As I posted previously, planetary magnetic fields give us strong evidence for a young solar system and a young earth. It’s not just that the young-earth theory reproduces data that were known when the theory was produced, but it also predicted data that were not measured until later. Given that no old-earth theory comes close to doing this, it seems clear that from a planetary magnetic field standpoint, it is more reasonable to believe the earth and solar system are young than it is to believe they are old.
Moving on, I would like to discuss the next set of data that leads me to believe in a young earth: dendrochrology. This is just a fancy word for counting tree rings, and it probably represents the most reliable way to date things for which there is no historical date available. This reasonably accurate dating method once again gives us strong evidence for a very young earth.
Let’s start with the basics. In the spring, a tree does a lot of growing, since conditions are ideal for such activity. As a result, the new wood is not very dense. As spring turns to summer and summer to autumn, growth slows down. As a result, the wood becomes more dense. A typical turn of the seasons, then, produces light, not-so-dense wood followed by dark, dense wood. This produces a visible ring. Thus, in general, each year results in a ring. So if you cut down a tree, by counting the rings, you can determine how old the tree is:
Now it turns out that you don’t actually have to cut down a tree to count its rings. You can drill through its diameter to make a rod of wood called a “core.” This allows you to see all the rings, and it does not kill the tree.
So…how old is the oldest living tree? The oldest living tree (called Methusalah) has roughly 4,840 rings today1. There was actually an older tree (called Prometheus), that had roughly 4,862 rings when it was cut down in 19642. So even if that tree hadn’t been cut down, it would be less than 5,000 years old today.
Now you might think that the oldest living trees are the majestic sequoias, but in fact, these long-lived trees are the not-so-majestic Great Basin bristlecone pines, Pinus longaeva:
They don’t look like much, do they? Nevertheless, they are the oldest living things dated by dendrochronology.
An interesting question now arises: How old can a bristlecone pine get? After all, we know of one living one that is just under 5,000 years old and one dead one that would be slightly older but still under 5,000 years old today. Is that the limit? No, it isn’t. In fact, if the scientist who cut Prometheus down had any inkling that he was cutting down the oldest living tree, he never would have done it. While it was clear Prometheus was old (because it was in a grove previously identified as having old trees and was one of the more well-developed ones), there was no inkling that this was a tree “on its last leg.” I can’t see Methuselah myself, since its location is a closely-guarded secret so as to keep it from Prometheus’s fate. Nevertheless, from all accounts I have read, Methuselah gives no indication of being anywhere near death. Why is it, then, that the oldest living tree is less than 5,000 years old, at least as far as dendrochronology is concerned? In an ancient earth, wouldn’t you expect a few ancient trees?
Now of course, that’s not the end of the story. Since tree rings are formed by patterns of growth in a tree, individual rings can tell us about the weather to which the tree was exposed during the year it was formed. Thick rings, for example, are a sign of abundant rainfall and good growing conditions. Thin rings indicate poor growing conditions like not much rain, a very cool spring and summer, etc. So…a series of thick and thin tree rings denote a series of good and bad growing seasons. Often, there are distinct patterns of several good and bad growing years in a row. These patterns are called master tree ring patterns.
So…let’s say I take a core from a live tree and find one of those master tree ring patterns at a point where dendrochronology tells me the pattern started 3,500 years ago. Then, suppose I find a fossilized tree that has that same pattern. The fossil tree probably died a long time ago, and we don’t know when that was. However, because I know that the pattern of weather (and thus the master tree ring pattern) started 3,500 years ago, I know that the part of the fossil tree with the master tree ring pattern is 3,500 years old. I can then count rings backwards from there to get more years. So…suppose there are 3,000 more rings inside the master tree ring pattern on the fossilized tree. Now I have two trees that, when the master tree ring patterns are overlapped, cover a total of 6,500 years.
In other words, master tree ring patterns allow dendrochronologists to extend their dating further back than can be accomplished with just one tree. As long as you can find enough fossilized trees with enough master tree ring patterns, you can extend a history of tree rings back across many trees.
So…how far back can we extend tree ring histories? Well, probably the most reliable, unbroken tree-ring history goes back just over 11,000 years. 3 If you want to get really creative, you can mesh a couple of chronologies together to get a bit over 13,000 years, but at that point, you are making a lot of assumptions. 4
Now these are upper limits, because it is possible for trees to grow multiple rings in one year5. The tendency to do this is species-dependent, and the weather conditions required are reasonably rare. Nevertheless, it does happen. If gymnosperms have been around for hundreds of millions of years, why do these chronologies extend only to a little over 10,000 years, which is an upper limit?
Given the fact that tree rings indicate the oldest living tree to be about 5,000 years old (roughly when you would expect the worldwide flood to have happened), and given the fact that the oldest tree ring chronologies (which are upper limits) extend only to a bit over 10,000 years, it is hard to believe that these kinds of trees have existed for hundreds of millions of years.
2. Currey, D.R., “An Ancient Bristlecone Pine Stand in Eastern Nevada,” Ecology 46:564–566, 1965
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3. Becker, B. and B. Kromer, “The continental tree-ring record — absolute chronology, 14C calibration and climatic change at 11 ka,” Palaeogeography Palaeoclimatology Palaeoecology 103: 67-71, 1993.
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4. Stuiver, Minze et al., “Radiocarbon age calibration back to 13,300 years BP and the 14C age matching of the German oak and US bristlecone pine chronologies,” Radiocarbon 28: 969-979, 1986
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5. Evgeniĭ Aleksandrovich Vaganov, et. al., Growth dynamics of conifer tree rings, Springer-Verlag, Berlin, p. 232, 2006
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