An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

The proposition that the → square of the → hypotenuse of a → right triangle is equal to the → sum of the squares of the other two sides: a² + b² = c².

After Pythagoras (c570 BC-c495BC), Greek philosopher and mathematician; → theorem.

Any group of three → integers that satisfy the relations specified by the → Pythagorean theorem. Some examples: 3, 4, and 5; 5, 12, and 13; 8, 15, 17.

→ Pythagorean theorem; → triple; → triplet.

The Compass Box. A faint constellation in the southern hemisphere, at 9h right ascension, 30° south declination, representing a mariner's compass. Its brightest star, Alpha Pyxidis, is magnitude 3.7. Abbreviation: Pyx; genitive: Pyxidis.

L. pyxis, from Gk. pyxis "box."

Qotbnamâ literally "pole indicator," from qotb, → pole, + namâ "displayer, indicator," from nemudan "to show" (Mid.Pers. nimūdan, nimây- "to show," from O.Pers./Av. ni- "down; into" (Skt. ni "down," nitaram "downward," Gk. neiothen "from below," cf. E. nether, O.E. niþera, neoþera "down, downward, below, beneath," from P.Gmc. *nitheraz, Du. neder, Ger. nieder; PIE *ni- "down, below") + māy- "to measure;" cf. Skt. mati "measures," matra- "measure;" Gk. metron "measure;" L. metrum; PIE base *me- "to measure").