Cylon detector

A Cylon detector is a scientific method of determining whether a subject is human or a humanoid Cylon.

Created by Dr. Gaius Baltar, the test is administered by subjecting a person's blood to plutonium embedded in a carbon nanotube matrix. It filter preferentially ionizes synthetic molecules; this is because Cylons are susceptible to certain kinds of radiation. The plutonium was taken from one of Galactica's nuclear warheads, at the suggestion of Number Six (Bastille Day). The test results are simple: either "red", indicating Cylon, or "green", indicating human. Yet with a single test cycle lasting approximately eleven hours, Baltar estimates it will take over 60 years (not counting breaks for sleep, food, bathroom, etc.) to test the whole fleet (numbering almost 50,000 people) (Tigh Me Up, Tigh Me Down).

Development work on the Cylon detector had previously been halted when Dr. Baltar was accused by Shelly Godfrey of being a traitor and temporarily thrown in the brig (Six Degrees of Separation). Baltar's "innocence" was proven, however, by Lieutenant Felix Gaeta, who had previously been ordered by Commander William Adama to assist Baltar in the development of the device (Water). Although considered a military secret, the Cylon detector is nevertheless the subject of constant rumor and innuendo (Act of Contrition).

Curiously, the Cylons themselves (in the form of Number Six) are the ones who initially suggest the construction of the Cylon detector by using the nuclear materials. Moreover, Baltar was only put in charge of the project because of his earlier detection of the fleet's first Cylon infiltrator, Aaron Doral, which was also greatly influenced by Number Six. (Miniseries) So, ironically, the Cylon detector is very much a product of Cylon invention.

The Cylon detector does, in fact, work. It confirmed that Sharon Valerii was, indeed, a Cylon – a fact that Baltar hid from Valerii, fearing what her Cylon persona would do were he to tell her. (Flesh and Bone) After discovering that it would be easier for Baltar to make all the results "green", Baltar altered the device to mimic his method of thinking (Tigh Me Up, Tigh Me Down).

The Lymphocytic encephalitis virus is accidentally discovered as fatal to humanoid Cylon physiology but harmless to humans. This revelation could be used as a future detector (A Measure of Salvation).