Measuring the Impossible: How We Detected Gravitational Waves

Two black holes collide over a billion light-years away, creating waves in the fabric of spacetime. But by the time those waves reach us, their effect is so small that they would change the light-years of distance by less than the width of a human hair. When Einstein predicted gravitational waves as a consequence of his theory of general relativity, detecting them seemed far beyond what experiments could achieve. Doing so would require an instrument more sensitive than anything ever built before. At this extraordinary level of precision, almost everything gets in the way: ground motion, the thermal vibrations of atoms making up the detector, even the quantum nature of light. In this talk, Dr. Alexandra Mitchell will explore how generations of scientists and engineers turned a measurement that once seemed impossible into one of the great experimental achievements of modern physics. She will also highlight some LIGO’s recent gravitational-wave discoveries and what they have revealed about our Universe, and how researchers are pushing these instruments even further to discover what we haven’t yet been able to see.

Speaker: Alexandra Mitchell, Stanford University

Attend in person or watch online.  Register at weblink.