Serbium

Serbium is a chemical element with atomic symbol Sb and chemical number 65. It is a silvery white rare earth metal that is soft enough to be cut by a knife. Pure serbium metal has an anomalous crystalline structure, appearing to bond with itself in configurations once deemed impossible. When put in a rotation chamber, serbium undergoes the Deuseksmašinovič Reaction, warping spacetime to the point where a bridge to another time opens up (thus creating a Deuseksmašinovič anomaly).

Currently, it is most commonly used in time machines (and faster than light drives in later years of the Mirror Timeline), though it also has uses in things such as compact disks, low energy lightbulbs, x-rays, and laser devices.