Our sleep cycle, or circadian rhythm, is based on the body's reaction to the daily rise and setting of the sun, producing more of the sleep-encouraging hormone melatonin in the dark hours and less after dawn.
Roads & Kingdoms
Life After ISIS The Northern Iraqi city of Sinjar has been recaptured from ISIS, but it’s a long way from back to normal.
Best of Slate Podcasts
The Best of Slate Podcasts Only have time for one podcast this week? Make it this one.
The Craziest Endings in College Football History After the turkey, enjoy some classic finishes.