To dust we return

In case you haven’t heard, the people behind the Planck┬ásatellite have released their analysis of the region of the sky observed by BICEP earlier this year. They find higher levels of dust than those found in BICEP’s foreground models. In fact, the amount of dust is large enough to completely explain BICEP’s detection.

This doesn’t rule out the possibility that there is some cosmological signal in the BICEP data, but it does mean there’s no strong evidence for such a signal.

I should disclose that I haven’t read the Planck paper yet; I’ve just skimmed the key sections. But at a quick glance the analysis they’ve done certainly looks sensible, and for a variety of reasons I’d be surprised if they got this wrong. Of course, I already thought there was significant reason to doubt the original interpretation of the BICEP results.

I don’t have much more to say, so here are some links: Peter Coles, Sean Carroll, BBC.

Actually, I will make one quick meta observation. Some people are once again castigating the BICEP team for going public with this result prematurely. I think that that criticism is largely misguided. They may well be subject to fair criticism for getting the analysis wrong, of course, but that’s different from saying that they shouldn’t have made it public. I’m fine with people seeing the process by which science gets done, which includes everyone scrutinizing everyone else’s work.


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Ted Bunn

I am chair of the physics department at the University of Richmond. In addition to teaching a variety of undergraduate physics courses, I work on a variety of research projects in cosmology, the study of the origin, structure, and evolution of the Universe. University of Richmond undergraduates are involved in all aspects of this research. If you want to know more about my research, ask me!

One thought on “To dust we return”

  1. I agree with your last paragraph. Note that there are some pundits who advocate putting papers on arXiv at submission, rather than after acceptance, in order to generate comments, but some of these same pundits criticize the press release. I’m sure that even if the BICEP-2 people just put their paper on arXiv, there would still have been almost the same amount of media coverage.

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