the light beams triggered?), described clearly how it avoids or mitigates any remote observing and relativity issues, and backed it all up with some simple calculations.

Part 3 coming up ...

* or at least that part of the audience who was responding, by posting in the thread

 

[Ziggurat]

There's every reason to cite Einstein when people support pseudoscience assertions with "GR tells us".

Yet we're still faced with the problem that Einstein has explicitly refuted some of your claims. You can't have it both ways, Farsight. You can't claim him as the authority on GR and simultaneously ignore what he says about GR that you find inconvenient.

Other words of Einstein don't "directly refute some of my claims".

Yes they do. For example, your claim that we can't use an earth-centric reference frame is explicitly contradicted by Einstein's statement that we can use any reference frame.

I know what the theory predicts.

You have repeatedly proven otherwise.

I've already referred to The Confrontation between General Relativity and Experiment by Clifford M Will. Read it.

And what precisely do you think I will find? Because what I find is that "general relativity has held up under extensive experimental scrutiny." The author suggests further experimental testing, which is precisely the point I made about not knowing the accuracy of the theory under conditions we have not yet tested it under. But again, that's completely different from what you're arguing. You're arguing that the experimental evidence already available refutes standard GR, and this paper contradicts your position in that regard.

Yet another epic fail: just like with your Wikipedia page on entropy, you don't understand your own links.

I'm no crank.

You could have fooled me.

Cranks are the guys who say "Einstein was wrong".

So you are making an argument from authority.

No, that's not what makes a crank. A crank is someone who claims that the entire edifice of modern physics is wrong, that even though they have no real understanding of that physics, they know it better than the professionals, and that math doesn't matter.

Oh, and you have claimed that Einstein was wrong.

That's what Einstein did.

And it's also what you refuse to do.

Yes. Standard MTW GR teaches you that the speed of light is constant, when you can see it isn't. Just like Einstein said.

No. MTW teaches that the coordinate speed of light depends on what coordinates you use. And its predictions, regardless of coordinates, all agree with observations. Once again: the predictions match the observations. How can the theory be proven wrong if the predictions match observations? That's a logical impossibility which you keep falling over.

Irony isn't your strong suit, is it Zig? Why don't you tell everybody about your negative carpet again?

I've told you everything you need to know. And your only response has been incredulity. Never once have you actually addressed the substance of what I've said.