September 2014

Shivaraj Kandhasamy (University of Mississippi): The Big Bang and its cosmic messengers

In 1929 Edwin Hubble discovered that most of the galaxies are receding with velocities proportional to their distances from the Milky Way. This observation suggests that the universe was once very small in size and has expanded ever since. The beginning of the expansion (or "explosion") is what we now call the Big Bang. If the universe started with a Big Bang, traces of the primordial explosion should be observed in the form of electromagnetic radiation, gravitational waves and neutrinos across the sky. The cosmic (microwave) background of electromagnetic radiation was first observed by Penzias and Wilson in 1964. Recently, the BICEP2 experiment reported some indirect evidence for the presence of cosmological primordial gravitational waves. The next generation of gravitational-wave ground- or space-based detectors may directly detect these gravitational waves.

September 23, 2014, Lusa Pastry Café, 6pm - 7pm.