Vulcan Science Directorate

The Vulcan Science Directorate was the head scientific authority of the Vulcan High Command, well known for its reluctance to embrace unorthodox ideas. The Vulcan Science Directorate has studied the question of time travel in great detail. By the mid-22nd century, they found no evidence that it exists or that it can exist, ultimately believing that its concept was "illogical". However, the Directorate had no trouble accepting the existence of micro-singularities or the notion that regions of space in the Delphic Expanse fail to conform to the laws of physics. 

In the mirror universe, the Vulcan Science Directorate (now simply "the Science Directorate" after being conquered by the Terran Empire) claimed that no mirror universes existed. This seemed to be disproven by evidence gathered by Commander Archer concerning the USS Defiant (NCC-1764).