Relativity in ancient India
Long time ago there lived a king who had a glorious daughter. He searched for a suitable groom for the princess and couldn't find one. So using his powers, he reaches Brahmaloka, the highest place in the Universe. When he reaches there a heavenly music was being played at Brahma's court. The king gets immersed in the music for a short time. When the music is stopped, the king consults with Brahma about who among his people will be a suitable groom for the princess. Brahma laughs at him and says, during your short visit here thousands of years (It's actually Yugas) have passed on Earth. Not even the name of your great grandsons are heard on Earth. Go to your place, The lord has taken birth as Krishna and Balarama. Balarama would be an ideal match for your daughter.
Though this story looks small, the definition of relativity of time discussed here is amazing. It's very similar to the twins paradox implied by general theory of relativity. To those who are curious of the science behind the story, the time flow depends upon the Space-Time curvature and space-time curvature is caused by gravity. so greater the curvature (gravity) greater is the space packed into it and greater the speed of time flow.