When using radio telescopes to observe the world in 1964, physicist Arno Allan Penzias and radio astronomer Robert Woodrow Wilson observed a strange noise that was always humming away in the background.
No matter which way they directed the telescope toward the sky, the noise seemed to be there, like static on a radio. Initially, the two thought it may be caused by the telescope itself, urban interference, or even pigeons nestled inside the telescope’s antenna. Even after the pigeons were taken out and every other potential source of terrestrial influence was ruled out, the noise persisted.
Other astronomers had heard the noise, but they had written it off as random noise. Teams using various telescopes and pointing them in all directions were able to hear the annoying noise because it was, in fact, the cosmic microwave background (CMB), barely detectable radiation left behind from the Big Bang that permeates the known universe. After realizing what they were seeing and that it supported the Big Bang hypothesis, Penzias and Wilson were awarded the Nobel Prize in Physics for their research.
There are other methods besides radio telescopes to obtain this CMB. You have probably heard about or seen the Big Bang leftovers if you are old enough to have had an analog radio or seen an analog TV. Another horrifying relic from the past was seeing a pattern of “snow” on the screen while switching stations on outdated TVs. As one may expect from the name, the CMB peaks in the microwave wavelength, which accounts for some of the static, but the majority is caused by other types of interference.
The young will not know the simple joy of flicking halfway between stations and witnessing the remnants of the universe’s radiation as you hunt for The Price Is Right since modern digital TVs and radios do not pick up and display the CMB.