Physical Society Colloquium

Going to the ends of the Earth to study the Evolving Universe

William Holzapfel

University of California, Berkeley

Observations of the Cosmic Microwave Background (CMB) radiation provide a window to the Universe as it existed 400,000 years after the Big Bang. This snapshot of the early Universe encodes a wealth of information about its composition and perhaps the mechanism of inflation. High resolution observations of the CMB are an important compliment to the results of experiments with coarser resolution such as WMAP. The Arcminute Cosmology Bolometer Array Receiver (ACBAR) is a 16 element 230mK bolometer array that was used to produce high signal to noise maps of the CMB with 5' resolution. I will discuss the results from the first two years of ACBAR observations and describe what we can expect from the upcoming release of the complete 4-year data set. It is also possible to use the CMB as a backlight to study the growth of structure in the Universe. We have recently returned from deploying the 10m South Pole Telescope (SPT) with a 960 element bolometric receiver. I will describe this uniquely capable new instrument and how we will use it to illuminate the nature of the Dark Energy dominating the dynamics of the Universe.