Euctemon (unknown-fl. 432 BC) was an Athenianastronomer. He was a contemporary of Meton and worked closely with this astronomer. Little is known of his work apart from his partnership with Meton and what is mentioned by Ptolemy. With Meton, he made a series of observations of the solstices (the points at which the sun is at greatest distance from the equator) in order to determine the length of the tropical year. Geminus and Ptolemy quote him as a source on the rising and setting of the stars. Centuries: 6th century BC - 5th century BC - 4th century BC Decades: 480s BC 470s BC 460s BC 450s BC 440s BC - 430s BC - 420s BC 410s BC 400s BC 390s BC 380s BC Years: 437 BC 436 BC 435 BC 434 BC 433 BC 432 BC 431 BC 430 BC... Athens (Greek: Αθήνα - AthÃna) is the largest city and capital of Greece, located in the Attica periphery of central Greece. ... An astronomer or astrophysicist is a person whose area of interest is astronomy or astrophysics. ... Meton of Athens was a mathematician, astronomer and engineer who lived in Athens in the 5th century BCE. He is best known for the 19-year Metonic Cycle which he introduced into the Athenian luni-solar calendar as a method of calculating dates. ... A medieval artists rendition of Claudius Ptolemaeus Claudius Ptolemaeus (Greek: ; ca. ... Two images showing the amount of reflected sunlight at southern and northern summer solstices respectively (watts / m²). A solstice occurs twice a year, whenever Earths axis tilts the most toward or away from the Sun, causing the Sun to be farthest north or south at noon. ... Geminus of Rhodes was a Greek astronomer and mathematician. ...
The lunar craterEuctemon is named after him. Wikipedia does not yet have an article with this exact name. ... Euctemon is a lunar crater that is located in the northern part of the Moon, along the northwest rim of the Baillaud crater. ...
The tropical zodiac, as a spatial projection of Euctemon's solar calendar, is thus actually based on the sun's movement in declination, which is intrinsically independent of the sun's motion in longitude through the sidereal zodiac.
Even if Euctemon arrived at his solar calendar (underlying the tropical zodiac) independently of the Babylonian solar calendar, the line of descent as a principle in the history of astronomical ideas is nevertheless apparent, i.e.
This new calendar principle introduced by Euctemon is mirrored in the definition of the tropical zodiac, in which the vernal and autumnal points are placed at 0° Aries and 0° Libra and the summer and winter solstitial points are located at 0° Cancer and 0° Capricorn.
Feeds |
Contact