The Professor's Lie Detector is an extraordinary creation by the Professor to test the honesty of the fellow Castaways on behalf of the Howells, but it's exact workings are unrevealed. A traditional lie detector works off the principle of detecting involuntary, minute fluctuations in body responses (predominantly pulse rate) to questions posed to the subject. Several control questions establish a baseline for normal pulse rate when responding to questions. Questions where the subject's pulse rate is recorded at higher than the control are interpreted to mean deception.
The Professor's lie detector appears to operate off a different principle of brain waves. It is unclear exactly how this is supposed to have worked as the gourds have no internal connections to the subject's head and appears ill-fitting on all except the Skipper. It is also unclear as to what logic circuitry is used to determine guilt or innocence when sounding the horn.
The device is tested on the Professor who is caught lying when he claims he wants to stay stranded and never get rescued. The Skipper is also caught lying when he claims to be entirely truthful, but the device completely burns out on Gilligan playing with it when Mary Ann interrogates him over a missing pie.
- Ship's horn
- Radio batteries
- Gourd (Helmet)
- Coconuts & Bamboo (Structure)