Ancient Hindus were first to suggest a heliocentric solar system. Speed of light was calculated as 1,85,016 miles/sec. They had even calculated the distance between Earth and Moon as 108 diameters of Moon and Earth and Sun as 108 diameters of Sun. These figures are very close to the modern day values. All these were stated several thousand years before the famous scientist Galileo postulated in the west that sun was the center of the planetary system and Earth was not flat, which was against the prevailing religious doctrines and he died during his house-arrest by clergy. Another astonishing invention was ancient Hindus calculated the age of Earth as 4.3 billion years. The modern estimate is 4.5 billion years. Just remember that the biblical age of the Earth, as per Christians, is just 6,000 years!.
Heliocentric Solar System