From Star Wars' hyperspace to Star Trek's warp drive, sci-fi makes interstellar travel look easy. But physics has a stark ...

The principle of relativity, as initially described by Galileo, posits that the laws of physics remain consistent regardless of an observer's relative motion. Einstein's special relativity ...

The idea was first hypothesized about 70 years ago. When you purchase through links on our site, we may earn an affiliate commission. Here’s how it works. In a bizarre repercussion of Albert ...

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 ...

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, ...

Light is faster than anything else in the known universe, though its speed can change depending on what it's passing through. When you purchase through links on our site, we may earn an affiliate ...

James is a published author with multiple pop-history and science books to his name. He specializes in history, space, strange science, and anything out of the ordinary.View full profile James is a ...

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, ...