That is, the equilibrium point should have long since been reached given the present rate of carbon-14 production and the old age of the earth.
Figure 19.5, curve C, shows the dipole field strength calculated from measurements of magnetism of lava flows and of artifacts such as pottery and bricks, whose age can be determined.The curve is roughly fitted to mean values determined about every 500 to 1,000 years...This argument was popularized by Henry Morris (1974, p.164), who used some calculations done in 1968 by Melvin Cook to get the 10,000-year figure. Whitelaw, using a greater ratio of carbon-14 production to decay, concluded that only 5000 years passed since carbon-14 started forming in the atmosphere!The argument may be compared to filling a barrel which has numerous small holes in its sides.We stick the garden hose in and turn it on full blast.
The water coming out of the hose is analogous to the continuous production of carbon-14 atoms in the upper atmosphere.
When the dipole moment is strong, carbon-14 production is suppressed below normal; when it is weak, carbon-14 production is boosted above normal.
What the magnetic field does is to partially shield the earth from cosmic rays which produce carbon-14 high in the atmosphere.
Contrary to creationist Barnes' totally discredited claims, which I've covered in Topic 11, the earth's magnetic field (dipole moment) has, indeed, increased and decreased over time.
Strahler presents a graph of the earth's dipole moment going back 9000 years.
It's a great argument except for one, little thing.