Imperium of Man - Imperial Communications: Just as travel within the Imperium is a complicated and inexact science, so too is the business of exchanging messages between the many and varied planets that make up the Imperium. Planetary communications systems such as radio-based Vox-casters, hardwired telegraph and telephony lines and the more advanced Vox-communicators suffice to pass messages amongst the nations of a world, yet have almost no use beyond the bounds of the planet's surface. Such devices can require many Terran years for their signal to reach even the nearest planet of a star system and have no surety of even being detected when they arrive. The perils of travel ensure that Human or servitor messengers are just as unreliable and potentially as slow as radio or other energy wave communications.The Imperium is forced to rely upon communication by psychic, or astro-telepathic means. Astropaths communicate with symbols and iconic images, projecting these messages through vast distances of space by means of psychic power drawn from the Warp. This process is usually exhausting and requires ritual and focus in order to keep the psyker in the right frame of mind. These can take a wide variety of forms, such as use of the Emperor's Tarot, vision quests, automatic writing, trances, séances and the like. The Gaolist Astropaths of Hredin for example, spend many years etching their messages onto painstakingly illuminated sheets of iron and then destroy the work of art upon a massive grinding wheel when they are ready to transmit the information. The pain of annihilating a much-loved labour is said to produce psychic messages of unparalleled clarity.These messages are received by fellow Astropaths in various ways. Some appear as vague and troubling dreams, whilst others appear as visions or mystic portents. Others appear within whatever ritual method or divination technique the receiving psyker happens to practise. Thus warning of an Ork invasion might appear as a glistening imperfection in fish entrails, a looming cloud of smoke, bleeding orifices or a worrying combination of runes or sigils within a holographic matrix. Astropathic messages must not only be transmitted from one Astropath to another but decoded at the other end. Each Astropath employs slightly different symbols and each has a preferred style or "flavour." Some messages take solar weeks of poring over tomes of augurs and symbolism before they can be reconstructed, though the best Astropaths can do this word for word. Some remain a mystery forever. Some messages are received by Astropaths at entirely the wrong end of the galaxy and must be passed on to others who are nearer the place in question.Some messages simply do not get to their intended recipient or are drastically misinterpreted along the way. In addition, there are too few Astropaths. Most worlds, especially those with small populations or on the fringes of the Imperium, have no Astropaths at all, and must rely on the infrequent visits of passing Chartist ships or Administratum census-takers to make contact with the outside galaxy at all. For this reason the Adeptus Terra cannot react quickly to every event in the Imperium, even when an event occurs that is great enough to attract the notice of the vast and ponderous Imperial bureaucracy. On most worlds, the Imperium feels very far away.