The fastest Olympic sprint was Usain Bolt’s 100 meters at the London Games, averaging more than 23 miles per hour for 9.63 seconds. Marathoners, who run for two hours, top out around half of Bolt’s ...

So, you’re driving a car at half the speed of light. (Both hands on the wheel, please.) You turn on the headlights. How fast would you see this light traveling? What about a person standing by the ...

Forbes contributors publish independent expert analyses and insights. The Universe is out there, waiting for you to discover it. One of the fundamental rules we all learn in physics — set forth by ...