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 ...

Scientists have discovered the fastest possible speed of sound, a zippy 22 miles (36 kilometers) per second. This exercise was largely theoretical: The researchers found that the answer, which is ...

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 ...

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