A spacecraft traveling at 99 percent the speed of light toward Alpha Centauri would cross 4.3 light-years in what feels like ...

Andromeda sounds far away because 2.5 million light-years sounds far away. It lands with authority. It feels exact. It gives you the comfort of a labeled universe, one where galaxies, stars and ...

Speed alone may be the factor that draws many sports fans to the bobsled, luge and skeleton events at this year's Beijing Winter Olympics. But beneath the thrilling descents of the winding, ...