First discovered in the mid-1960s, no cosmic signal has taught us more about the Universe, or spurred more controversy, than the CMB.
There have been a few momentous discoveries throughout the history of science that have literally revolutionized our understanding of the Universe. The relationship between electricity and magnetism, the deflection of starlight by the gravity of the Sun, the fact that matter and energy are quantized into individual packets and particles, and the fact that the Universe is expanding were all examples of extraordinary discoveries that fundamentally changed how we viewed the Universe. And yet, there’s one discovery that’s arguably even more important than all of those in our quest to understand the nature of reality and the origin and history of our Universe: the CMB, or the cosmic microwave background.
Discovered quite by accident in the mid-1960s, its discovery not only validated the Big Bang while refuting all then-viable competitors, but ongoing, more refined measurements have taught us an enormous suite of cosmic lessons that have continued to push the frontiers of our understanding for 60+ years, and counting. While there are many conundrums that loom large in cosmology today — from the Hubble tension to…
