No evidence for circles in the CMB; contrary to claims by Penrose and Gurzadyan

[nicksauce]

http://arxiv.org/abs/1012.1268

http://arxiv.org/abs/1012.1305

These papers seem to claim that the circles found by Penrose and Gurzadyan in the WMAP data, which were presented as evidence of pre-big bang activity, are entirely consistent with what we would expect the CMB to look like from LCDM simulations.

 

[Coin]

These analyses are quite good. I particularly liked this toss-off toward the end of the first paper:

Indeed, it is straightforward to repeat the above analysis, but searching for low-variance features of shapes other than circular annuli. As an example, we performed the analysis looking for low-variance 'triangular annuli', i.e., the regions between concentric equilatural triangles of different sizes... there are directions around which there are similarly low-variance triangles to the low-variance circles found above. Therefore there is nothing special about the presence of low-variance circles on the sky.

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Something I cannot help but find interesting: Penrose initially proposes his theory, and suggests a search for circles in the sky. There was no response to this plea as far as I am aware. Then Penrose publishes an apparently faulty claim of having found circles in the sky, and the physics community produces two high quality searches for said circles in short order. I am reminded of a method I discovered years ago for getting help on Linux IRC channels. If you walk in and say, "how do I get a blu-ray player working on my Linux machine?", people will probably not help, because people are busy and they expect you could do the work yourself. But if you walk in and say, "Linux sucks, you can't watch blu-rays!" people will be falling over themselves to prove you wrong...

 

[Sourabh N]

These analyses are quite good. I particularly liked this toss-off toward the end of the first paper:


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Something I cannot help but find interesting: Penrose initially proposes his theory, and suggests a search for circles in the sky. There was no response to this plea as far as I am aware. Then Penrose publishes an apparently faulty claim of having found circles in the sky, and the physics community produces two high quality searches for said circles in short order. I am reminded of a method I discovered years ago for getting help on Linux IRC channels. If you walk in and say, "how do I get a blu-ray player working on my Linux machine?", people will probably not help, because people are busy and they expect you could do the work yourself. But if you walk in and say, "Linux sucks, you can't watch blu-rays!" people will be falling over themselves to prove you wrong...

That was cool, Coin :D

Here's what Sean Carroll had to say on this http://blogs.discovermagazine.com/cosmicvariance/2010/12/07/penroses-cyclic-cosmology/

 

[twofish-quant]

Something I cannot help but find interesting: Penrose initially proposes his theory, and suggests a search for circles in the sky. There was no response to this plea as far as I am aware. Then Penrose publishes an apparently faulty claim of having found circles in the sky, and the physics community produces two high quality searches for said circles in short order.

Usually what happens is that people have already done the analysis but aren't publishing because there is no point. I've established that there isn't a Bengal Tiger outside my bedroom, but there is no point in mentioning that unless someone argues that there is.

Also this sort of statistical analysis is used a lot by hedge funds in Wall Street. One big problem (with obvious financial consequences) is when to know that you *haven't* got a pattern.

 

[twofish-quant]

One implication of those other papers is seems to be that if you point your telescope at the right patch of sky, you will see a pattern that spells out "GOD".