Will the Cosmic Microwave Background Ever Disappear?
The earliest signal we've ever directly detected from the Universe comes to us from shortly after the Big Bang: when the Universe was merely 380,000 years old. Known today as the Cosmic Microwave Background, it's alternatively been called the primeval fireball or the Big Bang's leftover glow. It was an astonishing prediction dating back to George Gamow all the way in the 1940s, and it shocked the astronomical world when it was directly detected back in the 1960s.