13 Things You Shouldn't Do on Friday the 13th

TECH SPACE HUMAN EARTH HISTORY ANIMALS ADVENTURE VIDEO View Online 13 Things You Shouldn't Do on Friday the 13th Feeling lucky? Push your luck with this list of 13 things you should never do, according to various superstitions. READ MORE Violent 'Wake-Up Machine' Slaps You Awake This frightening alarm made from a Halloween prop hand, motor, and clock is the anti-snooze button. READ MORE WATCH VIDEO: Why Your Brain Needs Sleep Scientists for the first time see the brain cleaning itself while its owner is asleep. After Mass Extinction: Just Animals at Extremes As human civilization drives more animals to extinction, extreme sizes will likely become the new norm. READ MORE WATCH VIDEO: Are Men Going Extinct? For years now, it's been widely debated whether the Y chromosome will disappear. Did Dark Matter Play a Hand in Dinosaur Fate? A geophysicist wonders what sent a big rock crashing into Earth – killing the dinosaurs. He pins the deadly event on a novel culprit. WATCH Follow Discovery News on Facebook! Get your sci-tech headlines all day on Twitter too! At Discovery Communications, we value your privacy. If you would like to be removed from future communications like this, please click here. Privacy Policy Discovery Communications, LLC One Discovery Place Silver Spring, MD 20910 © Copyright 2015 Discovery Communications, LLC