August 15, 2019 | David F. Coppedge

# Dating Method Assumptions Can Be Way Off

Poking holes in long-held assumptions can make you very unpopular.

Are scientists immune from false beliefs? No; scientists are people, too. Often, they don’t have time to investigate everything outside their narrow specialty, and so, like politicians and laymen, they rely on what other experts have told them or taught them. Here’s an uncontroversial example of an assumption that led to vastly incorrect calculations, and how scientists and politicians reacted when told what they had long believed was wrong. The response was to shun the messenger. This can be a warning about trusting assumptions about more controversial subjects, like Darwinism.

How Old Is This Tree?

A man named John White came up with a formula for estimating the age of trees: measure the tree’s circumference, and you can know how old it is (see details in this 2005 PDF). This was a convenient rule of thumb, because you could get a ballpark estimate of the age without cutting the tree. Phys.org now says that other scientists “poke a hole” in this formula:

Some of Britain’s most majestic ancient trees are probably not as ancient as we previously thought, one of the country’s leading tree-ageing experts has suggested.

Until now, the ages of some of Britain’s best-loved trees, including yews, sweet chestnuts and oaks, have largely been estimated from measuring the girth of their trunks—measurements which often result in a tree being declared hundreds or sometimes thousands of years old.

Even White himself realizes that many other variables than girth could distort the results of his formula. Dr. Andy Moir of Brunel University London and colleagues decided to test White’s formula against tree ring data. How wrong could the formula be?

Most recently, Dr. Moir, alongside his colleagues Toby Hindson from the Ancient Yew Group and Peter Thomas from Keele University, published a paper in the Quarterly Journal of Forestry which used tree-ring analysis—taking a core from the tree and measuring the annual rings—to demonstrate that some of Britain’s oldest yew trees are thousands of years younger than previously thought. Old yew trees previously declared as 5000 years old using a derivative of White’s formula, were calculated to be only 950 years old when their rings were measured.

Needless to say, an error of 526% is embarrassing. This was not an isolated incident:

“People have been applying up to 6000 years onto the age of our largest yew trees—we’re saying we don’t believe there is anything still standing over 2000 years old. So potentially we have a 4000-year gap. Of course, two thousand years is still ancient for a tree—these yew trees are ridiculously old. All we’re doing is getting rid of some of the mystique and exaggeration.

One of Moir’s colleagues also sifted through records, and determined that Britain’s famous sweet chestnut trees—which were thought to have been brought by the Romans—were probably a medieval introduction. So did scientists, politicians and tree owners congratulate these scientists for setting the record straight?

Dr. Moir said that some people had now stopped asking him to age their trees, for fear that he’ll give them an age far younger than the one they want to hear.

“We have a lot of huge oak trees on commons and cricket grounds in England, and each generation of locals will basically add a hundred years to the age of the tree,” said Dr. Moir. “So, within a few generations you have a supposedly three or four-hundred-year-old tree. It comes back to myths and legend which can be incredibly strong, but that’s where I become involved to add a bit of science to it.

“I don’t do oak trees on cricket greens any more though, because when I tell people they’re not four or five hundred years old, I’m not very popular.

Moral: Truth seeking is not necessarily the best way to win friends.

The next question to ask is: what are the assumptions that go into tree-ring dating? Before thinking every ring represents one year, you had better be sure there are no exceptions. Could unusual cycles of wetting and drying in a single year produce multiple rings?

If a case this accessible can be this wrong, what about dating methods that cannot be cross-checked? What about formula-based ages based on stalactites, or radioactivity, that yield ages in the hundreds of thousands, millions, or billions of years? People have experienced thousands of years, but not billions. And what about “molecular dating” that assumes rates of evolution? We have found some evolutionists adjusting the rates of evolution to get the date “they want to hear.”

Let this case be a reminder that experts do not know everything, and neither do other experts who falsify the experts.

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