The universe is getting larger, and we don't know why, or how it relates to the Big Bang. Last March researchers made a lot of fanfare announing that they had measured the polarization patterns of light from the early universe, proving the theory of cosmic inflation, or that the universe went from very small to very big very fast. New data suggests these findings may have been off due to cosmic dust. 

Subir Sarkar, head of the particle theory group at the University of Oxford said, "They had based this on the preliminary results shown by Planck last spring, but the rather approximate procedure they used has been widely criticized ... and this criticism is clearly justified in the light of the updated Planck results," Sarkar wrote in an e-mail. He added that he and others await a collaborative effort between the two teams, in which they put their data side by side to clarify just how much of their signal might be attributed to dust.

"Meanwhile, it is clearly premature to assert (as so many have!) that BICEP2 has found evidence for inflation," Sarkar wrote.

New data from the Planck team, specifically dealing with the innacuracy, will be published in Astronomy and Astrophysics. The report will discuss the models the BICEP2 team were using and how they underestimated the effects of light scattering off of galactic dust. All of that being said, the teams findings cannot be entirely ruled out due to galactic dust either.

In the new paper, the researchers report that "even in the faintest, dust-emitting regions there are no 'clean' windows in the sky" where measurements can be made without taking into account the dust contamination. Essentially the team assumed they could find a clear place to point their telescope, but no such places exist.

"This paper confirms in more detail the trend which was already indicated," John Kovac, an associate professor in the astronomy department at Harvard University who led the BICEP2 work, wrote in an e-mail.

"Since we submitted this, paper new information on polarized dust emission has become available from the Planck experiment in a series of papers. ... While these papers do not offer definitive information on the level of dust contamination in our field, they do suggest that it may well be higher than any of the models considered," the authors wrote then. "More data are clearly required to resolve the situation."

"This means that at least the majority of the signal is caused by dust. However, I think it will still be interesting to see the joint analysis between BICEP2 and Planck," wrote Raphael Flauger, a physicist at the Institute of Advanced Study.

Flauger said he did a "very preliminary" analysis of the two data sets and expects at least half of the signal to be caused by dust -- possibly more. It's uncertain whether a signal would remain once that contamination is removed.

The two teams are now collaborating to create a map that will allow them to see whether the measurement is just dust or the key evidence for inflation,

"However," said Jonathan Aumont, another of the Planck authors, "our work does not imply that they did not measure at all a cosmological signal. Moreover, due to the very different observation techniques and signal processing in the Bicep2 and Planck experiments, we cannot say how much of the signal they measured is due to dust" and how much to gravitational waves.

Richard Bond, an early universe expert at the University of Toronto and a Planck team member, said "Planck showed that dust could possibly be the entire Bicep2 signal, but Planck alone cannot decide. We have to do this in combination with Bicep2."

Michael S. Turner, a cosmologist at the University of Chicago, said: "This is going to be a long march, but the goal of probing the earliest moments of the universe makes it well worth the effort. Dust is the bane of the existence of astrophysicists - and cosmologists. It is everywhere, and yet our understanding of it is very poor."

The Bicep observations are the deepest look yet into cosmic background radiation, left over from when the universe was about 380,000 years old. Cosmic inflation, which began in the first fraction of a fraction of a fraction of the first second of time should have left ripples in space-time known as gravitational waves. They would manifest as corkscrew patterns in the direction of polarization of the cosmic microwaves, and are what the Bicep 2 was looking for.

The Bicep group - its name is an acronym for Background Imaging of Cosmic Extragalactic Polarization - is led by Dr. Kovac; Jamie Bock of Caltech; Clement Pryke of the University of Minnesota; and Chao-Lin Kuo of Stanford. They have deployed a series of radio telescopes at the South Pole in search of the swirl pattern.

Dr. Kovac said, "It's really important as an experimentalist that you can divorce yourself from an investment in what the answer is.One thing that would distress me bitterly is if a major mistake in the measurement or of the analysis would come to light. The most pressing question is, what are the dust contributions to the signal?" 

"Planck has wider spectral coverage, and has mapped the entire sky; BICEP2 is more sensitive, but works at only one frequency and covers only a relatively small field of view," says Peter Coles from Sussex University. "Between them they may be able to identify an excess source of polarization over and above the foreground, so it is not impossible that a gravitational wave component may be isolated."

"We are focused on these new, more powerful analyses and data sets, which should give a much more constraining answer within the next several months," Kovac wrote in an e-mail.

 University of Sussex physicist Peter Coles wrote, "I think the public needs to understand more about how science functions as a process, often very messily," he wrote on his blog, "but how much of this mess should be out in the open?" Indeed the original press conference caused quite a stir and a lot of attention, and many scientists fear people will take this the wrong way, as a final answer rather than part of an ongoing discussion.

You can read the new paper here. 

The BICEP team from the March discovery and the authors' of today's paper are joining forces to see what implications today's paper has on the initial discovery. That assessment is expected to be released by the end of the year.