Psionics is the study of paranormal phenomena in relation to the application of electronics. The term comes from psi ('psyche') and the -onics from electronics (machine). It is closely related to the field of radionics. There is no scientific evidence that psionic abilities exist.
A notable device in psionics was the Hieronymus machine. The machine was described by scientists as pseudoscientific and an example of quackery.
Parapsychologists associated with psionics have included John Hasted and Robert G. Jahn. Their experiments were heavily criticized by the scientific community due to weak controls, methodological flaws and no independent replication.
Psionic abilities appear frequently in science fiction and provide characters with supernatural abilities.John W. Campbell, an editor of a science fiction magazine, became excited about fringe science, and went on to define psionics as "engineering applied to the mind". His encouragement of psionics led author Murray Leinster and others to write stories such as The Psionic Mousetrap.
Science writer Martin Gardner wrote that the study of psionics is "even funnier than dianetics or Ray Palmer's Shaver stories", and criticized the beliefs of Campbell as anti-scientific nonsense.