Peter Galison, Harvard University

"Philosophy of the Shadow."

In thousands of atlases depicting the working objects of inquiry—from bodies, clouds, plants, to crystals and insects-, physicians and natural philosophers worked out what counted as scientific objectivity.  This long-term history, with its various takes on what a reliable image should be, converged in the years-long struggle of the Event Horizon Telescope (EHT) to produce a picture of a black hole robust enough to make public.   On April 10, 2019, the team released the first image of a black hole, an image viewed within a very few days by more than a billion people.  This is a talk about how the EHT team of some 200 scientists came to judge the glowing, crescent-like ring as objective.