Definition

1. 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

1. the distance light travels in a vacuum in one minute; approximately 18 million kilometers