The warp is a strange and terrible place. You might as well throw a traveller into a sea of sharks and tell him to swim home as send him through the warp unprotected. Better it is not to let common man travel through the stars. Better still, let him not know such a thing is feasible. Fra Safrane, 5th aide to Navigator De'el. The never-ending tides of the warp's madness The Immaterium (also referred to as the Empyrean, the Aether, the Sea of Souls, the Realm of Chaos, Warpspace or most commonly, the Warp) is an alternate dimension of purely psychic energy that echoes and underlies the familiar four dimensions of the material universe. It is the source of all psychic powers and known instances of so-called "sorcery" or "magic" as well as the home dimension of the Chaos Gods and their myriad daemonic servants. In fact, the terms "Chaos" and "the Warp" are often used interchangeably by those aware of their existence within the Imperium of Man. Superficially, the Immaterium is Mankind's solution to the problem of faster-than-light travel. This function as a faster-than-light medium for space travel is achieved because the Immaterium is a domain of pure psychic energy, with spacecraft navigating between its currents, as in an ocean. The psychic energy that makes up the Immaterium is believed to be the direct result of the existence of sentience in the universe, in particular the intelligent species of the Milky Way Galaxy. Considered to be a dark reflection of the material universe, the Warp is an ocean of chaotic psychic energy, raw emotion given physical form. Stirred by emotion and action, the Immaterium is the true Realm of Chaos, home to the Dark Gods who comprise the Ruinous Powers and their legions of daemonic followers. The Immaterium is also rumoured by many cultures, human and xenos alike, to be the final resting place of the spirits of the dead, and therefore can be considered the "Underworld" of the Warhammer 40,000 universe. Time Displacement The time differences between realspace and Warpspace are quite drastic. Not only does time pass at different rates in both kinds of space, but it also passes at very variable rates. Until a voidship finishes its jump, it is impossible for a ship’s crew to know exactly how long their journey has taken. Time passing in realspace is referred to as real time. Time passing on board a spacecraft is referred to as Warp time. Realm of Chaos The Ruinous Powers of Chaos and their daemonic servants are known to inhabit the portion of the Immaterium often called the Realm of Chaos. Daemons are only able to exist within the Immaterium, unless certain conditions are met within the material realm. The Immaterium is what empowers the daemonic and mortal servants alike of the four Dark Gods -- Khorne the Blood God, Slaanesh the Prince of Pleasure, Tzeentch the Architect of Fate, and Nurgle the Lord of Decay -- and their followers will undertake any action to increase this power and their standing with their unholy masters. Each of the Chaos Gods maintains his own kingdom within the Realm of Chaos, the nature of which matches his own personality and interests exactly. The Realm of Chaos is marked by nearly constant warfare and strife between the daemonic servants of the Ruinous Powers, who constantly scheme and battle against once another in an eternal struggle for dominance that can never be won. The Chaos Gods and their servants are consumed by this struggle and in truth pay very little attention to the doings of realspace, save when the actions of mortals either present a threat to all of the Chaos Gods' continued activities or an opportunity for the Ruinous Powers to enhance their position against one another in their eternal conflict