Light Year:Light Year is a unit of length and Light year is the distance that light travel in vacuum in one year ( 365.25 days ) because in Light Year is the symbol of the light which travel in one year. Measurably Light Year is an ASTRONOMICAL DISTANCE in our solar system.According to the INTERNATIONAL ASTRONOMICAL UNION ” A Light Year is the distance that light travel in vacuum in one Julian year ( 365.25 days ). “1 Light Year Equal To ( One Light Year Equal To ) = 9460730472580800 meters (Exactly) = 9.461 pentameters = 9.461 trillion kilometers = 5.878625 trillion miles = 63241.077 astronomical units = 0.306601 parsecsSymbols And Abbreviation which are used to defines Light Years are given below-“ly” is equal to light year.”kly” is equal to kilolight year.”Mly” is equal to megalight year.”Gly” is equal to gigalight year.Speed and Velocity of LightSpeed of light and velocity in vacuum, air and water is given below in interesting question answer format. Few Important factor about Light Year is given below-Question- How many Human year are equal to the one light year ?Answer- 37,200 Humans year are equal to the one light year.Question- How do you calculate a light year ?Answer- We can calculate a light year with help of distance formula-“Speed= Distance/Time”Where speed of light in vacuum and time should be taken in Second.Question- What is the Velocity of light ?Answer- Velocity of light in vacuum is 2.9979*10^10 centimeter per second. Approximately 3*10^8 meter per second.Question- Is the speed of light constant ?Answer- According to the Einstein’s theory of relativity speed of light in vacuum is constant, 3*10^8 meter per second.Question- Does the speed of light change in air or water or vacuum ?Answer- Yes, Light is air is 1.003 times slower than in vacuum.Refractive Index of light in water is 1.33.Refractive Index of light in air is 1.0003.Refractive index of light in Ethyl Alcohol 1.36.Refractive index of light in Vacuum 1.Index of refractive is represent by “n”.Question- What is the Astronomical units per day of speed of life ?Answer- The Astronomical units per day of speed of life is 173 days.Question- What is the miles per second of speed of light ?Answer- Speed of light miles per second is 186000 second.Question- What is speed of light in miles per hour ?Answer- Speed of light in miles per hour is 671 million (6.71*10^8).Question- What is the value of speed of light in meters per second ?Answer- speed of light in meters per second is 299792458.If You like to more about OUR COSMOS and AGE OF COSMOS than click on it. You will enjoy the interesting facts anobt it.