Hypothetical theory allowing for the transmission of information to be passed between two points at greater than the speed of light.
Or a theory about string (but not a string theory).
Imagine a piece of string one au in length being held taught by two opposing spacecraft attempting to fly in opposite directions.
If I cut the string in the middle, the two spacecraft will fly apart almost instantaneously, whereas from the middle, it would take four minutes for light to reach either spacecraft.
alternatively I could just push down in the middle, both ships should instantaneously feel increased force pulling them backwards, faster than it would take light to travel between the point of depression, and either spacecraft.
Take that relativity!
Disclaimer!!!
I appreciate relativity precludes a number of physical properties because of their contradictory nature (such as a perfect rigid body), and guess that the tension carried in any conceivable substance might be offset over large distances by an element of stretchiness?