Introductory Astronomy Complete University Course - Source of the Cosmic Microwave Background

During the first 300,000 years of the universe, there was a balance between the interactions of light and matter. As the universe expanded and got older, atoms were able to form, however, they were dissociated by the energetic photons that permeated the cosmos. As the universe expanded, it stretched the wavelengths of these photons until they no longer had the energy to ionize the atoms. That's when the CMB was formed. See all of Jason’s videos in the online class series here: http://www.jasonkendall.com Books to read to learn about the CMB: https://www.goodreads.com/review/list/106246694-jason-kendall?ref=nav_mybooks&shelf=cosmology-and-big-bang Music: Isolated by Kevin MacLeod is licensed under a Creative Commons Attribution 4.0 license. https://creativecommons.org/licenses/by/4.0/ Source: http://incompetech.com/music/royalty-free/index.html?isrc=USUAN1100792 Artist: http://incompetech.com/