Technology developed for radio communications during World War II helped enable radio telescopes, which contributed to the discovery of the cosmic microwave background and the subsequent Big Bang explanation.

“illustrating is like look could you have just figured out that there was a big bang by first principles reasoning maybe but what actually happened is we had world war two and we discovered radio um radio communications in order to fight and effectively communicate during the war and then that technology helped us build radio telescopes and then we discovered cosmic microwave background and then we had to come up with an explanation for cosmic and then then we discovered like the big bang as a result of like world”