Data sources: David Ropeik/Harvard University, National Weather Service, World Health Organization, Northeastern University Laboratory for the Modeling of Biological and Socio-Technical Systems, National Geographic, United States Census Adam Cole and Ryan Kellman/NPR hide caption

itoggle caption Adam Cole and Ryan Kellman/NPR

The cruise ship Carnival Magic floats behind a catamaran off Cozumel, Mexico on Oct. 17. The ship skipped a planned stop there Friday, the cruise line says, after Mexican authorities delayed granting permission to dock. Reuters/Landov hide caption

itoggle caption Reuters/Landov

I told him he would break his arm if he did that. But he did it anyway. iStockphoto.com hide caption

itoggle caption iStockphoto.com

Whether or not you'll someday get cancer or any disease can feel like a roll of hundreds of dice. Calculating the odds --€” and knowing what they mean --€” is tricky. Katie Harbath/Flickr hide caption

itoggle caption Katie Harbath/Flickr