Flux capacitor

A flux capacitor is the fictional core component of Dr. Brown's time traveling De Lorean in the popular 1985 movie Back to the Future and its two sequels. The flux capacitor is what makes time travel possible.

It is not made clear in the movie exactly how the flux capacitor works. It consists of a box with three small, flashing incandescent lamps arranged in an upside-down 'Y', located above and behind the passenger's seat of the De Lorean time machine. At the end of the third film in the series, when Doc Brown has converted a steam train into a time machine, the flux capacitor is located on the front of the train, in place of the lamp.

It requires 1.21 gigawatts of electricity, supplied during its first two trips (one minute forward in time, and thirty years into the past) by a plutonium powered nuclear reactor, during its next trip (thirty years forward in time) by a bolt of lightning. Plutonium was used once again for a trip thirty years into the future, and thereafter the power was supplied by a "Mr. Fusion" home energy generator from the future which was fueled by garbage, except for one accidental trip (70 years into the past) when another bolt of lightning triggered the flux capacitor.

The flux capacitor is activated the moment the time traveling vehicle reaches 88 miles per hour. Therefore, the unleaded gasoline that fueled the automobile (or the steam train that was used to push the automobile) was another energy source that was needed to activate the flux capacitor.