The orca's pale underbelly and dark back is a form of camouflage called countershading. When viewed from below, the white belly blends better with the lightness of the sky. From above, the black back ...

If you have a Sky Q box tucked under your TV, here are some tricks to try, including getting a bonus remote for free.

The brightest star in the nighttime sky, Sirius ... tens or even hundreds of billions of years—a white dwarf cools until it becomes a black dwarf, which emits no energy. Because the universe's ...