The universe..

"Om eesaavaasyam idagam sarvam. Yat kincha jagatyaam jagat."

Every moving object in the universe, including the moving universe, is indwelt, pervaded, enveloped by it!
-Isavasya upanishad.

This was written at a time when they didnt know about the solar system.. when the earth was at the center of the universe... they didnt know about galaxies, red giants, the big bang, curving spacetime or blackholes..  particles, atoms, photons, quarks were unknown.. It was looong before even calculus was developed. And yet, they were able to imagine the concept of infinity soo beautifully. And come up with concepts that increase in relevance with each passing day as our knowledge "grows".

It's just amazing!