Measurements of radiocarbon concentration are usually expressed in terms of a notional age, in numbers of years before 1950. For example, the radiocarbon result 1000±25BP indicates that the notional age is 1000 years with a standard uncertainty of 25 years.

What does Cal ka BP mean?

calibrated years before the present The scientific term cal BP is an abbreviation for calibrated years before the present or calendar years before the present and that is a notation which signifies that the raw radiocarbon date cited has been corrected using current methodologies.

How is radiocarbon measured?

In the early years of radiocarbon dating a products decay was measured, but this required huge samples (e.g. half a human femur). Many labs now use an Accelerator Mass Spectrometer (AMS), a machine that can detect and measure the presence of different isotopes, to count the individual 14C atoms in a sample.

What does BP mean in radiocarbon dating?

Before Present Before Present (BP) years, or years before present is a time scale used mainly in archaeology, geology, and other scientific disciplines to specify when events occurred before the origin of practical radiocarbon dating in the 1950s.

What does BP stand for in baseball?

The period, often before a game, when players warm up or practice their hitting technique. Sometimes refers to a period within a game when one teams hitters have so totally dominated a given pitcher that the game resembles a batting practice session. Referred to colloquially as well as abbreviated as BP.

What does C stand for in history?

Often dates will be preceded with a c. or a ca. These are abbreviations of the Latin word circa which means around, or approximately. We use this before a date to indicate that we do not know exactly when something happened, so c. 400 B.C.E. means approximately 400 years Before the Common Era.