Lensing is a Draconian technique which uses specially treated mirrors to refract different versions of the time stream. It allows the user to look at alternative paths, see how their current time could have been. Lensmen spend years learning how to interpret the many-layered multiverse that the Lens exposes, an experience which is known to induce nausea in the uninitiated.
Lensing is disputed by members of the Copernican guild who believe that the act of observing the alternate timelines affects their existence and prevents them from terminating – effectively creating impossible parallel realities. No one has ever been able to prove that this is the case, although some Copernican theorists spend many lonely hours concocting hypotheses of impossibility based on Kolmogorov complexities, Cantor’s diagonal argument, Gödel’s incompleteness theorem, and of course Turing’s halting problem.
Lensing was discovered by Marius Hibbert, a temporal physicist, whilst experimenting with Euclidian planes and the quantum properties of light. He found a correlation between the curvature of a Neuman mirror and the four-dimensional qualities of light. One particularly revealing experiment allowed him to observe his wife’s lover leaving their house on several occasions. During the ensuing divorce she was able to refute the existence of a relationship based on the fact that it had obviously happened in another reality, and therefore she had in fact not been an adulterer. The court sided with the defendant and Hibbert was ordered to pay damages, after which Hibbert was approached by the Draconian Navigational Dept (known as Nautonniers) and offered a position within the research and development department (X division).
Lenses come in a variety of types and sizes, the largest is held in the Draconian Observatory in Greenwich, 11,566. The most common version is a ‘Tesseract,’ a small sphere of lenses that can be held in one hand, which is used by Lensman for the detection of breaches.