How to carbon dating

Libby had first started using the dating method in 1946 and the early testing required relatively large samples, so testing on scrolls themselves only became feasible when methods used in the dating process were improved upon. Davies made a request to date a number of scrolls, which led to a series of tests carried out in Zurich on samples from fourteen scrolls.

Among these were samples from other sites around the Dead Sea, which contained date indications within the text to supply a control for the carbon dating results.

This represents the ideal date for the amount of 14C measured for the sample.

However, as the quantity of 14 absorbed by all life fluctuates from year to year, the figure must be calibrated based on known fluctuation.

Think of it like a teaspoon of cocoa mixed into a cake dough—after a while, the ‘ratio’ of cocoa to flour particles would be roughly the same no matter which part of the cake you sampled.

The fact that the C doesn’t matter in a living thing—because it is constantly exchanging carbon with its surroundings, the ‘mixture’ will be the same as in the atmosphere and in all living things.

magazine has been continuously published since 1978, we are publishing some of the articles from the archives for historical interest, such as this.

For teaching and sharing purposes, readers are advised to supplement these historic articles with more up-to-date ones suggested in the Related Articles below.

Anything that dies after the 1940s, when Nuclear bombs, nuclear reactors and open-air nuclear tests started changing things, will be harder to date precisely.

The following table shows all the Qumran-related samples that were tested by Zurich (Z), Tucson (T) and Libby (L).

The column headed "14C Age" provides a raw age before 1950 for each sample tested.

A child mummy is found high in the Andes and the archaeologist says the child lived more than 2,000 years ago.

How do scientists know how old an object or human remains are?

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