A tree's age can be dated to within one year by "counting" the number of these rings that a tree possesses.
The results of the RATE team supposedly bring into question the accuracy of radiometric dating and attempt to show a young Earth.
Trees continally grow outward during their lifespan by surrounding the central, live section with dead cells, or bark.
However, trees grow faster in summer and slower in winter, causing 'tree rings' of different growth rates to form.
Instead, dendrochronologists determine the qualities of each ring and determine whether other local trees possess the same qualities in the same ring in a process called "skeleton plotting".
If the tree rings between different trees formed in a similar way, then it's likely that those trees have undergone the same variation at the same time.