Sometimes there is Smoke without Fire
…Or at least, not always the fire you’re looking for. So, as suspected for several months now, the signal seen by BICEP2 experiment and dubbed “a smoking gun” type of direct evidence for cosmic inflation (for which we have lots of strongly suggestive indirect evidence, by the way) is likely an artefact of the effects of galactic dust. I spoke about this in a post a while back, so I won’t repeat myself here. What everyone has been waiting for has been the results of a joint analysis between the BICEP2 people and the ESA’s Planck mission. The Planck satellite, you may recall from reading here or elsewhere, is also designed to
carefully study the polarisation of the cosmic microwave background (the earliest light to shine in the universe), and so can (through thorough analysis of the effects of dust that it has measured independently) help rule in or out whether there is a signal. Planck studies essentially the whole sky, not just the patch that BICEP2 was carefully looking at, and one of […] Click to continue reading this post
