Light second: Difference between revisions

Revision as of 11:53, 17 September 2007

The light second is the distance that the light travels in vacuum in one second and so is a unit of distance.

As opposed to the light year, whose value more or less depends on the definition of year, the value of the light second is defined exactly.

the average distance between earth and moon is about 1.3 light seconds
the average distance between earth and sun is about 499 light seconds or 8.3 light minutes

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 Similar units are the [[light minute]], [[light hour]], [[light day]], [[light week]], [[light month]], [[light year]].
+A [[light minute]] is 60 light seconds and a [[light hour]] is 60 [[light minute]]s, or 3600 light seconds.
+===numerical value===
+As opposed to the [[light year]], whose value more or less depends on the definition of [[year]], the value of the light second is defined exactly.
+* [[velocity]] of [[light]] in [[vacuum]]: 2.99792456 * 10<sup>8</sup> m/s ([[meter]]s/[[second]])
+* 1 light second = 2.99792456 * 10<sup>8</sup>m
+===Comparison to other Units===
+* 1 [[astronomical unit| AU]] = 499 light seconds
+* 1 light second = 299,792.456 [[km]]
+* 1 light second = 186,282.3958 [[mi]]
+* 1 light second = 983,571,049.9 [[ft]]
+* 1 light second = 327,857,016.6 [[yd]]
+===Distances in Light Seconds===
+* the average distance between [[earth]] and [[moon]] is about 1.3 light seconds
+* the average distance between [[earth]] and [[sun]] is about 499 light seconds or 8.3 [[light minutes]]
-==numerical value==
-As opposed to the light year, whose value more or less depends on the definition of [[year]], the values of the light second is defined exactly.
 [[Category:CZ Live|Light second]]
 [[Category:Astronomy Workgroup|Light second]]