Atomic bombs 80 years ago doesn’t have anything to do with assessing the age of things over 80 years old. I’m not even sure if that is used for anything but steel. Also, way more bombs than just those have been detonated in atmospheric (above ground) nuclear tests.
Carbon dating is based on the idea that cosmic rays interact with nitrogen in the upper atmosphere and produce carbon-14, which is then consumed somehow by organisms. When an organism dies, it stops absorbing new carbon-14, and the isotope decays. Measuring the extent of that decay is how the age is estimated.
Atomic bombs 80 years ago doesn’t have anything to do with assessing the age of things over 80 years old. I’m not even sure if that is used for anything but steel. Also, way more bombs than just those have been detonated in atmospheric (above ground) nuclear tests.
Carbon dating is based on the idea that cosmic rays interact with nitrogen in the upper atmosphere and produce carbon-14, which is then consumed somehow by organisms. When an organism dies, it stops absorbing new carbon-14, and the isotope decays. Measuring the extent of that decay is how the age is estimated.
“Somehow” being plants using it in photosynthesis and then it going up the trophic food chain.