Has Gravity Probe B been a waste of money?

[Nereid]

Please do not ask Garth to justify SCC by supplying proofs for my "speculation".

I have been thinking about my "speculations" for years, and have pursued them more vigorously for the past few months. Garth has been working very hard and sticking his neck out for decades. He should not be asked to defend the "speculations" of an amateur in cosmology.

Thanks.

My apologies to any reader who, like turbo-1, may have misunderstood what I was saying.

To clarify, I was trying to say that the proponents of *any* approach (other than 'the concordance model') could be asked to provide estimates of the (free) parameters in their model(s), as determined from analysis of (publicly available) astronomical datasets. IOW, don't just 'tell us what your theory is', also tell us what 'analysing the best available data, we find that our model is consistent, and estimates of the key parameters are {list, inc error bars, with a statistical metic}.'

 

[Garth]

I'll drink to that ! Garth

 

[Chronos]

Garth, I appreciate the effort you have put into SCC. I read your paper and it is interesting. I still think the biggest problem you face is that SCC predicts a universe that forms too early and collapses before stars and galaxies can form. Can you reform your model that explains how the universe behaves now? I think not. The model Nereid suggests has observational evidence. In fact, she has a mountain of evidence in her favor.

 

[turbo]

turbo-1 - An interesting question... hmmm...thank you.

In SCC there would appear to be no difference in the way matter and anti-matter react to the gravitational field. The differences are to be found when the internal pressure becomes significant. Actually photons obey the equivalence principle, it is slow moving particles that experience an upwards scalar field force, which decouples as the pressure increases to 1/3density c^2. Unless the internal pressure of anti-matter is different to that of ordinary matter there would be no difference. The false vacuum on the other hand experiences anti-gravity of 1/2g..makes you think...
Garth

I chewed on this question quite a while yesterday. Until then (as I posted above regarding black hole evaporation) I had assumed that ZPE particle-antiparticle masses and fall rates are essentially equivalent. It occurred to me though that if space-time (as expressed by the EM ZPE field) can be curved by matter, there should be a simple mechanism to cause the curvature. Going back to the basics (my automatic fall-back position, since I have to do all this in my head...duh), I considered what could be different about the matter-antimatter particles in virtual pairs that would align them in a gravitational field. I thought about the field of pairs flipping like magnets to their most entropic state (antimatter oriented toward the large mass, matter particles oriented away) using the "opposites attract" approach... That may ultimately be a proper model, but it left me wondering what would cause the "opposites attract" approach to work, aside from "force acting over a distance". That led me to the notion that the fall rate of antimatter in a gravitational field might be higher than that of matter. We really need a definitive test of the fall rate of antimatter - the CERN data were inconclusive.

That bit of asymmetry could polarize the ZPE field in the presence of large masses. It could perhaps explain a few other things. One implication for such virtual-pair alignment in the process of black hole "evaporation" would be that the black hole would capture more anti-particles than particles. That would result in more particles than anti-particles being promoted from virtual to "real" status outside the event horizon. After the inevitable (and very energetic) annihilation events near the event horizon, there would remain a net excess of new real particles to form matter (after they cooled from the ultra hot plasma state!). This is probably not going to be testable in any real sense, unless quasars are what we see when black holes behave this way.

As an extension: We see matter all around us, not anti-matter. Assuming that the universe began with equal proportions of each, could this black-hole behavior be a model for how anti-matter and matter were separated? If so, beyond the event horizons of these massive objects would be domains dominated by anti-matter. Lee Smolin has described our Universe as one fine-tuned to produce black holes (a rational alternative to the anthropic principle!), and he speculated that a prospective inhabitant of the universe in a black hole would look out through his universe's past toward a singularity, much as we view our universe in standard cosmology. I can't find that paper, now, but I'm pretty certain he didn't cite a matter/antimatter selection effect. To go one step farther out on the limb , these antimatter "universes" should all have equivalent black holes that preferentially eat matter, creating nice matter-rich pockets like the one we live in. Yep, it's turtles all the way down.

 

[Garth]

Garth, I appreciate the effort you have put into SCC. I read your paper and it is interesting. I still think the biggest problem you face is that SCC predicts a universe that forms too early and collapses before stars and galaxies can form. Can you reform your model that explains how the universe behaves now? I think not. The model Nereid suggests has observational evidence. In fact, she has a mountain of evidence in her favor.

I do not know where your concept of the SCC universe came from. In the Einstein frame it expands linearly, more slowly than the GR model R(t) =t, and does not contract at all, in the Jordan frame it is static R(t) = Ro. An expanding universe with fixed rulers is replaced by a fixed universe and shrinking rulers. Garth

 

[Garth]

Yep, it's turtles all the way down.

Perhaps the last turtle is standing on the first?

 

[Garth]

, don't just 'tell us what your theory is', also tell us what 'analysing the best available data, we find that our model is consistent, and estimates of the key parameters are {list, inc error bars, with a statistical metic}.'

Sorry my quip about drinking to that was in response to your previous post. I take this post seriously and say I'm working on it - but I could do with some help! Perhaps the work will never be completed, or perhaps if GPB comes up trumps for SCC others will take on the baton!
Garth

 

[turbo]

Perhaps the last turtle is standing on the first?

Good one!

 

[Chronos]

I do not know where your concept of the SCC universe came from. In the Einstein frame it expands linearly, more slowly than the GR model R(t) =t, and does not contract at all, in the Jordan frame it is static R(t) = Ro. An expanding universe with fixed rulers is replaced by a fixed universe and shrinking rulers. Garth

I may have misinterpretted what SCC was saying. I read it to mean there was no exponential expansion of the early universe. On that point I disagree. It is very difficult to avoid an expansion model that makes any sense. I don't see where an Einstein frame expands or contracts, until you add a cosmological constant.

 

[Garth]

I may have misinterpretted what SCC was saying. I read it to mean there was no exponential expansion of the early universe. On that point I disagree. It is very difficult to avoid an expansion model that makes any sense. I don't see where an Einstein frame expands or contracts, until you add a cosmological constant.

Okay - the presence of the scalar field and the violation of the Equivalence Principle - it is replaced in SCC by the postulate of the Principle of Mutual Interaction (PMI)* - results in a different, though related theory to GR. The Friedmann equations are modified and the SCC cosmological equations have to be solved from scratch. The result is, in the Einstein Frame of measurement in which particle masses are conserved, that the universe expands strictly linearly R(t) = t. This model has already been examined by the Indian team mentioned elsewhere and it is surprisingly concordant with cosmological constraints. It does not need Inflation, there are no horizon, density or smoothness problems in this model, as there are in the GR models, for Inflation to 'fix'. In that sense it requires less extra hypotheses than the standard theory. It does make sense, I find it is Inflation that is difficult to make sense of, especially as the Higgs boson is so elusive!
Because the cosmological field equations have changed these results are obtained without adding a cosmological constant, although it depends how you define the scalar field, its effect could be interpreted as such. The scalar field is that which endows particles with rest energy, or (rest) mass, it is all gravitational potential energy, the work necessary to 'lift' the particle 'out of the Big Bang'. You may not like or agree with these postulates, it is only a suggested alternative gravitational theory but it does work and it is testable, hence the value for me of the GPB.
- Garth

* The PMI :- "The scalar field is a source for the matter-energy field if and only if the matter-energy field is a source for the scalar field."

 

[Chronos]

Thanks Garth. I think I get it now. I ran across this rather bold paper the other day. For some reason, it got me to thinking about SCC. You may find it amusing.
http://arxiv.org/abs/gr-qc/0406023

 

[Garth]

Thanks Garth. I think I get it now. I ran across this rather bold paper the other day. For some reason, it got me to thinking about SCC. You may find it amusing.
http://arxiv.org/abs/gr-qc/0406023

Chronos thank you, I have already downloaded that paper when it first came out on the arXiv but I must confess I have not had the time to study it and do it justice.

There are one or two points of contact with SCC. The implication that GR does not fully include Mach's Principle, and therefore GR has to be revised, is one thought; and the cosmological preferred frame of reference another albeit a related one.

My point I have made elsewhere in these forums is that the basis of SR is "no preferred frame of reference", which manifests itself in GR as the Equivalence Principle and the conservation of energy-momentum. However SR is formulated for an empty universe, flat space-time. As soon as you put matter into such a universe you can select a preferred frame of reference, the Centre of Mass/Momentum of that matter! So as soon as you introduce gravitational fields the basic premise falls down. In SCC the field equations are manifestly covariant, however in order to solve them you have to select a frame of reference, normally for convenience the Centre of Mass/Momentum of the system. In SCC, as soon as you do this, then, in its Jordan conformal frame, energy is locally conserved. In the Einstein frame, which is canonical GR, this feature is lost and it is energy-momentum that is conserved as normal.
As Unnikrishnan points out in his paper this preferred Machian frame of reference also identifies an absolute time, and therefore, as he says, introduces a second Mach's principle for time. (But I would see the two MPs as one)
-Garth