Many of you reading this have undoubtedly read or heard about Faster-than-Light travel, or FTL travel for short. Always a part of science fiction movies, novels and the like, it has for long been regarded as one of mankind's wildest fantasies. However, with relatively recent events such as the debacle at CERN over neutrino particles allegedly travelling at superluminal speeds, huge amounts of public interest has again been piqued. Nevertheless, let us first examine what exactly is superluminal travel.
To begin, superluminal travel, as aforementioned, is fundamentally travelling at speeds exceeding the speed of light. Why this is so difficult and highly debated is due to the theory of relativity, where light is held as the absolute limit the any matter can achieve, and even doing so would taking incredible amounts of energy. For example, reaching the speed of sound was not easy task for mankind, much less the speed of light, a speed more than a hundred thousand times greater than the former. In addition, travelling at superluminal speeds would transport one back in time, in theory, which would conflict with the theory of causality. However, what this theory did not cover was other ways, more subtle and indirect, that would allow this fantasy, this idea, this dream of superluminal travel; to turn into reality.
Before we move into the technicalities of superluminal travel, however, the importance of superluminal travel will be examined.
First and foremost, the mere vastness of the universe would mean travelling even at the speed of light would take decades, even centuries, just to reach another solar system. Much less can be said about a journey to another galaxy; a journey which would probably and literally take aeons. What about the billions of galaxies which are rumored to exist in this universe? Thus, to effectively traverse such huge distances, superluminal travel has to be made possible.
Now time for the million-dollar question: So how can we achieve superluminal travel?
Even though we are unable to achieve superluminal travel via direct means such as by building up sufficient momentum, advancements into fields such as quantum entanglement, Alcubierre drives as well as theoretical particles such as tachyons are being made. For example, Alcubierre drives are basically an engine concept which expands the space behind a spacecraft, while contracting the space in front of it. This then allows the spacecraft to move through space at a speed faster than light, without conflicting any fundamental theories about the laws of matter.
Thus, we can see that these fields work in a way that do not conflict with Einstein's theory of relativity, which in turn offers a glimmering hope that one day, mankind would be able to traverse the stars through superluminal travel.