# On Dark Energy.

by quasar987
Tags: dark, energy
Emeritus
PF Gold
P: 4,005
 Quote by Garth One concern of mine is the absolute confidence placed in the standard model: it is called "precision cosmology", its deductions are presented as facts, it is assumed that it has been robustly established beyond doubt as an intellectual edifice standing on several pillars. Attack one we are told (RAS lecture 2004) and the others will continue to securely support the paradigm.
Wasn't it ever thus? Aren't these folk human too? On top of which, the big institutions now pay marketing folk to write PRs; they have to justify their jobs too!

Best address it by good work, not moaning.
 However this confidence ignores the fact that three of these pillars are invisible, Inflation which depend on the Higgs field (we have detected the Higgs boson have we?), Dark Matter (we know what is it do we?) and Dark Energy (we know what we are talking about do we?) In their day the addition of epicycles to the Ptolemaic system was no more "ad hoc" than our addition of these "entities".
Do you have a link to the RAS lecture? AFAIK, the three pillars are nucleosynthesis (primordial nuclide abundance), the Hubble relationship (expanding universe), and the CMBR.
 The reason "the Standard Model has an imposing mountain of observational and theoretical support" is because it has been so well funded and the alternatives not, yet it is the essence of the scientific method that alternative theories against which the standard model can be tested should be encouraged. As I have pointed out on several posts cosmological observations are all theory dependent, change the theory and those observations change too. The important thing is to have consistency and an economy of "entities".
It's worth taking the time to look at these in some detail.

First (she said, sounding once again like a broken record), most of the top quality data is in the public domain; anyone can get it and do their own analyses.

Second, I'll issue an open challenge on the 'cosmological observations are all theory dependent, change the theory and those observations change too' claim: while the *papers* reporting the observations may be written with certain theories built into the analyses, can you show that the underlying *data* have such built in? This PF thread, about the CMBR, has a link to a 1999 Tegmark paper on analysing the BOOMERANG, WMAP, and Planck data, to remove foregrounds (it was written before all three even started); unless I misunderstood the paper, the *data* from these three could comprise both the 'cosmological signal' (free of any theory) as well as the 'foregrounds'; how a researcher chooses to analyse the data - wrt a particular cosmological model - is up to her!

The challenge: what (cosmologically relevant) observational data has been collected with 'cosmological theories' built-in?
Emeritus
PF Gold
P: 4,005
 Quote by turbo-1 I guess you've had a bad day, Chronos, so I'll let the rudeness slide. Observational evidence = Galactic clusters exhibit very strong lensing. They lens so strongly that if you try to extrapolate their masses using the simple relativistic model, the calculated mass will be many times larger than that of the observed matter in the cluster. Conventional astronomers cannot reconcile this with the standard model, but instead of trying to find where the model is broken, they instead claim that the "missing" mass is really there in the form of non-baryonic "dark matter".
With respect turbo-1, I think it's a little different:
- GR works
- GR predicts the bending of light by mass
- we observe something that looks exactly like what GR predicts (many tests done to support this)
- the mass (amount, distribution) estimated by assuming GR is large, this amount of mass is larger than what we would expect from the M/L ratios of luminous objects (e.g. galaxies).
- However, the 'non-luminous mass' estimated from straight application of GR is ~OOM the 'total mass' estimated from not one but TWO independent sets of observations (X-ray and velocity dispersion).

So the choices are: 1) throw out GR (the only mass that's 'really there' is that we can estimate from the distribution of light); 2) keep GR (the mass that we estimate from the images and GR is much higher than that we infer from the light).
 These are the same people who invoke non-baryonic "dark matter" to explain the discordant rotational curves of spiral galaxies. Of course, the "dark matter" again obligingly distributes itself in a very special non-uniform way to fix the rotational problem.
Indeed; again, if the only thing were rotational curves, it'd qualify as an epicycle; however, to sound even more like a broken record, the DM estimates that you get from the galaxy rotation curves are consistent with estimates of the amount of DM from independent observations!
 Somehow conventional cosmologists cannot bring themselves to examine these fundamental problems with their models. Instead, they invent "dark matter" that behaves in very special ways in each relevant circumstance. You might as well substitute obedient "fairies" or "angels" for "dark matter". As a very wise man once sang "When you believe in things you don't understand, you will suffer."
Hmm, remind me again what a wise woman said about the wisdom of throwing out GR?
PF Gold
P: 3,273
Thank you Neried for some much valued constructive criticism of SCC!

 Quote by Nereid Garth, doesn't it bug you intensely that you haven't got a handle on what form the 'missing' baryonic matter is in? I mean, just about every possibility has been constrained - in many cases quite severely - and the sums keep coming up way short.
Not really! Though it would be nice to resolve this problem, I don't pretend, or even expect, to be able to solve all the questions at once!

But let me ask you, doesn't it bug you that you haven't got a handle on what form the DM is in? I know there is a whole zoo of possibilities but each seems to have its own problems, just this last week New Scientist reports that neutrinos are now out of the picture. : (NS 4 Sep 04 pg 39 "Weighing the invisible")

As for Bruno's Leibundgut comments "Compared with Friedmann models of the universe, the distant SNe are too faint even for a freely coasting, "empty" universe, barring other influences that could dim the events." He was referring to an empty Friedmann universe, the Freely Coasting universe requires a new gravitational paradigm, it is not empty and so his analysis is not appropriate. "Change the theory and the observations/deductions change too".
 Quote by Nereid One may dislike 'epicycles', but short of saying 'gee, I haven't a clue about what the good observational data are telling us', what alternatives to 'dark energy' and 'dark matter' are there?
May I humbly suggest SCC for your consideration?

 Quote by Nereid so Gehlaut et al, let's have precise predictions on nuclide abundances
The work on nuclide abundances in the freely coasting cosmology is coming along, despite a lack of funds I believe, and one problem is that Deuterium comes out with a low primordial abundance that has to be reconciled by spallation later. But the nuclide abundances of the Standard $$\Lambda$$CDM model developed out of about two decades of intense research - give the alternatives a chance!
 Quote by Nereid Best address it by good work, not moaning. Do you have a link to the RAS lecture? AFAIK, the three pillars are nucleosynthesis (primordial nuclide abundance), the Hubble relationship (expanding universe), and the CMBR.
I am not moaning, just asking questions and seeking possible alternative against which the standard models may be tested, isn't this what good science is all about?
The RAS lecture was given by Prof. J.P. Ostriker (IoA) entited "Concordance Cosmology" on May 14th at the RAS Monthly meeting. It was very good but I couldn't help reflect on the invisibility of those three pillars I mentioned. Of course I agree that your pillars are sound, just that there are other ways of explaining them viz: SCC and the freely coasting universe.

In the Standard model the theory that all our cosmological observations are dependent on is GR! I distinguish between the raw data (red shift, angular size, apparent magnitude etc.) and observation, which is deduced from the data (recession, curvature etc.) For example, the fact that the CMB WMAP data indicate flatness is taken to mean that the cosmological density parameter is unity, but this only applies if the GR cosmological equations hold. They do not in alternative theories such as BD or SCC

I thank you again for a decent discussion and criticism of my ideas - Garth.
PF Gold
P: 7,368
 Quote by Nereid With respect turbo-1, I think it's a little different: - GR works - GR predicts the bending of light by mass - we observe something that looks exactly like what GR predicts (many tests done to support this) - the mass (amount, distribution) estimated by assuming GR is large, this amount of mass is larger than what we would expect from the M/L ratios of luminous objects (e.g. galaxies). - However, the 'non-luminous mass' estimated from straight application of GR is ~OOM the 'total mass' estimated from not one but TWO independent sets of observations (X-ray and velocity dispersion).
Yes GR works for LOTS of observations, but it seems not to work very well at the galactic scale and it fails utterly at very small scales. Now why does GR fail to predict the behavior of clusters without plugging in dark matter? My hunch is that GR fails to properly model the effects of matter on ZPE (classical space-time in the GR view) and vice-versa, which is why I have been digging up papers on LQG, ZPE etc, and bugging people like you by stating cosmological problems in non-relativistic terms. When the dust clears, I believe we will find that the mysterious "missing mass" is simply ZPE interacting with matter. The ZPE that we observe in the Casimir effect is 120 OOM weaker than predicted by theory, possibly because the virtual pairs that form ZPE are oriented quite randomly. It may be that the potential of the ZPE field is not unlocked until it is polarized (oriented, densified, etc) by the presence of very large masses. The folks at CIPA model both inertial mass and gravitational mass as interactions between matter and the ZPE field. Since I found their site yesterday, I've been devouring papers and articles linked to it.

http://www.calphysics.org/index.html

 Quote by Nereid So the choices are: 1) throw out GR (the only mass that's 'really there' is that we can estimate from the distribution of light); 2) keep GR (the mass that we estimate from the images and GR is much higher than that we infer from the light).Indeed; again, if the only thing were rotational curves, it'd qualify as an epicycle; however, to sound even more like a broken record, the DM estimates that you get from the galaxy rotation curves are consistent with estimates of the amount of DM from independent observations!Hmm, remind me again what a wise woman said about the wisdom of throwing out GR?
Nereid, I would not throw out GR, any more than I would throw out the Newtonian model of gravitation. They are both useful. When you have a useful tool you do not throw it away. If you encounter a job where your tool is not appropriate to the task, however, you should realize its limitations, use the tool only where appropriate, and try to develop a better tool for the tough jobs. That one is choice 3), which you did not list. Choice 4) is to establish an extension for GR that keeps it from breaking down at very small scales. I don't hold out much hope for 4), but think 3) is promising.

GR breaks down at very small scales (where ZPE lives) and I believe that this failure is the source of the misapprehension about the "missing mass" on very large scales. If the CIPA folks are right, we do not need dark matter, dark energy, Higgs Bosons, WIMPS, etc. to explain the gravitational behavior of the Universe, simply the interaction of matter with vacuum energy.

If I understand ZPE properly, its energy potential is 120 OOM larger than the observed Casimir Effect, so plenty of energy could be developed from just a small amount of polarization. The reason we don't see ZPE in the macro world is that it is all pervasive and exists at the lowest energy possible. There is no "contrast" in the ground state.
PF Gold
P: 3,273
 Quote by turbo-1 If I understand ZPE properly, its energy potential is 120 OOM larger than the observed Casimir Effect, so plenty of energy could be developed from just a small amount of polarization. The reason we don't see ZPE in the macro world is that it is all pervasive and exists at the lowest energy possible. There is no "contrast" in the ground state.
But shouldn't we see massive curvature from all this energy? Garth
PF Gold
P: 7,368
 Quote by Garth But shouldn't we see massive curvature from all this energy? Garth
I stole this directly from the CIPA site:

 But isn't the energy density of the ZPF so high that it would have an enormous gravitational effect, just like a huge cosmological constant? Not necessarily. If gravitation derives from the ZPF (and possibly the other quantum vacua) and changing dielectric properties of space, then the energy of the ZPF cannot gravitate. Gravitation would consist of minute changes in the ZPF in the presence of matter in analogy to the minute changes in the ZPF that an accelerating particle experiences. Indeed, one would be able to derive the principle of equivalence if we had a complete quantum vacuum-based theory of inertia and gravitation (including possibly the weak and strong interaction zero-point fields). But certainly the ZPF would not act on itself to gravitate; that would be impossible in this picture. The argument about a huge cosmological constant arising if you take the ZPF literally misses the point that a self-consistent ZPF basis for both inertia and gravitation would necessarily preclude this.
I haven't discovered how this was derived (in a published paper) yet, but am still searching. CITEbase is addictive and each relevant citation can lead to other interesting paper. For instance, I have been chided for using optical models to explain the "gravitational" refraction of light, and having never been a researcher in physics I meekly assumed that my approach was novel and unconventional enough to earn me status as a crackpot. Thanks to CITEbase, earlier today I ran across this paper, in which the author cites the work of over a dozen physicists who have developed non-relativistic optical models for gravitational refraction over the course of the last 80+ years. This does not mean my optical approach is correct, of course, but If I'm wrong, I've at least got company.

http://citebase.eprints.org/cgi-bin/...2Dph%2F0302273
Emeritus
PF Gold
P: 4,005
 Quote by turbo-1 Yes GR works for LOTS of observations, but it seems not to work very well at the galactic scale
Really?
 and it fails utterly at very small scales.
Well, maybe. All we know is that it and QM are mutually inconsistent at those small scales; AFAIK, no one has done any experiments in the relevant regime to actually take a look and see what happens! (of course, thousands would just love to do that, but no one has a spare $trillion or eight)  Now why does GR fail to predict the behavior of clusters without plugging in dark matter? But if you say GR fails, you must also say that the virial theorem fails, and gas equilibrium considerations fail ... and they all fail in the same way!  My hunch is that GR fails to properly model the effects of matter on ZPE (classical space-time in the GR view) and vice-versa, which is why I have been digging up papers on LQG, ZPE etc, and bugging people like you by stating cosmological problems in non-relativistic terms. When the dust clears, I believe we will find that the mysterious "missing mass" is simply ZPE interacting with matter. But you don't have to tie yourself in knots about distant galaxy clusters to test these ideas, after all, there's plenty of DM in our own Milky Way halo, and lots of interesting mass concentrations quite local that any ZPE-matter interactions can be tested with.  The ZPE that we observe in the Casimir effect is 120 OOM weaker than predicted by theory, possibly because the virtual pairs that form ZPE are oriented quite randomly. It may be that the potential of the ZPE field is not unlocked until it is polarized (oriented, densified, etc) by the presence of very large masses. It is a most extraordinary miss, isn't it!  P: 215 Gravity probe B may yet produce a surprising result that tells us more about dark energy/ dark matter.But if it does not then general relativity will be harder to knock in future. PF Gold P: 7,368  Quote by Nereid Really? Well, the amount of dark matter that is required to hold clusters together is huge, the amount of dark matter required to cause the flat rotation curves of spiral galaxies is huge, and the distributions of dark matter in both cases must be rather special (put in by hand, with clear intent to fix the failures). This indicates to me that GR is not predictive at very large scales.  Well, maybe. All we know is that it and QM are mutually inconsistent at those small scales; AFAIK, no one has done any experiments in the relevant regime to actually take a look and see what happens! (of course, thousands would just love to do that, but no one has a spare$trillion or eight)
Could there ever be enough money, space, or electrical power to construct and operate an accelerator to probe those energies?
 But if you say GR fails, you must also say that the virial theorem fails, and gas equilibrium considerations fail ... and they all fail in the same way!
I'm not at all familiar with how "gas equilibrium" is used to estimate masses. Do you have a link? As for GR and the virial theorem, they both rely on the classical concept that inertial mass and gravitational mass are intrinsic to matter. The CIPA folks and others are working on the concept that neither gravitational mass nor inertial mass are intrinsic properties of matter, but instead arise out of matter's interaction with quantum fields. Central to this concept is that the interaction is mutual, and matter polarizes (creates differentials in) quantum fields. In matter-rich clusters, where the quantum fields are highly polarized (aligned, densified...), the fields may endow matter with far more inertial and gravitational mass than we might otherwise expect - enough to hold the cluster together without dark matter. If gravity and inertia are endowed on matter through its interaction with quantum fields, we must expect that an increase in field strength will result in an increase of those properties. Ergo, the matter populating extremely dense clusters (with highly polarized quantum fields) will have more inertial mass and more gravitational mass than identical matter in less-dense surroundings. I forgot to mention that it will lens like crazy.
 But you don't have to tie yourself in knots about distant galaxy clusters to test these ideas, after all, there's plenty of DM in our own Milky Way halo, and lots of interesting mass concentrations quite local that any ZPE-matter interactions can be tested with.
Local won't be easy. The effects of ZPE-matter interactions will be most visible in the domains containing the most mass, thus the interest in galactic clusters. The effects may also be visible where the distribution of matter is such that differences in inertia/mass caused by interaction with a strongly curved ZPE field might give rise to anomolous velocities. MOND, anyone? I've been searching CITEbase for clues that somebody is studying ZPE inertia in light of MOND. Nothing yet.

Correction! I should have searched out Milgrom's papers first of all. He speculates here that MOND could be a modification of inertia due to a vacuum effect. It's an older paper, so he doesn't refer to the EM ZPE work being done by CIPA. MOND would be a perfect experimental test bed for CIPA.
http://citebase.eprints.org/cgi-bin/...tro-ph/9805346
 It is a most extraordinary miss, isn't it!
Yes it is. Please read the quote in my last post to Garth above. I lifted it off the CIPA site after wondering about the cosmological effect of SUCH a large energy potential.

Note that CIPA concentrates on the EM Zero-Point Energy field because it shows the most promise for manipulation in terms of Breakthrough Propulsion. NASA is picking up the tab.
Emeritus
PF Gold
P: 4,005
 Quote by turbo-1 Could there ever be enough money, space, or electrical power to construct and operate an accelerator to probe those energies?
No earthly accelerator using any technology currently conceivable could begin to probe these regions; the only useful thing to spend the on would be satellite observatories like a super-GLAST, a super-SNAP, a super-LISA, or earthly observatories such as a super-AMANDA or super-LIGO.  The CIPA folks and others are working on the concept that neither gravitational mass nor inertial mass are intrinsic properties of matter, but instead arise out of matter's interaction with quantum fields. Central to this concept is that the interaction is mutual, and matter polarizes (creates differentials in) quantum fields. In matter-rich clusters, where the quantum fields are highly polarized (aligned, densified...), the fields may endow matter with far more inertial and gravitational mass than we might otherwise expect - enough to hold the cluster together without dark matter. If gravity and inertia are endowed on matter through its interaction with quantum fields, we must expect that an increase in field strength will result in an increase of those properties. Ergo, the matter populating extremely dense clusters (with highly polarized quantum fields) will have more inertial mass and more gravitational mass than identical matter in less-dense surroundings. I forgot to mention that it will lens like crazy. I seem to recall someone recently talking about epicycles ... as I read these words here, my mind kept flashing 'epicycle! epicycle!' ... I can't imagine why {maybe marcus can give us a tune, 'you say "tomato", I say "ZPE"; you say "potato", I say "dark matter"'!} PF Gold P: 7,368  Quote by Nereid No earthly accelerator using any technology currently conceivable could begin to probe these regions; the only useful thing to spend the on would be satellite observatories like a super-GLAST, a super-SNAP, a super-LISA, or earthly observatories such as a super-AMANDA or super-LIGO.I seem to recall someone recently talking about epicycles ... as I read these words here, my mind kept flashing 'epicycle! epicycle!' ... I can't imagine why {maybe marcus can give us a tune, 'you say "tomato", I say "ZPE"; you say "potato", I say "dark matter"'!}
OK, I can see you just a teensy bit uncomfortable with inertia and gravity arising from masses interaction with ZPE fields. Poke around here a bit, though, and see what you think:

http://www.calphysics.org/index.html

You may view mass-ZPE-interaction as an epicycle. I see it to be just the opposite - an elegant solution to a couple of GR's biggest problems.

It is economical of entities (reduces rather than creates necessary entities) and it is testable. Occam would demand that we give it a shot. Rotation curves of spiral galxies can provide experimental evidence. MOND appears to work, and ZPE field-induced differential inertia may be why. The slick thing is that all the elements needed are already out there - 1) matter in 2) a bound system existing in 3) space-time suffused by 4) quantum fields. No need for obedient, prescient dark matter clumping up in just such densities and distributions to keep our precious GR accurate. Another potential test - can ZPE explain the mass/luminosity ratio of X-ray clusters? MOND has a problem with this class of objects.

I predict that the first researcher to create a testable model of ZPE inertia as the cause of differental rotation in spiral galaxies will have to buy a new dinner jacket and learn a few words of Swedish.
Emeritus
PF Gold
P: 4,005
 Quote by Garth Not really! Though it would be nice to resolve this problem, I don't pretend, or even expect, to be able to solve all the questions at once! But let me ask you, doesn't it bug you that you haven't got a handle on what form the DM is in? I know there is a whole zoo of possibilities but each seems to have its own problems, just this last week New Scientist reports that neutrinos are now out of the picture. : (NS 4 Sep 04 pg 39 "Weighing the invisible")
I don't particularly like, or dislike, DM, DE, or any other concept; when reading a theoretician's paper I ask "is this consistent with the observational data?". If the 'freely coasting' folk say 'nuclide abundances? no problem!' then I expect to see something a bit more falsifiable than "the same as the lowest metallicities currently observed" (or words to that effect)

Re neutrinos: I have thought for some time that they can't be more than a minor player (unless there's a whole unknown new spectrum of types as yet unobserved).
 May I humbly suggest SCC for your consideration?
Someone like Pete or DW can comment better than I as to how well SCC fits the honourable tradition of "let's tweak GR a bit, to better test GR itself"
 The work on nuclide abundances in the freely coasting cosmology is coming along, despite a lack of funds I believe, and one problem is that Deuterium comes out with a low primordial abundance that has to be reconciled by spallation later. But the nuclide abundances of the Standard $$\Lambda$$CDM model developed out of about two decades of intense research - give the alternatives a chance!
maybe, but all that work is there for folk to take and modify; there's little trail-blazing to do.
 The RAS lecture was given by Prof. J.P. Ostriker (IoA) entited "Concordance Cosmology" on May 14th at the RAS Monthly meeting. It was very good but I couldn't help reflect on the invisibility of those three pillars I mentioned. Of course I agree that your pillars are sound, just that there are other ways of explaining them viz: SCC and the freely coasting universe.
Thanks. I forgot a 'pillar' - large scale structure, per 2dF and SDSS. BTW, I expect that the second year of WMAP data will enable some pretty discriminating tests ... of the concordance model, free coasting, ... but not, maybe, SCC or turbo-1's ZPE ideas
 In the Standard model the theory that all our cosmological observations are dependent on is GR! I distinguish between the raw data (red shift, angular size, apparent magnitude etc.) and observation, which is deduced from the data (recession, curvature etc.) For example, the fact that the CMB WMAP data indicate flatness is taken to mean that the cosmological density parameter is unity, but this only applies if the GR cosmological equations hold. They do not in alternative theories such as BD or SCC
maybe, but you can use the data - yourself - to test SCC, surely?
PF Gold
P: 3,273
 Quote by Nereid , but you can use the data - yourself - to test SCC, surely?
That is precisely what the "freely coasting" team claim to have done.
As I said in an earlier post apart from having an obvious interest in SCC, what I, and others **, are concerned about is the "over" confidence placed in the standard paradigm. I would have thought alternatives would have been of more interest in the name of good scientific practice. But the key point is that some these alternatives are testable in experiments such as GPB. Even then Kenneth Nordtvedt has said that the GPB experiment was worth doing when it was first planned in the 1960s, but that today the result is a foregone conclusion.

** see http://www.cosmologystatement.org/
PF Gold
P: 7,368
 Quote by Garth That is precisely what the "freely coasting" team claim to have done. As I said in an earlier post apart from having an obvious interest in SCC, what I, and others **, are concerned about is the "over" confidence placed in the standard paradigm. I would have thought alternatives would have been of more interest in the name of good scientific practice. But the key point is that some these alternatives are testable in experiments such as GPB. Even then Kenneth Nordtvedt has said that the GPB experiment was worth doing when it was first planned in the 1960s, but that today the result is a foregone conclusion. ** see http://www.cosmologystatement.org/
My name is there. I had to sign. As a former chemist (process chemist in pulp and paper mills and later consultant to various corporate entities, including Westvaco, Georgia-Pacific, and Du Pont) and even later as an optician in a large opthalmic practise (avoiding the need to fly all over the country and eat diner food) I have some basic familiarity with the scientific method.

I am not a physicist by training, but my avocation of observational astronomy and astrophotography led me to relate problems in astronomy and cosmology to the fields that I am familiar with, particularly optics. I have for a very long time followed the work of Halton Arp, Geof and Margaret Burbidge and others in the popular press, and as soon as the Internet became available here in the Hinterlands, I followed them there as well. One in-depth correspondence with Mr. Halton "Chip" Arp (arising from a letter I wrote in reference to an article by one of his detractors) gave me an enduring respect for the man. I already knew that he is a disciplined observational astronomer. The correspondence cemented the fact that I was dealing with a real gentleman. It also showed me that I was dealing with a man who understood the significance of proposing paradigm-altering concepts in a field that is firmly committed to nearly 100 years of conventionality. He is quite philosophical about that. A gentleman, as I said.

I have had similar interactions with two equivalent intellects in other fields - Cecil Rhodes who was Professor Emeritus of English Literature at the University of Maine (and a Rhodes Scholar). He tried to ride herd over a bunch of us Engineering students with high SATs, and he actually turned me to the Dark Side of the Force, and was a pivotal force in my switch from Chemical Engineering to English Literature, with a concentration on the Romantic Period. The other man was Erling Skorpen, Dean of Philosophy, who let me into his grad-student and senior-only Meta-ethics course after a "brief" 3-hour "lunchtime" Q&A that I was led to believe would last less than 15 minutes. He had a 3pm class and begged off with a commitment that we would re-engage. I was a sophomore, and had never taken a basic philosophy course. I never had to take one after either, and maintained a double major - in English Lit and Ph. All these men are gentlemen in the truest sense of the word. As the son of a mill-worker living in a very poor town, their treatment of me was greatly appreciated. I felt the same way dealing with Halton Arp.
Emeritus
PF Gold
P: 4,005
 Quote by turbo-1 OK, I can see you just a teensy bit uncomfortable with inertia and gravity arising from masses interaction with ZPE fields. Poke around here a bit, though, and see what you think: http://www.calphysics.org/index.html You may view mass-ZPE-interaction as an epicycle. I see it to be just the opposite - an elegant solution to a couple of GR's biggest problems. It is economical of entities (reduces rather than creates necessary entities) and it is testable. Occam would demand that we give it a shot. Rotation curves of spiral galxies can provide experimental evidence. MOND appears to work, and ZPE field-induced differential inertia may be why. The slick thing is that all the elements needed are already out there - 1) matter in 2) a bound system existing in 3) space-time suffused by 4) quantum fields. No need for obedient, prescient dark matter clumping up in just such densities and distributions to keep our precious GR accurate. Another potential test - can ZPE explain the mass/luminosity ratio of X-ray clusters? MOND has a problem with this class of objects. I predict that the first researcher to create a testable model of ZPE inertia as the cause of differental rotation in spiral galaxies will have to buy a new dinner jacket and learn a few words of Swedish.
You know turbo-1, I had to go get myself a nice glass of one of my favourite Australian cab-savs before I could answer your post; I mean, is this the same turbo-1 who wrote all those other posts???

Shall I wave my hands, invoke gorgons, angels, and the spirits of long-since enjoyed chardonnays? "Hey, I've got a really cool idea, seems kinda plausible, and (nudge, nudge, wink, wink) will rid the world of corns and carbuncles to boot, oh and explains AIDS too. What? Consistency with observations? Don't be silly! Of course I haven't done any calculations yet!! But just feel the plausibility! What? Explain, with equations, how ZPE-matter interactions account for the observed CMBR? That's got nothing to do with it! I'm only talking about what poor deluded astronomers call 'gravitational lensing', and only that to do with distant galaxy clusters! What? If these ZPE-matter interactions could explain 'cluster lensing', then there'd be humongous early universe effects too? even affecting the CMBR?? Hmm, maybe ... but feel the plausibility!"

If you "[color=blue]see it [mass-ZPE-interaction] to be [...] an elegant solution to a couple of GR's biggest problems[color]" then show us how! With equations!! If not, why shouldn't we move these speculations off to TD?
 PF Gold P: 7,368 Do you have a favorite year for AU Cab-Sauvs? If not, do you have a region that is consistently good for recent years? I'm cheap, but discriminating!
PF Gold
P: 9,093
 Quote by Nereid You know turbo-1, I had to go get myself a nice glass of one of my favourite Australian cab-savs before I could answer your post; I mean, is this the same turbo-1 who wrote all those other posts??? Shall I wave my hands, invoke gorgons, angels, and the spirits of long-since enjoyed chardonnays? "Hey, I've got a really cool idea, seems kinda plausible, and (nudge, nudge, wink, wink) will rid the world of corns and carbuncles to boot, oh and explains AIDS too. What? Consistency with observations? Don't be silly! Of course I haven't done any calculations yet!! But just feel the plausibility! What? Explain, with equations, how ZPE-matter interactions account for the observed CMBR? That's got nothing to do with it! I'm only talking about what poor deluded astronomers call 'gravitational lensing', and only that to do with distant galaxy clusters! What? If these ZPE-matter interactions could explain 'cluster lensing', then there'd be humongous early universe effects too? even affecting the CMBR?? Hmm, maybe ... but feel the plausibility!" If you "[color=blue]see it [mass-ZPE-interaction] to be [...] an elegant solution to a couple of GR's biggest problems[color]" then show us how! With equations!! If not, why shouldn't we move these speculations off to TD?
Plays well with others.. C .. I am a bad influence.
PF Gold
P: 7,368
 Quote by Nereid What? Explain, with equations, how ZPE-matter interactions account for the observed CMBR? That's got nothing to do with it! I'm only talking about what poor deluded astronomers call 'gravitational lensing', and only that to do with distant galaxy clusters! What? If these ZPE-matter interactions could explain 'cluster lensing', then there'd be humongous early universe effects too? even affecting the CMBR?? Hmm, maybe ... but feel the plausibility!" If you "[color=blue]see it [mass-ZPE-interaction] to be [...] an elegant solution to a couple of GR's biggest problems[color]" then show us how! With equations!! If not, why shouldn't we move these speculations off to TD?
You are quite correct. They are thought-experiments only. I have linked to some relevant papers (with math) that illustrate some of the concepts I'm struggling to explain, but unfortunately, I don't have the math skills to explain how to "connect the dots" in a way that will satisfy you. Nor will logical argument suffice - not rigorous enough. I'm stuck. Maybe if I try to explain myself in a strictly GR language (which I don't speak that well )...

By the way, you misstated me just a bit. If you read that post, you will see that I said that the effects of space-time distortions on matter and light would likely be easiest to see and measure in places where there is a LOT of matter (clusters) or where matter distribution is non-uniform (spiral galaxies). I didn't say that is those are the only places or the only times we might see a measurable effect, just that those might be productive places to look first. Gravity is a very weak force, and it stands to reason that anomalous gravitational effects (ones not yet predictable by GR) would most easily be seen where there are dense concentrations of matter and/or strong gradients the distribution of matter.

Cluster lensing is a strong effect that has been well-modeled in one study (at least in terms of describing the extent and density of the "missing mass"),
http://antwrp.gsfc.nasa.gov/apod/ap030814.html
so that's a more productive place to look, as opposed to studying shear effects caused by individual galaxies, which are small. Also, since the galactic rotation curves of a LOT of spirals have already been measured, and the density ratios of the central bulges and arms have already been calculated, the concept of distorted (densified or aligned...) space-time fields interacting with matter could be tested and subjected to falsification very quickly. It may be that ad-hoc MOND is a description of inertia/mass variation across a gradient in a space-time field. I hope someone with good math skills will try modeling it.

I have avoided any reference to quantum fields in this post. I have used only the term space-time. I do this because GR folks will readily agree that matter curves (distorts) space-time and that curved space-time determines the paths of entities traveling through it. A bigger logical step is considering that since curved space-time mediates gravity, variations in the structure or "curvature" (in the GR sense) of space-time itself might result in variable gravity for the objects embedded in it.

Might an object have more gravitiational mass and/or inertia in a densely-curved space-time field than it would have in a space-time field that is more relaxed? It is a very basic question, and because it bears on a fundamental concept in GR, it will engender strong reactions. Intuitively, most people will reject it out of hand, but I think that's a mistake. Most people (including a VERY smart guy who knew a little something about GR) would reject quantum physics out of hand, too, because so much of it is counter-intuitive and seemingly illogical, but we know now that quantum physics is quite valuable and predictive.

If more strongly curved space-time results in more gravitational mass/inertial mass for matter embedded in it, we could explain why clusters act far more massive than we expect (excess lensing, given the visible matter there) and could at the same time explain how the clusters manage to hold together, even though the member galaxies have high relative motions and seemingly have insufficient mass to remain bound. We could also explain how the rotational curves of spiral galaxies flatten out as we look farther out from the very dense central bulges. Stars farther and farther from the massive central bulge exist in less-distorted space-time fields and have therefor have less inertial/gravitational mass. (I'm not going to even contemplate breaking that mass equivalence lest Nereid hunt me down like a dog. ) I called this idea elegant before, and I still believe it to be so. It provides a resolution to some seemingly intractable problems without having to invoke additional entities beyond sensible baryonic matter and the space-time field in which it exists.

The folks working on quantum gravity may one day come up with a robust dynamical model that can describe how mass distorts space-time, and how distorted space-time affects mass. Judging from the papers I've found, that is likely to be many years away, at best. We may be at a point where observational astronomers can model and measure the effects of variable gravity in a space-time gradient, and express it in a GR framework long before the theorists can explain why it works. It won't be a TOE, but there might never be anyway, despite the best efforts of the theoreticians.

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