‘As far as explaining what the dark energy is, I certainly won’t kid you, I have no idea! (Likewise inflation.) I’m extremely interested in alternatives, including modified gravity and back-reaction of perturbations, and open-minded about different candidates for dark energy itself.’ – Sean

Look, Phil Anderson’s comment is EXACTLY the correct prediction made via the October 1996 issue of Electronics World, which was confirmed experimentally two years later by Perlmutter’s observations.

The lack of deceleration is because the expansion causes general relativity: http://feynman137.tripod.com/#h

This existing paradigm tries to take general relativity (as based on local observations, including Newtonian gravity as a limit) to the universe, and force it to fit.

The reality is that gravity and contraction (general relativity) are predicted accurately from the big bang dynamics in a quantum field theory and spacetime context. There is nothing innovative here, it’s old ideas which have been ignored.

As Anderson says, the universe is ‘just not decelerating, it isn’t really accelerating’, and that’s due to the fact that the gravity is a proved effect surrounding expansion:

http://electrogravity.blogspot.com/

This isn’t wrong, it’s been carefully checked by peer-reviewers and published over 10 years. This brings up Sean’s point about being interested in this stuff. It’s suppressed, despite correct predictions of force strengths, because it doesn’t push string theory. Hence it was even removed from arXiv after a few seconds (without being read). There is no ‘new principle’, just the existing well-known physical facts applied properly.

Shall we just talk about the beginning of this universe, while others like to speak about the “whole process”?

So you have to have some idea here, and condensed matter theorist would have fell short on trying to explain what is driving the expansion.

There had to be a “negative valuation geoemtrically enhanced” to have recognized curvatures parameters as a possibility?

All things would have to have issue from a supersymmetrical point of view? Even from that state, what was it’s predecessor?

Regarding astro-ph/0503582, it’s true enough that it makes a good case against superhorizon fluctuations a la Kolb et.al. being the cause of the purported acceleration, but that’s only one of the mechanisms based on inhomogeneity which have been proposed recently. Kolb et.al. have since moved on to another contender,

http://arxiv.org/abs/astro-ph/0506534

Brandenberger has his own version,

http://arxiv.org/abs/astro-ph/0510523

and Mansouri claims to be able to do it non-perturbatively even:

http://arxiv.org/abs/astro-ph/0512605

There’s much more out there, some of it discussed at Cosmocoffee:

http://cosmocoffee.info/viewforum.php?f=2

Nitpicking verbiage — fine, I agree.

Smoothness of the baryonic component — well, I think there are several empirical reasons to think that it’s smooth on large scales. First and foremost is of course the CMB. Yes what we measure are the photons, but they are certainly affected by the matter distribution. If the latter were notably inhomogeneous, it would definitely perturb the CMB temperature at a level greater than 1 part in 100,000. But also, direct galaxy surveys have been getting better and better, and the number-density fluctuations of galaxies are unmistakably less on large scales than on small ones. In fact, they fit extremely well to a model in which all the primordial fluctuations were that famous 1 part in 100,000 (see e.g. astro-ph/0601168). There have been astrophysicists who have argued for a fractal distribution, and I remember a “debate” in Princeton around 1992, with Marc Davis defending the conventional view — suffice it to say that the fractal viewpoint didn’t gain any new adherents that day.

It’s true that nobody has done much work on very inhomogeneous universes, just because the data are so very inconsistent with them. Sorry to be repetitive, but the CMB can’t be that smooth if the matter distribution isn’t! (Infrared surveys of galaxy positions on the sky are also extremely smooth, although it’s not as precise as the CMB.)

As an empirical matter, I think the universe really is accelerating; see e.g. astro-ph/0512586. That’s not a conclusion that relies on theory.

As far as explaining what the dark energy is, I certainly won’t kid you, I have no idea! (Likewise inflation.) I’m extremely interested in alternatives, including modified gravity and back-reaction of perturbations, and open-minded about different candidates for dark energy itself. But large-scale fluctuations just won’t do it; people have tried and failed, see astro-ph/0503582.

Concerning the probability exercise, sorry if I seemed flippant. But I don’t buy your analogy. My point wasn’t that your conclusion was wrong (since I agree with it), just that arguments of this type have been batted to death in the theological literature. I would welcome more input into those conversations from scientists, but out of respect for other scholars I think we should try to make that input be as well-informed as possible.

Nitpicking about verbiage-”-radiant”, perhaps I should have used “radiating”.
“hadronic”, I wanted a word for made of heavy particles such as the supersymmetric equivalent of hadrons–whatever it is, it has to have some mechanism like ordinary matter to keep it from decaying away; and my point that it is odd that it’s also very few quanta is valid and puzzling even to the local experts–and to you.

I may be missing something but I know of no survey of the radiating component, as opposed to CBR, that assures its smoothness. There are a lot of theoretical arguments (Sachs-wolf, is it, for instance?) but nothing direct.
And the history of cosmology is that holes in theoretical arguments appear with most new data.

Maybe I’m wrong., I’m not a relativist; but my points were A] that noone has done cosmology on a seriously inhomogeneous universe;B] that the flat universe is just not decelerating, it isn’t really accelerating; C] there’s a bit of the “phlogiston fallacy” here, one thinks if one can name Dark Energy or the Inflaton one knows something about it. And yes, inflation predicts flatness, and I even conditionally accept inflation, but how does the crucial piece Dark Energy follow from inflation?–don’t kid me, you have no idea.

The remark about my probability exercise amount to saying that I should consult Mobil-Exxon before saying anything about global warming. That paragraph should have been left off if you wanted to look cool and impartial.

Still, it might be worth going on record as saying “dark matter does not exist”. This could be an easy way to be considered prophetic.

Kea, you should ask about the Mansouri paper on cosmocoffee.info

Nonetheless they are much heavier than the quanta of CBR, so they have, all told, much more mass, and have some cosmological effect on slowing down the Hubble expansion

I don´t see exactly what is the “weight” of the quanta of CBR (ok, during all the thing he was referring to “density” instead…), but in any case radiation also contributes to slow down the Hubble expansion…

Moroever, seeing the amount of cross-fertilization between condensed matter and high energy today, it is very unfortunate that lot of leading physicists still adopt such a narrow attitude.

or:
http://arxiv.org/abs/gr-qc/0012094

has to consider the photons source?

Which is I guess the fact that the Big-Bang has to be considered an “Anhilation” event?

What event was the ‘Big-Bang’, has a baring on what photon count you can do, if there were particles of matter, emitting and absorbing “photons”, then one has to know the total number of Proton/Anti-Proton number.

Andersons handwaving into the expectation of “another kind of matter”, is not that much wayward, according to:
http://arxiv.org/abs/hep-ph/0102090

infact:http://arxiv.org/abs/hep-th/0410286

has proposed with:http://arxiv.org/abs/hep-ph/9911386
and :

http://arxiv.org/abs/hep-ph/0409232

that there is a high probability that ‘Quark-Condensate’ is the “missing” form of matter?

Kea, Sean did read the Kolb et al. paper, I think he mentioned it on the blog. The Mansouri paper just came out, Kolb et al.’s previous work which Sean criticized has nothing to do with this new paper. So it is perfectly acceptable to criticize the first without reading the second (kinda like saying how can you criticize coca-cola when you haven’t tried pepsi??).

And as far as I can see from a very quick perusal of the Mansouri paper, he is explaining the Type Ia SN evidence for acceleration (correctly or not, I don’t know) but not touching CMB, x-ray, or other compelling evidence for it.

There are a number of ways of making a formal probability theory which incorporate Ockham’s razor, the principle that one must not multiply hypotheses unnecessarily. Two are called Bayesian probability theory, and Minimum Entropy. …

I believe Anderson meant to say Maximum Entropy, in reference to Maximum Entropy methods.

If you are so willing to criticise the ideas of Kolb et al. (I’m not saying they’re not wrong) perhaps you should actually read the Mansouri paper.

An “artistic philosophy on strings” that might issue from my neck of the woods:)

Blackgold?

Go check it out for yourself.

Elliot