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What actually is 1 light year? What is the equivalent time in Earth time space?

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closed as not a real question by dmckee, David Z Feb 23 '11 at 17:46

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en.wikipedia.org/wiki/Light-year –  Marek Feb 23 '11 at 17:26
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This question seems to be founded on a misunderstanding. "Light year" is a measure of distance, not time. See the link Marek gave. –  dmckee Feb 23 '11 at 17:27
    
blog.stackoverflow.com/2011/02/are-some-questions-too-simple applies here (except that they haven't added the "general reference" close reason yet). –  David Z Feb 23 '11 at 17:48
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dmckee, +1 because exactly the sentence you wrote was said by Sheldon Cooper to Penny in The Big Bang Theory. "I wouldn't say it: light year is not a unit of time." He added that "foot-pound is a similar problem as it is not a unit of weight." –  Luboš Motl Feb 23 '11 at 19:07
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1 Answer 1

"One lightyear" is "the distance that light travels in one year if it goes through empty space." Since the speed of light is 299,792,458 meters per second, one lightyear is 9,460,730,472,580.8 kilometers.

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