A central idea of physics is that reference frames don't change fundamental laws. It shouldn't matter where you observe an event or how fast you are moving, the laws of physics should remain the same ...

Special relativity has changed the way we think about time and the order of events. Einstein famously showed that two events can look simultaneous to one observer but not to another. In fact, it’s ...

We've all heard of relativity, but what is it? How does it relate to light and motion? So we've all heard of relativity, right? But... what is relativity? And how does it relate to light? And motion?

Well connected: an optical clock at PTB was used in the comparison. (Courtesy: PTB) Atomic clocks in France, Germany and the UK have been used to perform the best-ever confirmation of time dilation as ...

In the beginning of the year 1905, Albert Einstein was an unknown 25-year-old clerk in the Swiss patent office. By the end of the year, he had published four papers of extraordinary importance. His ...