Earlier this year, the team behind the Background Imaging of Cosmic Extragalactic Polarization instrument, or BICEP2 (photo below by “Amble”), reported the discovery of primordial gravitational waves – supporting the theory of cosmic inflation. It now seems that their observations could instead be explained by cosmic dust polarisation. In a recent Nature column, Princeton physicist Paul Steinhardt outlines some ideas for analysing the results of future experiments of this kind. He also makes the rather disturbing suggestion that inflationary theory may be unfalsifiable. If that is true, is it really science at all?
This image, recently taken by the ESA’s Planck spacecraft, shows the best view to date of the cosmic microwave background radiation. Given certain cosmological assumptions, the data in the image imply an age for the universe of about 13.8 billion years, and an expansion rate of about 68 km per second per megaparsec. The Jester puts his own inimitable spin on this.