Radiocarbon Dating
A radiometric dating method that measures the residual decay activity of Carbon-14 in organic materials to determine their age up to ~50,000 years.
Governing formula
t = -(t_½ / ln 2) ln(A(t) / A₀), t_½ = 5730 years
SI unit
Years Before Present (BP)
In depth
Cosmic rays constantly produce radioactive Carbon-14 (¹⁴C) in the atmosphere. Living organisms absorb ¹⁴C into their tissues in equilibrium with atmospheric ratio. Upon death, ¹⁴C intake stops and decays with a 5,730-year half-life.
Examples in the real world
Determining the biological age of ancient wooden artifacts, mummies, and prehistoric charcoal samples.