Scientists have seen something magical happening inside graphite, the stuff that your pencil lead is made of: Heat moved in waves at the speed of sound. That's pretty rad for a couple of reasons: Heat ...

Ryan Duncan froze. He had just performed a new experiment examining common graphite—the stuff of pencil lead—but the results seemed physically impossible: Heat, which typically disperses slowly, had ...

The universal speed limit of any kind of wave – be it electromagnetic or gravitational – travelling through a vacuum has been known since Albert Einstein developed his theory of special relativity in ...

Sound has a speed limit. Under normal circumstances, its waves can travel no faster than about 36 kilometers per second, physicists propose October 9 in Science Advances. Sound zips along at different ...

Editor’s Note: Sign up for Unlocking the World, CNN Travel’s weekly newsletter. Get the latest news in aviation, food and drink, where to stay and other travel developments. Savior of many a cramped ...