Session M1: Invited Session: Astronomy

Saturday, October 20, 2007

Since Galileo's time, our ability to study the universe has been driven by our ability to collect light from distant objects. Due to tremendous technological advances in the last few decades, we can now study the most distant galaxies known in the universe. In addition to seeing fainter objects at higher resolution, we can also view the universe at many different wavelengths ranging from gamma rays to radio waves. I briefly review the major advances that have been made with, e.g. the Keck telescope, Hubble Space Telescope, and Wilkinson Microwave Anisotropy Probe (WMAP), and discuss why we need to continue pushing our observational limits by developing and building new telescopes.   

Saturday, October 20, 2007

Nearly all stars in the Universe form deep within clouds of gas and dust. This gas and dust obscures the light emitted from these stars and radiates it as heat in the infrared. I will present a brief history of astronomical observations of infrared light, and I will discuss how we learn about star formation from infrared observations. In particular, I will discuss the Spitzer Space Telescope (the last of NASA's Great Observatories), which is extremely sensitive to the infrared light from faint sources that are otherwise invisible from the Earth. I will focus on several recent results from the Spitzer Space Telescope that have both revolutionized our understanding of how stars form in nearby galaxies and improved our understanding of the formation of the most distant galaxies.   

Saturday, October 20, 2007

In this public talk, we will review the different steps followed by astronomers to measure the age of the Universe. In order to achieve this goal, we need to be able to measure precise distances. We will learn about parallax, Cepheid variables, and supernovae explosions. We will also discuss recent discoveries in this area and their implications for the ultimate fate of the Universe.