He passed the preliminary and went on to the finals. a boxing match or other athletic contest that takes place before the main event on the program: A preliminary was fought at 8:00. a preliminary examination, as of a candidate for an academic degree.
A light year is a measure of distance, or the distance a particle of light will travel through a pure vacuum in one Earth year. This distance is approximately 5.8785 x 1012 [5.87 trillion] miles, or 9.4605 x 1012 [9.46 trillion] kilometers.n one year, light can travel about 10 trillion km. One light-year is equal to 9,500,000,000,000 kilometers. A light year is the distance covered by light in one year travelling at 186,000 miles per second.
Most objects in space are so far away, that using a relatively small unit of distance, such as an astronomical unit, is not practical. Instead, astronomers measure distances to objects which are outside our solar system in light-years.A light-year (ly) is the distance that light can travel in one year in a vacuum (empty space).he speed of light is about 186,000 miles or 300,000 kilometers per second. So, in one year light travels a distance of about 5,880,000,000,000 miles or 9,460,000,000,000 kilometers or 63,240 A.U.. This distance is 1 light-year.