unobtanium

The term Unobtanium is also used in SF/sci-fi/science fiction and/or engineering circles to describe a fictional substance with sets of physical properties (density, tensile strength, etc.) that are unnaturally exceptional. For example, an unobtanium garbage can lid that can withstand an artillery shell, yet only weighs an ounce.

This sense of the word is usually used to describe structural or mechanical designs, realor fictional, that play fast and loose with materials science as we know it. For instance, if one wanted to try to justify how Godzilla is able to stand and walk, despite the square-cube law, one might claim that Godzilla's bones are either made of or laced with a very strong type of unobtanium.

One should probably smile while saying that, though.

Of course, YMMV; aluminum, titanium, and steel were considered unobtanium in their days. Even so, if your plans demand unobtanium of any kind to succeed - make other plans.

The word is also a (light) play on the incredibly silly, boring and politically correct method of naming the higher elements when credit for their discovery is in dispute. When U.S. and Soviet teams, for example, both claimed to have synthesized element 105 (Atomic number 105) in the lab before the other team, periodic tables published in many places around the world (including, to their credit, the U.S. and the U.S.S.R.) listed the name of the element as 'Unnilpentium.' The name is a direct transliteration of the atomic number's digits: 'Un' (1) 'nil' (0) 'pent' (5) -ium.

Unobtanium is also, therefore, one of the only elements which, by the very rules of logic, cannot be observed in its raw state. Any information concerning an actual piece of unobtanium typically involves quantum proof of the existence of that piece, which would have had to be obtained for measurement.