Physics

Physics (from Ancient Greek: φυσική (ἐπιστήμη), romanized: physikḗ (epistḗmē), lit. 'knowledge of nature', from φύσις phýsis 'nature')[1][2][3] is the natural science that studies matter,[4] its motion and behavior through space and time, and the related entities of energy and force.[5] Physics is one of the most fundamental scientific disciplines, and its main goal is to understand how the universe behaves.[a][6][7][8]

Relativity and the nature of time

https://www.youtube.com/watch?v=NrjFE_Rd2OQ

https://www.youtube.com/watch?v=-6rWqJhDv7M