نور-ثانیه
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The light-second is a unit of length useful in astronomy, telecommunications and relativistic physics. It is defined as the distance that light travels in free space in one second, and is equal to exactly (approximately or ).
Key facts
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- Earth and Moon Size and Distance scale - with real-time light speed!.webm
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- The distance between the Earth and the Moon is approximately 1.3 light-seconds
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- length
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- SI units
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- astronomical units
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- imperial/US units
via Wikipedia infobox