Psychic Powers

These are powers that allow a person to influence the world about themselves by the power of their minds rather than by physical or technological interaction. That is, rather than walking over to a table and picking up a glass, you could imagine yourself just picking up that glass and having it come to your hand. Depending on the author, this ability may not need as much effort as physically undertaking the action, but when such powers are depicted they are usually shown as taking as much out of the person as the physical equivalent would. This would mean that a person so endowed would be unable to undertake an action that they would physically be incapable of - a good example of this would be Larry Niven's Gil Hamilton as depicted in The Long Arm of Gil Hamilton of the ARM. Here Gil has lost an arm and his psychic ability replaced the physical presence of this arm, but he is unable to use it in any other fashion than as an invisible arm.

There are a number of types of powers:

• Clairvoyance - the ability to 'see' things at a distance. This is equivalent to your average televisual device-of-choice. It is usually limited by distance - mostly to places on the same planet. Another limit is that the clairvoyant has some familiarity with the target destination.
• Teleportation - the ability to move yourself from location A to location B. Although this can be as simple disappearing from A and re-appearing at location B, the better author will also take account of the Law of Conservation of Momentum. Again, this is often limited in a variety of ways - the mass that a person can carry with them in the teleportation, or having to have a knowledge of your location. The best example of this is The Stars My Destination which also shows how security can be maintained in such a society, and how such an ability is expressed.
• Telekinetics - the ability to move an object, as distinct from yourself, from location C to location D, or affect it without physically touching it. One is usually limited to being able to affect things that you could physically affect, i.e. you can't mentally lift a weight you couldn't lift physically.
• Telepathy - the ability to converse mind-to-mind. This is the most common psi power seen in stories and suffers from the least restriction, the most common being that the recipient of a telepathic message also has to be telepathic to understand what is happening though non telepathic recipients can sometimes 'hear' the sender as an unspecified voice in the head.