Difference between revisions of "Light-time"
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'''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.<ref>[https://www.merriam-webster.com/dictionary/light-time “Light-Time.”] n.d. In ''Marriam-Webster Dictionary''.</ref> | '''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.<ref>[https://www.merriam-webster.com/dictionary/light-time “Light-Time.”] n.d. In ''Marriam-Webster Dictionary''.</ref> | ||
| + | |||
| + | 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. Mars is 13.4 light minutes from the sun. | ||
==Common units of light-time== | ==Common units of light-time== | ||
| − | The light-second, light-minute, and light-year are the most common light-time units used. | + | The light-second, light-minute, and light-year (and to a lesser extent light-hour) are the most common light-time units used. |
{| class="wikitable" | {| class="wikitable" | ||
|+Common units of light-time | |+Common units of light-time | ||
| Line 20: | Line 22: | ||
|<math>1.1177\times10^{7}\mathsf{mi}</math> | |<math>1.1177\times10^{7}\mathsf{mi}</math> | ||
|0.12 AU | |0.12 AU | ||
| + | |- | ||
| + | |1 Light-hour | ||
| + | |<math>1.079\times10^{12}\mathsf{m}</math> | ||
| + | |<math>6.706\times10^{8}\mathsf{mi}</math> | ||
| + | |7.214 AU | ||
|- | |- | ||
|1 Light-year | |1 Light-year | ||
| − | |<math> | + | |<math>9.4607\times10^{15}\mathsf{m}</math> |
|<math>5.8786\times10^{12}\mathsf{mi}</math> | |<math>5.8786\times10^{12}\mathsf{mi}</math> | ||
|63000 AU | |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== | ==References== | ||
<references /> | <references /> | ||
Latest revision as of 12:54, 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. Mars is 13.4 light minutes from the sun.
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.
| 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
- ↑ “Light-Time.” n.d. In Marriam-Webster Dictionary.
