Speaker: Dr. Harald Pfeiffer (CITA, University of Toronto)
One hundred years ago, Albert Einstein revolutionized our understanding of space, time and gravity. His insights led to two extraordinary predictions: First, Black Holes, regions of space with so intense gravity, that nothing, not even light, can escape. Second, gravitational waves, ripples in space and time itself that travel with the speed of light. Gravitational waves are created by black holes and other objects with intense gravitational fields, and ever more sensitive instruments have searched for these waves during the last decades, a quest culminating on September 14, 2015, when the LIGO observatories in the United States measured gravitational waves for the very first time. This talk traces this momentous discovery. I will introduce black holes, and will explain how the LIGO detectors reach their nearly unbelievable measurement precision. I will also detail how scientists have deduced that the gravitational waves passing through the Earth last September were emitted by the collision of two black holes more than a billion years ago.