Psychokinesis (Greek ψυχή κίνησις, "mind movement"), or telekinesis (τῆλε κίνησις, "distance movement"), is an alleged psychic ability allowing a person to influence a physical system without physical interaction. Psychokinesis and telekinesis are sometimes abbreviated as PK and TK respectively. Examples of psychokinesis could include moving an object and levitation. There is no conclusive evidence that psychokinesis is a real phenomenon.
PK experiments have historically been criticized for lack of proper controls and repeatability. Furthermore, some experiments have created illusions of PK where none exists, and these illusions depend to an extent on the subject's prior belief in PK. (Wikipedia)