Why do we cry? It’s weird. Humans leak water out of their faces when they get sad. Are we the only animals that do this? What does it mean? What is it for? Here’s the science of human tears!

This is an installment of the PBS – It’s OK to be Smart series. If no film or link appears in this email, go to the blog to view it by clicking on the blog title above. If the film stops & starts in an annoying manner, press pause (lower left double bars ||) to let it buffer and get ahead of you.  [Chuck Almdale]