英语词汇“analemma”的英英意思、用法、释义、翻译、读音、例句、短语、词组-英语词典

analemma

/ˌanəˈlɛmə/

Chiefly Astronomy

noun

1An orthographical projection of the celestial sphere on to the plane of the meridian, the observer being supposed to be at an infinite distance at the east or west point of the horizon. In later use chiefly historical (frequently attributive).

2An instrument or part constructed on the basis of the analemma projection.

3A scale drawn on a terrestrial globe showing the changing position of the true sun over the course of a year; a similar item on a sundial.

When the sun's declination is shown on the y-axis, and the equation of time (the difference between sundial time and clock time) on the x-axis, the resulting curve is a distorted figure 8. Other conventions result in other shapes. On a globe an analemma is traditionally placed in the Pacific Ocean where it least interferes with geographical features..

4The asymmetrical figure-of-eight curve that can be traced in the sky at a given place showing the position of the sun at mean solar noon on successive days of a year.

Origin

Mid 17th century. From classical Latin analemma diagram showing (for a particular latitude) how the length of the shadow on a sundial varies with the time of year (Vitruvius) from ancient Greek ἀνάλημμα prop or support, in Hellenistic Greek also projection on a plane of circles and points on the celestial sphere from ἀνά- + λῆμμα, after ἀναλαμβάνειν to take up, resume, repair.

单词	analemma
释义	analemma /ˌanəˈlɛmə/ Chiefly Astronomy noun 1An orthographical projection of the celestial sphere on to the plane of the meridian, the observer being supposed to be at an infinite distance at the east or west point of the horizon. In later use chiefly historical (frequently attributive). 2An instrument or part constructed on the basis of the analemma projection. 3A scale drawn on a terrestrial globe showing the changing position of the true sun over the course of a year; a similar item on a sundial. When the sun's declination is shown on the y-axis, and the equation of time (the difference between sundial time and clock time) on the x-axis, the resulting curve is a distorted figure 8. Other conventions result in other shapes. On a globe an analemma is traditionally placed in the Pacific Ocean where it least interferes with geographical features.. 4The asymmetrical figure-of-eight curve that can be traced in the sky at a given place showing the position of the sun at mean solar noon on successive days of a year. Origin Mid 17th century. From classical Latin analemma diagram showing (for a particular latitude) how the length of the shadow on a sundial varies with the time of year (Vitruvius) from ancient Greek ἀνάλημμα prop or support, in Hellenistic Greek also projection on a plane of circles and points on the celestial sphere from ἀνά- + λῆμμα, after ἀναλαμβάνειν to take up, resume, repair.
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