| 释义 |
terrestrial dynamical time
Thesaurus| Noun | 1. |  terrestrial dynamical time - (astronomy) a measure of time defined by Earth's orbital motion; terrestrial time is mean solar time corrected for the irregularities of the Earth's motionsephemeris time, TDT, terrestrial time, TTastronomy, uranology - the branch of physics that studies celestial bodies and the universe as a wholetime unit, unit of time - a unit for measuring time periods |
terrestrial dynamical time
terrestrial dynamical time (TDT) See dynamical time.ephemeris timeThe uniform measure of time defined by the laws of dynamics and determined in principle from the orbital motions of the planets, specifically the orbital motion of the earth as represented by Newcomb's Tables of the Sun. An ephemeris day equals 84,600 ephemeris seconds. An ephemeris second was the fundamental unit of time of the International System of Units of 1960; it equals ⅓1556925.9747 of the tropical year defined by the mean motion of the sun in longitude at the epoch 1900 January 0 day 12 h. Also known as terrestrial dynamical time.AcronymsSeeTDTterrestrial dynamical time
Related to terrestrial dynamical time: universal time, ephemeris timeSynonyms for terrestrial dynamical timenoun (astronomy) a measure of time defined by Earth's orbital motionSynonyms- ephemeris time
- TDT
- terrestrial time
- TT
Related Words- astronomy
- uranology
- time unit
- unit of time
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