Light day

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

Similar units are the light second, light minute, light hour, light week, light month, 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.

• velocity of light in vacuum: 299,792,458 m/s (meters/second)
• 1 day = 24 hour = 1440 minutes = 86400 seconds
• 1 light day = 25,902,068,371,200 m = 2.5902067 * 10¹³m

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 = 1.6094799 * 10¹⁰ mi
• 1 light day = 84,980,539,275,590.551 ft = 8.4980539¹³ ft
• 1 light day = 28,326,846,425,196.850 yd = 2.8326846 * 10¹³ yd

Distances in Light days

• the maximum distance between sun and Sedna is about 133,593 Mio km or 5.1 light days

External links

• Particle Data Group & WWW edition of Review of Particle Physics
• 2006 Review of Particle Physics in printed layout