And that is absolutely 100% accurate, with no measurement errors. But Jack, I hear you say, what are you talking about? The reason we know that that's exactly the speed of light, is that we defined it ...

When Galileo's name comes up, most people think about his contributions to observational astronomy. However, he did lots of other stuff including investigating the speed of light. During his time, ...

You might think that if you have a need to measure the speed of a projectile that is too fast for your high-speed camera, you would have to invest in some significantly expensive equipment. That was ...

You see the yellow box, you check the speedometer an then, two weeks later, a ticket lands on your doormat. How? You barely had time to register the camera. Here's the thing — it didn't need much time ...

Special relativity is one of the most strongly validated theories humanity has ever devised. It is central to everything from space travel and GPS to our electrical power grid. Central to relativity ...

The motion of any object is relative. On Earth we tend to ignore that, because the vast background of the ground gives us a seemingly fixed and absolute frame of reference. Sitting comfortably at our ...

Imagine living sometime around the early 1600s. You're standing on the deck of a wooden ship. The wind's biting, the sky's endless. And your captain's yelling, "Drop the log!" Back then, before sonar ...

You might think that if you have a need to measure the speed of a projectile that is too fast for your high-speed camera, you would have to invest in some significantly expensive equipment. That was ...

Scientists have demonstrated the fastest distance measurement so far. The researchers demonstrated on-the-fly sampling of a gun bullet profile with micrometer accuracy. The experiment relied on a ...