Why do we sleep? We spend a third of our lives in slumber, but science has yet to determine exactly why we have do it. Here’s a look at how sleep works, why we’re not getting enough sleep, what happens if you DON’T sleep, and an idea about where sleep came from in the first place.

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]