Every year a new ring is added to a tree's trunk and branches, just beneath the bark. The thickness of this ring depends on how much the tree grows during the year—favorable growing conditions ...

Dendrochronology—the art of tree-ring counting—allows us to precisely date trees. Based on the rings in its trunk, a bristlecone pine in eastern California known as Methuselah is said to be ...

But few people know that the rings in trees can tell us much more than just a tree’s age. And perhaps even fewer know that there is a field of science dedicated to the study of tree rings.