Dictionary of Hallucinations. J.D. Blom. 2010.
Optical illusion — This article is about visual perception. For the Time Requiem album, see Optical Illusion (album). An optical illusion. The square A is exactly the same shade of gray as square B. See checker shadow illusion. An optical illusion (also called a… … Wikipedia
Optical parametric oscillator — Infrared optical parametric oscillator An optical parametric oscillator (OPO) is a parametric oscillator which oscillates at optical frequencies. It converts an input laser wave (called pump ) into two output waves of lower frequency (ωs,ωi) by… … Wikipedia
optical illusion — The term optical illusion is used in a narrow and a broad sense. In the narrow sense, it denotes an illusion attributable to the optics of the eye. In the broad sense, it is used as an equivalent of the term visual illusion, denoting any… … Dictionary of Hallucinations
Fermi paradox — The Fermi paradox is the apparent contradiction between high estimates of the probability of the existence of extraterrestrial civilizations and the lack of evidence for, or contact with, such civilizations.The extreme age of the universe and its … Wikipedia
Curry's paradox — For Paul Curry s optical illusion and dissection puzzle, see Missing square puzzle. Curry s paradox is a paradox that occurs in naive set theory or naive logics, and allows the derivation of an arbitrary sentence from a self referring sentence… … Wikipedia
Loschmidt's paradox — Loschmidt s paradox, also known as the reversibility paradox, is the objection that it should not be possible to deduce an irreversible process from time symmetric dynamics. This puts the time reversal symmetry of (almost) all known low level… … Wikipedia
Search for extraterrestrial intelligence — The search for extraterrestrial intelligence is sometimes abbreviated as SETI. For other uses, see SETI (disambiguation). Screen shot of the screensaver for SETI@home, a distributed computing project in which volunteers donate idle computer power … Wikipedia
Quantum Zeno effect — The quantum Zeno effect is a name coined by George Sudarshan and Baidyanaith Misra of the University of Texas in 1977 in their analysis of the situation in which an unstable particle, if observed continuously, will never decay.Citation | last =… … Wikipedia
SETI — Search for Extra Terrestrial Intelligence (SETI) is the collective name for a number of activities to detect intelligent extraterrestrial life. The general approach of SETI projects is to survey the sky to detect the existence of transmissions… … Wikipedia
number game — Introduction any of various puzzles and games that involve aspects of mathematics. Mathematical recreations comprise puzzles and games that vary from naive amusements to sophisticated problems, some of which have never been solved.… … Universalium
