SylvanieWallington2Dr. Sylvanie Wallington, Harvard Educated Astronomer, will speak about Dark Matter. Over the last 80 years astronomers have observed that the motion of some stars in galaxies and other celestial behavior cannot be explained without there being much more total mass in the universe than we detect from observations. Things don’t “add up” unless there is some mysterious “dark matter” that cannot be directly observed since it neither emits nor absorbs light. And this “missing mass” is not insignificant: it makes up about 85% of all the mass in the universe! As such, it plays a crucial role in our understanding of the structure and evolution of the universe. Dr. Wallington presents the evidence for this dark matter in simple layman’s terms. We follow the scientific trail that led to our understanding of dark matter in the universe by examining how astronomers gather light from celestial objects, how they use that light to understand the motions of stars and galaxies, and how they calculate the gravity needed to explain those motions. Step by step, we build the case for this mysterious substance, whose existence is widely accepted by the scientific community. Dr. Wallington is a graduate of Princeton University, and has a Ph.D. in astronomy from Harvard, where she specialized in the theoretical modeling of gravitational lenses. After a number of years of teaching she left the field and currently works as a web designer and programmer. She has lived in Old Greenwich with her husband and two children for more than a decade, during which time she has given a number of astronomy talks in the public schools. Arranged by Bob Smith