People have long dreamed of traveling to other stars and planets and wandering in the universe with a starship. However, such things only exist in sci-fi, because even the closest star to the sun, Proxima Centauri, is more than four light-years away. This means that even if you could travel at the speed of light, it would take you more than four years to reach the closest star.
To allow the Star Trek characters to quickly reach any part of the universe, Star Trek introduced the concept of “warp speed,” which lets the starships travel faster than light. However, according to Albert Einstein’s theory of general relativity, it is impossible to go faster than light.
