Join my Physics Tutoring Class: https://zphysicslessons.net/physics-tutoring Join my free Physics Newsletter: https://zphysicslessons.net/about My Physics Workbooks: https://zphysicslessons.net/my-workbooks My revision videos on other topics:    • A Level Physics Revision Videos   My full online lessons on Cosmology and Astrophysics:    • Astrophysics and Cosmology   More on Dark Matter and Dark Energy: https://www.youtube.com/watch?v=QAa2O_8wBUQ Chapters: 00:00 Intro 00:10 Units 01:05 Parallax and parsecs 05:37 The Cosmological Principle 06:03 The Doppler Shift 08:36 Hubble's Law 10:48 Converting Hubble's constant 12:26 Age of the universe 14:11 The Big Bang Theory 15:34 Cosmic Microwave Background Radiation 16:17 Dark Energy and Dark Matter