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borman
2012-Mar-20, 04:55 AM
GR is great, but it has to fail sometime.

“ http://arxiv.org/abs/1203.3827 There's always someone around the physics forums who thinks he'll prove Einstein wrong... (as though that would make this guy a bigger genius than Einstein). This paper looks at the realistic situations in which we could/should expect General Relativity to not be a good model/approximation to reality. GR is great, but it has to fail sometime.”

Sorry, but I can’t let this paper pass without a comment or two.

The main issue is that the basic thesis appears to be heavily prior dependent. The underlying assumption to be questioned is whether it is within the GR paradigm to explain the dark sectors.

Yes, while it is true that at one time Einstein considered a lambda to counteract gravity to prevent collapse after a finite amount of time, he later discarded the idea after expansion was discovered. More recently, when there was a failure to observe a deceleration parameter, but instead an acceleration of expansion was observed, the lambda was ressurected and irreverantly slapped back onto the original equations without further ado.

Prior to this, another dark sector, localised C(old)DM, was invoked to exist to supplement visible matter to account for the flat rotation curves observed.

In addition to this is a possible third dark sector, non-local C(osmological)DM, often lumped together with localised CDM, has its own observational evidence that distinguishes it from CDM.

The question is : Are we justified in laying these anomalies at the feet of GR and modifying or adding new terms to GR to account for them? Do these really point to a weakness in GR? Or could we be abusing GR by asking GR to answer questions that are beyond GR’s domain of application?

GR has been quite succesful at the solar system level so far. The PPN is consistent with alpha=beta=1 so far. Lorentz violations will soon be constrained to less than 1 part in 10^20 which can effectively rule out a number of competitor theories.

While no Dark Matter Particles have been created or discovered, there have been hints from some subsurface experiments that point to some modulation on an annual scale. But even here, the different experimental results can not be brought into concordance with each other without violating the premise of the Standard Halo Model (SHM) they are trying to demonstrate.

Clearly, there are some anomalous phenomena that need explanation. But are we right to demand of GR that it provide the answers? Is it not possible that GR a very fitting and possilby correct theory that explains all that is actually within its domain of application? Should it not perhaps be overextended beyond this domain to explain phenomena not in its domain? Is it not possible that Kepler’s laws actually continue to work to infinity and to vanishingly small accelerations while something else begins to take ascendancy that is not within the Kepler domain?

The alternative perspective suggested here is that the question of the validity or failure of GR seems to be premissed upon the assumption that GR must account for the dark sectors. Rather than questioning GR, perhaps it is this prior that should be questioned.

antoniseb
2012-Mar-20, 03:30 PM
... The question is : Are we justified in laying these anomalies at the feet of GR and modifying or adding new terms to GR to account for them? Do these really point to a weakness in GR? Or could we be abusing GR by asking GR to answer questions that are beyond GR’s domain of application?

GR has been quite succesful at the solar system level so far...

For local stuff travelling slowly, GR looks a lot like Newtonian Mechanics, as well it should, because NM describes what we see very well up to a point. At some point, we will have accurate enough measurements of *something* to such a degree that you can look at what will replace GR, but whatever that is, it will have to look a lot like GR under most circumstances that we can see now.

I think the issues of whether DM end DE fit into GR are valid to keep as open questions when assembling the next model ... until we discover what DM and DE are more concretely than we know now. That being said, I think the observations so far tend to strongly favor dark matter being consistent with GR, localized, and not a sign of a problem. DE is a less well observed phenomenon.

What will the replacement be? We might be a decade away from getting a sense of that, or we might be a century. We need more observations of things that are just within or just beyond our ability right now.

Jerry
2012-Mar-20, 04:28 PM
It is vexing.

Looking back at Eddington's first proof/prediction of GR; we find that he posed a false dichotomy: "Newtonian gravitation lensing" Verses relativistic lensing. The scatter from the actual telescopes used in the experiment was quite broad; and really didn't conform with either. Subsequent probes likewise produced unexpected signatures of curvature that varied with wavelength. Eventually a GR component was teased out, but I have wondered if this isn't a case of assuming a correct GR coefficient and adjusting the other parameters until victory could be declared for GR. A similar approach was taken with Gravity B probe data.

What sets GR apart from other solutions is the absolute limit of the speed of light and the minimal number of auxillary terms necessary to define most of what we see. We each additional step in complexity, the magic of the GR solution is diminished. If we have neutrinos moving at too high of velocity to retain the absolute limits imposed by GR dimensions, the theory should be put on the shelf with the rest of the twentieth century.

Cougar
2012-Mar-20, 04:36 PM
Are we justified in laying these anomalies at the feet of GR and modifying or adding new terms to GR to account for them?

If the shoe fits....

It it doesn't, then you go looking for another shoe.

Tensor
2012-Mar-20, 05:02 PM
Subsequent probes likewise produced unexpected signatures of curvature that varied with wavelength.

What probes are those Jerry? You have a link?


Eventually a GR component was teased out, but I have wondered if this isn't a case of assuming a correct GR coefficient and adjusting the other parameters until victory could be declared for GR. A similar approach was taken with Gravity B probe data.
It appears that you are saying the experimenters just change their data, until they get the data the need to show GR correct, is this right? And if this isn't the case, what exactly are you saying here?


If we have neutrinos moving at too high of velocity to retain the absolute limits imposed by GR dimensions, the theory should be put on the shelf with the rest of the twentieth century.

Yeah, but it doesn't look as if those neutrinos (http://press.web.cern.ch/press/PressReleases/Releases2011/PR19.11E.html) were actually moving at too high of a velocity.

antoniseb
2012-Mar-20, 05:05 PM
... If we have neutrinos moving at too high of velocity to retain the absolute limits imposed by GR dimensions, the theory should be put on the shelf with the rest of the twentieth century.
Really, the neutrino thing is make or break? Ignore all other predictions from GR, because it is useless and broken? Thankfully the neutrino thing DID get resolved in favor of GR, but even if it didn't, GR doesn't claim to cover the tiny stuff, just the macroscopic.

borman
2012-Mar-21, 03:13 AM
The Flat Earth Extrapolation Syndrome

Even though Greeks had used sticks and shadows to get a first approximation of the Earth’s circumference, this information would occasionally be misplaced and some would resort to immediate observation and note that the nearby landscape appeared flat. Maps seem to work. With enough experiences like this, one might extrapolate the immediate observations to conclude that the world is flat. Even though we now know that these global extrapolations may lead to errors, the tendency to continue to make extrapolations based on prior experiences still guides the first reasonable guesses about horizons not yet explored or at least not well understood.

When we get signals from these horizons, in the present case from the dark sectors, that was not anticipated or predicted from our “local maps” or GR, a red flag of caution might be waved before a global extrapolation that would augment GR to account for the signals. This does not need mean that GR in the immediate manner of use is inadequate or wrong, but there is a risk that the extrapolation may be wrong. GR could still be the most accurate theory within its domain of application, but extrapolating it beyond its domain of application may lead to errors.

So the question is: Are the dark sectors actually within the GR domain of application? If one insists that they are, then extrapolation may lead to unavoidable additional terms to the equations first given by Einstein. If the dark sectors do not belong within the GR domain of application, then Einstein’s original equations will continue to suffice and attention can be drawn to describing the new domains that house the dark sectors.

Tensor
2012-Mar-21, 04:10 AM
When we get signals from these horizons, in the present case from the dark sectors, that was not anticipated or predicted from our “local maps” or GR, a red flag of caution might be waved before a global extrapolation that would augment GR to account for the signals.

If it was simply a case of using this much Dark Matter for this one observation, and this different amount for this other observation, and a third different amount for an additional problem, I could see where a red flag should be raised. However, within error bars, most cases indicate that using enough Dark Matter to solve one problem, pretty much solves the other problems. I'm not going to tell you that every problem is solved with exact precision, that isn't the case. And there are some observations that present us which are quite difficult to explain, no matter what you are using.


This does not need mean that GR in the immediate manner of use is inadequate or wrong, but there is a risk that the extrapolation may be wrong.

You don't think that they've thought that an extrapolation of GR might be wrong, why?


GR could still be the most accurate theory within its domain of application, but extrapolating it beyond its domain of application may lead to errors.

You don't think that they've thought that some of these ideas may push GR past its domain of applicability, why?


So the question is: Are the dark sectors actually within the GR domain of application?

You seem to be under a misunderstanding the Dark Matter somehow augments GR, it doesn't. GR is GR using Dark Matter. What is found is that there isn't enough observable mass. Dark Matter is simply additional mass that cannot be seen currently, except by gravitational interaction. It doesn't seem to interact (or, if it does, that interaction is somehow hidden from us), via EM radiation or collisions.



If one insists that they are, then extrapolation may lead to unavoidable additional terms to the equations first given by Einstein.

Let's make this clear. There are no additional terms in the equations for Dark Matter, period. An additional term was put in by Einstein over 90 years ago to allow a static universe. If you want additional terms, look at some of the other idea they are coming up with to explain these things. Ideas that add new forces that no one has ever seen. New theories of gravity that have variable terms, depending on what you need. New theories of gravity that still need Dark Matter and Dark Energy. New theories of gravity that work fine in the Newtonian limit, but fail in the relativistic limit, so, they have to add additional terms, just to get their theory to work in the relativistic limit. How about you complain about these ideas and point out the red flags for these that should be raised?


If the dark sectors do not belong within the GR domain of application, then Einstein’s original equations will continue to suffice and attention can be drawn to describing the new domains that house the dark sectors.

Now, Dark Energy is a bit more vacuous. However, what is interesting about Dark Energy is that you can model it quite well by simply including the lambda term in the GR field equations. Using, of course, a different value than Einstein used to keep the universe static.

Why is it always assumed that mainstream science only cares about protecting current theories and has no interest in actually finding answers to the questions. Your entire quoted post appears to me to be nothing more than saying that current scientists don't know what they are doing. You also seem not to know exactly what the idea behind Dark Matter and Dark Energy actually are, as Dark Matter doesn't add any terms, and Dark Energy is already a term that was added over 90 years ago. And you don't think scientists are at work trying to do what you suggest in you post, why?

Tensor
2012-Mar-21, 05:14 AM
Sorry, I can't let some of these misconceptions pass without a comment or two.


GR is great, but it has to fail sometime.

“ http://arxiv.org/abs/1203.3827 There's always someone around the physics forums who thinks he'll prove Einstein wrong... (as though that would make this guy a bigger genius than Einstein). This paper looks at the realistic situations in which we could/should expect General Relativity to not be a good model/approximation to reality. GR is great, but it has to fail sometime.”

Sorry, but I can’t let this paper pass without a comment or two.

Yes, while it is true that at one time Einstein considered a lambda to counteract gravity to prevent collapse after a finite amount of time, he later discarded the idea after expansion was discovered. More recently, when there was a failure to observe a deceleration parameter, but instead an acceleration of expansion was observed, the lambda was ressurected and irreverantly slapped back onto the original equations without further ado.

It was not irreverently slapped back onto the original equations. It was added back on, calculations were done, the answers to those calculations were compared to observations, and those comparisons match observations. I would suggest you actually do some study into the process. Your comment here is amazingly ignorant as to what actually happened and how the calculations and comparisons were done. If the results of the calculations didn't match the observations, lambda wouldn't be part of cosmology today, it's that simple.


Prior to this, another dark sector, localised C(old)DM, was invoked to exist to supplement visible matter to account for the flat rotation curves observed.

In addition to this is a possible third dark sector, non-local C(osmological)DM, often lumped together with localised CDM, has its own observational evidence that distinguishes it from CDM.

It's all Cold Dark Matter. Some of it is in halos around galaxies, some in clusters. You seem to be confused on what the different dark terms mean.


GR has been quite succesful at the solar system level so far. The PPN is consistent with alpha=beta=1 so far. Lorentz violations will soon be constrained to less than 1 part in 10^20 which can effectively rule out a number of competitor theories.

Lorentz violations have been constrained to less than 1 part in 1033GeV on Earth for the Neutron and less than 2.5 parts in 1043 GeV for differences in photon polarization, from astronomical observations. What's most interesting is that the paper states that MeV energies should have constraints less than 1036 for electrons and should be less for more energetic particles. Guess where that Neutron fits and what its constraint does to the paper?


The alternative perspective suggested here is that the question of the validity or failure of GR seems to be premissed upon the assumption that GR must account for the dark sectors. Rather than questioning GR, perhaps it is this prior that should be questioned .

Actually, the perspective presented here is more premised on there being Lorentz symmetry violations, which haven't been seen at the level that the author says they should be seen if his "Gravitational Aether" idea has any merit. You know, I've enjoyed the posting and back and forth of the different articles, and discussion we've had in the other gravitational thread, but the comments you made here seemed to be more of a uninformed swipe at GR rather than a considered response.

Jerry
2012-Mar-22, 04:50 AM
Really, the neutrino thing is make or break? Ignore all other predictions from GR, because it is useless and broken? Thankfully the neutrino thing DID get resolved in favor of GR, but even if it didn't, GR doesn't claim to cover the tiny stuff, just the macroscopic.
Absolutely - under GR - there is no way neutrinos could move faster than photons; nor could they under most of the proposed alternatives. My point is it should only take one well-collaborated experimental failure to negate the theory, no matter how many trees have been lining up.


It appears that you are saying the experimenters just change their data, until they get the data the need to show GR correct, is this right? And if this isn't the case, what exactly are you saying here?Experimenters looked for unanticipated physical phenomenon that could explain the difference between what they were predicting, and what they observed. You can't do that, because there is no way to verify a 'variable polhode moment' exists. You can say 'there is room for the GR signature inside this unexpected envelope'; but you shouldn't cite this as an affirmation of GR. Apply the Jerry test: Can I say the unexpected signal found in the G-B probe proves GR is wrong? I can't assume the 'variable polhode moment' does not exist either: this was just a failed experiment, not a failure or affirmation of GR.

Tensor
2012-Mar-22, 05:43 AM
Absolutely - under GR - there is no way neutrinos could move faster than photons; nor could they under most of the proposed alternatives. My point is it should only take one well-collaborated experimental failure to negate the theory, no matter how many trees have been lining up.

I guess this means that we also throw out QED then, right?


Experimenters looked for unanticipated physical phenomenon that could explain the difference between what they were predicting, and what they observed. You can't do that, because there is no way to verify a 'variable polhode moment' exists. You can say 'there is room for the GR signature inside this unexpected envelope'; but you shouldn't cite this as an affirmation of GR. Apply the Jerry test: Can I say the unexpected signal found in the G-B probe proves GR is wrong?

Is that the test where we say all mainstream theories are wrong, make disparaging comments about the theories, without presenting any actual evidence?


I can't assume the 'variable polhode moment' does not exist either: this was just a failed experiment, not a failure or affirmation of GR.

Well, then, you should have no problem pointing out where in the paper that explained the experiment the problem is, right? Oh, and this "Subsequent probes likewise produced unexpected signatures of curvature that varied with wavelength." What probes Jerry? Or is this another of your throw away lines?

swampyankee
2012-Mar-22, 11:19 AM
Well, yes, GR would be broken if a particle could carry information faster than light. So far, there have been no experiments that have found either GR or QM to be in error. On the other hand, there have been calculations which show contradictory results between QM and GR under some conditions that may be physically realistic. This is the genesis of string theory (I keep wanting to put scare quotes around "theory" in that term; it should be "string hypothesis").

antoniseb
2012-Mar-22, 12:12 PM
Absolutely - under GR - there is no way neutrinos could move faster than photons; nor could they under most of the proposed alternatives. My point is it should only take one well-collaborated experimental failure to negate the theory, no matter how many trees have been lining up.

If the experiment is not near the boundary of what the theory predicts, sure, I agree. In the neutrino case, it came up supporting GR in the end, but even if it didn't, it wouldn't invalidate the theory, but simply provide a concrete boundary showing the conceptual space it covers accurately and the space it doesn't. Had this instead been some experiment having to do with momentum and acceleration of massive clocks, I'd have to agree with you.


Experimenters looked for unanticipated physical phenomenon that could explain the difference between what they were predicting, and what they observed. You can't do that, because there is no way to verify a 'variable polhode moment' exists. You can say 'there is room for the GR signature inside this unexpected envelope'; but you shouldn't cite this as an affirmation of GR. Apply the Jerry test: Can I say the unexpected signal found in the G-B probe proves GR is wrong? I can't assume the 'variable polhode moment' does not exist either: this was just a failed experiment, not a failure or affirmation of GR.

Eh? No one says that any experiment "proves" GR. The G-B probe came back with some wide error bars because of some unexpected issues with the equipment (it had never been tried before, so who could know)... but GR is within the error bars. Had GR been outside the error bars, then the current frame-dragging part of the GR model would be falsified... It wasn't but it could have been, and so that satisfies Karl Popper's falsifiability.

I suggest reading this paper. The abstract itself is not enough to build your case that the current view is broken and unusable.

John Mendenhall
2012-Mar-22, 04:55 PM
Was Newtonian Mechanics thrown away because the nodes of Mercury's orbit precessed too much? No, as a subset of GR Newtonian works just fine. Whatever expands GR must also recognize GR as a subset. See korjik quote below.

Hetman
2012-Mar-22, 07:38 PM
Was Newtonian Mechanics thrown away because the nodes of Mercury's orbit precessed too much?

Mercury's nodes move too much?

I suspect that nobody has ever tried to calculate the orbital node motion (better: the precession of the orbital plane) from the equations of GR.

Tensor
2012-Mar-22, 08:53 PM
Mercury's nodes move too much?

I suspect that nobody has ever tried to calculate the orbital node motion (better: the precession of the orbital plane) from the equations of GR.

Why bother? If the perihelion precesses, the nodes precess by the same amount. Unless, you're suggesting Mercury's orbital parameters are changing. Of course, other than the perihelion, we don't have any kind of observations for that.

Hetman
2012-Mar-22, 09:57 PM
Why bother? If the perihelion precesses, the nodes precess by the same amount. Unless, you're suggesting Mercury's orbital parameters are changing. Of course, other than the perihelion, we don't have any kind of observations for that.

Precession of nodes is almost always different than precession of the apses, because there are other effects: first results from an external torque, and the other of radial forces.

Precession of Mercury's nodes... probably: -455'' / cy (nodes move in the opposite direction - normal precession).

It is possible that there exists a minimum proportion of the two, which is: 3/4 / 2/3 = 9/8 (apses faster).

John Mendenhall
2012-Mar-22, 10:09 PM
Mercury's nodes move too much?

I suspect that nobody has ever tried to calculate the orbital node motion (better: the precession of the orbital plane) from the equations of GR.

Thank you, Tensor, perihelion shift is more accurate.

Indeed the calculation has been done, see the Wiki article 'Tests of General Relativity'. And for Earth and Venus also. To quote:

"The other planets experience perihelion shifts as well, but, since they are farther from the sun and have longer periods, their shifts are lower, and could not be observed accurately until long after Mercury's. For example, the perihelion shift of Earth's orbit due to general relativity is of 3.84 seconds of arc per century, and Venus's is 8.62". Both values are in good agreement with observation.[7] The periapsis shift of binary pulsar systems have been measured, with PSR 1913+16 amounting to 4.2o per year.[8] These observations are consistent with general relativity.[9] It is also possible to measure periapsis shift in binary star systems which do not contain ultra-dense stars, but it is more difficult to model the classical effects precisely - for example, the alignment of the stars' spin to their orbital plane needs to be known and is hard to measure directly - so a few systems such as DI Herculis have been considered as problematic cases for general relativity."

You are falling into the trap of thinking the professional astronomy mainstreamers have made a dumb mistake. Not likely. That's what peer review is all about. These fellows (and I am not one of them) beat on each other unmercifully all the time about their observations, theories, and conclusions. And they are very, very good at what they do.

Regards, John M.

Hetman
2012-Mar-22, 10:17 PM
Fine, but the orbits of pulsars rather nobody has ever seen.

And orbital nodes in binary systems do not move - there is no orbital nodes!

John Mendenhall
2012-Mar-22, 10:44 PM
Fine, but the orbits of pulsars rather nobody has ever seen.

And orbital nodes in binary systems do not move - there is no orbital nodes!

They very much have periapsis (-ses?). See the Wiki article 'Two-body problem in General Relativity'.

Regards, John M.

Hetman
2012-Mar-22, 11:28 PM
Hmm... I understand, but Mercury's orbit has nodes too. :rofl:.

pzkpfw
2012-Mar-23, 12:38 AM
...

That emoticon, in that context, can be seen as an insult to BAUT members. Don't do it again, please.

Nereid
2012-Mar-23, 08:55 PM
Fine, but the orbits of pulsars rather nobody has ever seen.

I don't understand this; what does "the orbits of pulsars rather nobody has ever seen" mean?

Would you please clarify?

Jerry
2012-Mar-23, 10:51 PM
I guess this means that we also throw out QED then, right?
Qed is different. It is phenomenologically derived. It has only proven to have limited predictive power beyond the domain we have studied: When we crank up the power we develope new rules. We use it where we know it works.


Is that the test where we say all mainstream theories are wrong, make disparaging comments about the theories, without presenting any actual evidence?That is the test where we apply the burdon of evidence to at veracity to a well-established theory that we would to support a new one. We can't tell the jury he passed the lie detector test when we know the test is unreliable. There are a large number of affirmations of GR where the noise level of the experiment was too high to make this claim. (There are also many, many supportive works that represent good science.)



Well, then, you should have no problem pointing out where in the paper that explained the experiment the problem is, right? Oh, and this "Subsequent probes likewise produced unexpected signatures of curvature that varied with wavelength." What probes Jerry? Or is this another of your throw away lines?Mariner 9 did not see the doppler shifts expected near the sun. We now know the magnetic fields near the sun play havoc on radio waves, but the Mariner 9 attempts to improve upon the science of Eddington failed.

There was a Cassini paper that announce a substantial improvement on GR limits, but it was withdrawn. You should also look at the solar radius paper I posted in fun papers: Look at why measurements of the the solar radius have been wrong, and why there was missplaced confidence in the accuracy of so many tests. Keeps in mind that a good handle on where the limb of the sun is is necessary to draw hard conclusions about whether or not the bending predicted by Einstein is consistent with the results...since we can't assay the sun, we don't know whether or not a dark matter parameter is needed, too.

Finally, lets listen closely to what Messinger is telling us about the gravity fields of Mercury. What makes sense and what might not?

Hetman
2012-Mar-24, 11:43 PM
I don't understand this; what does "the orbits of pulsars rather nobody has ever seen" mean?

Would you please clarify?

The formula for apsydial precession for the two bodies could be wrong, so it should first be verified on directly observed orbits.

http://en.wikipedia.org/wiki/Two-body_problem_in_general_relativity
http://upload.wikimedia.org/wikipedia/en/math/b/8/5/b85ebd6a777ebd17532175d05dcdcd23.png

It is a combination of solutions GR's equations for the central field, with correction of Kepler's third law.

What would be the precession of the perihelion of Mercury, if its mass was equal to the mass of the Sun?

2 * 1.414 * 43'' / cy = 122'' / cy?

Probably not, because here the gravitational acceleration increases twice, so the system will be harder to disturb.

Celestial Mechanic
2012-Mar-25, 04:17 AM
{Snip!} What would be the precession of the perihelion of Mercury, if its mass was equal to the mass of the Sun?

2 * 1.414 * 43'' / cy = 122'' / cy? {Snip!}Where did the extra factor of square root of two come from? :think:

Hetman
2012-Mar-25, 02:24 PM
Where did the extra factor of square root of two come from? :think:

Due to the shorter orbital period.

I said earlier that the acceleration increases, which is not true.
The acceleration does not change, so this precession should also be maintained (per orbit).

This effect is proportional to v^2, which is equal to the potential (2Ek = -Ep):

GM/a = v^2

and generally:
G(M + m)/a = v_1^2 + v_2^2 = v^2

Probably the precession in general does not depend on the masses of bodies.

Hetman
2012-Mar-25, 03:00 PM
Okay, but it's the same formula - with the sum of the masses!
So there is missing some factor, probably with reduced mass of system.

Yes. Here should be reduced potential, ie. true potential of system.

V_r = w^2\cdot(a_M^2 + a_m^2) = \frac{G(M+m)}{a^3} [a^2 - 2a_M a_m] =\\ =\frac{G(M+m)}{a} [1 - \frac{2a_M a_m}{a^2}] = ...

and the precession: d\varphi \approx const . V_r/c^2

borman
2012-Mar-26, 12:01 AM
Pinning the tail on the Donkey(s)

The reputed Cosmological Dark Matter has a rather poor press agent. With a much higher frequency, papers abound about Dark Energy and Cold Dark Matter from either the perspective of the concordance paradigm or competing alternative paradigms, for example such as quintessence or MOND.

It often seems cosmologists are engaged in a game like “pin the tail on the donkey” to assign prospective causes to phenomena that are not readily explained by currently accepted models. As I understand it, the Cosmological Dark Matter has not always been constant like the Lambda for Dark Energy, and it has a sign that is opposite to Dark Energy so that it acts as a governor to Dark Energy to help keep it in check. The sign is the same as the proposed Cold Dark Matter and normal matter/light energy density. An a priori assumption could be that at the beginning of linear time when space-time started, at t=0, these four “Donkeys” zero summed and followed conservation rules and then evolution of large scale structure is governed by modulations between sectors.

It appears that DE begins to get the upper hand back around z=.5 with something possibly unusual happening back around 1<z<2. These are “recent” or late time changes that did not show themselves during the early growth of the universe.

There were various proposals.

One is that perhaps DE is not as constant as hypothesized; perhaps it is clumpy and/or not steady over time. This may have created an opportunity for the quintessence paradigm. But quintessence is supposed to be traced back to t=0 and the “recent” events create rather severe coincidence problems for what would then be a “crazy quintessence”.

Another proposal was that DE still stays a constant but there was a cosmological dark matter that suffered a phase change, a possible decay route if not entirely stable, or some evolution change such as reaching asymptote that slowed its ability to be a governor on DE.

Another proposal was that perhaps one of the other Donkeys, GR, might be in need of modification. Readers might recall back in 2009, there was an initial stir in the popular press regarding the first or second version of a paper by Rachel Bean with the infamous figure 1 showing an offset from GR. One can still look at this interesting earlier paper version here:

A weak lensing detection of a deviation from General Relativity on cosmic scales
http://arxiv.org/pdf/0909.3853v2.pdf

However one is cautioned that the third version was to announce the withdrawal of the paper as the conclusions were affected by over-constraints or over-specification: here essentially 4 unknowns with 5 equations.

The change to withdrawal was in no small part based on a subsequent paper by Daniel et al:
Testing General Relativity with Current Cosmological Data
http://arxiv.org/abs/1002.1962

When the test was done with different data and redone with the Bean data without over-specification, the offset disappeared and the conclusion was that at 95% confidence there is no apparent reason to modify GR. I.e., there is no reason to ‘pin the tail” on the GR Donkey.

All the same, Bean still explores some of these other scenarios including clumpy Dark Energy (Accepted by Physical Review D):
Current constraints on the cosmic growth history
http://arxiv.org/abs/1002.4197
(Note that Afshordi is listed in the Acknowledgements)

The overall point here is that whether the proposed solution was falsified is independent of the observations, prior to the proposal, which led to the proposal being formed in the first place. It would indeed be unusual for a theorist to suggest a theory to explain observations that have never been witnessed.

It is an open question how the Cosmological Dark Matter Donkey slowed its control over the DE Donkey and either went “out to pasture” or transferred some of its energy to either the GR or Cold Dark Matter Donkeys.

One possibility, really just pure speculation, is to suggest a connection to another current problem of UHECR sources. Some have suggested that some excesses such as the PAMELA excess might be due to Cold Dark Matter decay or self-annihilation. However, extended looks at Cold Dark Matter dominated sources have yet to reveal the required signal from their direction. There is an extra issue with UHECRs in that the nearest possible astrophysical sources are too far away to source them as scattering off CMB photons would bleed pion energy off until the GZK cutoff is reached. But it appears to be still lightly “raining” UHECRs from every direction with no originating source within range. One way out of conundrum is that UHECR kinetic energy is sourced cosmologically from a transfer of energy from the domain of the Cosmological Dark Matter Donkey to that of the GR Donkey. The “rain” would have been falling much heavier back during 1<z<2.

To prove that I am not just inventing a new concept and coining a new term, Cosmological Dark Matter just for the propose of this thread, it is sufficient to cite even just one earlier reference that already uses the term. I shall pick a 7 Nov 2011 paper by Milgrom:

MOND–particularly as modified inertia
http://arxiv.org/pdf/1111.1611v1.pdf

On page 5, in the section 1.4 “all is not roses” Milgrom reviews the two major conundrums that MOND faces. One is the extra lensing in some galaxy clusters, particularly in x-ray clusters, which is too much to be attributed to luminous matter. MOND does not yet allow for variations in intensity or how intensely “dark” the dark matter effect can be. For example, transfer of darkness of cluster galaxies as compared to their field counterparts increases core lensing and excessive dimming from darkness intensity transfer explains the lack of k-curves around the gas bullet of the bullet cluster. [ I thought Clowe made an important observation with respect to the hoops MOND would have to jump through regarding a need for flexibility here but no one seems to have taken it seriously.] MOND is a bit rigid in this respect. So the usual proposition is that there is additional non-luminous but still baryonic matter present to produce the lensing. So far this is all in respect to the MOND alternative to Cold Dark Matter.

But a more severe challenge to MOND is in attempting to account for cosmological dark matter. Here hopes are pinned the discovery of a relativistic MOND that can save the day.

In spite of its successes, which should be retained while getting rid of the problems, it could be that MOND or MI suffers a bit from the Flat Earth Extrapolation Syndrome. As a prior, it offers to stay within the GR domain of application and suggest an alteration of Newtonian Dynamics upon transitioning from a high gravity zone where v^2 is proportional to mass to a weak gravity acceleration, a_0, where v^4 is proportional to mass, or else an alteration of specifically Newton-Einstein inertia which in addition has a trajectory dependence.

Like the result from the Daniel paper, it appears possible that MOND or MI is trying to pin the tail on the wrong Donkey. GR should be left well enough alone as in Type I theories rather than Type III gravity modifying theories. It may be possible to sort out which Type theory should be sought after a LISA Pathfinder mission is performed near a saddle point of low gravity. There might not be a MOND bubble formed because of a potential EFE preventing a weak enough field for transition. However, standard GR can be tested at very low accelerations below a_0 because GR is premised upon the Equivalence Principle. If GR continues to work just fine well below a_0, this would suggest Type I theories may be more accurate. See section II of either paper for further discussion in case a MOND bubble forms:

Testing Different Formulations of MOND Using LISA Pathfinder
http://arxiv.org/abs/1112.5443

The case for testing MOND using LISA Pathfinder
http://arxiv.org/abs/1107.1075

The conundrum of cosmological dark matter for MOND would not apply since they located on different Donkeys that both also differ from the GR Donkey.

Jerry
2012-Mar-30, 05:33 PM
Was Newtonian Mechanics thrown away because the nodes of Mercury's orbit precessed too much? .

No, but it should have been. Adding more and more epicycles is a valid mathematical solution, but not a scientific principle.

antoniseb
2012-Mar-30, 06:13 PM
No, but it should have been. Adding more and more epicycles is a valid mathematical solution, but not a scientific principle.

This sounds like you are advocating making no models until after we have all of science absolutely right. Am I reading you correctly?

Hornblower
2012-Mar-30, 08:00 PM
The Newtonian model, with some empirically determined fudge terms added for extreme cases such as Mercury's perihelion advance rate, is still a useful tool for practical calculations of planetary orbits.

Jerry
2012-Mar-31, 03:17 AM
This sounds like you are advocating making no models until after we have all of science absolutely right. Am I reading you correctly?
Abstractions are useful as long as they don't impede scientific progress. We should question the basic assumptions when significant efforts to advance the theory are frustrated.

Tensor
2012-Mar-31, 04:10 AM
Abstractions are useful as long as they don't impede scientific progress. We should question the basic assumptions when significant efforts to advance the theory are frustrated.

Well, see, that's a problem with your complaints of mainstream science Jerry. Those people who actually study and work in these areas don't believe that scientific progress is being impeded. When we ask you to provide some kind of support for your contentions, you don't normally provide such support or worse, you provide papers that generally refute your own contention.

You flat out said that Newtonian Mechanics (actually gravity) should have been thrown out, which is ridiculous. It only needs to be extended, or generalized, to work in regions where it fails. Which is what GR does. But Newtonian Gravity is just fine for everything else in the solar system.

Celestial Mechanic
2012-Mar-31, 04:44 AM
{Snip!} You flat out said that Newtonian Mechanics (actually gravity) should have been thrown out, which is ridiculous. It only needs to be extended, or generalized, to work in regions where it fails. Which is what GR does. But Newtonian Gravity is just fine for everything else in the solar system.
As I have pointed out before, Jerry wants to "efface and replace" whereas I (and most of us here) prefer to "amend and extend".

I also get tired of Jerry's constant appeal to "epicycles". Any new terms added and treated as perturbations to Newtonian celestial mechanics are not abitrary parameters chosen to fit the data, but actually depend on orbital elements and masses already known and measured. All current ephemerides such as those from JPL take GR into account, and guess what? -- the ephemerides work.

I'm beginning to think that maybe I should assess penalties for gratuitous use of the word epicycles just as I do for gratuitous use of the phrase "paradigm shift". How many points should it be? Five or ten?

Tensor
2012-Mar-31, 04:55 AM
I'm beginning to think that maybe I should assess penalties for gratuitous use of the word epicycles just as I do for gratuitous use of the phrase "paradigm shift". How many points should it be? Five or ten?

I would think five is more appropriate. After all, epicycles is only an "amend and extend". Since a paradigm shift is a "efface and replace", that should be worth ten, more points for a complete replacement. :D ;)

Celestial Mechanic
2012-Apr-01, 04:23 AM
I would think five is more appropriate. After all, epicycles is only an "amend and extend". Since a paradigm shift is a "efface and replace", that should be worth ten, more points for a complete replacement. :D ;)Good argument! Five it is! :D

{Writes in the Armaments book:}
"Neither shalt thou assess four points, nor shalt thou assess six. Five shall be the count of the penalty. Seven is right out!"

borman
2012-Apr-02, 02:38 AM
Barbarians at the Horizon

Many of the earlier theorists including Einstein sought logic in Nature and developed ideas that appealed to an aesthetic. They looked for both simplicity and beauty in their ultimate expressions. GR is no exception. As Friedmann first noted, the equations are naturally dynamic leading to either expansion or contraction and the Lambda was considered and ultimately rejected by Einstein as an aesthetic violation to its dynamic nature or a “great blunder”.

While the observations attributed to the dark sectors can not be denied, is it correct to incorporate their effects into the “canvass” that GR is “painted” upon?

Would it be correct to assert that DaVinci did not appreciate saints and proceed to add a “halo” about the head of the Mona Lisa and then add a Lambda shaped moustache to express accelerated aging?

Would it be correct to assert that Beethoven took his “Fate Knocking at the Door” motif opening his 5th symphony too seriously and proceed to scrape off the three flats of the key signature to create a lighter “halo” suggestive of bellowing laughter of a jolly giant, and then append to the Allegro con brio tempo a “ma poco a poco accelerando quasi Lambda”?

Einstein is not here to defend the aesthetic integrity of his work any more than DaVinci or Beethoven. While it may seem temporarily expedient to incorporate the LCDM on top of GR, into its “canvass” as it were, it detracts from its original aesthetic quality. As these myopic crutches become more entrenched and mar the original beauty, possible failures of the additions might be errantly also associated with the original theory which did not incorporate them and improperly suggest the original theory might be at fault as well.

Furthermore, as the LCDM blemish continues over time to be associated with GR leading to a GR + LCDM paradigm on the same canvass, the searching for their own aesthetic “canvass” for each of separately Lambda and separately CDM is less considered.

Not all unifications are beautiful.

Tensor
2012-Apr-02, 03:28 AM
Barbarians at the Horizon

Non-supported complaints in the Circus Maximus.


Many of the earlier theorists including Einstein sought logic in Nature and developed ideas that appealed to an aesthetic. They looked for both simplicity and beauty in their ultimate expressions. GR is no exception. As Friedmann first noted, the equations are naturally dynamic leading to either expansion or contraction and the Lambda was considered and ultimately rejected by Einstein as an aesthetic violation to its dynamic nature or a “great blunder”.

Aesthetics had nothing to do with lambda being a great blunder. The great blunder lies in the fact that he could have predicted the expansion of the universe, but didn't. By that time, many of his ideas concerning unifications are much less aesthetic, but bothered him not at all. It doesn't appear that you know the history behind lambda or Einstein's work.


While the observations attributed to the dark sectors can not be denied, is it correct to incorporate their effects into the “canvass” that GR is “painted” upon?

I don't know, what quantitative arguments do you have?


Would it be correct to assert that DaVinci did not appreciate saints and proceed to add a “halo” about the head of the Mona Lisa and then add a Lambda shaped moustache to express accelerated aging?

Can you put that into some mathematics for us? If not, then no, it wouldn't be correct to assert that.


Would it be correct to assert that Beethoven took his “Fate Knocking at the Door” motif opening his 5th symphony too seriously and proceed to scrape off the three flats of the key signature to create a lighter “halo” suggestive of bellowing laughter of a jolly giant, and then append to the Allegro con brio tempo a “ma poco a poco accelerando quasi Lambda”?

Can you put that into some mathematics for us? If not, then no, it wouldn't be correct to assert that.


Einstein is not here to defend the aesthetic integrity of his work any more than DaVinci or Beethoven.

snip...

Lambda and separately CDM is less considered.

Your last few posts have had no actual evidence or calculations to back up your complaints. It seems you don't like the idea of a lambda, but you don't seem to want to show us why exactly.


Not all unifications are beautiful.

Yeah, neither are complaints about GR and lambda cosmology, without using math.

Jerry
2012-Apr-02, 04:12 AM
Well, see, that's a problem with your complaints of mainstream science Jerry. Those people who actually study and work in these areas don't believe that scientific progress is being impeded. When we ask you to provide some kind of support for your contentions, you don't normally provide such support or worse, you provide papers that generally refute your own contention.

You flat out said that Newtonian Mechanics (actually gravity) should have been thrown out, which is ridiculous. It only needs to be extended, or generalized, to work in regions where it fails. Which is what GR does. But Newtonian Gravity is just fine for everything else in the solar system.

I don't think so.

Notice that I am not sure.

There is little variability from where we sit: On the surface of the earth, plane geometry dominates, so an inverse square law works very well.

As for the rest of the solar system, (and indeed the rest of the galaxy), there are puzzles that resist solutions - everything from the mascons of the moon to the core composition of comets. There are some interesting observations here:

http://arxiv.org/abs/1109.0266 Mercury and frame-dragging in light of the MESSENGER flybys: conflict with general relativity, poor knowledge of the physical properties of the Sun, data reduction artifact, or still insufficient observations?

From the abstract:

The Lense-Thirring precession of the longitude of perihelion of Mercury, as predicted by general relativity by using the value of the Sun's angular momentum S = 190 x 10^39 kg m^2 s^-1 from helioseismology, is -2.0 milliarcseconds per century, computed in a celestial equatorial reference frame. It disagrees at 4-{\sigma} level with the correction 0.4 +/- 0.6 milliarcseconds per century to the standard Newtonian/Einsteinian precession, provided that the latter is to be entirely attributed to frame-dragging...
In other words, taken at face value, there is no measurable Lense-Thirring effect and the General Relativistic prediction is falsified. Iorio's take on this if found in a subsequent paragraph:


By taking the figure of eq. (7) as valid, the prediction of general relativity for the
Lense-Thirring effect is questioned by eq. (8), even if one takes into account a 19%
uncertainty in it resulting from the recent outcome of the GP-B mission (Everitt et al.
2011). Indeed, by reducing the predicted Lense-Thirring perihelion precession of Mercury
down to −1.6 mas cty−1, a discrepancy of more than 3 − σ with respect to eq. (1) would
still linger. On the other hand, if one assumes the validity of general relativity, it is the
magnitude of the Sun’s angular momentum in eq. (7) to be challenged by eq. (8): S⊙
should be much smaller than it was considered so far. It must be stressed again that such
considerations would be valid if the supplementary advance of the perihelion of Mercury of
eq. (1) were entirely explained in terms of frame-dragging.

(my bold)

So is it the Lense-Thirring effect that is not being realized, or have we really screwed up in our estimates of the solar angular momentum? (Which would really throw off the predicted degree of relativistic gravitational lensing.)
Or, as Iorio further speculates:


Actually, in principle, there is the possibility that the unmodeled gravitomagnetic effect was partially or totally removed from the post-fit signature in the data reduction process, having been somewhat “absorbed” in the values of some of the standard parameters estimated in the fits like, e.g., the planetary initial conditions.

Actually, in principle; if you have to throw in major unanticipated 'gravitomagnetic' effects that cancel the expected motions, nobody has game. I can just as reasonably speculate that both the unanticipated gravitomagnetic effects and the Lense-Thirring effects are null; and everything we see that does not agree with Newton is simply because Newton never gave us true causality in the first place: He gave us a set of equations that work near the earth. But we must prove, without broad prior assumptions, that they work elsewhere.

Right now, Messenger scientists are trying to make sense out of the extraordinary gravity fields they are observing. (I don't think they can!) On Earth, gravitational scientists are pouring over data; looking for the slightest glimmer of a gravitational wave, and LHC scientists are trying to draw lines between the latest round of experiments and what they are observing. What they all have in common, is that they are not seeing what they anticipated. Far from being ridiculous, Newton's fundamental assumptions can and should be challenged.

Jerry
2012-Apr-02, 02:20 PM
As I have pointed out before, Jerry wants to "efface and replace" whereas I (and most of us here) prefer to "amend and extend".
There is nothing more frustrating to the theoriest or the experimenter, than trying to extrapolate and have the curve bending in ways that you did not predict. I am reminded of all the hoops the designers of vacuum tubes jumped through to extent the effective range of amplifying valves; and likewise, all the corrections to solid state circuits.

Most of the time; the corrections applied are experimental errors - interference from neighboring circuits; or electron clouds or cascading breakdowns; but once in a while a new and unpredicted phenomenon pops up - such as the Hall effect.

It takes time and patience to determine if the another knob is needed or another theory. If adding another knob improves the predictive power, it is sometimes the correct solution. (Sometimes a small planet just drifts into the picture and gets blamed for causing the problem.)



I also get tired of Jerry's constant appeal to "epicycles". Any new terms added and treated as perturbations to Newtonian celestial mechanics are not abitrary parameters chosen to fit the data, but actually depend on orbital elements and masses already known and measured. All current ephemerides such as those from JPL take GR into account, and guess what? -- the ephemerides work.Noted. Knobs it is!

caveman1917
2012-Apr-02, 02:36 PM
I'm beginning to think that maybe I should assess penalties for gratuitous use of the word epicycles just as I do for gratuitous use of the phrase "paradigm shift". How many points should it be? Five or ten?

Epicycles to be included for penalties? Now that's quite a paradigm shift! :)

Hornblower
2012-Apr-02, 05:54 PM
snip...

Right now, Messenger scientists are trying to make sense out of the extraordinary gravity fields they are observing. (I don't think they can!)Can you be more specific?
On Earth, gravitational scientists are pouring over data; looking for the slightest glimmer of a gravitational wave, and LHC scientists are trying to draw lines between the latest round of experiments and what they are observing. What they all have in common, is that they are not seeing what they anticipated. Far from being ridiculous, Newton's fundamental assumptions can and should be challenged.

My bold. Shouldn't you be saying Einstein here? We all know that Einstein's GR outperforms Newton's simple theory in extreme cases and thus has superseded it.

Strange
2012-Apr-02, 06:22 PM
We should question the basic assumptions when significant efforts to advance the theory are frustrated.

I'm sure people do that all the time. One good example is when the missing energy (which later turned put to be neutrinos) was identified, one of the suggestions was that conservation of energy might have to be modified/abandoned. You don't get much more basic than that.

borman
2012-Apr-02, 11:34 PM
Some have suggested that some excesses such as the PAMELA excess might be due to Cold Dark Matter decay or self-annihilation. However, extended looks at Cold Dark Matter dominated sources have yet to reveal the required signal from their direction.

A new paper out looking for gama-ray signals from interacting Dark Matter in a larger collection of Dark Matter Effect dominated sources.

Still no signal detection and constraints on the energy of potential signals improved.

Press release from NASA:
http://www.nasa.gov/mission_pages/GLAST/news/dark-matter-insights.html

Paper:
A model-independent analysis of the Fermi Large Area Telescope gamma-ray data from the Milky Way dwarf galaxies and halo to constrain dark matter scenarios
http://arxiv.org/abs/1203.6731

antoniseb
2012-Apr-03, 07:02 PM
... Still no signal detection and constraints on the energy of potential signals improved. ...
The various efforts to hunt Dark Matter are interesting, but I really don't think that CDM is an issue for GR. The nature of Dark Energy is probably connected to GR.

Jerry
2012-Apr-08, 10:47 AM
Can you be more specific?

http://web.mit.edu/newsoffice/2012/mercury-close-up-view-0322.html


“Prior to MESSENGER’s comprehensive observations, many scientists believed that Mercury was much like the moon — that it cooled off very early in solar system history, and has been a dead planet throughout most of its evolution,” says co-author Maria Zuber, the E.A. Griswold Professor of Geophysics at MIT. “Now we’re finding compelling evidence for unusual dynamics within the planet, indicating that Mercury was apparently active for a long time.”
...
“We had an idea of the internal structure of Mercury, [but] the initial observations did not fit the theory so we doubted the observations,” Smith says. “We did more work and concluded the observations were correct, and then reworked the theory for the interior of Mercury that fit the observations. This is how science is supposed to work, and it’s a nice result.”

It is nice, but not necessarily correct. It bumps against planet formation theory and is very curious. Basins are showing gravity anomalies of up to 100 mgal. That is unreal. http://www.lpi.usra.edu/meetings/lpsc2012/pdf/sess401.pdf

http://www.sciencemag.org/content/early/2012/03/20/science.1218809.abstract


Given Mercury’s extremely thin mantle, as revealed by MESSENGER, Zuber says it’s challenging to understand how convection operated to raise broad expanses of terrain to the elevations observed.

Then there is this:

http://meetings.copernicus.org/epsc2009/abstracts/EPSC2009-653-1.pdf


During both flybys the orbital perturbations by the Mercury gravity field were larger than anticipated on the basis of the gravity field inferred from observations made during the Mariner 10 flybys of 1974-75. Those perturbations could not be modeled fully by adjustments only to the planet’s mass, gravitational flattening, and equatorial ellipticity. The Doppler residuals to the new gravity model suggest that additional gravity information is contained in the tracking data but is not resolved in HgM001.

By the way, I didn't know these articles were out there until I went looking for them. I knew the gravity fields would be difficult-to-impossible to model because they have been for every other moon and planet: I expected unreal gravity field solutions because Newtonian rules are not really working anywhere.

Here are the session papers: http://www.lpi.usra.edu/meetings/lpsc2012/pdf/sess401.pdf

The current solutions are not well constrained- there is significant uncertainy due to the solar wind and radiation pressure.




My bold. Shouldn't you be saying Einstein here? We all know that Einstein's GR outperforms Newton's simple theory in extreme cases and thus has superseded it.
Nope. Einstein buffered the errors in the Newtonian solution by redefining space and time. It is a curious solution; because it says the non-Newtonian results are spacial and not caused by any active force. It also means that when the bent-space solution does not work; non-baryonic matter is required. This is an iffy solution - can I use unobtainium?

Jerry
2012-Apr-14, 11:21 PM
Here are the session papers: http://www.lpi.usra.edu/meetings/lps...df/sess401.pdf

The first year of Messenger orbital data has created many more mysteries than it has resolved. First, the libation and core-to-crust solution requires a eggshell-thin crust over a heavy (liquid)mantle with perhaps a solid core. A thin crust should mean mascons of the denser materials percolating through the bottom of craters, such as we have identified on the moon. But there is a snag on mercury: while some mascons may exist, the composition, so far, is similar to the surface composition; a low-Iron crust that is high in sulfur. The one possible exception is the Calois impact basin; which has a center that has risen above the creater rim, and displays a positive anomaly of greater than 100Mgal.

There are several problems with this solution: in order to lift a large heavy mass in the center of a crater higher than the rim; there should also be displacement of the rim - the thin crust should have trouble supporting such an upswell without more displacement in the over all crater structure.

So there are challenges in the composition and topography that make the current solution difficult to model, not to mention the problem with the core not cooling enough in the time frame Mercury has been getting pummelled with rocks to solidify the outer core.

Mercury is going to be hard nut to crack, and as I said, It is a major challenge to model Mercury using known physics.

Shaula
2012-Apr-15, 06:10 AM
By the way, I didn't know these articles were out there until I went looking for them. I knew the gravity fields would be difficult-to-impossible to model because they have been for every other moon and planet: I expected unreal gravity field solutions because Newtonian rules are not really working anywhere.
Then why have you just presented Mercury as an example? Surely something this dramatic you should be able to easily find dozens of papers covering just about every mission out there?

captain swoop
2012-Apr-15, 09:29 AM
Jerry DO not post ATM ideas outside the ATM Forum. You know this and we have seen your 'alternative' ideas on gravity before, keep them out of mainstream threads.

Hetman
2012-Apr-15, 01:31 PM
Nope. Einstein buffered the errors in the Newtonian solution by redefining space and time. It is a curious solution; because it says the non-Newtonian results are spacial and not caused by any active force. It also means that when the bent-space solution does not work; non-baryonic matter is required. This is an iffy solution - can I use unobtainium?
Can you identify these errors?

antoniseb
2012-Apr-15, 01:36 PM
Can you identify these errors?
We just asked him not to... This is a recurring ATM idea for Jerry. You can ask him to open an ATM thread to discuss it, but this GR thread is not the place.

Hetman
2012-Apr-15, 01:45 PM
But I'm not interested in another sensational theory of gravity.
He could only point out what he meant, without going into details.

antoniseb
2012-Apr-15, 02:31 PM
But I'm not interested in another sensational theory of gravity.
He could only point out what he meant, without going into details.

If he does so, it should be in a new thread. It is off topic to *this* thread.

nutant gene 71
2012-Apr-15, 07:56 PM
Jerry, per yours above: The Lense-Thirring effect (some think it should be called, per GR, the Einstein-Thirring-Lense effect) can very easily be described with the Sun's angular momentum and its inverse square law application to Mercury's perihelion period (when its spin coincides with its orbital velocity, so appears to stop), as I had done in this simple calculation, FYI: (Sept. 1, 2006) http://www.humancafe.com/discus/messages/88/97.html#POST1733

It works out rather neat, though crude. Einstein's GR had more elegant finesse. :)