By Andrew Grant
An elusive signal from the dawn of the cosmos is officially still elusive.
Galactic dust accounts for much of the signal that researchers originally interpreted as ripples in spacetime imprinted on the universe’s first light, a new analysis confirms. The study, conducted by the BICEP2 team that claimed the discovery and scientists with the Planck space telescope, nullifies a result that would have provided the first direct evidence of cosmological inflation, a brief moment after the Big Bang when the universe rapidly ballooned in size.
The new analysis, announced by the European Space Agency on January 30, does not mean that the theory of inflation is wrong or that these primordial ripples, called gravitational waves, don’t exist. In fact, it’s possible that the signature of inflation is subtly embedded in BICEP2’s data. But after properly factoring in the pesky influence of dust, Planck and BICEP2 researchers agree that there is not enough evidence to back up the original extraordinary claim.
“It’s perfectly plausible that there are primordial gravitational waves,” says Raphael Flauger, a cosmologist at Carnegie Mellon University in Pittsburgh. “But experiments right now are just not accurate enough to determine this.”