From Koinonia House
From their first books on dinosaurs, our children are told that life was evolving "millions of years ago." The majority of geologists today tell us that radioisotope dating has narrowed the age of Earth to about 4.5 billion years, give or take 330 million. Recently, two dating methods have been updated, and scientists say the earth might not be as old as they thought it was, but they may not recognize how "off" the dating methods truly are.
How accurate is radiometric dating? Should we accept the "millions of years" scenario that easily, or are there alternate possibilities that get rejected because they don't fit an evolutionary model of origins?
The Grand Canyon:
The age of the earth is not a purely academic matter. The deepest held values and beliefs of many people are tied into whether the earth has been around billions - or only thousands - of years. The Bible says God created the physical universe in seven days. That doesn't leave a lot of time for life to evolve from primordial amino acids.
Where does the evidence honestly lead? On one hand, Hadrian's Wall has survived the erosional forces of wind and rain and ice for nearly 1900 years. With that in mind, it is obvious the Colorado River would have required a great deal more than 6,000 years to scratch out the Grand Canyon. On the other hand, perhaps the mighty Colorado River did not carve the Grand Canyon at all. Consider, mud flows after the eruption of Mount St. Helens gouged sizeable canyons through solid rock in just a few days…
Radioisotopes:
The measurable breakdown of radioactive isotopes, like the Grand Canyon, appear to give an ancient age for the Earth. Measuring the amount of uranium-238 parent material as well as the lead-206 daughter material in a zircon theoretically allows geochronologists to date the zircon in which these "before" and "after" materials are found. By comparing the derived date to that produced by U-235 and Pb-207 in the same sample, geochronologists believe they can get fairly close results.
The age-dating methods are not perfect, however. There is far less U-235 than U-238 in natural uranium, and by consensus, geochronologists have long used a U-238/U-235 ratio of 137.88 to simply calculate the amount of U-235 in a zircon rather than try to measure it. The original consensus ratio was determined to have some flaws, however, and researchers from the British Geological Survey and the Massachusetts Institute of Technology recently did do some careful measuring. They found the average ratio to be a more accurate 137.818 ± 0.045.
"Firstly, the consensus value of 137.88 couldn't be traced back to international standard units like the kilogram. Secondly, the old consensus ratio had no uncertainty assigned to it, [and] thirdly, the previous measurements were made on materials like uranium ores — and not on naturally occurring minerals that are routinely used for U-Pb dating studies," wrote Joe Hiess, a Marie Curie ITN Experienced Researcher.
This ratio adjustment would take a few hundred thousand years off the widely accepted view of the planet's age. That's not much, but it does raise a question: how many other dating method particulars have been accepted by consensus while including glaring flaws?