WHO CALCULATED THE AGE OF EARTH AS 4.3 BILLION YEARS OLD ?

" The Vedic civilisation subscribed to the idea of a spherical earth at a time when everyone else, even the Greeks, assumed the earth was flat.
By the Fifth Century A.D. INDIANS had calculated that the age of the earth was 4.3 billion years; as late as the 19th Century, English scientists believed the earth was a hundred million years old, and it is only in the late 20th Century that Western scientists have come to estimate the earth to be about 4.6 billion years old "