Earlier this year, physicists celebrated results from the BICEP2 experiment which reported evidence of gravitational waves, a signature of cosmic inflation immediately after the Big Bang.
But earlier this week, results from the Planck space telescope cast doubt on the BICEP2 findings. Instead of showing gravitational waves at the beginning of time, BICEP2 might actually have picked up interstellar dust within our own galaxy.
Andy Albrecht, a UC Davis physics professor and well-known theorist on cosmic inflation, wrote this blog post reflecting on the “emotional roller coaster” of the BICEP2 and Planck findings. The lack of a gravitational signal at the level detectable by BICEP2 does not rule out cosmic inflation, because there are models that include a weaker signal, he wrote. But the story “has given people a wonderful window on the emotional energy that goes into doing science,” he wrote.
This is certainly a story about the passion that goes into doing science, but it is also a success story for science. While I do feel the BICEP2 team should have been more careful about how they presented their results, their over-optimistic beliefs about the limited impact of galactic dust on their data reflected a (mistaken) perspective that was widely held in our community regarding the overall strength of the dust emissions. The relentless march of progress is clearing up these misconceptions, and progress was in fact stimulated by the excitement surrounding the original announcement.
Interestingly, UC Davis physicist Lloyd Knox noted in a blog post at the time of the original result that he was concerned about contamination from interstellar dust.