Is the Conventional Wisdom About the Universe Wrong?

[bapowell]

A universe that suddenly starts to accelerated was not expected and requires a change to the laws of physics to explain.

Not expected based on what...a naive extrapolation of our recent expansion history?
As far as needing new physics, if you accept the existence of scalar fields, then no, it doesn't. If you don't accept the existence of scalar fields, then I'm sure you are equally as discontent with the Higgs mechanism, gauge theories, and inflation.

As to the question of whether dark energy does or does not exist, recent analysis of fluctuations in the CMB in the Northern Hemisphere do not support an accelerating universe. (The CMB is affected by clusters if the cluster velocity changes during the period in which the CMB passes by the cluster. The timing of the falling into and out of the gravity well is different if the universe is accelerating.) The Shanks announcement referenced this finding.

That doesn't sound right. The integrated Sachs-Wolfe effect depends on the time dependence of the gravitational wells of intervening galaxy clusters -- not on the velocity of the cluster. Besides, there you go again citing a single study that may claim results that contradict some model of dark energy. When faced with many data sources that seek to test a particular hypothesis, scientists should consider all of them, taking into account sample sizes, quality of the data, etc. If a scientist has several, high quality results with good statistics that say one thing, and one result that says another, he doesn't simply throw his hands up and call it a wash. He needs to do a little thing called Bayesian analysis, and rigorously investigate the problem. Surely you'd agree that if I did a single experiment with one data point that (somehow) refuted Newton's 2nd law, nobody in their right mind would consider my single experiment sufficient to overturn centuries of experimental work which support Newton's 2nd law. This is essentially what you are doing by cherry-picking a small number of studies that run counter to a large body of accumulated evidence in support of dark matter (and dark energy, but less so). For example, why would you conclude that results from a study done of the Northern Hemisphere only should trump (or even strongly call into question) results from (nearly) full sky studies??

 

[Chalnoth]

I provided a link the Planck satellite as it is expected there will be additional and better data to answer some of these questions. Let's keep watching for new data and new papers. That is what makes it interesting for me. Unanswered problem and additional data on the way to provide answers.

Well, that's not going to be for a couple of years yet, so it really doesn't have much bearing on the current discussion.