# An Etymological Dictionary of Astronomy and AstrophysicsEnglish-French-Persian

## فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

### M. Heydari-Malayeri    -    Paris Observatory

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Number of Results: 5 Search : inequality
 Aristarchus' inequality   ناهموگی ِ اریستارخوس   nâhamugi-ye AristarchusFr.: inégalité d'Aristarque   Put in modern notation, if α and β are acute angles and if β <α, then sin α / sin β <α / β < tan α / tan β. Aristarchus probably used this inequality to show that the Sun is between 18 and 20 times as far from the Earth as the Moon is.Aristarchus of Samos (c.310-c.230 BC); → inequality. Bell's inequality   ناهموگی ِ بل   nâhamugi-ye BellFr.: inégalité de Bell   Any of a large number of inequality relations developed to study the → hidden variable hypothesis suggested in the → EPR paradox. Using Bell's inequalities, the → Aspect experiment showed that no local hidden variable theory can make predictions in agreement with those of quantum mechanics. If, in a measurement, the inequality is violated, the measurement is in agreement with the predictions of the quantum theory. If the equality is satisfied, it suggests that a classical, causal, and local model is adequate to explain the outcome of the measurements. See also → quantum entanglement.John Stewart Bell (1928-1990); → inequality. inequality   ناهموگی، نابرابری   nâhamugi, nâbarâbariFr.: inégalité   1) A statement of the form a ≠ b, a > b, or a < b, asserting one quantity is greater than or less than another quantity. → equality. 2) An irregularity in the movement of a celestial object in its orbit about another which cannot be explained by their mutual gravitational attraction. Irregularities are often due to perturbation by other neighboring objects.→ in-; → equality. parallactic inequality   ناهموگی ِ دیدگشتی   nâhamugi-ye didgaštiFr.: inégalité parallactique   An irregularity in the Moon's motion caused by the Sun's gravitational attraction, which sets the Moon ahead or behind its normal orbital position. The Moon is about 2 arcminutes ahead of its expected position at first quarter, and a similar amount behind at last quarter. triangle inequality   ناهموگی ِ سه‌بری   nâhamugi-ye sebariFr.: inégalité triangulaire   1) A theorem according to which any side of a triangle is always shorter than the sum of the other two sides. 2) The third requirement for a → distance function describing a → metric space.→ triangle; → inequality.