Difference between revisions of "Light-time"

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m (→‎Common units of light-time: fixed exponent error, was using km not meters.)
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|1 Light-hour
 
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|<math>1.079\times10^{12}\mathsf{m}</math>
 
|<math>6.706\times10^{8}\mathsf{mi}</math>
 
|<math>6.706\times10^{8}\mathsf{mi}</math>
 
|7.214 AU
 
|7.214 AU

Revision as of 12:51, 26 October 2024

Light-time is the product of the speed of light in a vacuum and time it takes light to travel a certain distance in space. It is most commonly used in light-years to calculate interstellar distances.[1]

For example, the Earth can be said to be 8.3 light minutes from the sun, since it takes 8.3 minutes for light to cross that distance.

Common units of light-time

The light-second, light-minute, and light-year (and to a lesser extent light-hour) are the most common light-time units used.

Common units of light-time
Unit Meters Miles Astronomical Units
1 Light-second 0.0020 AU
1 Light-minute 0.12 AU
1 Light-hour 7.214 AU
1 Light-year 63000 AU

For Mars, light time translates into communication times. For example, it could be said that at its closest Mars is about 4 minutes away from Earth, while at maximum separation it is about 20 minutes away.

References

  1. “Light-Time.” n.d. In Marriam-Webster Dictionary.