In ancient Greece, the best-known remedy for a long-standing headache was to drill a small hole in the skull to drain supposedly infected blood. Fortunately, doctors today don’t resort to power tools to cure headaches, but we still have a lot to learn about this ancient ailment. Dan Kwartler shares what we know (and don't know) about headaches.
Aerogels are the world's lightest (least dense) solids. They are also excellent thermal insulators and have been used in numerous Mars missions and the Stardust comet particle-return mission. The focus of this video is silica aerogels, though graphene aerogels are now technically the lightest.