First experiment to calculate speed of light done by 1629, Isaac Beeckman
The first quantitative estimate of the speed of light was made in 1676 by Ole Christensen Rmer
In the 19th century Hippolyte Fizeau developed a method to determine the speed of light based on time-of-flight measurements on Earth and reported a value of 315,000 km/s. His method was improved upon by Lon Foucault who obtained a value of 298,000 km/s in 1862.James Clerk Maxwell observed that this value was very close to the parameter c appearing in his theory of electromagnetism as the propagation speed of the electromagnetic field, and suggested that light was an electromagnetic wave.http://en.wikipedia.org/wiki/Speed_of_light#cite_note-mactutor-124
A light‑year is the distance light travels in one year, around 9461 billion kilometers, 5879 billion miles
Now my question would be.... how my leaned friend came to know speed of light and it properties, by reading Quran or via vera?
bro the science have found the speed of light by all these workouts but Quran have mentioned it way before but at tht time no one was interested in speed of light now you have found it so it can be proved by quran ALLAH give the signs for the believers. If you still have the doubt so listen to your new era scientists.
bro i can post hundereds of links where people are accepting the Quran's authentication.
THE ONLY THING IS TO LOOK WITH OPEN EYES AND ACCEPT IT WITH OPEN HEART.