Albert Einstein, in his theory of special relativity, determined that the laws of physics are the same for all non-accelerating observers, and he showed that the speed of light within a vacuum is the same no matter the speed at which an observer travels. As a result, he found that space and time were interwoven into a single continuum known as space-time. Events that occur at the same time for one observer could occur at different times for another.
Physicists just completed the last missing piece of Albert Einstein's theory of relativity. This has massive implications, and could even be a jump towards time travel. Learn more in the video given below: