Unfortunately, once the initial excitement died away, a number of voices asked whether BICEP2's signal had a more humble origin -- dust in our own galaxy. Dust can mimic a gravitational wave signal if it interacts with the galaxy's magnetic field. From a cosmic perspective, anything inside our galaxy is a "foreground" – dirt on the window through which we peer at the microwave background, the fossil light from the big bang coming to us from the furthest reaches of space.
Tag: Planck
Planck Live Blog
Planning to live blog the Planck live blog data release tonight. In the meantime, read Renee Hlozek and Shaun Hotchkiss's blogposts which give good discussions of what is at stake, or watch Ed Copeland giving a quick survey of cosmology.