2007 Physics & Astronomy Events

Abstract: Over the last three decades the field of cosmology has matured into a precision science with a wealth of observational data such as the Cosmic Microwave Background Radiation Anisotropy (CMB). This data reveals information about the primordial quantum fluctuations responsible for galaxy and star formation in our universe. The CMB observations combined with Type Ia supernovae data tell us a shocking story about the composition of the universe; that most of the substance around us is a mysterious dark fluid with negative pressure, dark energy. We know very little about dark energy except that it brings back Einstein's 'greatest blunder', the cosmological constant. In this colloquium I will discuss the nature of the cosmological constant problem and why it poses a problem for another phenomena in the early universe: Inflation. I will also present a potential solution to this problem by importing a cherished notion from Condensed Matter Physics (superconductivity), the Cooper Instability.

Abstract: This talk is both a personal account of my path to become and my approach to research in theoretical physics; a reflection on the evolution of ideas and challenges that have influenced my research. I will also discuss how my other passion, playing jazz music, has complemented and benefited my science. This talk will be informal and full of stories of the various scientists and musicians who have shaped me. Finally, I will briefly talk about my latest idea on what may happen before the Big Bang as seen from a quantum gravitational description.

Abstract: The freezing and melting of crystals are fascinating phenomena that are very common in nature yet difficult to study in the laboratory. Micron-sized particles suspended in solution (colloidal particles) serve as a useful model of these phenomena. Colloidal particles obey the same laws of statistical mechanics that govern how ice melts into water, but they are much larger and slower than molecules, and are thus visible with optical microscopy. By tracking the motions of thousands of individual particles, one can observe phase transitions at the single-'molecule' level - and uncover some surprises.