Question

If the sun were to suddenly "turn off’, we would not know about it for about 8 minutes. Why?

Answer 1

avrage distance between sun and earth( avrage becuasse it changes during whole year )

=149.6 billion meter

and light travels with the speed = 3*10^8

so time taken to reach this light to earth =distance /velocity = 149.6 *10^9 / ( 3*10^8) = 498.66 sec

or 498.66 /60 = 8.3 light min

so it takes alomst 8 min to reach light to earth

all information travels at or below the speed of light. "Information" may be light itself, gravity, or any form of communication. Therefore, no matter what we do, there is no way to know what happened at a distance of 8 light-minutes from us until the information from there gets to us, which would take at least 8 minutes.

i hope this clear your doubt if not  let me know in comment