A light-year, alternatively spelled lightyear, is a unit of length used to express astronomical distances and is equivalent to about 9.46 trillion kilometers or 5.88 trillion miles. As defined by the International Astronomical Union, a light-year is the distance that light travels in vacuum in one Julian year. Because it includes the word "year", the term light-year is sometimes misinterpreted as a unit of time. The light-year is most often used when expressing distances to stars and other distances on a galactic scale, especially in non-specialist contexts and popular science publications. The unit most commonly used in professional astronomy is the parsec which derives from astrometry: it is the distance at which one astronomical unit subtends an angle of one second of arc.
关于Lightyear
Computer-animated feature film serving as a back story to the beloved Toy Story character Buzz Lightyear. The film follows the exploits of the person that the action figure is based off of in the Pixar universe.
Lightyear的成就
The film marks Pixar's twenty sixth animated feature film.
您不知道Lightyear的热门事实
Distance measures (cosmology) - Distance measures are used in physical cosmology to give a natural notion of the distance between two objects or events in the universe. They are often used to tie some observable quantity to another quantity that is not directly observable, but is more convenient for calculations.. Einstein protocol - Einstein synchronisation is a convention for synchronising clocks at different places by means of signal exchanges.. Orders of magnitude (length) - The following are examples of orders of magnitude for different lengths.. Units of measurement in astronomy.. Light.. Units of length.
