Assumptions behind radiometric dating
It is based on the idea that a pre-Flood vapor canopy protected the earth's atmosphere from cosmic radiation and thereby caused a decrease in radiocarbon production. .) Something like a vapor canopy could affect the atmospheric radiocarbon concentration, but this fact is, once again, irrelevant to the validity of modern tree-ring calibrated radiocarbon dates.
Assertion 3 is a special case of Assertion 1, and, like it, is false.
This idea is similar to Assertion 3, but suggests instead that the cosmic radiation was shielded in the past by a stronger magnetic field of the earth.
Unfortunately, a lot of misinformation about radiocarbon dating has been circulated by individuals who have neither training nor hands-on experience in this area.
We feel a responsibility to make sure readers of this site go away with factual, truthful information, and this requires a frank correcting of some prevalent misinformation.
This idea is advanced, for example, in The Young Earth: C ratio was like before the industrial revolution, and all radiocarbon dating is made with this in mind.
How do we know what the ratio was before then, though--say, thousands of years ago?
(Ham et al., page 72.) As with Assertion 1, Assertion 2 fails to account for the tree-ring calibration which is a routine part of modern radiocarbon dating.Although no convincing argument for a change in the speed of light over time has been made, the question is irrelevant to the validity of tree-ring calibrated radiocarbon dates.