We know that the universe is filled with a background radiation that is a relic of the Big Bang. How was it discovered? Who came up with the idea? How do we observe it? How do we know it's really there? Where did it come from? This is the sixth of the videos in my new series of Cosmology. I'm going through Dr. Barbara Ryden's textbook "Introduction to Cosmology". I used this textbook at William Paterson University. This course will cover the current state of the science of Cosmology. Here are the topics of this video: Introductory Cosmology Chapter 02: Fundamental Observations Section 05: Cosmic Microwave Background Some things covered: The Nature of Photons. Blackbody Radiation. An overlooked origin story to the CMB, starring: Ralph Alpher, Robert Hermann, George Gamove, Arno Penzias, Robert Wilson, and Robert Dicke. COBE, WMAP, and Planck CMB Missions. The origin of the CMB from Quark-Anti-Quark soup to the epochs of Recombination and Decoupling. Alpher–Bethe–Gamow paper: Ralph Alpher: Setting the Record Straight: More on Setting the Record Straight: Alpher and Hermann's 1948 work: Remarks on the Evolution of the Expanding Universe: FIRAS Images: Measurement of the Cosmic Microwave Background Spectrum by the COBE FIRAS Instrument: What I saw at the AAS: Cosmology and the Cosmic Background Explorer Results: COBE AAS poster papers: Observing the Big Bang: A Journey of Light Through Space and Time: Textbook:.