40 years ago researchers discovered two continent-sized blobs wrapped around Earth's core, and they're still trying to figure out what they are. Here's what they know so far.
A Vaping-Related Illness Has Turned Deadly, Here’s What You Need to Know
Vaping has soared in popularity, with now more than 40 million users worldwide. But an unexplained respiratory illness has swept the U.S. in recent weeks, and many health investigators suspect that vaping might be to blame.