Penrose: WMAP Shows Evidence of ‘Activity’ Before Big Bang

[Lievo]

If he really believes it, let him do the work.

Sure

The real difficulty here that mucks things up tremendously is instrument noise.

Oh? So it's not true, as they suggest, that finding the same features in both the maps of WMAP and of BOOMERanG’s excludes that instrumental noise can account for the result?

 

[Chalnoth]

Oh? So it's not true, as they suggest, that finding the same features in both the maps of WMAP and of BOOMERanG’s excludes that instrumental noise can account for the result?

Well, it does show that the general shape isn't due to the instrument noise. The difficulty is that when you want to talk about the statistical significance of the result, you have to look at things much more carefully than just considering the general shape. I fully expect the instrument noise to be a very subdominant effect here, but nevertheless necessary to get the right answer for the statistical significance of the effect. Same with foregrounds (but in that case, looking at another instrument doesn't help you much).

 

[Lievo]

Well here I would respectfully disagree. It's an extraordinary claim in need for a clear cut result. So to me the exact sigma doesn't matter to much: 6-10 sigma would be good enough, 2-4 won't. To me the present result is questionnable not because the sigma could be slightly different, but because it could be completely different, and we don't have enough information to assess it except by redoing the job they should have shown.

Anyway, thank you for your insights.

 

[twofish-quant]

Chalnoth, this is a very clear explanation of why the reported features could be by chance. But of course proving that there is truly nothing requieres some statistical testing. I was thinking at one test one could do (or that the authors could have done...), I wonder if you agree with the idea.

Statistical testing is something has a lot of gotchas.

If it's true that there is no anormality in the number of 'concentric' feature at some points in the CMB, then you could prove it by showing that real and sham distribution are the same even when considering the points with several 'concentric' features. What do you think?

Part of the hard part of statistics is to decide when something is the "same" or not. It's much more difficult than it first appears. There's also a problem in that there is a huge difference in looking at the probability of an anomaly in a specific place rather than an anomaly *somewhere*. The odds that you will find an anomaly somewhere is considerably higher than finding an anomaly at a specific location.

 

[twofish-quant]

Oh? So it's not true, as they suggest, that finding the same features in both the maps of WMAP and of BOOMERanG’s excludes that instrumental noise can account for the result?

Also you have to realize that you have the same sort of detectors so you could have the same sort of instrumental noise.

 

[Coin]

It seems like a problem unto itself that Penrose has stated his claim so vaguely that someone trying to refute it has to start by trying to guess at what he was even trying to say :|

 

[Lievo]

proving that there is truly nothing requieres some statistical testing.

Here it is.

http://arxiv.org/PS_cache/arxiv/pdf/1012/1012.1268v1.pdf
http://arxiv.org/PS_cache/arxiv/pdf/1012/1012.1305v1.pdf

 

[Chalnoth]

Here it is.

http://arxiv.org/PS_cache/arxiv/pdf/1012/1012.1268v1.pdf
http://arxiv.org/PS_cache/arxiv/pdf/1012/1012.1305v1.pdf

Haha, two papers on the same day, I am amused :)

I know some of the guys in these papers. Really great guys on this sort of thing.

 

[Lievo]

Haha, two papers on the same day, I am amused :)

Birthday unparadox