Light day: Difference between revisions

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As opposed to the [[light year]], whose value more or less depends on the definition of '[[year]]', the value of the light hour is defined exactly.  
As opposed to the [[light year]], whose value more or less depends on the definition of '[[year]]', the value of the light hour is defined exactly.  
* [[velocity]] of [[light]] in [[vacuum]]: 299,792,458 m/s <ref>Review of Particle Physics
* [[Velocity]] of [[light]] in [[vacuum]]: 299,792,458 m/s <ref>Review of Particle Physics
  [http://stacks.iop.org/JPhysG/33/1 Particle Data Group: W.-M. Yao ''et al.'', J. Phys. G 33, 1 (2006).]</ref> ([[meter]]s/[[second]])
  [http://stacks.iop.org/JPhysG/33/1 Particle Data Group: W.-M. Yao ''et al.'', J. Phys. G 33, 1 (2006).]</ref> ([[meter]]s/[[second]])
* 1 [[day]] = 24 [[hour]] = 1440 [[minutes]] = 86400 [[seconds]]
* 1 [[day]] = 24 [[hour]] = 1440 [[minutes]] = 86400 [[seconds]]
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===Distances in light days===
===Distances in light days===


* the maximum distance between [[sun]] and [[Sedna]]<ref>2003 VB12, 90377</ref> is about 133,593 million km or 5.1 light days
* The maximum distance between [[sun]] and [[Sedna]]<ref>2003 VB12, 90377</ref> is about 133,593 million km or 5.1 light days


===Notes===
===Notes===

Revision as of 01:09, 7 December 2008

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A light day is the distance that light travels in a vacuum in one day (thus a unit of distance, not time). Similarly, there are the light second, light minute, light hour, light week, light month and light year.


Numerical value

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


Comparison to other units

  • 1 light day = 25,902,068,371.200 km = 2.5902068 * 1010 km
  • 1 light day = 16,094,799,105.225 mi[2] = 1.6094799 * 1010 mi
  • 1 light day = 84,980,539,275,590.551 ft[3] = 8.498053913 ft
  • 1 light day = 28,326,846,425,196.850 yd [4] = 2.8326846 * 1013 yd


Distances in light days

  • The maximum distance between sun and Sedna[5] is about 133,593 million km or 5.1 light days

Notes

  1. Review of Particle Physics Particle Data Group: W.-M. Yao et al., J. Phys. G 33, 1 (2006).
  2. 1 mi = 1609.344 m
  3. 1 ft = 0.3048 m
  4. 1 yd = 0.9144 m
  5. 2003 VB12, 90377