Chaotic space is an area of space where the laws of physics are in a state of flux. It appears randomly and unexpectedly, and it has been observed throughout the galaxy. It intersects "normal" space at the eighteenth dimensional gradiant.
The region of space appears to be home to a race of aliens beyond normal Human comprehension. To communicate with humanoid carbon-based lifeforms, they alter the brain in a way so that the communications are often misinterpreted as hallucinations by the humanoids.
Chaotic space was encountered in the Delta Quadrant by USS Voyager in 2375, when they entered through a trimetric fracture. At that point the Borg had been aware of the phenomena for a long time, and only one cube had ever survived an encounter with chaotic space. While in chaotic space, the native aliens eventually were able to communicate to Chakotay that to escape, they would need to alter their warp field to a rentrillic frequency and set the deflector dish to induce a paralateral rentrillic property. Chakotay was able to make these modifications to Voyager after being shown detailed instructions, allowing him to modify the sensors using the deflector dish. (VOY: "The Fight")
- While speculating why this phenomonen had never been seen in the Alpha Quadrant or recorded by any Starfleet vessels, Chakotay noted that many Federation starships disappear in mysterious circumstances and may have fallen prey to this effect.