Explore the history and significance of the cosmic microwave background (CMB) in this 35-minute lecture by John Mather from NASA's Goddard Space Flight Center. Delve into the 50-year journey of CMB research, from its initial detection to its role in precision cosmology. Learn about the standard model of cosmology, dark matter, dark energy, and cosmic inflation. Discover breakthrough concepts in instrument development and theory, and gain insights into potential future discoveries in CMB research. Examine the spectrum, anisotropy, and polarization of the CMB, and understand its implications for our understanding of the early universe and fundamental forces. Engage with topics ranging from radio astronomy and the Hubble constant to NASA missions and angular power spectra.