Black holes

[sol invictus]

This thread is getting increasingly bizarre. We've got Zig talking about negative carpets and nurses who don't take temperatures, and now you're trying to suggest that a mirror on the wall is accelerating outwards?

Outwards? No. Upwards.

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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Let's be sure we're clear on precisely what you're saying. You're asserting that two light clocks in radial free fall near a black hole horizon, at relative rest, with one at larger r than the other, will not stay in sync (as judged by, say, an observer watching them from a freely falling position midway in between). Is that correct?

Because if so, you're wrong, and I can prove it easily. But first I want you to confirm that's what you're saying.

And you still won't say what it represents! What's the problem?

See above. You're fighting shy of revealing your metric.

What?? I've told you literally five times now precisely what it represents - flat, empty, spacetime. Is this some sort of cognitive dissonance so extreme you can't read what I'm writing?

That makes a certain amount of sense - you can't deal with that, because it demonstrates in a very clear and simple way that what you've been saying for the last five (?) years is wrong. The consequences of understanding this are so painful that your brain just shuts down when you get close to it.

 

[sol invictus]

To this question: Is it your position that the Kruskal-Szekeres coordinates predict that clocks held in place close to a black hole horizon - at fixed areal radius, or fixed "r" in Schwarzchild coordinates - do not run slow compared to clocks far away?

Farsight answers:

No.

So, Farsight now says he agrees that the Kruskal-Szekeres coordinates (correctly) predict that clocks held at lower radius near a black hole will run slow.

And yet, earlier Farsight asserted:

Kruskal-Szekeres coordinates are defined using a "new time coordinate" which ignores the scientific evidence that light clocks tick slower with gravitational potential. They ignore the infinite gravitational time dilation that means those clocks stop.

You're contradicting yourself, Farsight.

 

[Farsight]

Based on his request for me to use the term "relativity+" in place of "FGR" (near the end of this post), my money would be on him thinking of the ideas he expressed in the Relativity+ thread. It's his "theory of everything" in which particles we normally think of as fundamental are in fact photons somehow trapped in "self-bound states", or something like that. Every particle would then carry a kind of internal clock that runs at a rate proportional to the speed of light. If that's what FGR (as presented in this thread) depends on then it obviously cannot be some "correct", "true-to-Einstein" interpretation of GR.

It goes further than GR, which doesn't cover particle physics, but it is true to Einstein. See Einstein talking about the history of field theory in 1929 and pay attention to the "structures in space". See bits like this:

"The two types of field are causally linked in this theory, but still not fused to an identity. It can, however, scarcely be imagined that empty space has conditions or states of two essentially different kinds, and it is natural to suspect that this only appears to be so because the structure of the physical continuum is not completely described by the Riemannian metric".

But anyway, we aren't talking about me. We're talking about black holes, and how the patent scientific evidence for the variable speed of light, which was advocated by Einstein, favours the original "frozen star" interpretation rather than the "point singularity" interpretation.

 

[Roboramma]

Not so. Now go and show somebody your negative carpet with three edges measuring -3m -4m and -5m. Or any other negative lengths and number of edges. Then get real. A length can't be less than zero. Nor can a speed.

What do those lengths mean farsight? They refer to the distance between two points, obviously.

Say I've got a piece of paper, and I want to draw a shape on it. Tell me how?

I need to specify some point, and draw some length from that point in some direction. And then I need to do that again. That you some how think I can do this without direction is pretty weird.

But if direction is an aspect of a shape, then clearly it's also an aspect area.

 

[Farsight]

Recall that Farsight's method of measuring the local speed of light is to time a light pulse as it travels between emitter and detector (whose separation has been determined by a local ruler, calibrated using the SI definition of meter), using a pulsar clock...

... What a wondrous thing light is! The very same light can have so many different, local, speeds, all at the same time!!

If anybody is still reading Dopa's posts, my advice is: don't. He hasn't conducted the gedankenexperiment using clocks calibrated against a distant pulsar, and he's ended up trying to tell you the equivalent of a train is running at two speeds at the same time. It's nonsense sophistry. Don't fall for it. Take note though of anybody who doesn't point it.

 

[DeiRenDopa]

Perhaps he had different priorities, such as writing and promoting his book.

But you are right, and he could have been writing and publishing papers in credible journals instead.

---

(ETA: It seems this goes back to at least 2006. Note the last sentence of the opening post .)

I think, given the obvious lack of communication between Farsight and (every?) other JREF member actively participating, some quotes from that 2006 thread might be enlightening.

Quite early on - in the second half of the first page (the thread has 18 pages), someone using the handle Euler asked this of Farsight:

1) How do you define motion without time?
2) How do you expect to disprove someone's armwaving interpretation of time? You have given no formal definitions, no precise statements, no derivations.
3) Why don't you actually learn some mathematics and then some theoretical physics, so you will actually be in a position to comment on current theory?

Many posts later, and with considerable prodding, Farsight responded to the first question thusly*:

Euler: we can define motion without time because motion exists whilst time is a product of motion ratios and counting. Motion is fundamental and is actually there. Motion ratios are also there, and we do count them. But our concept of time that allows travel in the direction of counting is a false concept. There is no such direction. And if you'd actually read Time Explained you wouldn't need to ask.

After more prodding, Farsight answered the other two of Euler's questions like this (it's on page 3): "If you've got anything to contribute fine. Otherwise go play."

With further prodding, Farsight elaborated, with words that have a MM-esque feel to them:

[on 2)] This is a "when did you stop beating your wife" question. A considered explanation is dismissed as arm waving because somebody can't show me the maths.

[on 3)] So's this. It's merely another insult.

These aren't genuine questions. Somebody on this forum is wasting everybody else's time. And it ain't me.

Like I said Euler: go play.

* there's an immediate, succinct, response by Euler, which is well worth reading (but it would take me too far from the point I want to make)

 

[Farsight]

...That's what it looks like to outside observers, because outgoing light is swimming against the stream of infalling space...

Oh boy. This is where I came in. With the waterfall analogy. And Clinger, who has totally evaded the scientific evidence and everything Einstein ever said, who has absolutely no counterargument and who hides behind maths, still thinks that in a gravitational field, space is falling inwards. Like the black hole is some cosmic vacuum cleaner that sucks in space. Groan.

 

[Farsight]

Combined with several others' posts (and an earlier one of your own), this make it clear that whatever set of ideas Farsight has presented in this (and other) threads, on GR, they are not Einstein's GR...

So, much like MM, Farsight has not - in the last ~five years - been able to either a) put quantitative meat on the word-skeleton of his ideas, or b) explain his ideas in a sufficiently clear way that others* can understand them^...

Also, much like MM, Farsight seems to have a tin ear. Given the enormous amount of time he's put in to writing posts here, and his stunning lack of success at communicating his ideas, I think a reasonable response would have been to deeply examine the form and content of the communication. Try to find some common ground on which to start building a meaningful dialog. Ask questions. Etc. Yet what Farsight actually writes is this sort of thing: "LOL. Don't bother. Your "interesting variation" demonstrates that you still don't get it."

Someone - perhaps PS - characterized MM's posting as having a strong narcissistic tendency; why else persist in behavior that is so obviously unsuccessful (in terms of attaining its explicit goal)? Perhaps Farsight too ...

LOL. You're out of your depth on the physics, your gedankenexperiment is an abject failure, and now out comes the snide ad-hominem abuse. You've not only failed the physics test, you've failed the integrity test too.

Next.

 

[Farsight]

Outwards? No. Upwards.

You said outwards. See post #609. Touché.

Let's be sure we're clear on precisely what you're saying. You're asserting that two light clocks in radial free fall near a black hole horizon, at relative rest, with one at larger r than the other, will not stay in sync (as judged by, say, an observer watching them from a freely falling position midway in between). Is that correct? Because if so, you're wrong, and I can prove it easily. But first I want you to confirm that's what you're saying.

No. Read what I said. I said 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. And you can't show me anything, because you and your two parallel-mirror light clocks are only falling because the speed of light at your feet is less than it is at your head. What are you going to do, presume it ain't so then reel off a pile of circular mathematics "proving" your own presumption?

What?? I've told you literally five times now precisely what it represents - flat, empty, spacetime. Is this some sort of cognitive dissonance so extreme you can't read what I'm writing?

That makes a certain amount of sense - you can't deal with that, because it demonstrates in a very clear and simple way that what you've been saying for the last five (?) years is wrong. The consequences of understanding this are so painful that your brain just shuts down when you get close to it.

You still won't say what your expression represents, you still won't define your terms, and you still won't explain the distinction between your expression and the invariant Lorentz interval that I explained in post #605. You're still hiding behind mathematics instead of addressing the evidence. And now you're hiding behind abuse? That's one way to end an argument I suppose. Especially when you've lost it.

 

[DeiRenDopa]

Recall that Farsight's method of measuring the local speed of light is to time a light pulse as it travels between emitter and detector (whose separation has been determined by a local ruler, calibrated using the SI definition of meter), using a pulsar clock...

... What a wondrous thing light is! The very same light can have so many different, local, speeds, all at the same time!!

If anybody is still reading Dopa's posts, my advice is: don't. He hasn't conducted the gedankenexperiment using clocks calibrated against a distant pulsar, and he's ended up trying to tell you the equivalent of a train is running at two speeds at the same time. It's nonsense sophistry. Don't fall for it. Take note though of anybody who doesn't point it.

What I've done is take the ideas you've posted in this thread, and tried to understand them.

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.

But let's do a little test, shall we?

What do other readers of this thread make of my Gedankenexperiment (part I, part II, part III; you may need to click a few arrows to get all of it, especially the context)?

Specifically:
1) where, exactly, is it inconsistent with what Farsight has posted, so far?
2) irrespective of what Farsight may think, are there any flaws in it?

As Ziggurat, Hellbound, D'rok, W.D.Clinger, ctamblyn, Guybrush Threepwood, and theprestige* have answered at least one of my earlier 'APB' questions, I'd particularly appreciate hearing from you.

* there are, undoubtedly, others who I have not mentioned; I did not attempt to make this a complete list

 

[DeiRenDopa]

LOL. You're out of your depth on the physics,

So, another question, specifically for those do have a better grasp of physics than I do: am I out of my depth, as Farsight claims?

your gedankenexperiment is an abject failure,

Perhaps.

But whatever failure there is, it does not stem from want of trying to first understand your ideas and then apply them. I think you'll find that this is a pretty good learning style, certainly better than cherry picking the non-quantitative parts of non-papers ...

 

[Ziggurat]

No it isn't. Matter is made of energy. Not entropy. And both temperature and entropy are emergent properties of a system.

Entropy is as much an emergent property as energy is. And contrary to your viewpoint, it's more fundamental than temperature.

No it isn't. Go look it up. See the ice in the glass? That ice is cold. Let's say the water in the glass is hot. The ice melts, and you're left with warm water. All the water is now at the same temperature. Entropy has increased.

I love it when people give sources that they don't understand and which contradict them. Read it yourself. Do you see anywhere in that article that entropy measures uniformity? No. Because no such definition exists, except in your head. Entropy measures the degree of disorder in a system. That apparently uniform water is actually more disordered than the water + ice, precisely because the molecules bouncing around in the water are NOT all similar. So again, let me quote from your source: "entropy is an expression of disorder or randomness".

And your inclusion of temperature here again betrays a deep misunderstanding. Temperature is defined by entropy, so logically entropy must be defined completely independently of temperature, or else you're just using circular logic, and there's nothing physical about that.

She's measuring the patient's temperature using a thermometer! Strewth!

And she's doing it by inferring the temperature from a volume measurement. The calibration has been done for her already, but it was always dependent on a theory of how temperature relates to volume.

Yeah yeah, we don't measure temperature with a thermometer.

Not directly.

No, the colour of the red-hot or yellow hot poker tells you what temperature it is. A device used in kilns is called a pyrometer.

And that device works by measuring light, and comparing the results against a theory. You are failing to make your case that temperature is fundamental, not abstract.

They're both emergent system properties. Temperature is a measure of the average motion, entropy is a measurement of the similarity.

Both definitions you have given are wrong.

Stow your pompous bluster. I know plenty about thermodynamics.

Evidently not, since you can't get even the basic definitions correct.

And as for making a fool of yourself, tell us about that negative carpet again. You know, the one where each edge is -4m long.

I never said it was -4 m long. I said you cut it out by cutting -4 m along a direction. You keep ignoring the direction, but if you do that in real life, I promise you won't end up with a square.

 

[Farsight]

What do those lengths mean farsight? They refer to the distance between two points, obviously.

That's right. And a distance cannot be negative. The distance from one corner of your carpet to another cannot be less than zero metres. A length cannot be negative, and nor can a speed. Once you reduce a length or a speed to zero, that's it.

Say I've got a piece of paper, and I want to draw a shape on it. Tell me how? I need to specify some point, and draw some length from that point in some direction.

Just draw a 3cm line in any direction you like.

And then I need to do that again. That you some how think I can do this without direction is pretty weird. But if direction is an aspect of a shape, then clearly it's also an aspect area.

You don't need any directions from me. Draw a 3 4 5 triangle. Use a pair of compasses or trigonometry or something. Think for yourself.

It isn't relevant anyway. A distance is a scalar and there's no such thing as a negative distance. A negative displacement is no problem, but the edge of a carpet has a length, and that's a distance, not a displacement. It cannot be negative. Zig knows this. He's just trying to claw himself out of a hole with this, but he's only digging himself deeper. Such is life in the surreal world of cargo-cult physics.

All: OK, it's been fun again guys, but I must go. Can somebody please try to address the hard scientific evidence instead of resorting to abuse. If you won't, I've won. Catch you later.

 

[sol invictus]

You said outwards. See post #609.

In post 609 we were discussing black holes, and "outwards" (away from the hole) is a clearer term than "upwards". In your post, you brought up a mirror on a wall, which is accelerating upwards.

Incidentally, since you seem unfamiliar with these concepts - were you aware that an accelerometer attached to a wall or sitting on a table will register an acceleration of 9.8 m/s^2 upwards?

No. Read what I said.

What you write is often incoherent and inconsistent, so "read what I said" doesn't help.

I said 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.

And that differs from my formulation.... how? Here it is again: "You're asserting that two light clocks in radial free fall near a black hole horizon, at relative rest, with one at larger r than the other, will not stay in sync (as judged by, say, an observer watching them from a freely falling position midway in between). Is that correct?"

If my formulation is accurate, you're wrong. If it isn't, you need to explain precisely why and how it differs from yours.

You still won't say what your expression represents

 

[Ziggurat]

Not so. Now go and show somebody your negative carpet with three edges measuring -3m -4m and -5m. Or any other negative lengths and number of edges. Then get real. A length can't be less than zero. Nor can a speed.

If you only have a distance and not a displacement, how can you even know how many sides a square (or triangle) of carpet should have? It's you, not me, who has that fact confused.

Are you sure about that Zig? Anybody else care to back him up?

Well, since you're so fond of Wikipedia, why don't we check there?

"The Schwarzschild solution, taken to be valid for all r > 0, is called a Schwarzschild black hole."

So it's a matter of convention, as W.D. said. But you kept referring to a particular plot which used the convention of taking all r as part of your solution. I'm just going by your source.

But we aren't talking about outside the event horizon.

You most certainly are. Every single bit of actual "evidence" you have provided refers to observations made outside the event horizon.

Whatever next? Is somebody going to tell me that a coordinate system where the sun goes round the earth is all fine and dandy?

Who would ever be crazy enough to make that claim?

Oh.

 

[DeiRenDopa]

This reminds me of the "discussion" we had with MM, on the Casimir effect, and the definition of pressure.

No it isn't. Matter is made of energy. Not entropy. And both temperature and entropy are emergent properties of a system.

Entropy is as much an emergent property as energy is. And contrary to your viewpoint, it's more fundamental than temperature.

No it isn't. Go look it up. See the ice in the glass? That ice is cold. Let's say the water in the glass is hot. The ice melts, and you're left with warm water. All the water is now at the same temperature. Entropy has increased.

I love it when people give sources that they don't understand and which contradict them. Read it yourself. Do you see anywhere in that article that entropy measures uniformity? No. Because no such definition exists, except in your head. Entropy measures the degree of disorder in a system. That apparently uniform water is actually more disordered than the water + ice, precisely because the molecules bouncing around in the water are NOT all similar. So again, let me quote from your source: "entropy is an expression of disorder or randomness".

And your inclusion of temperature here again betrays a deep misunderstanding. Temperature is defined by entropy, so logically entropy must be defined completely independently of temperature, or else you're just using circular logic, and there's nothing physical about that.

She's measuring the patient's temperature using a thermometer! Strewth!

And she's doing it by inferring the temperature from a volume measurement. The calibration has been done for her already, but it was always dependent on a theory of how temperature relates to volume.

Yeah yeah, we don't measure temperature with a thermometer.

Not directly.

No, the colour of the red-hot or yellow hot poker tells you what temperature it is. A device used in kilns is called a pyrometer.

And that device works by measuring light, and comparing the results against a theory. You are failing to make your case that temperature is fundamental, not abstract.

This last one in particular shows that Farsight has the same - or a very similar - fundamental misunderstanding of the relationship between physics and reality as MM so obviously does.

Our instruments and measuring devices work only within the context of a clear set of definitions (e.g. of SI units) and a set of theories of physics (or models constructed from them).

While it may be possible, even interesting, to develop a hierarchy of abstractions (used in physics), there's no getting away from the fact that 'temperature', 'entropy', and 'energy' (to pick just three) are abstractions.

 

[Ziggurat]

So, another question, specifically for those do have a better grasp of physics than I do: am I out of my depth, as Farsight claims?

I don't think so. In truth, I don't know if your understanding of GR is better or worse than mine, so take that for what it's worth. But I know that Sol's understanding is better than mine, I suspect WD's may be as well, and I know that Farsight's is worse than all of ours.

In fact, any time a poster has to start resorting to "math isn't real", well, that's pretty much a guarantee that the poster is a crank. We see it time and time again, and it usually arises from people who can't even do the math. It's also not what real scientists say when debating a theory. They'll say that the math is wrong (if it is) or the theory is wrong. Or they might say that the theory is untested under some conditions, and its accuracy under those conditions is unknown. That's even defensible in regards to black holes: we haven't actually seen any up close, so we haven't actually tested GR under such strong fields.

But "math isn't real"? That's an argument for losers.

 

[ben m]

Is somebody going to tell me that a coordinate system where the sun goes round the earth is all fine and dandy?

Yes. You use this coordinate system, I presume, every day: it's called "latitude, longitude, and height".

Can you, or can you not state the latitude, longitude, and height of the Sun right now? I can, can't you? Can you do that again an hour from now? Good. Do the laws of physics explain why the Sun's coordinates could change from (lat=40N,long=70W,height=1AU,t=12PM) to (lat=40N,long=85W,height=1AU,t=1PM)? Sure they do.

 

[Ziggurat]

This reminds me of the "discussion" we had with MM, on the Casimir effect, and the definition of pressure.

Yeah, that was hilarious. In fact, I think I may have gone through a debate like this with MM about temperature as well.

Temperature is particularly good for exposing such fuzzy thinking: it seems like such an ordinary quantity, and we're exposed to it so early and so frequently, that pretty much everyone inevitably makes some sort of internal conceptual model of what temperature is. But the true physics definition is necessarily much more subtle than the models people construct on their own (as well as what's possible to teach children), and if you can't learn to let go of your preconceptions and start thinking about the issue rigorously, then you'll never grasp the truth. So it's a great litmus test for cranks. Most people, cranks or not, don't know the real definition of temperature, but the non-cranks are willing to learn

 

[tsig]

Oh FFS, this is getting surreal. Ben, you're an experimental physicist. Surely you know the difference between distance and displacement? There is no such thing as a negative distance.

The hop skippety jump over the truth is to suggest that square carpets can be 4m on a side, or 3m, or 2m, or 1m. Or 0m. Or even shorter than that.

Jesus H Christ, fellas. This is getting bizarre. Ever been to a party or something, and some guy starts talking to you? Whilst initially you think he's a lively spark, it gradually dawns on you that he's stark raving mad. I'm sorry, but that's how I'm feeling right now. It's possible that I may have to cough politely, see somebody I need to talk to across the room, and make my excuses.

Sheesh ben, get a grip.

Next!

So am I.