Radioactive dating carbon dating
A stronger magnetic field deflects more cosmic rays away from the Earth.Overall, the energy of the Earth's magnetic field has been decreasing, so more C is being produced now than in the past.The flood buried a huge amount of carbon, which became coal, oil, etc., lowering the total C ratio in plants/animals/the atmosphere before the flood had to be lower than what it is now.Unless this effect (which is additional to the magnetic field issue just discussed) were corrected for, carbon dating of fossils formed in the flood would give ages much older than the true ages.
Understand how decay and half life work to enable radiometric dating.
Back in the 1940s, the American chemist Willard Libby used this fact to determine the ages of organisms long dead.
Most carbon atoms have six protons and six neutrons in their nuclei and are called carbon 12. But a tiny percentage of carbon is made of carbon 14, or radiocarbon, which has six protons and eight neutrons and is not stable: half of any sample of it decays into other atoms after 5,700 years.
In living organisms, which are always taking in carbon, the levels of carbon 14 likewise stay constant.
But in a dead organism, no new carbon is coming in, and its carbon 14 gradually begins to decay.