Twitter just changed the rules of tweeting. The company is now testing a change that doubles Twitter's character limit for "a small group" of accounts. It's not clear when the change will roll out ...

One of our most contentious debates may now have an answer. Dogs, it turns out, have about twice the number of neurons in their cerebral cortexes than what cats have, which suggests they could be ...

At 18, Katie Stubblefield lost her face. At 21, she became the youngest person in the U.S. to undergo the still experimental surgery. Follow her incredible story. Sixteen hours into a transplant ...