For a section of road that carries more than one numbered route, see coincidence (road).

Coincidence literally describes two or more events or entities occupying the same point in space or time, but colloquially means two or more events or entities possessing unexpected parallels, such as thinking about someone and then receiving an unexpected phone call from that person, when it is clear that there is no ordinary causal connection.

The index of coincidence can be used to analyze whether two events are related. A coincidence does not prove a relationship, but related events may be expected to have a higher index of coincidence. From a statistical perspective, coincidences are inevitable and often less remarkable than they may appear intuitively. The odds that two people share a birthday, for example, reaches 50% with a group of just 22 ^* (see the Birthday paradox).

Remarkable coincidences sometimes lead to claims of psychic phenomena or conspiracy theories. Some researchers (see Charles Fort and Carl Jung) have compiled thousands of accounts of coincidences and other anomalous phenomena.

In optics, coincidence is also used to refer to two or more incident beams of light that strike the same point at the same time.

Coincidences in film

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• Albert Markovski hires existential detectives to "solve" a coincidence in I ♥ Huckabees.
• V denies the existence of coincidences in V for Vendetta^*.

See also

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• Mathematical coincidence
• Coincidence theory
• Bible code
• Littlewood's law
• Post hoc ergo propter hoc
• Anomalous phenomenon
• Forteana
• Déjà vu
• Extra-sensory perception
• Randomness
• The Roots of Coincidence
• Synchronicity
• The Celestine Prophecy

References

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• Jung, Carl G.: Synchronicity: An Acausal Connecting Principle. Princeton, N.J.: Princeton UP, 1973.
• Arthur Koestler: The Roots of Coincidence

External links

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• Historic Coincidence A collection of unusual coincidences in History
• Coincidences: Learning from Synchronicity
• Unlikely Events and Coincidence (ASTOP)
• The Power of Coincidence by David G. Myers (Skeptic)
• The Power of Coincidence by Jill Neimark (Psychology Today)
• The Coincidence Theorist's Guide to 9/11
• "How to Search and Find Whatever is Most Important to You", an article that shows how a process which searches for large combinations of keywords in Google results in seeming coincidences of insightful results with the searcher's deep personal interests.

Coincidence | Forteana | Superstitions