Cavorium

Cavorium (Cv) is an element generally found in liquid form in deep underground reservoirs. Discovered by a Dr. Cavor in 641AV, cavorium's extremely high lighter-than-air properties takes the scientific and airship fields by storm.

No one could’ve imagined anything lighter than Hydrogen as it wasn't plausible with the scientific mentality of the time. The entire table of elements was put into question. "Are there elements between elements?" was the title in many newspapers.

Some scientists wanted to reweigh all the weights of the elements to be metered by the new element. In the end, the scientific community settled with giving the “kooky element” a weight based off of Hydrogen (0.2). The element has tremendous lifting power, which revolutionized the airship industry. Gas bags with a smaller volume, could now offer more lifting power and space for crew and cargo. Ships could become smaller.

The element, however, is rare, and its applications are limited to military vessels and rich transport companies.