That is, we can use carbon-14 dating on a given tree-ring (the 8000-year sequence having been assembled from the overlapping tree-ring patterns of living and dead trees) and compare the resulting age with the tree-ring date.A study of the deviations from the accurate tree-ring dating sequence shows that the earth's magnetic field has an important effect on carbon-14 production.Sometimes it slows down to a trickle so that much more water is leaking out the barrel than is coming in; sometimes it goes full blast so that a lot more water is coming into the barrel than is leaking out. Lingenfelter's paper was written in 1963, before the cycles of C-14 variation we described had been fully documented.
(The barrel is made deep enough so that we don't have to worry about water overflowing the rim.) Henry Morris argued that if we started filling up our empty barrel it would take 30,000 years to reach the equilibrium point.
Thus, he concluded, if our Earth were older than 30,000 years the incoming water should just equal the water leaking out.
Creationists don't want their readers to be distracted with problems like that -- unless the cat is already out of the bag and something has to be said.
Tree-ring dating (see Topic 27) gives us a wonderful check on the radiocarbon dating method for the last 8000 years.
(kär'bən) Symbol CA naturally abundant, nonmetallic element that occurs in all organic compounds and can be found in all known forms of life.