Mass Extinctions Happen Every 27 Million Years

(Checks math.) If you have trouble reading this message, view it in a browser.       Mass Extinctions Happen Every 27 Million Years   (Checks math.) Read More           Whoops, Humans Made a Space Barrier Around Earth   The kicker? It's actually saving us. Read More             25 Last-Minute Gifts and Stocking Stuffers on Amazon   When you're in a time crunch, you'll need great gift ideas—and some help from Amazon Prime doesn't hurt. Read More           Exclusive: AI Just Controlled a Military Plane for the First Time Ever   The U.S. Air Force tells us how it successfully flew an AI copilot on a U-2 spy plane—and kicked off the age of algorithmic warfare. Read More           Look What Would Happen If We Nuked the Moon   Yes, the Air Force actually once wanted to do this. Read More           Watch a Russian Sub Fire Nuke Missiles In a Preview of the End of Civilization   Good thing it was just a test. Read More         Read More on PopularMechanics.com       Follow Us     Unsubscribe  Privacy Notice   PopularMechanics.com ©2020 Hearst Communications Inc. All Rights Reserved. Hearst Email Privacy, 300 W 57th St., Fl. 19 (sta 1-1), New York, NY 10019