The answer is about 117 billion, but the number hides a stranger story. There are 8 billion of us alive today, give or take a ...

The human body is a wonderous thing, especially when you consider how intricate and efficient each bodily system is. For instance, an adult’s blood vessels could encircle the earth 2.5 times if ...

Have you ever sat down to watch a movie or show on Netflix only to be told, "Too many people are using your account right now"? Any account on the streaming service can have up to five profiles, ...

Beth Skwarecki is Lifehacker’s Senior Health Editor, and holds certifications as a personal trainer and weightlifting coach. She has been writing about health for over 10 years. Calories aren’t only ...