Cloaking device
From The Big Bang Theory Wiki
A cloaking device is a fictional stealth technique that enables an object to become invisible.
The idea was first used in Star Trek: The Original Series when a starship from the Romulans disappeared in front of the eyes of the surprised the crew of the Enterprise. The term has now been used in a number of science fiction shows. Recently, it was suggested that such a technology could indeed be invented in a few decades [1].
Sheldon suggests to Leonard that he might use a cloaking device when the guys attempt to time travel in The Nerdvana Annihilation.
See also Star Trek References.
