light minute
Học thuậtThân thiện
Definition
- Noun:
- A unit of astronomical distance: A "light minute" is defined as the distance that light travels in a perfect vacuum over the duration of one minute. This distance is approximately 18 million kilometers (or about 11.16 million miles).
Usage
- As a measurement of distance: Used primarily in astronomy and astrophysics to express vast distances within the solar system or to nearby celestial objects.
- The average distance from the Sun to Earth is about 8.3 light minutes.
- Scientists measured the flare's origin to be a few light minutes from the star.
Advanced Usage
- Comparative scale: Used to provide a tangible scale for the speed of light and the immense distances in space.
- Communications with Mars rovers have a delay of several light minutes, making real-time control impossible.
Variants and Related Words
- Light second: The distance light travels in one second; approximately 299,792 kilometers.
- Light hour: The distance light travels in one hour.
- Light year: A much more common astronomical unit; the distance light travels in one Julian year (365.25 days).
Synonyms
- Astronomical unit (AU): (Note: This is a different, though related, unit. 1 AU is the average Earth-Sun distance, roughly equal to 8.3 light minutes.)
- Distance
Notes
- This is a compound noun formed from "light" (referring to electromagnetic radiation) and "minute" (a unit of time). It is a fixed scientific term.
- It is not typically used in idiomatic expressions or phrasal verbs, as it is a precise technical measurement.
Noun
- the distance light travels in a vacuum in one minute; approximately 18 million kilometers