Out at the Dark Sector Lab (DSL) the awesome BICEP3 team is hard at work getting their latest telescope up and running before the end of the summer season. BICEP stands for Background Imaging of Cosmic Extragalactic Polarization, and they are currently working on the third installment in this series of experiments. The objective of BICEP3 is to use their new detector to map patterns in the polarization of the Cosmic Microwave Background (CMB) caused by gravitational waves and the expansion of the universe.
After the Big Bang, the universe was a hot and super dense mass of charged particles. The universe began to expand and cool down, and when the temperature cooled enough the electrons floating around could finally combine with protons to form atoms, and producing light (photons) as a byproduct. This is the CMB—the oldest light in the universe! By studying the CMB we can further understand what the universe was like in the very beginning.
The BICEP3 telescope will have 2560 detectors (compared to 512 from BICEP2) observing the polarization of light from the CMB. E-mode polarization is more commonly observed, and originates from the scattering CMB light. Gravity waves expanding through the universe cause a different polarization in the light: B-mode polarization. The BICEP2 telescope in 2014 found these B-mode patterns, and it was the first direct evidence for cosmic inflation and the enormous primordial gravity waves that could have expanded through the universe during the earliest moments of inflation.
Right next door to DSL and BICEP3, the Martin A. Pomerantz Observatory (MAPO) is home to BICEP’s sister project, the Keck Array, which is looking at the same stuff. The South Pole Telescope (SPT) that is also housed in DSL has additionally observed B-modes in the CMB. There’s quite an adorable family of telescopes down here at the South Pole.
Funny BICEP-related video coming soon! (I don’t have good enough internet to post it now.)