light-year

light-year
/luyt"year', -year"/, n.
1. Astron. the distance traversed by light in one mean solar year, about 5.88 trillion mi. (9.46 trillion km): used as a unit in measuring stellar distances. Abbr.: lt-yr
2. light-years,
a. a very great distance, esp. in development or progress: The new computer is light-years ahead of the old one.
b. a very long time: It's been light-years since I've seen my childhood friends.
[1885-90]

* * *

Distance traveled by light moving in a vacuum in one year, at its accepted speed of 186,282 mi/second (299,792 km/second).

It equals about 5.9 trillion mi (9.5 trillion km), 63,240 astronomical units, or 0.307 parsec.

* * *

      in astronomy, the distance traveled by light moving in a vacuum in the course of one year, at its accepted velocity of 299,792,458 metres per second (186,282 miles per second). A light-year equals about 9.46073 × 1012 km (5.87863 × 1012 miles), or 63,241 astronomical units. About 3.262 light-years equal one parsec.

* * *


Universalium. 2010.

Игры ⚽ Нужна курсовая?

Look at other dictionaries:

  • Light year — Light year, Light year Light year (Astron.) 1. The distance over which light can travel in a year s time in a vacuum, 5.88 trillion miles (9.46 trillion kilometers); used as a unit in expressing stellar distances. It is more than 63,000 times as… …   The Collaborative International Dictionary of English

  • Light-year — Light year, Light year Light year (Astron.) 1. The distance over which light can travel in a year s time in a vacuum, 5.88 trillion miles (9.46 trillion kilometers); used as a unit in expressing stellar distances. It is more than 63,000 times as… …   The Collaborative International Dictionary of English

  • light year — also light year, lightyear, distance light travels in one year, 1888, from LIGHT (Cf. light) (n.) + YEAR (Cf. year) …   Etymology dictionary

  • light year — n 1.) the distance that light travels in one year, about 9,460,000,000,000 kilometres, used for measuring distances between stars ▪ a star 3,000 light years from earth 2.) light years ahead/better etc than sth informal much more advanced, much… …   Dictionary of contemporary English

  • light year — light years 1) N COUNT A light year is the distance that light travels in a year. ...a star system millions of light years away. 2) N COUNT: usu pl, N prep/adv (emphasis) You can say that two things are light years apart to emphasize a very great …   English dictionary

  • light-year — [līt′yir΄] n. 1. Astron. a unit of distance equal to the distance that light travels in a vacuum in one year, c. 9,460,000,000,000 km (5,880,000,000,000 mi): abbrev. lt yr or ly: cf. PARSEC 2. a very great distance, amount of time, etc.usually… …   English World dictionary

  • light year — light ,year noun 1. ) count the distance that light travels in a year, used as a unit for measuring distances in space 2. ) light years plural INFORMAL a very long way in time, distance, or quality: Her life in Hollywood was light years away from …   Usage of the words and phrases in modern English

  • light-year — light′ year n. 1) astron. the distance traversed by light in one mean solar year, about 5.88 trillion mi. (9.46 trillion km): used as a unit in measuring stellar distances 2) cvb light years a) a very great distance, esp. in development or… …   From formal English to slang

  • light year — ► NOUN Astronomy ▪ a unit of distance equivalent to the distance that light travels in one year, 9.4607 x 1012 km (nearly 6 million million miles) …   English terms dictionary

  • Light-year — For other uses, see Light year (disambiguation). Image showing the scale of a light year (outer shell) and a light month (inner shell) surrounding the Sun compared to Comet 1910 A1 s orbit (yellow line) and Comet Hyakutake s orbit (orange line).… …   Wikipedia

  • light-year — noun the distance that light travels in a vacuum in 1 year; 5.88 trillion miles or 9.46 trillion kilometers • Syn: ↑light year • Hypernyms: ↑astronomy unit • Part Meronyms: ↑light hour, ↑light minute, ↑light second …   Useful english dictionary

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”