Before Present (BP) years is a time scale used in archaeology, geology, and other scientific disciplines to specify when events in the past occurred. Because the "present" time changes, standard practice is to use 1 January 1950 as the origin of the age scale, reflecting the fact that radiocarbon dating became practicable in the 1950s. The abbreviation "BP", with the same meaning, has also been interpreted as "Before Physics"; that is, before nuclear weapons testing artificially altered the proportion of the carbon isotopes in the atmosphere.
Read more about Before Present: Usage of "BP", Radiocarbon Dating, Radiocarbon Calibration
Famous quotes containing the word present:
“... it is an uneasy lot at best, to be what we call highly taught and yet not to enjoy: to be present at this great spectacle of life and never to be liberated from a small hungry shivering self—never to be fully possessed by the glory we behold, never to have our consciousness rapturously transformed into the vividness of a thought, the ardour of a passion, the energy of an action, but always to be scholarly and uninspired, ambitious and timid, scrupulous and dim-sighted.”
—George Eliot [Mary Ann (or Marian)