Double nexus particle

The Double nexus particle, Findecker's Folly, was a particle discovered by the scientist Sa Yy Findecker at some point before the 51st century. It led to the development of practical time travel through the application of a Zygma beam as a power source. This was put to use in devices like the time cabinet. However, it ultimately proved to be a technological cul-de-sac, as time travel in this way led to horrible and life-threatening mutations. (TV: The Talons of Weng-Chiang)