Playing with your children or meeting a friend for coffee are everyday activities that many people move between without giving much thought to how much mental or physical energy they take.

Our planet has had its annual health check, and the prognosis is pretty grim. Despite breached planetary boundaries, however, scientists argue that Earth can still have a safe and sustainable future.

Tennessee officials say they need more high-security facilities for kids who commit crimes. Experts say this approach flies in the face of crime data and research that shows youth prisons are not reha...

Using chemical clues in Tyrannosaurus rex teeth, scientists have shown that this massive predator was warm-blooded — with a body temperature close to that of a person — in a finding they said should prompt a ​fundamental change in the perception of the celebrity dinosaur.