Even with these weird––and challenging from an old-earth perspective––results, radiocarbon (or, **carbon**-14) **dating** remains one of the best tools for determining the ages of things that lived from 500 to 50,000 years ago. **Carbon**-14 (C) is a naturally occurring radioisotope of **carbon** and is found in trace amounts on Earth.

The method was developed by Willard Libby in the late 1940s and soon became a standard tool for archaeologists.

Libby received the Nobel Prize in Chemistry for his work in 1960.

After 11,460 years (two half-lives), only 256 atoms are left.

After ten half-lives (or 57,300 years), less than one-thousandth of the original amount remains.

Would you trust a *dating* technique that said living mollusks had shells 2,300 years old, or worse, 27,000 years?

What if that same technique yielded dates for Triassic wood (when the dinosaurs lived) at 34,000 years and dated millions-of-years-old coal, oil, and even diamonds at less than 100,000 years? Libby and others in 1949, radiocarbon *dating* revolutionized archaeology––and other scientific fields––by establishing robust dates for organic materials of a biological origin like wood, bone, or shell.

The ratios are consistent among species, and the slight (1-3%) differences can also be calculated from the ratio of C) decreases as the radiocarbon decays. Libby determined, one gram of pure **carbon** should produce about 14 (13.56) radioactive decays per minute.

The Beta-counting method detects the rate at which purified **carbon** decays. A rate of 7 decays/gram/minute would indicate an age of one half-life, or 5730 years old.

The older an organism's remains are, the less beta **radiation** it emits because its C-14 is steadily dwindling at a predictable rate.

So, if we measure the rate of beta decay in an organic sample, we can calculate how old the sample is. Question: Kieth and Anderson radiocarbon-dated the shell of a living freshwater mussel and obtained an age of over two thousand years.

Radiocarbon *dating* can easily establish that humans have been on the earth for over twenty thousand years, at least twice as long as creationists are willing to allow.