One of these assumptions is that nuclear decay rates have always been constant.
Although C decays fairly quickly, heavier isotopes (such as uranium-238) decay much more slowly.
We find that about 18 such halvings are required for the p MC value to drop below 0.001 (Figures 1 and 2).
(We could “round up” the value of 0.0007 p MC at 17 half-lives to 0.001 p MC, but the 0.00038 p MC at 18 half-lives is definitely below the detection threshold.) Since each half-life is 5,730 years, this means that no C has even been detected in diamonds, which some scientists claim are billions of years old!
And 4,500 years is less than one radiocarbon half-life, so from Figure 2 we might expect 4,500-year-old samples to have C found within organic samples thought to date from the time of the Flood is generally only about 0.1 to 0.5 p MC.
From Figure 1, a value of 0.098 ≈ 0.1 p MC corresponds to 10 half-lives, or about 57,000 years.
Evolutionists have long used the carbon-14, or radiocarbon, dating technique as a “hammer” to bludgeon Bible-believing Christians.
A straightforward reading of the Bible describes a 6,000-year-old universe, and because some carbon-14 (C) age estimates are multiple tens of thousands of years, many think that the radiocarbon method has soundly refuted the Bible’s historical accuracy.
Nearly anyone can verify this for themselves using basic multiplication and division.And a radiocarbon result that contradicts old-earth dogma is not a good enough reason by itself to invoke contamination!