BICEP Instrument: Right .

Whatever happened one should not forget that, at the instrumental level, BICEP was a huge success. The sensitivity to B-mode polarization at angular scales above a degree beats previous CMB experiments by an order of magnitude. Other experiments are following in their tracks, and we should soon obtain better limits on the tensor-to-scalar ratio. (Though it seems BICEP already comes close to the ultimate sensitivity for single-frequency ground-based experiment, given the dust pollution demonstrated by Planck).

. Whatever happened one should not forget that, at the instrumental level, BICEP was a huge success. The sensitivity to B-mode polarization at angular scales above a degree beats previous CMB experiments by an order of magnitude. Other experiments are following in their tracks, and we should soon obtain better limits on the tensor-to-scalar ratio. (Though it seems BICEP already comes close to the ultimate sensitivity for ground-based experiment, given the dust pollution demonstrated by Planck). ArXiv first: Right.

Some complained that the BICEP result were announced before the paper was accepted in a journal. True, peer-review is the pillar of science, but it does not mean we have to adhere to obsolete 20th century standards. The BICEP paper has undergone a thorough peer-review process of the best possible kind that included the whole community. It is highly unlikely the error would have been caught by a random journal referee.

Some complained that the BICEP result were announced before the paper was accepted in a journal. True, peer-review is the pillar of science, but it does not mean we have to adhere to obsolete 20th century standards. The BICEP paper has undergone a thorough peer-review process of the best possible kind that included the whole community. It is highly unlikely the error would have been caught by a random journal referee. Press conference: Right .

Many considered inappropriate that the release of the results was turned into a publicity stunt with a press conference, champagne, and YouTube videos. My opinion is that, as long as they believed the signal is robust, they had every right to throw a party, much like CERN did on the occasion of the Higgs discovery. In the end it didn't really matter. Given the importance of the discovery and how news spread over the blogosphere, the net effect on the public would be exactly the same if they just submitted to ArXiv.

. Many considered inappropriate that the release of the results was turned into a publicity stunt with a press conference, champagne, and YouTube videos. My opinion is that, as long as they believed the signal is robust, they had every right to throw a party, much like CERN did on the occasion of the Higgs discovery. In the end it didn't really matter. Given the importance of the discovery and how news spread over the blogosphere, the net effect on the public would be exactly the same if they just submitted to ArXiv. Data scraping: Right.

There was a lot of indignation about the fact that, to estimate the dust polarization fraction in their field of view, BICEP used preliminary Planck data digitized from a slide in a conference presentation. I don't understand what's the problem. You should always use all publicly available relevant information; it's as simple as that.

There was a lot of indignation about the fact that, to estimate the dust polarization fraction in their field of view, BICEP used preliminary Planck data digitized from a slide in a conference presentation. I don't understand what's the problem. You should always use all publicly available relevant information; it's as simple as that. Inflation spin: Wrong.

BICEP sold the discovery as the smoking-gun evidence for cosmic inflation. This narrative was picked by mainstream press, often mixing inflation with the big bang scenario. In reality, the primordial B-mode would be yet another evidence for inflation and a measurement of one crucial parameter - the energy density during inflation. This would be of course a huge thing, but apparently not big enough for PR departments. The damage is obvious: now that the result does not stand, the inflation picture and, by association, the whole big bang scenario is undermined in public perception. Now Guth and Linde cannot even dream of a Nobel prize, thanks to BICEP...

BICEP sold the discovery as for cosmic inflation. This narrative was picked by mainstream press, often mixing inflation with the big bang scenario. In reality, the primordial B-mode would be for inflation and a measurement of one crucial parameter - the energy density during inflation. This would be of course a huge thing, but apparently not big enough for PR departments. The damage is obvious: now that the result does not stand, the inflation picture and, by association, the whole big bang scenario is undermined in public perception. Now Guth and Linde cannot even dream of a Nobel prize, thanks to BICEP... Quality control: Wrong.

Sure, everyone makes mistakes. But, from what I heard, that unfortunate analysis of the dust polarization fraction based on the Planck polarization data was performed by a single collaboration member and never cross-checked. I understand there's been some bad luck involved: the wrong estimate fell very close to the predictions of faulty pre-Planck dust models. But, for dog's sake, the whole Nobel-prize-worth discovery was hinging on that. There's nothing wrong with being wrong, but not double- and triple-checking crucial elements of the analysis is criminal.

Sure, everyone makes mistakes. But, from what I heard, that unfortunate analysis of the dust polarization fraction based on the Planck polarization data was performed by a single collaboration member and never cross-checked. I understand there's been some bad luck involved: the wrong estimate fell very close to the predictions of faulty pre-Planck dust models. But, for dog's sake, the whole Nobel-prize-worth discovery was hinging on that. There's nothing wrong with being wrong, but not double- and triple-checking crucial elements of the analysis is criminal. Denial: Wrong.

The error in the estimate of the dust polarization fraction was understood soon after the initial announcement, and BICEP leaders were aware of it. Instead of biting the bullet, they chose a we-stand-by-our-results story. This resembled a child sweeping a broken vase under the sofa in the hope that no one would notice...





As you already know, Planck finally came out of the closet. The Monday paper shows that the galactic dust polarization fraction in the BICEP window is larger than predicted by pre-Planck models, as previously suggested by an independent theorist's analysis . As a result, the dust contribution to the B-mode power spectrum at moderate multipoles is about 4 times larger than estimated by BICEP. This implies that the dust alone can account for the signal strength reported by BICEP in March this year, without invoking a primordial component from the early universe. See the plot, borrowed from Kyle Helson's twitter , with overlaid BICEP data points and Planck's dust estimates. For a detailed discussion of Planck's paper I recommend reading other blogs who know better than me, see e.g. here or here or here . Instead, I will focus and the sociological and ontological aspects of the affair. There's no question that BICEP screwed up big time. But can we identify precisely which steps lead to the downfall, and which were a normal part of the scientific process? The story is complicated and there are many contradicting opinions, so to clarify it I will provide you with simple right or wrong answers :)To conclude, BICEP goofed it up and deserves ridicule, in the same way a person slipping on a banana skin does. With some minimal precautions the mishap could have been avoided, or at least the damage could have been reduced. On the positive side, science worked once again, and we all learned something. Astrophysicists learned some exciting stuff about polarized dust in our galaxy. The public learned that science can get it wrong at times but is always self-correcting. And Andrei Linde learned to not open the door to a stranger with a backpack.