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Space dust casts shadow on Big Bang breakthrough

Space dust casts shadow on Big Bang breakthrough


New report says 'gravitational waves' are likely just clouds of particles

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Back in March, a group of astronomers using data from the South Pole reported that they'd seen something astounding in the night sky — the birth of our universe. Using the BICEP2 telescope positioned at the bottom of our planet, the scientists said they were able to find evidence of gravitational ripples in space that they said were echoes of the Big Bang. But a new report has cast doubt on the BICEP2 team's findings, suggesting that the ripples might not be telltale waves left over from the moment of our universe's creation, but simply clouds of space dust that happened to coalesce into swirling shapes after being polarized by magnetic fields.

The apparent gravitational waves could just be clouds of dust

The report, authored by astronomers using data from the European Space Agency's Planck satellite, says that the dust is so pervasive in outer space that it's incredibly difficult to see the gravitational waves the BICEP2 team was looking for. If identified, the spiral waves would support the popular theory of Inflation, which says that the universe expanded exponentially a trillionth of a second after the start of the Big Bang. But the new report says that "even in the faintest dust-emitting regions there are no ‘clean' windows in the sky" through which the theorized gravitational waves could be fully observed.

The BICEP2 team asked Planck scientists for data at the time of the studies, but due to an apparent instrument failure, it was unavailable. The original BICEP2 report was questioned at the time of publication for ignoring the implication of space dust on the findings, and the original authors themselves tempered their findings in a revised paper. In an email quoted by The New York Times, Raphael Flauger of Princeton's Institute for Advanced Study said the new report's findings made it seem "clear that at least the majority of the signal is caused by dust." Princeton's Paul J. Steinhardt called for the BICEP2 report to be retracted.

The new report doesn't dismiss the previous findings outright

But the scientists using the Planck satellite were careful to specify that while dust might have led to inaccurate results, it doesn't mean the BICEP2 team's hypothesis is incorrect. Jonathan Aumont, one of the report's authors, says that his team's work "does not imply that [the BICEP2 team] did not measure at all a cosmological signal." Aumont says BICEP2 and Plank use "very different observation techniques and signal processing," and that he cannot say how much of the signal reported in March was produced by dust, and how much by the birth cries of our baby universe.

The scientists using the Planck data emphasized the need for a joint analysis, and both teams are set to combine their results by the end of the year. In the meantime, it's going to be tough to tell Stanford professor Andrei Linde about the new report's findings. Linde, a major proponent of Inflation theory whose jubilant response to the original BICEP2 report was captured on film, said in March that hoped the apparent discovery of the gravitational waves was not a trick. If the Planck report is correct, then the astrophysicist was indeed deceived — by dust.