Radiations is a weekly electronic newsletter published by the Physics and Astronomy Department of Carleton College. The deadline for materials to be included in Radiations is 9:00 AM Monday of the week you would like the information to appear. Contact tfields@carleton.edu if you want to be added or removed from this mailing list.

Volume 19, Issue 17 (February 18, 2013)

Andrew Chael Comps Talk

January 17, 2013

Cosmology and the Cosmic Microwave Background

In 1964, Arno Penzias and Robert Wilson discovered the Cosmic Microwave Background (CMB), a uniform microwave radiation incident from all directions in space. Immediately, the CMB provided the key piece of evidence confirming the Big Bang theory by showing that the early universe was a hot, dense plasma of fundamental particles.  In the fifty years since, study of the CMB has revolutionized cosmology, the study of the of the shape and history of the universe. In my talk, I will first discuss the cosmological theory behind the Big Bang model and how the composition of the universe drives its expansion. I will then discuss in detail the processes of the early universe leading to the emission of the CMB 380,000 years after the Big Bang. Finally, I will explain how modern observations of small fluctuations in the otherwise uniform CMB have established the current understanding of the composition, shape, and fate of the universe and transformed the once speculative field of cosmology into a precision science.