Dendrochronology (from Greek, dendron, "tree"; khronos, "time"; and, -logia) or tree-ring dating is the method of scientific dating based on the analysis of tree-ring growth patterns. This technique was developed during the first half of the 20th century originally by the astronomer A.E. Douglass, the founder of the Laboratory of Tree-Ring Research at the University of Arizona. Douglass sought to better understand cycles of sunspot activity and...