Big Bang scientists now hedge their bets

  • Article by: DENNIS OVERBYE
  • New York Times
  • June 19, 2014 - 7:33 PM


A group of astronomers who announced in March that they had detected space-time disturbances — gravity waves — from the beginning of the Big Bang repeated that claim Thursday but conceded that dust from the Milky Way galaxy might have interfered with their observations.

The original announcement, apparently heralding what they said was “a new era” in cosmology, astounded and exhilarated scientists around the world. At a splashy news conference March 17 at the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass., the talk quickly turned to multiple universes and Nobel Prizes.

But even as reporters and scientists were gathering there, others convened on Facebook and elsewhere to begin picking apart the findings. What ensued was a rare example of the scientific process — sharp elbows, egos and all — that has played out over the past three months.

If indeed true, the detection of those gravity waves would confirm a theory that the universe began with a violent outward anti-gravitational swoosh known as inflation — a notion that would explain the uniformity of the heavens, among other mysteries, and put physicists in touch with quantum forces that prevailed when the universe was only a trillionth of a trillionth of a second old.

As everyone involved said at the time, however, the results needed to be confirmed.

Now, after weeks of public and private wrangling, discussion and debate with peer reviewers and other astrophysicists, the group, which goes by the name BICEP, has published its official paper in the journal Physical Review Letters.

The authors, led by John Kovac of the Harvard-Smithsonian Center for Astrophysics, write that they stand by their original claim — but they also now acknowledge it is possible that dust in the Milky Way galaxy might have interfered with their observations, producing much or even all of their signal.

Nobody knows for sure — yet. New data expected within weeks from the European Space Agency’s Planck satellite, and other experiments now underway should help clarify the situation, they say.

Many of the BICEP team’s critics had said the astronomers might have spoken too soon, before all the uncertainties were nailed down.

“We’re not saying it’s not there,” Raphael Flauger, a theorist who splits his time between the Institute for Advanced Study in Princeton and New York University, said of the gravity wave signal. But because of uncertainty about the dust, he said in a recent paper, “no cosmological inference can be drawn at this time.”

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