This post is for you both, Neeraj and Pritam. I tried to give the answer of your question – “What is the light year distance of the Sun from Earth?”
As the light year is a big unit which is used to measure long distances (length). It is not feasible to convert it from km to light year. Let’s see how it is difficult.
To understand all this, first you need to understand the concept of light year. Light year is not a unit of time; it is the unit of distance. Usually people misunderstood the term because of the word ‘year’. Light year is the distance traveled by light in a year.
The mean distance from Sun to Earth is 149.6 million km i.e. 1 AU (Astronomic Unit). The distance between Sun and Earth is varies according to the the Earth moves.
1light year = 9460800000000 km = 9.4 trillion km
and Sun to Earth distance is 149.6 million km
So, the distance between Earth and the Sun is very small (in million km) as compare to 1 light year (9.4 trillion km). So it is not feasible to give that distance in light year. (This is same as, you are asking the distance between Jalgaon to Bhusawal in Millimeter).
Rather than giving the distance in light year, I am giving it in light minute.
1 light second = 300 000 km/s = 3X108 m/s (light travel the distance in 1 second)
1 light minute = 18 000 000 km/s = 18 million km/s
As we know, it takes 8.31 min to travel light from Sun to the Earth.
The distance between Sun and Earth is 8.31 light minutes.
18 000 000 X 8.31 = 149580000 = 149.58 million km
Note:- Moon – Earth distance is about 1.282 light Seconds
Note:- Vacuum is the absence of matter, so there is no any such place exist in the universe where vacuum is present. (This is not part of your query but this is important for your project work)