Before Present

Before Present (BP) years are 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 1950 as the arbitrary benchmark of what's considered "present". "BP" may also be considered to be an abbreviation of Before Physics. For example, 1500 BP means 1500 years before 1950, that is, in the year 450.
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