Backlash to Big Bang Discovery Gathers Steam

[n2doc]

By Michael D. Lemonick

On March 17 Paul Steinhardt, a physicist at Princeton University, abandoned a theory he’d been championing for more than a decade. Known as the “ekpyrotic universe” model, it was an alternative to the prevailing theory of inflation, which says the cosmos expanded faster than the speed of light in the first fraction of a fraction of a second of the big bang. If so inflation is true, then the process should have released a burst of gravity waves; in Steinhardt’s model, they shouldn’t exist. On that day in March a team of observers announced at a major press conference at the Harvard–Smithsonian Center for Astrophysics that they had indeed detected the waves, thus providing the first clear look at the universe’s earliest moments. The announcement made a huge splash. “Space Ripples Reveal Big Bang’s Smoking Gun,” trumpeted The New York Times front page. “Discovery Bolsters Big Bang Theory,” proclaimed The Wall Street Journal. Dozens of similar headlines appeared, seemingly everywhere. Steinhardt promptly pronounced his theory dead.

But now he’s not so sure. “The situation,” Steinhardt says, “has changed.” Right from the moment results from the BICEP2 microwave telescope at the South Pole were released, many cosmologists had a sense that the discovery rested on shaky ground. “I think it’s fair to say,” argues William Jones, a physicist also at Princeton, “that the claims struck a lot of people, myself included, as far overreaching what the data can support.” Charles Bennett, a physicist and astronomer at Johns Hopkins University who led research on the Wilkinson Microwave Anisotropy Probe (WMAP) satellite, agrees. “Several of the plots in their paper looked odd to me,” he says.

In the ensuing two months, the doubts have only grown stronger, as physicists have attempted, and failed, to reproduce the BICEP2 team’s calculations—admittedly, without the original data, which the team hasn’t yet provided, and without the “systematics” paper, laying out the possible sources of error, which the team has promised but not yet completed. The paper describing the results themselves has not yet been published by a peer-reviewed journal, although that process is underway.

Growing doubts in the astronomical community, meanwhile, have been raised, first in private and over e-mail, then in a blog post by physicist Adam Falkowski, of the French National Center for Scientific Research, in Paris, and most recently by articles in The Washington Post, New Scientist, Science News and other outlets.

more

http://www.scientificamerican.com/article/backlash-to-big-bang-discovery-gathers-steam/

[Maedhros]

1. Behold, the beauty of the scientific method!

Someone publishes a finding, and scores of colleagues immediately race to disprove it. If they can't, then the original finding stands. If they do disprove it, then we learn something new.

It's win-win.

[gcomeau]

2. Was about to make almost that exact comment. :-) eom

[frogmarch]

3. As was I.

Go, Science!

[longship]

4. Sean Carroll Blogged about this earlier this week.

http://www.preposterousuniverse.com/blog/2014/05/14/arrrgh-rumors/

Today’s hot issue in my favorite corners of the internet (at least, besides “What’s up with Solange?”) is the possibility that the BICEP2 discovery of the signature of gravitational waves in the CMB might not be right after all. At least, that’s the rumor, spread in this case by Adam Falkowski at Résonaances. The claim is that one of the methods used by the BICEP2 team to estimate its foregrounds (polarization induced by the galaxy and other annoying astrophysical stuff, rather than imprinted on the microwave background from early times) relied on a pdf image of data from the Planck satellite, and that image was misinterpreted.

Is it true? I have no idea. It could be. Or it could be completely inconsequential. (For a very skeptical take, see Sesh Nadathur.) It seems that this was indeed one of the methods used by BICEP2 to estimate foregrounds, but it wasn’t the only one. A big challenge for the collaboration is that BICEP2 only observes in one frequency of microwaves, which makes it very hard to distinguish signals from foregrounds. (Often you can take advantage of the fact that we know the frequency dependence of the CMB, and it’s different from that of the foregrounds — but not if you only measure one frequency.) As excited as we’ve all been about the discovery, it’s important to be cautious, especially when something dramatic has only been found by a single experiment. That’s why most of us have tried hard to include caveats like “if it holds up” every time we wax enthusiastic about what it all means.

(Much more at link)

Sean is skeptical that the rumors will hold up, attributing it to possibly bad reportage. CalTech is holding a seminar on the topic and Sean promises to report back after it has finished.

Who knows where this ends up. But one thing is sure, there will likely be new physics, one way or another.

But without the data, systematics, and a published paper, what can one say?

R&K

[Thor_MN]

5. Well, that's just, like, your theory, man.

[sakabatou]

6. Science...

[Lionel Mandrake]

7. Your subject line could be misinterpreted

by young-earth creationists and other anti-science types as saying that the big bang theory is in trouble. Nobody posting here has made such a ridiculous mistake, but let's not forget how the anti-Darwin brigade has misinterpreted minor disagreements among evolutionary biologists as evidence that the theory of natural selection is in trouble.