Light day: Difference between revisions

From Citizendium
Jump to navigation Jump to search
imported>Thorsten Alteholz
mNo edit summary
imported>Meg Taylor
(copyedit)
 
(10 intermediate revisions by 4 users not shown)
Line 1: Line 1:
The '''light day''' is the distance that the [[light]] travels in [[vacuum]] in one [[day]] and so is a unit of distance.
{{subpages}}
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===


Similar units are the [[light second]], [[light minute]], [[light hour]], [[light week]], [[light month]], [[light year]].
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.  
A light minute is 60 [[light second]]s and a light hour is 60 [[light minutes]], or 3600 [[light second]]s.
* [[Velocity]] of [[light]] in a [[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]])
===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.  
* [[velocity]] of [[light]] in [[vacuum]]: 2.99792456 * 10<sup>8</sup> m/s ([[meter]]s/[[second]])
* 1 [[day]] = 24 [[hour]] = 1440 [[minutes]] = 86400 [[seconds]]
* 1 [[day]] = 24 [[hour]] = 1440 [[minutes]] = 86400 [[seconds]]
* 1 light day = 2.5902067 * 10<sup>13</sup>m
* 1 light day = 25,902,068,371,200 m = 2.5902067 * 10<sup>13</sup>m
 
 
===Comparison to other Units===
 
* 1 light day = 2.5902068 * 10<sup>10</sup> [[km]]
* 1 light day = 1.6094799 * 10<sup>10</sup> [[mi]]
* 1 light day = 2.2898053 * 10<sup>14</sup> [[ft]]
* 1 light day = 2.8326844 * 10<sup>13</sup> [[yd]]


===Comparison to other units===


===Distances in Light Days===
* 1 light day = 25,902,068,371.200 [[km]] = 2.5902068 * 10<sup>10</sup> [[km]]
* 1 light day = 16,094,799,105.225 [[mi]]<ref>1 mi = 1609.344 m</ref> = 1.6094799 * 10<sup>10</sup> [[mi]]
* 1 light day = 84,980,539,275,590.551 [[ft]]<ref> 1 ft = 0.3048 m</ref> = 8.4980539<sup>13</sup> [[ft]]
* 1 light day = 28,326,846,425,196.850 [[yd]] <ref> 1 yd = 0.9144 m</ref> = 2.8326846 * 10<sup>13</sup> [[yd]]


===Distances in light days===


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


[[Category:CZ Live|Light day]]
==Notes==
[[Category:Astronomy Workgroup|Light day]]
{{reflist}}

Latest revision as of 20:33, 20 February 2010

This article is developed but not approved.
Main Article
Discussion
Related Articles  [?]
Bibliography  [?]
External Links  [?]
Citable Version  [?]
 
This editable, developed Main Article is subject to a disclaimer.

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 the 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