Sarah Hagen shares her popular lecture "Ancient Greeks and the Eclipse: A Geometry Story." Below is the abstract:

"Using eclipse events and the geometry of triangles, the ancient Greeks were able to measure the size and distance to both the moon and the sun with surprising accuracy. In this presentation, participants will learn how the Greeks were able to make such astounding measurements, and will leave with the tools to make such measurements themselves. No mathematical background is required."

(donations)