Something else to add to the discussion, the idea of faster than light travel got a bit of a boost last year when Alcubierre's theoretical warp drive became a real possibility with the accidental discovery of a warp bubble by scientists working on an unrelated DARPA project.
For those who don't know, it was theorized back in the 90's that warp drive was indeed a possibility, bending space for and aft of a vehicle and allowing for faster than light travel. The
Alcubierre warp drive engine relied on exotic elements to generate the immense power required to create the gravity well to bend space. The requirement of exotic elements was what brought much derision to the theory and not thought to be possible. Alcubierre's theory also played within the boundaries of General Relativity, which made it that much more interesting.
Fast forward to August of last year, when a DARPA researcher
accidentally created a warp bubble while researching Casimir cavities. This was all done at a nano scale, but was exactly as Alcubierre had proposed/theorized almost 30 years ago, except without the need of exotic elements. This may be one of the most exciting developments in history, yet the researchers have back-burnered further research until they complete their study and work on Casimir cavities.
Further proof that we don't know what we don't know, and science fiction isn't always fiction.