Spontaneous regression is an unexpected improvement or cure from a disease which is usually taking a different course. It is a term that is mainly used for unexpected transient or final improvements in cancer.

It has long been assumed that spontaneous regressions from cancer are a rare phenomenon, and that some forms of cancer are more prone to unexpected courses than others. Frequency is estimated to be about 1/100000, however, in reality this ratio might be largely underestimated. Not all cases of spontaneous regression can be apprehended, either because the case was not well documented, the physician was not willing to publish, or simply because the patient did not show up in a clinic any more.

For small tumors, the frequency of spontaneous regression was probably drastically underrated. In a carefully designed study on mammography it was found that 22% of all breast cancer cases underwent spontaneous regression.

In many of the collected cases, it must be acknowledged that the factors or mechanisms responsible for spontaneous regression are unknown in the light of present knowledge. In some of the cases, available knowledge permits one to infer that hormonal influences probably were important. In other cases, the protocols strongly suggest that an immune mechanism was responsible.

The sailing stones are a geological phenomenon found in the Racetrack Playa located in the northern part of the Panamint Mountains in Death Valley National Park, California. The stones slowly move across the surface of the playa without human or animal intervention leaving a track as they go. They have never been seen or filmed in motion. Racetrack stones only move once every two or three years and most tracks last for just three or four years.

Stones with rough bottoms leave straight striated tracks while those with smooth bottoms wander. Stones sometimes turn over, exposing the other edge to the ground and leaving a different-sized track in the stone’s wake.

The sailing stones are most likely moved by strong winter winds of up to 90 mph. Once it has rained enough to fill the playa with just enough water to make the clay slippery, the winds push the stones across the slick surface. The prevailing winds across Racetrack Playa blow from southwest to northeast, with most of the rock trails parallel to this direction, lending support to this hypothesis.

An alternate hypothesis builds upon the first. As rain water accumulates, strong winds blow thin sheets of water quickly over the relatively flat surface of the playa. A layer of ice forms on the surface as night temperatures fall below freezing. Wind then drives these floating ice sheets, their aggregate inertia providing the necessary force required to move the larger stones.

The uncanny valley is a hypothesis regarding the field of robotics and computer graphic animation. The theory holds that when robots and other facsimiles of humans look and act almost like actual humans, it causes a response of revulsion among human observers. The valley in question is a dip in a proposed graph of the positivity of human reaction as a function of a robot’s lifelikeness.

A number of theories have been proposed to explain the cognitive mechanism underlying the phenomenon. As appearance and motion become less distinguishable from a human being, an evolved cognitive mechanism for the avoidance of selecting mates with low fertility, poor hormonal health, or ineffective immune systems based on visible features of the face and body is activated.

In addition, the viewing of a not quite real human animation or robot elicits an innate fear of death, pathogen avoidance, and the irrational belief that aging and death as a central premise of life apply to all others but oneself. The jerkiness of an android’s movements could be unsettling because it elicits a fear of losing bodily control.

The uncanny valley may be symptomatic of entities that elicit a model of a human other but do not measure up to it. If an entity looks sufficiently nonhuman, its human characteristics will be noticeable, generating empathy. However, if the entity looks almost human, it will elicit our model of a human other and its detailed normative expectations.

The concept of the uncanny valley is taken seriously by the film industry due to negative audience reactions to CGI animations. The 2004 CGI animated film The Polar Express was criticized by reviewers who felt that the appearance and movements of the characters were creepy or eerie.

Stendhal syndrome is a psychosomatic illness that causes rapid heartbeat, dizziness, fainting, confusion and hallucinations when an individual is exposed to art, usually when the art is particularly beautiful or a large amount of art is in a single place. The term can also be used to describe a similar reaction to other circumstances, as when confronted with immense beauty in the natural world.

The illness is named after the famous 19th century French author Marie-Henri Stendhal, who described his experience with the phenomenon during his 1817 visit to Florence, Italy in his book Naples and Florence: A Journey from Milan to Reggio.

Although there are many descriptions, dating from the early 19th century on, of people becoming dizzy and fainting while taking in Florentine art, the syndrome was only named in 1979, when it was described by Italian psychiatrist Graziella Magherini, who observed and described more than 100 similar cases among tourists and visitors in Florence. The syndrome was first diagnosed in 1982. The term is also used when describing the reactions of audiences to music of the Romantic period.

It is similar but not identical to Paris Syndrome, a transient psychological disorder encountered by some people visiting or vacationing in Paris, France. The symptoms occur during a trip which confronts the traveller with things they had not previously experienced and did not anticipate. The symptoms did not exist before the trip and they disappear with a return to familiar surroundings.

An interobject is a phenomenon of dreams, in which there is a perception of something that is “between” two objects. Interobjects differ from typical dream manifestations in which two objects are fused into one. Instead, the object is incomplete. An example from the literature on dreams includes “something between a record player and a balance scale.” Interobjects are new creations derived from partially-fused blends of other objects.

Interobjects, like disjunctive cognitions, would sound bizarre or psychotic as perceptions in waking life, but are accepted by most people as commonplace in dreams. They have implications for both the theory of dreaming and the theory of categorization. Interobjects show the dreaming mind grouping items together whose connection may not be apparent to the waking mind. “Something between an aqueduct or a swimming-pool” reveals the category of “large man-made architectural objects that contain water.” “Something between a cellphone and a baby” reveals a category combining a relatively new piece of technology and a live infant: both make noise when you don’t expect it, both are held close to your body, and both can give you a feeling of connectedness.

Most adults tend to regularize interobjects when discussing them in waking life. Children are better able to sustain interobjects in their original form. A child told his father a dream in which he was in trouble at sea and a seal swam up to them. They thought it was just a seal, but then they looked and under the water it was a whole boat, it was huge, so they climbed onto the seal/boat, and it brought them to the shore of the mainland. When the boy told his father the dream in the morning, the father, speaking like an adult who cannot tolerate contradictions, said to him: “So really, it was a boat, a big, safe boat.” The child, holding fast to the integrity of his dream, said, “It was a boat, but it was still a big, friendly seal.” This child had not yet learned to regularize his perceptions to fit the way the world works. Adults may learn to reject interobjects in waking life, but still retain them in their dreams.

Interobjects may have an elementary function in human thought. By transgressing the normal mental categories described by Eleanor Rosch, interobjects may be the origin of new ideas that would be harder to come by using only fully-formed, secondary process formations. They may be one example of “Oneiric Darwinism” in which new thought-mutations are created during dream-life and rejected or retained in waking life depending on their usefulness.

The 2007 Siberian orange snow was an anomalous phenomenon that happened on February 2, 2007 when an orange-tinted snow fell across an area of 580 square miles in the Siberian Federal District in Russia, as well as into the neighbouring oblasts of Tomsk and Tyumen. It was most likely caused by a heavy sandstorm in neighbouring Kazakhstan. 

This orange snow was malodorous, oily to the touch, and reported to contain four times the normal level of iron. Though mostly orange, some of the snow was red or yellow. It affected an area with about 27,000 residents. It was originally speculated that it was caused by industrial pollution, a rocket launch or even a nuclear accident. It was later determined that the snow was non-toxic. However, people in the region were advised not to use the snow or allow animals to feed upon it. Coloured snow is uncommon in Russia but not unheard of, as there have been many cases of black, blue, green and red snowfall. 

The phenomenon was most likely caused by a heavy sandstorm in neighbouring Kazakhstan. Tests on the snow revealed numerous sand and clay dust particles, which were blown into Russia in the upper stratosphere. The speculation that the colouration was caused by a rocket launch from Baikonur in Kazakhstan was later dismissed, as the last launch before the event took place on January 18th.

Russia’s environmental watchdog originally claimed that the coloured snowfall was caused by industrial pollution. It stated that the snow contained four times the normal quantities of acids, nitrates, and iron. However, it would be nearly impossible to pinpoint a culprit if pollution were the cause, as there are various industries nearby, such as the city of Omsk, which is a centre of the oil industry in Russia.

Earworm is a term for a portion of a song or other musical material that repeats compulsively within one’s mind, known colloquially as “music being stuck in one’s head”. The Germans use the word Ohrwurm (rhymes with “door worm,” where the “w” is pronounced like a “v”) to denote these cognitively infectious musical agents. Use of the English translation was popularized by James Kellaris and Daniel Levitin.

Kellaris’ studies demonstrated that different people have varying susceptibilities to earworms, but that almost everybody has been afflicted with one at some time or another. The psychoanalyst Theodor Reik used the term “haunting melody” to describe the psychodynamic features of the phenomenon. Another scientific term for the phenomenon, involuntary musical imagery, was suggested by the neurologist Oliver Sacks in 2007.

People with obsessive-compulsive disorder are more likely to report being troubled by ear worms. In some cases medications can minimize the effects. Earworms should not be confused with endomusia, which is a serious affliction in which someone actually hears music that is not playing externally.

Indian summer is an informal expression given to a period of sunny, warm weather in autumn in the northern hemisphere, typically in late October or early November, after the leaves have turned but before the first snowfall.

The origins of the term Indian Summer are most commonly thought to have derived from the timing of Summer in India to correlate with good weather in Autumn in the Western world.

In former times in Europe, Indian summer was called Saint Martin’s Summer, referring to St. Martin’s day, November 11, when it was supposed to end. 

In Bulgaria, the phenomenon is sometimes called Gypsy Summer and in some places Gypsy Christmas and refers to unseasonably warm weather in late fall, or a warm spell in between cold periods.

In Sweden it is called brittsommar, which is derived from Birgitta and Britta, who have their name day in the Swedish calendar on October 7. That is when Britt Mass, an official fall open-air market, was held.

In Germany and Austria it is called Altweibersommer (Old Ladies Summer) because the many white spider silks seen at this time of the year have been associated with the norns of Norse folklore or medieval witches.

There are around 43 different theories concerning the origin of the term.