Radiocarbon dating is commonly used to date
Our editors will review what you’ve submitted and determine whether to revise the article.Join Britannica's Publishing Partner Program and our community of experts to gain a global audience for your work!If a Bigtooth Maple were cut down on Mount Lemmon in 2016 and it had 400 rings, you would know the tree started growing in 1616. The rings could still tell how many years the tree lived, but not necessarily when. He set out on a series of expeditions across the southwest to bridge the gap between contemporary wood and wood beams from the ruins of civilizations long gone.He noticed that trees across the same region, in the same climate, develop rings in the same patterns.It’s unusually long and consistent half-life made it great for dating.
A contemporary tree — that is, a tree that was either just cut down or still living — can tell you not just how many years it has lived, but which years in which it lived. What if it’s been used to build a home or a ship or a bonfire?
Carbon-14 is continually formed in nature by the interaction of neutrons with nitrogen-14 in the Earth’s atmosphere; the neutrons required for this reaction are produced by cosmic rays interacting with the atmosphere.
Radiocarbon present in molecules of atmospheric carbon dioxide enters the biological carbon cycle: it is absorbed from the air by green plants and then passed on to animals through the food chain.
“Every year the trees in our forests show the swing of Time’s pendulum and put down a mark.
They are chronographs, recording clocks, by which the succeeding seasons are set down through definite imprints,” he wrote in the pages of National Geographic.
Sometimes important and large groups of matching samples, called “floating chronologies,” remain undated.