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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

Researchers have developed a new kind of lidar system that simultaneously measures the location, speed and material ...

Microresonator-based optical frequency combs enable highly-precise optical distance ranging at a rate of 100 million measurements per second – publication in Science: Scientists of Karlsruhe Institute ...