''SPEED OF LIGHT '' IN RIGVEDA

A verse from RIGVEDA (I,50-4):-

''Yojananam Sahashtra Dwe Dwe Shate 

Dwe Cha Yojane Aken Nimishardhena Krammana Namastute''

      

In this verse , the author pays respects to the one (The Sun light) who moves 2202 Yojans in half Nimish. 

1Yojan= 4 Kose

1 Kose =8000 British Yards

1 Yard=0.9144m

The definition of the time unit ''Nimish'' can be found in SHRIMADBHAGWAT (III,11-3 to 10) :-

15 Nimishas =1 Kashta

15 Kashtas = 1 Laghu

30 Laghus = 1 Muhurta

30 Muhurtas = 1 Diva -Ratri(Day -Night)

1 Diva Ratri=24 Hours in modern language

Now when we convert 2202 yojans per half nimish in SI units , it turn out to be 3.0X100000000 meter per second up to two significant digits , a value quite accurate as we know it today.