Last Word is New Scientist’s long-running series in which readers give scientific answers to each other’s questions, ranging ...

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 ...

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 ...

We wouldn’t notice. Or we’d die. Depends on how much it changed. Relativity already tells us what would happen if the speed of light were to change, and the answer is nothing. Consider a stationary ...

There's nothing faster than the speed of light. So, what would happen if a human managed to move at this universal speed limit? When you purchase through links on our site, we may earn an affiliate ...

Chris Impey receives funding from the National Science Foundation and the Hearst Foundation. Curious Kids is a series for children of all ages. If you have a question you’d like an expert to answer, ...

According Einstein's Theory of Relativity, the speed of light operates as a universal speed limit on anything with mass. When you purchase through links on our site, we may earn an affiliate ...

Since then, countless experiments have confirmed that light always travels at the same speed in a vacuum — about 300,000 ...

Images of the cube and sphere created by the Vienna team. At rest, the cube appears normal. When simulated at 99.9% of light speed, the sphere remains round but reveals parts of its far side. (Image ...

The biggest issue you'd face is reaching that speed in the first place. When you purchase through links on our site, we may earn an affiliate commission. Here’s how it works. In science fiction, ...