A flux capacitor is the fictional core component of Dr. Brown's time traveling DeLorean in the popular 1985 movie Back to the Future and its two sequels. The flux capacitor is what makes time travel possible. It requires 1.21 gigawatts of electricity, supplied at first by a plutonium powered nuclear reactor, which was later replaced by a "Mr. Fusion" home energy generator from the future which was fueled by garbage. The flux capacitor is activated the moment the time travelling vehicle reaches 88 miles per hour.
It is not exactly clear how the flux capacitor works. One could assume it involves some sort of quantum tunneling. This is based on the observation that the DeLorean, after travelling through time, seems to be extremely cold. In quantum tunneling, electrons pass through a high energy barrier. This is expressed as a probability. Electrons that pass through the barrier, experience a loss in energy. Although a DeLorean is infinitely more complex than an electron, we can make this playful hypothesis. Other possibilities involve the creation of a wormhole, through which the DeLorean travels.
