Vacuum energy

Vacuum energy is an underlying background energy that exists in space throughout the entire universe. One contribution to the vacuum energy may be from virtual particles, particle pairs throughout the universe that blink into existence and then annihilate in a timespan too short to observe. Their behavior is codified in Heisenberg's energy–time uncertainty principle. The effects of vacuum energy are thought to influence the behavior of the universe on cosmological scales. In the early 21st century, humanity contemplated the theoretical possibility of using vacuum energy to create free energy machines. It was argued that due to the broken symmetry (in quantum electrodynamics), free energy does not violate conservation of energy, since the laws of thermodynamics only apply to equilibrium systems.

Vacuum energy originates from the beginnings of infinite numbers of alternate realities. When harnessed for power supply, these fledgling universes are drained of energy in their infancy, resulting in their premature deaths. Virtually all Forerunner technology utilized the practically infinitely available vacuum energy as a power source, making possible their myriad of technological marvels. These included the Halo Array, as well as the systems used to make their shield worlds, such as Requiem, completely self-sufficient. Forerunner reaction drives utilized vacuum energy to expel virtual neutrons from the rear of the vessel, giving it propulsion.

When designing the MJOLNIR Powered Assault Armor, Dr. Catherine Halsey made a note in her journal to ask Déjà about research on vacuum energy as a potential power source. Being of Forerunner origin, 's slipspace drive is equipped with a vacuum energy siphon.

The effects of malfunctioning vacuum energy extraction machinery can be disastrous: when guano dust seeped into Covert Support Base 4276's vacuum energy extractor, its calibrations were corrupted, unleashing a "cyclone of quantum fury" that tore through the facility, warping both space and time and dimensionally displacing anything in its way. A wave of subatomic agitation was also released, softening metal and disintegrating polymers and thus damaging most of the facility's equipment. Even well after the incident, the extractor continued to generate a space-time anomaly in its vicinity: when Frederic-104 looked directly into the device, he experienced an overwhelming vision of cosmic grandeur, witnessing the life cycles of entire universes while losing his sense of self, time and place. This phenomenon was accompanied by a peculiar time dilation-like effect, in which Fred's mission clock had only recorded the passing of ten minutes while two hours had passed outside his frame of reference. When six HAVOK tactical nuclear weapons destroyed Salvation Base and the Forerunner Suluhu Contemplarium it was built within, the destruction caused the moon of Taram upon which the Contemplarium was build to implode into the vacuum energy extractor that was powering the Contemplarium.

Ancient humans and Ancient San'Shyuum were also known for using vacuum energy during prehistoric era.

List of appearances

 * Halo: Reach
 * Dr. Halsey's personal journal
 * Halo: Cryptum
 * Halo: Silentium
 * Halo: Last Light
 * Halo Wars 2
 * Halo: Retribution