"We can look at the tree rings as a timeline and connect with people that lived in the past, and I think that gives us more of a sense of who we are, but also a sense of where we're going and perhaps ways to deal with some of the issues that we might collectively face.
"Radiocarbon dating has been a revolution in terms of the way stuff is dated in the past and is used by scientists all over the world," Pearson adds.
The first modern humans did not evolve in Africa until about 1.8 million years ago.
The time between then and now is just a single tick on the universe's clock.
In its most conventional form, dendrochronology works like this. They have no bias, and they have no political agenda; they just stand at locations all over the world," says Charlotte Pearson, an assistant professor of dendrochronology at the UA, studies samples under a microscope.
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. Credit: credit: Mari Cleven But what if the wood is older?
In 1929, with a beam from Show Low, Arizona, Douglass was able to bridge the gap for the first time ever.
By 1949, he had published a paper in Science showing that he had accurately dated samples with known ages, using radiocarbon dating.Sometimes a wood sample doesn't have enough tree rings or rings with growth patterns that match an already dated sample.Sometimes important and large groups of matching samples, called "floating chronologies," remain undated.The 18-year space race between the Soviet Union and United States yielded the first moon landing.It took just short of 10 years for the Ancient Greeks to build the Parthenon on the Acropolis of Athens. Charles Darwin spent just five weeks in the Galapagos, a voyage without which he would have never written On the Origin of Species.He noticed that trees across the same region, in the same climate, develop rings in the same patterns.Douglass, with his knack for pattern-recognition, discovered that he could take younger wood with a known date, and then match its rings alongside the pattern of an older sample.Indeed, the "Secret Of The Southwest" was revealed.An Isotope Called Carbon-14 But alas, pattern-matching in order to date when a tree was cut isn't always possible.Douglass passed away just two years after Libby received the Nobel Prize for his work in 1960.Radiocarbon Dating Tree Rings Today Today, dendrochronologists all over the world follow in Douglass' footsteps, and whenever it is not possible to use tree-ring dating to place wood samples in time, they use radiocarbon to date wood samples.