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:
“yet when all is said
It was the dream itself enchanted me:
Character isolated by a deed
To engross the present and dominate memory.”
—William Butler Yeats (1865–1939)