Related Units
Other units of length can similarly be formed by multiplying units of time by the speed of light. For example, the light-second, useful in astronomy, telecommunications and relativistic physics, is exactly 299792458 metres or 1⁄31557600 of a light-year. Units such as the light-minute, light-hour and light-day are sometimes used in popular science publications. The light-month, roughly one-twelfth of a light-year, is also used occasionally for approximate measures. The Hayden Planetarium specifies the light month more precisely as 30 days of light travel time.
Read more about this topic: MLY
Famous quotes containing the words related and/or units:
“Becoming responsible adults is no longer a matter of whether children hang up their pajamas or put dirty towels in the hamper, but whether they care about themselves and othersand whether they see everyday chores as related to how we treat this planet.”
—Eda Le Shan (20th century)
“Even in harmonious families there is this double life: the group life, which is the one we can observe in our neighbours household, and, underneath, anothersecret and passionate and intensewhich is the real life that stamps the faces and gives character to the voices of our friends. Always in his mind each member of these social units is escaping, running away, trying to break the net which circumstances and his own affections have woven about him.”
—Willa Cather (18731947)