In 1676, by studying the motion of Jupiter's moon Io, Danish astronomer Ole Rømer calculated that light travels at a finite speed. Two years later, building on data gathered by Rømer, Dutch ...

The speed of light is a fundamental constant, approximately 299,792,458 meters per second. It's the same for all observers and hasn't changed measurably over billions of years. Nothing can travel ...

Scientists have revealed a futuristic 'communication with light' system that uses light pulses instead of radio waves to transmit data.

Light is the fastest-moving thing in the universe. So what would happen if the speed of light were much, much slower? In a vacuum, the speed of light is about 186,000 miles per second (300,000 ...

Whenever light interacts with matter, light appears to slow down. This is not a new observation and standard wave mechanics can describe most of these daily phenomena. For example, when light is ...

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 ...

University of Illinois Physics Professor Paul Kwiat and members of his research group have developed a new tool for precision measurement at the nanometer scale in scenarios where background noise and ...

Researchers at Tampere University and the University of Eastern Finland have reached a milestone in a study where they derived a new kind of wave equation, which applies for accelerating waves. The ...