Atmospheric C-14 is in equilibrium
This assumption is wrong. It has been estimated that the C-14 in the earth’s atmosphere would reach equilibrium (the formation rate would be equal to the decay rate) in about 30,000 years. The amount of C-14 in the atmosphere is still increasing. This research indicates a young earth (probably less than 10,000 years).
The same research also modifies all dates obtained by C-14 decay. As the earth’s magnetic field decays, more cosmic radiation penetrates our atmosphere. On a Geiger counter, 16 clicks per minute per gram (16DPM/Gc) is typical in living objects today. Plants and animals that lived on the earth four thousand years ago would have had much less C-14 in their body to start with. The low amount of C-14 would make them appear to be thousands of years older than they really are. Several factors can affect the rate of C-14 formation. The 11-year solar sunspot cycle is one such factor.
Decay rate remains constant
Many times this assumption has been shown to be uncertain. Because the rate of decay may not be constant, dates obtained by C-14 may be accepted, but only with caution.
Initial amounts of C-14 can be known
Many times this assumption has been demonstrated to be wrong. Different parts of the same sample often yield different ratios. Various living samples give very different ratios. Some items will not be tested with carbon dating even though they contain carbon (see number 5 below). Would a mollusk have the same amount of C-14 per gram of carbon as a tree? Probably not. Living penguins have been carbon dated at 8,000 years old! The oldest sample of independently known age is Hemaka, the Egyptian mummy from 2700—œ3100 BC. (Secular writers of antiquity tend to exaggerate ages, so even these dates are suspect.)
The sample being tested has not been contaminated for thousands of years.
This assumption is very difficult (if not impossible) to prove. Parent or daughter products may have leached in or out of the sample. Many lab tests have confirmed that this can happen.
The geologic column can be used as a base to calibrate the C-14 dates
This assumption is not wise. The ages applied to the geologic column (invented in the 1800s to discredit the Bible) do not exist anywhere in the world except in textbooks. Polystrata fossils, missing layers, layers out of order, misplaced fossils, and layers in reverse order all invalidate the geologic column.1