Since its invention in 1947, carbon dating has revolutionised many fields of science by allowing scientists to estimate the age of an organic material based on how much carbon-14 it contains. However, carbon-14 has a half-life of 5,700 years, so the technique can’t determine the age of objects older than around 50,000 years.
In 1979, scientists suggested using calcium-41, with a half-life of 99,400 years, instead. It’s produced when cosmic rays from space smash into calcium atoms in the soil, and is found in the earth’s crust, opening the door to dating fossilised bones and rock. But several problems need to be overcome before it can be used to reliably date objects.
One important advancement was reported in Nature Physics in March 2023.
