Recently I have gotten my hands on a spectacular game called "Elite Dangerous" by Frontier Developments. It is a realistic space adventure, trading, and combat simulator that is the fourth installment in the Elite video game series. Frontier Developments designed the game to include as much real world physics as possible.
Piloting a spaceship, the player explores a realistic 1:1 scale open world galaxy based on the real Milky Way. That means that the player is able to explore the game's galaxy of some 400 billion star systems. With a galaxy this big, there seems to be a problem though, how would one travel from one star system to another let alone to the 400 billion others without breaking one of the most important theories ever conceived. Einstein's special Theory of Relativity, which states that a particle (that has rest mass) with subluminal velocity needs infinite energy to accelerate to the speed of light.
The game uses what is called a Frameshift Drive which allows one to travel in a solar system up to 2000 times the speed of light, and make long distance jumps to a star 10 light years away in only a few seconds.
Even though a device like this does not exist in real life, it actually follows a very strong proposed theory that would allow one to travel lights years in seconds with out actually traveling faster than the speed of light. Confusing, I know.
In 1994, a Mexican physicist, Miguel Alcubierre, theorized that faster-than-light speeds were possible in a way that did not contradict Einstein by harnessing the expansion and contraction of space itself. Under Dr. Alcubierres hypothesis, a ship still couldn't exceed light speed in a local region of space. But a theoretical propulsion system he sketched out manipulated space-time by generating a so-called warp bubble that would expand space on one side of a spacecraft and contract it on another.
An Alcubierre Warp Drive stretches spacetime in a wave causing the fabric of space ahead of a spacecraft to contract and the space behind it to expand. The ship can ride the wave to accelerate to high speeds and time travel. The Alcubierre drive, also known as the Alcubierre metric or Warp Drive, is a mathematical model of a spacetime exhibiting features reminiscent of the fictional "warp drive" from Star Trek, which can travel "faster than light"
In this way, the spaceship will be pushed away from the Earth and pulled towards a distant star by space-time itself.
Alcubierres theory, however, depended on large amounts of a little understood or observed type of exotic matter that violates typical physical laws.
In general relativity, one often first specifies a plausible distribution of matter and energy, and then finds the geometry of the spacetime associated with it; but it is also possible to run the Einstein field equations in the other direction, first specifying a metric and then finding the energy-momentum tensor associated with it, and this is what Alcubierre did in building his metric. This practice means that the solution can violate various energy conditions and require exotic matter. The need for exotic matter leads to questions about whether it is actually possible to find a way to distribute the matter in an initial spacetime which lacks a "warp bubble" in such a way that the bubble will be created at a later time.
Yet another problem is that it would be impossible to generate the bubble without being able to force the exotic matter to move at locally FTL speeds, which would require the existence of tachyons. Some methods have been suggested which would avoid the problem of tachyonic motion, but would probably generate a naked singularity at the front of the bubble.
What this means, as stated by Dr. Alcubierre, "The warp drive on this ground alone is impossible. At speeds larger than the speed of light, the front of the warp bubble cannot be reached by any signal from within the ship. This does not just mean we cant turn it off; it is much worse. It means we cant even turn it on in the first place."
So even though at the moment it seems Highly unlikely for this to actually work, as we progress with more knowledge, we eventually will find some way to travel to another star, FAST!