Wonder what all the to-do was in August about the total solar eclipse?  Truro resident and long-time eclipse chaser Jay Vivian will lift the shadows on the mystery.  He’ll discuss the basics of eclipses, including why they’re so rare, even though there are at least two a year, and why they are visible over such a long but narrow path.  He’ll talk about partial eclipse, total eclipses, annular eclipses, and hybrid eclipses, and describe some of the experiences he’s had chasing eight total solar eclipses over more than 50 years.  Highlights include Reformed Druids trying to sacrifice a goat during totality, Saharans falling to the ground to pray the world wouldn’t end, and the largest airplane traffic jam in the history of Nantucket airport.