Artificial light makes the modern world possible. But not all kinds of light are good for us. Electric light has fundamentally altered our lives, our bodies and the very nature of our sleep.

This is an installment of the PBS Deep Look 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]