Life's Little Mysteries: Science questions, answered

How do Hula-Hoops keep from falling down as we twirl them around?

If you're wondering whether birds are reptiles, know this: The reptile family tree is more varied and diverse than you might realize.

Photokeratitis, or eye sunburn, can happen at any time of the year.

Alexander the Great died at age 32, but his cause of death is unclear. What killed him has been a long-standing source of debate.

Humans don't have hollow bones like birds do, so how big would our wings have to be to lift us off the ground?

Bats often hang upside down when they sleep instead of sitting right side up or lying down — why?

Organisms from three different natural kingdoms battle it out for the title "deadliest food."

The saying "weak in the knees" may be figurative for many, but can it really happen to people?

"Recycling" an already transplanted organ could help save lives, but the procedure comes with additional risks, physicians say.

Plate tectonics give Earth its mountains, earthquakes, continental drift and maybe even helped give rise to life itself. But do other planets in the solar system have them too?