Gravity: The why and the how:

[paddoboy]

Given profs. Unruh & Hamilton's 'waterfall/river' analogy has again made an appearance re 'flowing space', might be best to link to a few posts in an old thread:
http://www.sciforums.com/threads/gravitational-time-dilation.145889/page-30#post-3303745
and then #600, then over the page to #601, 602, with various heated member contributions before and after.

Thanks for linking those excellent professional replies Q-reeus.
Just kind of weird how those that have criticised the waterfall/river analogy, cannot see that like most cosmological descriptions, that's what we are dealing with.....analogies, that work.

 

[Q-reeus]

Thanks for linking those excellent professional replies Q-reeus.
Just kind of weird how those that have criticised the waterfall/river analogy, cannot see that like most cosmological descriptions, that's what we are dealing with.....analogies, that work.

Well the thing about waterfall/river model is it can seem to be made 'real' if the focus/application is strictly to that of a nominal BH. Which can be seen to be a bottomless pit via traditional matter & spacetime eating singularity. As discussed in that other thread, what kills it as having any literal significance is the realization that 'river flow' both interior AND exterior to EH has to be non-zero for consistency with the idea of a conserved spacetime 'current' continuity relation.

But the form of exterior Schwarzschild metric for static BH is indistinguishable to that of an ordinary static spherically symmetric mass e.g. NS or planet. The latter can obviously not have the 'bottomless pit' singularity feature of a BH. Yet owing to that indistinguishable form of both exterior metrics, both BH and 'normal' body e.g. planet/NS must possess the same 'river flow' in that region.

Which is paradoxical given the lack of any sink in NS or planet etc implies the 'inward flow' has nowhere to go hence 'banks up' virtually instantaneously (assuming one could magically 'turn on' the gravitating mass instantaneously). So you have the picture of a necessarily 'stagnant pond' in one case - all 'pressure' and no net flow, but an apparent 'free waterfall' in the other. Yet nothing whatsoever to distinguish the exterior gravitational fields. Obviously consistency can only be achieved by dropping the notion of a literal 'flow' of space/spacetime. It's legitimate use is as indicator of coordinate infall speed of free-falling objects. That start their journey far enough out to be considered to have fallen from 'infinite radius'.

 

[Q-reeus]

Last post didn't deal with the cosmological situation where +ve Hubble 'constant' implies large-scale expansion of space. Such expansion admits a 'flow-rate' of space in the observer-centric inferred sense. Where cosmological redshift of remote matter e.g. galaxies can be equated with an equivalent SR Doppler-shift recession velocity in notionally static and flat spacetime. Such a remote determination carries no sense of an accompanying local 'flow' of space anywhere, owing to the large-scale uniform, isotropic nature of the expansion.

 

[Schmelzer]

Just kind of weird how those that have criticised the waterfall/river analogy, cannot see that like most cosmological descriptions, that's what we are dealing with.....analogies, that work.

First, it is not like "most descriptions", but only like irrelevant popular descriptions.

What scientists use are simply solutions of the Einstein equations of GR. Of course, in the simplest possible coordinates, which, in the case of a homogeneous universe, are comoving coordinates. Everyone can work with them, independent of the interpretatation of GR he prefers. Which is, of course, for 99% the spacetime interpretation. But I use these solutions, in these coordinates, as well, and have no problem with this.

Then, I have criticized this analogy, for the reason that it is not applicable for all solutions, but only a few very special ones. And that it makes a wrong suggestion, namely the natural assumption that a flow is something described by a conservation law of what flows. Thus, the river analogy does not work. What I have suggested as a replacement is the Lorentz ether interpretation, which works much better. Locally, it works always. And, different from Hamilton's river picture, it gives a "flow" of the "river" which fulfills the usual conservation laws we know from classical theory - continuity and Euler equations.

 

[PhysBang]

What I have suggested as a replacement is the Lorentz ether interpretation, which works much better. Locally, it works always. And, different from Hamilton's river picture, it gives a "flow" of the "river" which fulfills the usual conservation laws we know from classical theory - continuity and Euler equations.

Except... it doesn't actually relate to any equations that can give us an exact solution that is not merely a stolen GR solution. If one's definition of "works" is merely "allows me to prefer the ether theory", then that's fine, but I think everyone else should move on.

 

[paddoboy]

Well the thing about waterfall/river model is it can seem to be made 'real' if the focus/application is strictly to that of a nominal BH.

All analogies that I'm aware of do have some limitation.

 

[paddoboy]

First, it is not like "most descriptions", but only like irrelevant popular descriptions.

You mean irrelevant as in the irrelevancy of your ether paper?

Then, I have criticized this analogy, for the reason that it is not applicable for all solutions, but only a few very special ones. And that it makes a wrong suggestion, namely the natural assumption that a flow is something described by a conservation law of what flows. Thus, the river analogy does not work. What I have suggested as a replacement is the Lorentz ether interpretation, which works much better. Locally, it works always. And, different from Hamilton's river picture, it gives a "flow" of the "river" which fulfills the usual conservation laws we know from classical theory - continuity and Euler equations.

What can I say?
Really Schmelzer in the kindest possible way, you are so full of yourself!

 

[Schmelzer]

Except... it doesn't actually relate to any equations that can give us an exact solution that is not merely a stolen GR solution. If one's definition of "works" is merely "allows me to prefer the ether theory", then that's fine, but I think everyone else should move on.

Ether theory is preferable if is has advantages. This is the case, and I have not seen serious objections.

1.) GR in the spacetime interpretation has a very serious problem with quantization. The principles of GR (more accurate, its spacetime interpretation) are in deep conflict with those of quantum theory.
This is not the case for ether theory. We know how to quantize classical condensed matter theories, and, once GR in the ether interpretation fits into this scheme, its quantization is unproblematic.

2.) GR has no local energy and momentum conservation laws, my ether theory has them.

3.) GR allows to prove, if combined with causality or realism, to prove Bell's inequalities. These have been empirically falsified. This is not so in my ether theory. This makes my ether theory compatible wirh realism and fundamental principles of causality, like Reichenbach's common cause principle.

 

[The God]

Ether theory is preferable if is has advantages. This is the case, and I have not seen serious objections.

1.) GR in the spacetime interpretation has a very serious problem with quantization. The principles of GR (more accurate, its spacetime interpretation) are in deep conflict with those of quantum theory.
This is not the case for ether theory. We know how to quantize classical condensed matter theories, and, once GR in the ether interpretation fits into this scheme, its quantization is unproblematic.

2.) GR has no local energy and momentum conservation laws, my ether theory has them.

3.) GR allows to prove, if combined with causality or realism, to prove Bell's inequalities. These have been empirically falsified. This is not so in my ether theory. This makes my ether theory compatible wirh realism and fundamental principles of causality, like Reichenbach's common cause principle.

Can you please link your paper........Your approach appears to have certain logical fallacy which is apparent from Sr#1 above. GR makes no sense if you take off the concept of spacetime (you are questioning spacetime interpretation of GR), but in the very next statement you make a claim that "GR in the Ether interpretation is Ok"...... Please note that there is absolutely no ambiguity about GR spacetime interpretation and it debunks ether, right or wrong. I feel what you trying to do is while maintaining maths, you are bringing in Ether....

 

[PhysBang]

Ether theory is preferable if is has advantages. This is the case, and I have not seen serious objections.

Again, I fear you are using a standard that we cannot accept in general.

1.) GR in the spacetime interpretation has a very serious problem with quantization. The principles of GR (more accurate, its spacetime interpretation) are in deep conflict with those of quantum theory.
This is not the case for ether theory. We know how to quantize classical condensed matter theories, and, once GR in the ether interpretation fits into this scheme, its quantization is unproblematic.

I agree that ether theory doesn't have quantization problems relative to QM. However, this is because it does not produce any mathematical description of physical events. That ether theory cannot do relevant physics is not an advantage overall.

2.) GR has no local energy and momentum conservation laws, my ether theory has them.

Great. However, we still need to do all of physics. When your theory can be used to do physics, then we can start considering it.

3.) GR allows to prove, if combined with causality or realism, to prove Bell's inequalities. These have been empirically falsified. This is not so in my ether theory. This makes my ether theory compatible wirh realism and fundamental principles of causality, like Reichenbach's common cause principle.

You may have got the wrong end of the modus tolens you are attempting. Your ideas of causality and realism may be incorrect. As many people have pointed out, Bell's Inequalities have more to do with the notion of separability than either causality or realism.

 

[Schmelzer]

My papers for the ether theory of gravity http://arxiv.org/abs/gr-qc/0205035 and if its viable near black holes http://arxiv.org/abs/1003.1446
for the ether explanation of the SM http://arxiv.org/abs/0912.3892

GR makes no sense if you take off the concept of spacetime (you are questioning spacetime interpretation of GR), but in the very next statement you make a claim that "GR in the Ether interpretation is Ok"...... Please note that there is absolutely no ambiguity about GR spacetime interpretation and it debunks ether, right or wrong. I feel what you trying to do is while maintaining maths, you are bringing in Ether....

I don't understand your point. In SR, we have two interpretations - the spacetime interpretation and the Lorentz interpretation. They differ. So, one rejects the other. But they have exactly the same math.

In GR, it is a little bit more complex. Roughly, there are the same two interpretations. They differ, and each rejects the other. The math is almost the same, but no longer exactly the same. In variant 1, which I name Lorentz interpretation of the Einstein equations, the equations of GR, the Einstein equations, remain untouched. But some solutions of these equations are rejected, in particular those with nontrivial topology and with closed causal loops. (My ether theory is yet another step away from this interpretation of the Einstein equations, it modifies the equations a little bit.)

But where you see a logical fallacy I do not understand. I use from GR the equations, and the physical predictions about clocks and rulers and so on. I reject the spacetime interpretation and propose another one. This requires even some modifications of the math - I introduce harmonic coordinates, which are nice coordinates but otherwise irrelevant in GR spacetime, as a new physical equation, introduce new objects (absolute space and time) with equations for them, so this is, of course, essentially another theory, even if the same Einstein equations are used.

I agree that ether theory doesn't have quantization problems relative to QM. However, this is because it does not produce any mathematical description of physical events. That ether theory cannot do relevant physics is not an advantage overall.

Why do you think so? It produces mathematics. It produces the standard quantum GR mathematics where GR is quantized as a field theory in harmonic gauge, which works fine. It is, of course, non-renormalizable - but renormalizability is a property which is not expected for a large distance approximation, for an effective field theory. It presupposes, by construction, some atomic ether, and the atomic distance of the ether is, of course, the critical distance where quantum ether theory fails, in the same way as quantum continuous condensed matter theory fails.

Great. However, we still need to do all of physics. When your theory can be used to do physics, then we can start considering it.

The formulas for local energy and momentum tensors you find in the paper.

You may have got the wrong end of the modus tolens you are attempting. Your ideas of causality and realism may be incorrect. As many people have pointed out, Bell's Inequalities have more to do with the notion of separability than either causality or realism.

Of course, as any physical theory and physical principle, causality and realism may be wrong. So what? The point is that if you reject the ether, you have to give up causality (with Reichenbach's common cause) as well as realism. This is without any choice. What many people think does not change this fact.

And, by the way, to give up Reichenbach's common cause is giving up an important part of the scientific method - the search for causal explanations of observed correlations. The tobacco industry would favor it, they would no longer have to care about some correlations of smoking and whatever. Correlations shmorrelations, so what? And without realism, we do no longer have to search for realistic explanations of what we observe at all. So, let's observe if the claims of astrologist's about correlations between planets and events in human lifes exist or not. This is a nice experimental question, and about realistic causal explanations we no longer have to care. Of course, this is overexaggeration, I know we will continue to search for causal realistic explanations. But there will be, obviously, some special domains, of special science, where this is no longer allowed.

 

[rpenner]

to give up Reichenbach's common cause is giving up an important part of the scientific method

I'm not sure Reichenbach's principle has a place in fundamental physics where the causes are presumably the laws of physics which we don't have an alternative to.

Formally, if events A and B have correlated statistics then Prob(A and B) > Prob(A) × Prob(B) while uncorrelated statistics give us Prob(A and B) = Prob(A) × Prob(B).

In this case, Reichenbach's common cause principle expects us to find event or contingency C that favors A and B happening such that Prob(A|C) > Prob(A|¬C) and Prob(B|C) > Prob(B|¬C) but that this contingency is special in that it screens off the correlation: Prob(A and B|C) = Prob(A|C) × Prob(B|C) and Prob(A and B|¬C) = Prob(A|¬C) × Prob(B|¬C).
Then C would be a purported cause that probabilistically "explains" the correlation between A and B.

Experimentally we can only measure these values to finite precision and we may never have enough data to prove C is a fluke or merely correlated with some true cause.

Likewise if a neutral pion (spin-0) decays into two gamma rays, the correlation of the spins of the gamma rays is fixed by conservation of momentum and not any cause that we have the opportunity to observe the converse of.

Ferromagnetic materials at finite temperature establish spontaneous symmetry breaking in the orientation of their magnetic domains. The direction the spins align in doesn't have or need a cause because there is more than one equivalent orientation possible. So while a correlation exists in the microscopic coordination of electron spins, the principle doesn't lead to a "cause" for the particular direction selected by the ensemble.

So Reichenbach's common cause principle may be a great way to conceptualize a class of "smoke" but doesn't help you find the "fire" or even prove that it exists.

Causality in fundamental physics is a slippery beast. But at the macroscopic level the fundamental physics gives us hypothetical mechanisms within the game rules of existing fundamental theories to say the correlation between smoking and rates of cancer is causal in the direction of smoking leading to increased rates of cancer.

 

[Schmelzer]

That paddoboy loves to make personal attacks is well-known, and the forum obviously has to live with this. Now, it seems, to say "you are a cracy megalomaniac" seems no longer sufficient, and he decided to discredit the useful contribution which he often makes, namely interesting links and quotes to some scientific sites, with links and quotes to completely off-topic medical sites.

I'm not sure Reichenbach's principle has a place in fundamental physics ....
So Reichenbach's common cause principle may be a great way to conceptualize a class of "smoke" but doesn't help you find the "fire" or even prove that it exists.
Causality in fundamental physics is a slippery beast.

It is not the aim of Reichenbach's principle to find the cause. What it does, is to define where one has to find a cause, and what it means to have found a cause. Of course, a causal explanation remains a theoretical explanation, and, in the same way as one cannot prove physical theories, one cannot prove causal explanations. But what can be checked is if a given (hypothetical) theory gives causal explanations to the observed correlations or not. It defines, therefore, what is, in this particular domain, an open scientific question.

And this makes the rejection of this principle quite dangerous. Instead of solving the open problem, by giving a (however hypothetical) explanation for the violations of BI, we simply change the definition of what is an open problem. The problem is "solved" by no longer considering it to be a problem.

In my opinion, there is nothing slippery with causality in fundamental physics. The fundamental role of causality is, IMHO, simply part of the scientific method itself. All what is problematic is that we are, yet, not successful in giving causal explanations in fundamental physics. Or reject them, because they do not fit into our prejudices.

 

[paddoboy]

That paddoboy loves to make personal attacks is well-known, and the forum obviously has to live with this. Now, it seems, to say "you are a cracy megalomaniac" seems no longer sufficient, and he decided to discredit the useful contribution which he often makes, namely interesting links and quotes to some scientific sites, with links and quotes to completely off-topic medical sites.

That's rather funny Schmelzer, since you have just asked me in another posts, not to infer to you unless discussing with you. Do I smell hypocrisy.....again?

Could you please restrict your defamations against me to personal discussions with me?

On your other whinge, firstly, medicine is science. Secondly, the delusions of grandeur evident in some here, needs to be revealed and a reason given as to why some can be so obviously totally out of touch. Or is it the case that you see some semblance with yourself?

Or reject them, because they do not fit into our prejudices.

Isn't that exactly what you have been and are doing?
Is this going to create another senseless irrelevant rant?

 

[The God]

My papers for the ether theory of gravity http://arxiv.org/abs/gr-qc/0205035 and if its viable near black holes http://arxiv.org/abs/1003.1446
for the ether explanation of the SM http://arxiv.org/abs/0912.3892

I don't understand your point. In SR, we have two interpretations - the spacetime interpretation and the Lorentz interpretation. They differ. So, one rejects the other. But they have exactly the same math.

In GR, it is a little bit more complex. Roughly, there are the same two interpretations. They differ, and each rejects the other. The math is almost the same, but no longer exactly the same. In variant 1, which I name Lorentz interpretation of the Einstein equations, the equations of GR, the Einstein equations, remain untouched. But some solutions of these equations are rejected, in particular those with nontrivial topology and with closed causal loops. (My ether theory is yet another step away from this interpretation of the Einstein equations, it modifies the equations a little bit.)

But where you see a logical fallacy I do not understand. I use from GR the equations, and the physical predictions about clocks and rulers and so on. I reject the spacetime interpretation and propose another one. This requires even some modifications of the math - I introduce harmonic coordinates, which are nice coordinates but otherwise irrelevant in GR spacetime, as a new physical equation, introduce new objects (absolute space and time) with equations for them, so this is, of course, essentially another theory, even if the same Einstein equations are used.

Schmelzer,

You may like to start a new thread on your theory.

Read your first referencd paper, will read again in due course based on your counter...but there are few things.

1. Any theory which is based on the metric (for spacetime) need not be termed as GR or its offshoot. I prefer the term like Yilmaz Gravity or Schemelzer Gravity. Own it up.

2. Looking at your paper Holistically you are equivocating with respect to GR/SR. The best thing would be to clear your position and say emphatically that your approach is alternative to GR. You are trying to cling to both GR and SR and creating confusion in your paper.

3. Your motivation is to bring back ether, that alone debunks both SR and GR, so stay and say clear on that.

4. You start off with condensed matter, suggesting that you will give realistic materialistic property to your ether, but you do not do that. You gave some strange (your word) properties to the ether, that is incompressible, static, non interacting, kind of non matter...where is the link with condensed matter? You just shoved in condensed matter terminology.

5. And your ether creates negative pressure, this is where your clinging to GR becomes essential, please elaborate about this weirdo (this is there in GR also as DE), how an incompressible static ether create negative pressure. Or it is as open as in GR.

6. Then you talk of metric inside metric, cascaded metrics. This is bad, please note that if an ether based theory has to survive then it cannot have a background metric in a sense you are projecting. My point will be clearer once you read below points.

7. Only once you are using curvature of spacetime, so your gravity is the curvature of spacetime, but you have an absolute flat space in the background and possibly (pl correct me) you are talking of distortion in your ether media. Does it not contradict with your original hypo about incompressible static ether?

8. In a limiting scenario you are talking about Ether SR in a flat absolute space (that is always there in your theory), and then you incorporate length contraction and time dilation same as SR? The point is GR has a limiting scenario (absence of Gravity) and thus zero curvature resulting into flat spacetime, a domain for SR, but in your case you are always in flat absolute spacetime. Isn't it ? So what is the limiting case, qualitatively?

More after your response..

 

[paddoboy]

More after your response..

This thread is not about any alternative theory to gravity and GR. That won't happen here or on any science forum such as this, and certainly not as fabricated by a lay person.
No forum derived model of gravity will ever see the light of day, other than on forums such as this. Real scientists/cosmologists/physicists just don't operate that way.
This thread is about as shown in the OP, how gravity can be illustrated as accurately and as simply as possible.

 

[Schmelzer]

1. Any theory which is based on the metric (for spacetime) need not be termed as GR or its offshoot. I prefer the term like Yilmaz Gravity or Schemelzer Gravity. Own it up.

I have named in General Lorentz Ether Theory.

2. Looking at your paper Holistically you are equivocating with respect to GR/SR. The best thing would be to clear your position and say emphatically that your approach is alternative to GR. You are trying to cling to both GR and SR and creating confusion in your paper..

I think it is clearly said that it is an alternative theory.

3. Your motivation is to bring back ether, that alone debunks both SR and GR, so stay and say clear on that..

It does not change the fact that the physical predictions are quite close, and almost indistinguishable from those of GR.

4. You start off with condensed matter, suggesting that you will give realistic materialistic property to your ether, but you do not do that. You gave some strange (your word) properties to the ether, that is incompressible, static, non interacting, kind of non matter...where is the link with condensed matter? You just shoved in condensed matter terminology..

Sounds like a misunderstanding. The ether of my theory is compressible, non-static. The link with condensed matter is quite clear. $$\rho = g^{00}\sqrt{-g}$$ is the ether density, $$g^{0i}/g^{00}$$ is the ether velocity, and I have classical continuity and Euler equations for the ether.

5. And your ether creates negative pressure, this is where your clinging to GR becomes essential, please elaborate about this weirdo (this is there in GR also as DE), how an incompressible static ether create negative pressure. Or it is as open as in GR..

Again, the ether is nothing but incompressible. And about the negative pressure, this is nothing related with GR.

6. Then you talk of metric inside metric, cascaded metrics. This is bad, please note that if an ether based theory has to survive then it cannot have a background metric in a sense you are projecting. My point will be clearer once you read below points..

????? cascaded????? What is this?

7. Only once you are using curvature of spacetime, so your gravity is the curvature of spacetime, but you have an absolute flat space in the background and possibly (pl correct me) you are talking of distortion in your ether media. Does it not contradict with your original hypo about incompressible static ether?.

Gravity is not the curvature of spacetime. The mathematical expression of curvature is used, as a mathematical expression, and in some sense corresponds to inner stress of the ether.

8. In a limiting scenario you are talking about Ether SR in a flat absolute space (that is always there in your theory), and then you incorporate length contraction and time dilation same as SR? The point is GR has a limiting scenario (absence of Gravity) and thus zero curvature resulting into flat spacetime, a domain for SR, but in your case you are always in flat absolute spacetime. Isn't it ? So what is the limiting case, qualitatively?.

I have always absolute space and time in the background. But what is measured with clocks and rulers is always influenced by the ether. The formula for the clock time is the same formula as for proper time in GR. Curvature plays no role in this formula. The no gravity limit is the limit of a homogeneous (constant density) static (ether velocity zero). And once the velocity is zero, there will be also no compression, so, the ether will be incompressible in this limit too (the more accurate word would be uncompressed).

 

[Schmelzer]

That's rather funny Schmelzer, since you have just asked me in another posts, not to infer to you unless discussing with you. Do I smell hypocrisy.....again?

We are discussing here in this thread with each other, so that I don't get the point.

On your other whinge, firstly, medicine is science. Secondly, the delusions of grandeur evident in some here, needs to be revealed and a reason given as to why some can be so obviously totally out of touch. Or is it the case that you see some semblance with yourself?

I have not claimed medicine is not science, I have claimed it is off-topic. And once, quite obviously, the only aim of of quoting medicine was to make a "you are a megalomaniac" a more serious, scientific look, it is off-topic.

Isn't that exactly what you have been and are doing?

No.

 

[paddoboy]

We are discussing here in this thread with each other, so that I don't get the point.

You were not discussing anything with me....and the way you worded it testifies to that.

I have not claimed medicine is not science, I have claimed it is off-topic.
.

That's nice. Secondly, I will raise what I see fit, when needed and particularly when obvious delusions of grandeur are being constantly evidenced by a few "would be's if they could be's".
I suggest you approach the forum with an unbiased approach.

And yes, is most certainly the answer to the last question and others have recognised that fact.

 

[The God]

It does not change the fact that the physical predictions are quite close, and almost indistinguishable from those of GR.

Then Purpose of your theory? Why I said equivocating that you are not able to convincingly say that its a cear alternative to GR (you do mention that) but overall you maintain a stand as given in the quote.

Sounds like a misunderstanding. The ether of my theory is compressible, non-static.

Thus, in the no gravity limit we obtain a static and incompressible ether in a
Newtonian framework.

Ok, its clear, so basically what you are proposing is the distortion of the ether in the presence of mass. Why you have to make this specific observation which is misleading, if there is no mass, then there is no distortion and it may look static and incompressible even though it may not be.

But the density of the ether ρ is a qualitatively new entity. We have nothing
to compare it with: We cannot take one piece of ether and measure its weight in
g. Therefore, to assume that the ether density is measured in g/cm3
is physically
nonsensical. We also don’t know (yet) the size of the ether atoms, so we cannot
count their number in a given volume to measure the ether density in atoms/cm3
.
What is, in this case, the appropriate unit to measure the ether density in our
theory?

Well the unit does not matter (constant can be clubbed), you try to give a metaphore of water wave and water also, but the point is if this etheris getting stressed/distorted then it got to have materialistic property, at the end this stress is going to define the Gravitational Filed, is it ok to claim that I have a compressible ether without density?



GR is difficult due to non linearity and its a distortion of imaginary spacetime with no physical properties attached to it. You have an ether with flat space background (more or less irrelavant, you have just given space for your ether to stay put), any distortion or stress in the material is force...so that makes your theory distinctly different from GR and goes back to Newtonian with superfluous clinging on GR type equations.