As geological time-scales go, we are most familiar with the periods (Jurassic, Cambrian etc), which are subdivided into epochs. Many believe we are entering a new epoch – the Anthropocene, which recognises the influence of humans on Earth’s biological, atmospheric and geological systems. There’s much debate over exactly when the Anthropocene started. One possibility is 1945, the date of the first nuclear tests, which will leave a distinctive radioactive signature in the rock strata of the future.
Nuclear testing marks our epoch out from others.