List of alternative, speculative and disputed theories
This list of alternative, speculative and disputed theories includes examples of fields of endeavor that many consider to varying extents to be fringe or pseudoscientific. Many of these practices are often quite popular, in part because they sometimes work. Opinion on the validity of these practices is extremely diverse.
In addition to a postulated theory, inclusion in the list is possible because that theory is:
Asserting claims without supporting experimental evidence;
Asserting claims which contradict experimentally established results;
Failing to provide an experimental possibility of reproducible results; or
Violating Occam's Razor (the principle of choosing the simplest explanation when multiple viable explanations are possible).
Adhered to by a limited group.
Many of these theories are considered pathological science: a psychological process in which believers in a theory, who may have originally conformed to the scientific method, unconsciously veer from that method and begin a pathological process of wishful data interpretation.
The term ironic science was used by John Horgan in his book The End of Science to describe a "speculative, non-empirical mode" that mainstream science sometimes enters.
Astrology refers to any of several systems of understanding, interpreting and organizing knowledge about reality and human existence, based on the relative positions and movement of various real and construed celestial bodies.
Acupuncture, in the traditional sense, is the practice of inserting very thin needles in particular points on the body to redirect qi thereby improving health and well-being. This is one component of traditional Chinese medicine.
Applied kinesiology is a method of diagnosing malfunctioning organs and what the effect of substances on the body is or would be by testing whether certain muscles is weakened or not.
The Bates method of vision improvement, based on a theory of how the eye accommodates which is not accepted by mainstream ophthalmology or biology.
Biorhythm theory researches patterns of alterations in physiology, emotions, and intellect.
Some Chiropractic theories that ascribe ailments unrelated to the spine to spinal maladjustments.
Crystal power theory states that crystals have alleged healing and mystical paranormal powers.
Facilitated communication is alternative means of expression for people who cannot speak, or whose speech is highly limited (e.g. echoed, limited to one or a few word utterances), and who cannot point reliably.
Gene Ray's Time Cube, which states that there are 4 simultaneous days in a single rotation of Earth, and that Time is Cubic, not linear. Some people doubt whether this concept qualifies as a theory as they consider it to lack testable constructs.
Materialization creation of matter from nowhere and out of nothing by somebody's will power or concentration.
Welteislehre is the theory developed by Hanns Hörbiger in the early 20th century. It states that the universe is based on a constant struggle between ice and fire.
Graphology is the study of handwriting and its connection to behavior, personal information and other human traits.
Hypnosis is "a procedure during which a health professional or researcher suggests that a client, patient, or subject experience changes in sensations, perceptions, thoughts, or behavior."
Interpretation of dreams is the art of determining the meaning (or alleged meaning) of the symbols contained in a dream.
Parapsychology is the branch of science concerned with the study of mental phenomena, whether actual or purported, that are not currently explainable within the framework of mainstream, conventional science.
Phrenology claims to be able to determine personality traits and criminality on the basis of the shape of the head.
Photoreading is "mentally photographing" printed pages.
Physiognomy is based upon the belief that the study and judgement of a person's outer appearance, primarily the face, reflects the contents of their personality.
Polygraph or Lie detector is a device which measures and records several physiological variables such as blood pressure, heart rate, respiration and skin conductivity while a series of questions is being asked, in an attempt to detect lies.
Recovered memory is the act of discovering repressed memories and therapy to achieve such ends.
Cryptozoology is the study of rumored or mythological animals that are presumed by many to exist, but for which proof does not yet exist.
Pseudoarchaeology refers to the ideologically-driven, usually sensational interpretation of the past outside of a critical, scientific framework. Pseudoarchaeology also includes forms of protosciences.