Flux capacitor

File:Flux1.jpg

A fan-created Flux Capacitor

The Flux Capacitor is the core component of Doctor Emmett Brown's fictional time traveling De Lorean DMC-12. Brown states in the movie Back to the Future that the flux capacitor "is what makes time travel possible."

The term flux capacitor has become commonly used slang or buzz word for a device whose operation might be too complicated to briefly explain, especially if it fails to operate properly, as in "The file server went down due to a flux capacitor problem."

How it works

It is not made clear in the movie exactly how the flux capacitor works, beyond that of a typical deus ex machina device. It consists of a box with three small, flashing incandescent lamps arranged as a "Y", located above and behind the passenger's seat of the time machine. As the car nears 88 miles per hour, the light of the flux capacitor pulses faster until it has a steady stream of light. The stainless steel body of the De Lorean also has a beneficial effect on the "flux dispersal" as the capacitor activates, although Doc is interrupted before he can finish explaining it fully.

Fictional timeline

On November 5 1955, Doctor Emmett Brown came up with the idea of the flux capacitor after slipping and bumping his head while standing on his toilet to hang a clock. The idea came to him in a vision he had after being knocked out.

In order to travel through time, the vehicle integrated with the flux capacitor needs to be travelling at 88 mph (141.6 km/h), and requires 1.21 gigawatts of power (1,210,000,000 watts), originally (from 1985 to 1955) supplied by a plutonium-powered nuclear reactor. However, for the time machine's return trip (from 1955 back to 1985), plutonium was not available, so a lightning rod was connected directly to the flux capacitor and was used while the vehicle sustained 88 mph. Plutonium was used once again for a trip forward in time at least 30 years, and at some point thereafter the plutonium reactor was replaced by a "Mr. Fusion" home energy generator from the future that was fueled by extracting hydrogen atoms from garbage.

The De Lorean once again came back to 1985 and proceeded to travel to 2015, where it was stolen and taken back to 1955 and returned back to 2015 without the Doc's knowledge. When they returned in 1985, they found it was a different present, so they traveled back to 1955 to fix the timeline. The De Lorean was again struck by lightning in the year 1955, this time by accident. The lightning created an overload and destroyed the time circuits, if you watch closely you will see that the 1885 date was already displayed before the lightning hit, after the LED read-outs flashed, this is a reference to earlier in the film when Doc exclaims that he needs to fix them (they also flash a random date before he hits it and they are corrected), contrary to popular belief the 1885 date was not caused by the lightning hitting the De Lorean. It was then hidden in the Delgado mine for 70 years, "... because suitable replacement parts will not be invented until 1947." This is presumably a reference to the invention of the transistor. It was recovered from the mine in 1955 and repaired by Doc Brown's 1955 counterpart, thus restoring it to working order. Since both gasoline and garbage were available, the next trip back to 1885 was performed under the car's own power.

Due to a broken fuel line, the De Lorean's final trip from 1885 to 1985 was partially powered by a steam locomotive pushing the vehicle up to 88 mph while using Mr. Fusion to generate the 1.21 gigawatts required to activate the Flux Capacitor and break the Time barrier. Doc returns to 1985 in a time machine made from a train. This uses a flux capacitor that Doc was able to power using steam.

"Jiggawatt"

The power required is pronounced "one point twenty-one jiggawatts" (or "jigowatt"). This pronunciation of "gigawatt" is correct (as derived from its SI unit prefix giga); in fact many amateur radio operators from that timeframe correctly pronounced "giga" as "jiga", although it is more commonly pronounced with two hard "g" sounds as in "golf."

But while "jiggawatt" is a correct pronunciation, it is an incorrect spelling. Nevertheless, the pronunciation is considered humorous by many people.

Mr. Fusion

The Mr. Fusion Home Energy Reactor is the name of a power source used by the De Lorean time machine in the Back to the Future trilogy. It can be seen towards the end of Back to the Future when "Doc" Emmett Brown pulls into the McFlys' driveway after a trip to the year 2015, and is an obvious parody of Mr. Coffee machines, which were very popular at the time of filming. Ironically, the coffee maker from which the prop was made was actually made by Krups.

The Mr. Fusion Home Energy Reactor converts household waste to power the time machine's flux capacitor and time circuits using nuclear fusion. (It is thought that this is cold fusion.) In the film, Mr. Fusion allows the De Lorean time machine to generate the required 1.21 gigawatts needed to travel to any point in time. The energy produced by Mr. Fusion replaces plutonium as the primary power source of the De Lorean's time travel and flight capabilities. However, as stated in Back to the Future III, the car is still driven by its original internal combustion engine. Just as with the flux capacitor itself, the Mr. Fusion may also be considered a deus ex machina, allowing the characters to sidestep the ardurous power-generation requirements that the plot of the first film hinged upon.

When the De Lorean is parked in a 2015 alleyway, a "Fusion Industries" machine is briefly seen.

Electronics

The phrase "flux capacitor" has appeared in more serious contexts. U.S. patent 6,084,285 describes a "lateral flux capacitor having fractal-shaped perimeters." The idea being to make a capacitor in an integrated circuit, some of whose capacitance exists between two conductors on a single layer (hence, "lateral"). The device is not a lateral flux-capacitor but a lateral-flux capacitor; that is, lateral modifies flux, and lateral flux is attributive, rather than flux capacitor compound and lateral modifying capacitor.

Flux is commonly used in electronics and electromagnetic theory and application, but rarely in the context of a capacitor. In general terms, flux simply means the rate at which some quantity (such as electric charge) passes through a surface (e.g. charge flux). It is speculated that the movie terminology is used fictitiously to represent a new and unknown type of flux.

While they are not generally called "flux capacitors", the common inductor IS a device whose function in many contexts, e.g. the switching power supply, is exactly that which a flux capacitor would have - it stores electrical energy as a magnetic flux where it can be retrieved later, this way a pulsing current can be converted to a constant voltage higher or lower than the input voltage. Seeing as how the 1890s version of the flux capacitor (mounted on the train) is exactly that (a really large coil of wire) it seems clear that this is not lost on the movie makers.

Translations

• The Spanish (Spain only) dubbing of the film mistranslated flux as the nonexistent fluzo instead of flujo, adding to the exoticness of a condensador de flujos. However the Latin American version doesn't have this issue.

• The Italian dubbing of the film mistranslated the name as "flusso canalizzatore", which roughly means "channeling flux"; however, when Marty reads the letter from Doc in the third movie, it talks about the broken "condensatore di flusso", which is an exact translation of "flux capacitor", but at this point appears to be totally unrelated to the rest of the movies (at least for only-Italian-speaking people).

• In the German-dubbed version, the device was once again mistranslated and called the "Fluxkompensator" ("Flux compensator"). The correct German translation for the word capacitor, however, would be "Kondensator".

• In the French version, the De Lorean needs 2.21 gigawatts instead of 1.21. The flux capacitor was mistranslated to "convecteur temporel" ("temporal convector"). The correct French translation for flux capacitor would be "condensateur de flux".

• For the Brazilian version of the movie, the flux capacitor was successfully translated to: "capacitor de fluxo"

• In the Turkish version, the device was called "akı kapasitörü". But correct translation should be "akı kondansatörü".