Black holes

[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.

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?

Regarding question (1): Without more constructive participation and detail from Farsight it is hard to be certain. I think your Gedankenexperiment is consistent with what Farsight has posted so far on pulsar clocks. Then again, as sol invictus pointed out, Farsight has contradicted himself at least once in this thread, making attempts to understand his model especially difficult.

Thanks.

I have certainly struggled to understand Farsight's ideas, concerning pulsar clocks, the speed of light not being constant, vacuum impedance, and more. My Gedankenexperiments were motivated in large part by a desire to provide something of a concrete test of my understanding of Farsight's ideas*. That his posts contain multiple inconsistencies, that he does not provide any meaningful feedback, etc makes my efforts unnecessarily great (IMHO).

As for question (2): At higher elevations there would be a greater number of pulsar ticks between the emission of a photon at that elevation and its subsequent detection a centimetre (say) away - i.e. one tick of a P-MLC would take longer in terms of pulsar ticks. If c_Farsight is some setup-dependent constant divided by the number of pulsar ticks, c_Farsight should decrease with height. However, the diagrams you posted here suggested the opposite, unless I read them wrong or misunderstood something about the set-up (which is not unlikely). Those diagrams aside, the text itself looked alright to me.

Thanks.

That (backwards diagrams) may well be so (I haven't checked yet), and seems consistent with Farsight's terse feedback ("Oh, and dishonestly backing Dopa's and getting gravitational time dilation back to front.").

I appreciate this feedback, and note that it's consistent with Zig's earlier post ("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."). In this sense you have - inadvertently, for sure - helped make the case I outlined in my last post; namely that a key difference between a science-based approach and an MM/Farsight-based one is the difference between fecundity and sterility. In the former, there are new questions, new things to test, an opening up, ... ; in the latter, there is nothing but dead-ends, bleak unchanging sameness, and death.

* I am also, somewhat, interested in understanding GR better, but there are far more effective ways of doing that than constructing Gedankenexperiments to test Farsight's ideas!

 

[ctamblyn]

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.

I'd personally give a low-ish probability to "he doesn't care". I haven't seen enough evidence to rule out any of the others, though.

* I am also, somewhat, interested in understanding GR better, but there are far more effective ways of doing that than constructing Gedankenexperiments to test Farsight's ideas!

I fully agree.

In that regard, I found some of the non-FGR-related parts of this thread very helpful indeed. The river analogy particularly intrigues me, and is something I'd hoped this thread might pursue a little more (e.g. what class of situations does it usefully apply to, etc). But there will be other opportunities in future threads, I'm sure.

 

[sol invictus]

In that regard, I found some of the non-FGR-related parts of this thread very helpful indeed. The river analogy particularly intrigues me, and is something I'd hoped this thread might pursue a little more (e.g. what class of situations does it usefully apply to, etc). But there will be other opportunities in future threads, I'm sure.

Now that Farsight's done a runner, this thread can go back to normal and we can certainly continue to discuss that if you like.

Basically, it works to the extent that rivers can be described by the right kind of idealized fluid equations - which is up to a point. Ultimately water is made out of molecules and so doesn't obey continuum equations. That means, in the language of relativity, that various higher-order corrections to the equations break "Lorentz invariance" (rather, the symmetry that's like Lorentz invariance but based on the speed of sound rather than light).

But at leading order it really is a very good analogy.

 

[Farsight]

And still you persist with pseudoscience! It's a cargo-cult analogy that is totally at odds with Einstein's general relativity. Light curves because space is inhomogeneous, not because space is being sucked inwards in a gravitational field. Now go and read Einstein's Leyden Address. Note the bit that says "recognition of the fact that 'empty space' in its physical relation is neither homogeneous nor isotropic" And see the last line? The one that says: The idea of motion may not be applied to it. Pay attention to it.

 

[DeiRenDopa]

And still you persist with pseudoscience! It's a cargo-cult analogy that is totally at odds with Einstein's general relativity.

So you've said.

Many times.

Yet you have not provided any evidence of inconsistency between Einstein's own paper on GR and contemporary presentations of GR (such as in Wald or MTW), in terms of the mathematics.

You have also failed to provide any evidence of inconsistency between the quantitative, objective predictions/explanations derived from contemporary presentations of GR and the quantitative, objective experimental and observational tests of GR (as found in the Will paper you have cited).

Further, you have not shown how, and where, the analogy fails, by comparing details of the mathematics on which it relies with the mathematics of GR.

Need I go on?

In short, you have failed - dismally - to communicate what you're trying so hard to say, in a way that others can understand you.

Why is that?

 

[sol invictus]

And still you persist with pseudoscience! It's a cargo-cult analogy that is totally at odds with Einstein's general relativity.

And yet, you've repeatedly failed to identify even one single problem with the published, peer-reviewed scientific papers that demonstrate that the analogy works mathematically.

Just like you've repeatedly failed to find one shred of evidence that contradicts the standard, textbook, modern general relativity that you assert is wrong.

ETA - I see that DRD said almost exactly the same thing. Clearly there's a conspiracy against you, Farsight.

 

[Farsight]

I'm not wrong. The earth is not sucking in the surrounding space. The sky is not falling in. And your mistruths and ad-hominems directed at me aren't going to change that one iota.

 

[DeiRenDopa]

I'm not wrong. The earth is not sucking in the surrounding space. The sky is not falling in. And your mistruths and ad-hominems directed at me aren't going to change that one iota.

If you're so convinced of the validity of what you've written, why don't you sign off, take a long walk, clear your head. Then review what you've written - and the responses to it - from the perspective of communication.

Try to find concrete reasons why you have - objectively - failed so completely to communicate your ideas to others*, in a way that ends with them understanding your ideas.

Perhaps you could focus on just one, small, well-defined thing. Ask questions. Seek consensus understanding. Define terms. That sort of thing.

Perhaps you could approach the topic a different way. Develop different analogies. Make new diagrams. Structure your case differently.

...

In fact, almost anything except the forum equivalent of stamping your feet and repeating "I am not wrong, you are!" like a broken record.

* well, at least those who've participated

 

[sol invictus]

I'm not wrong. The earth is not sucking in the surrounding space. The sky is not falling in. And your mistruths and ad-hominems directed at me aren't going to change that one iota.

"And yet, you've repeatedly failed to identify even one single problem with the published, peer-reviewed scientific papers that demonstrate that the analogy works mathematically."

 

[Farsight]

I haven't demonstrated that an analogy for fairies doesn't work mathematically. So what? I went through the abstract of the Matt Visser paper and told you the problem. I didn't pursue it because his very latest paper on arXiv concerns gravastars. You're fifteen years behind the times, sol. The guy you quoted in support of your Chicken Little sky-falling-in is with me now.

 

[dafydd]

I haven't demonstrated that an analogy for fairies doesn't work mathematically. So what? I went through the abstract of the Matt Visser paper and told you the problem. I didn't pursue it because his very latest paper on arXiv concerns gravastars. You're fifteen years behind the times, sol. The guy you quoted in support of your Chicken Little sky-falling-in is with me now.

Most amusing. No evidence from you then.

 

[Ziggurat]

If you're so convinced of the validity of what you've written, why don't you sign off, take a long walk, clear your head. Then review what you've written - and the responses to it - from the perspective of communication.

"Anyone who says that they're great at communicating but 'people are bad at listening' is confused about how communication works." - XKCD

 

[sol invictus]

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

What "analogy for fairies", Farsight? See the problem?

I went through the abstract of the Matt Visser paper and told you the problem.

No, you didn't. And what an absurd statement. The abstract doesn't contain any of the mathematics, so it would be quite impossible to identify a problem with the math from the abstract.

I didn't pursue it because his very latest paper on arXiv concerns gravastars. You're fifteen years behind the times, sol. The guy you quoted in support of your Chicken Little sky-falling-in is with me now.

The fact that Visser wrote a paper about gravastars means he's "with you now"? Gravastars aren't black holes at all, they're an exotic kind of star made out of some sort of matter. You're not making any sense.

 

[dlorde]

The earth is not sucking in the surrounding space. The sky is not falling in.

AFAICS, the 'sky falling in' is your own red-herring or straw man. But AIUI no-one is saying the Earth is really 'sucking in' the surrounding space, or that spacetime is literally falling into a black hole - they are saying that what happens is analogous, i.e. not the same, but comparable in certain respects, typically in a way that makes clearer the nature of the things compared.

That's what an analogy means.

 

[dafydd]

The fact that Visser wrote a paper about gravastars means he's "with you now"? You're not making any sense.

Give him time.

 

[Ziggurat]

And still you persist with pseudoscience! It's a cargo-cult analogy that is totally at odds with Einstein's general relativity. Light curves because space is inhomogeneous, not because space is being sucked inwards in a gravitational field. Now go and read Einstein's Leyden Address. Note the bit that says "recognition of the fact that 'empty space' in its physical relation is neither homogeneous nor isotropic" And see the last line? The one that says: The idea of motion may not be applied to it. Pay attention to it.

Ah yes, "The Gospel according to Einstein". You take his word as immutable truth, except when you ignore it completely. You castigate Sol for being fifteen years behind the times, yet keep referring yourself to words spoken more than 90 years ago as if they trumped every development that has been made since.

In short, you contradict yourself.

 

[Farsight]

I'm the one who's with Einstein on this, Zig.

AFAICS, the 'sky falling in' is your own red-herring or straw man. But AIUI no-one is saying the Earth is really 'sucking in' the surrounding space, or that spacetime is literally falling into a black hole - they are saying that what happens is analogous, i.e. not the same, but comparable in certain respects, typically in a way that makes clearer the nature of the things compared. That's what an analogy means.

They are saying that, dlorde. See Clinger's post #15 for example. He uses the word metaphor, but it's quite clear that he really does think space is falling into the black hole. See my post #671 where I justify the frozen-star black hole interpretation. One could offer an analogy with water and waves propagating through it, but the water itself is static. See this paper re refractive index and gravitational lensing.

 

[ben m]

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?

Actually, gr-qc/0310107 has a nice opening paragraph:

Whereas researchers in the relativity community (and the bulk of the astrophysics and
particle physics communities) are by and large happy with our understanding of classical
black holes, there is a certain amount of polite dissent. Such dissent ranges from a careful sceptical analysis of what it physically means to observe an event horizon [1], through alternative models for compact objects [2], to more radical proposals that drastically modify the physics in the region where the event horizon would otherwise be expected to form [3, 4, 5, 6, 7, 8].

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.)

 

[W.D.Clinger]

I haven't demonstrated that an analogy for fairies doesn't work mathematically. So what? I went through the abstract of the Matt Visser paper and told you the problem. I didn't pursue it because his very latest paper on arXiv concerns gravastars. You're fifteen years behind the times, sol. The guy you quoted in support of your Chicken Little sky-falling-in is with me now.

Bare assertion, contradicted by evidence.

Matt Visser is currently teaching a course whose title is "General Relativity and Cosmology".

A course on differential geometry is the prerequisite for that course.

Misner, Thorne, and Wheeler's Gravitation is recommended reading for that course.

Exercises 11 through 15 of the first homework assignment deal with coordinate transformations.

Visser's 401 pages of online notes on general relativity cover "Schwarzschild geometry" in section 8.1. That section's discussion of the coordinate singularity agrees with us and with MTW. That section covers Painlevé-Gullstrand and Eddington-Finkelstein coordinates. One of the exercises in that section is essentially the same as exercise 25 of the homework problems I suggested to Farsight. That section lists seven six equivalent metric forms for the Schwarzschild geometry, and says

The central message you should be getting from all this is that it is very easy to get confused between coordinate artifacts and real geometrical differences.

Section 1.6 of Visser's notes says

Unfortunately, as soon as you study anything with Einstein’s name attached, you will quickly realise that the nutters come crawling out of the woodwork. Do not trust anything you find on the world-wide-web unless you have significant independent evidence that the source is reliable.

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

No sane person would agree that Matt Visser is on Farsight's side of this discussion.

 

[Ziggurat]

I'm the one who's with Einstein on this, Zig.

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.