Define radiocarbon dating

What is radiocarbon dating? This isotope lets scientists learn the ages of once-living things. Radiocarbon dating is a technique used by scientists to learn the ages of biological specimens — for example, wooden archaeological artifacts or ancient human remains — from the distant past. It can be used on objects as old as about 62, years. What is an isotope?

To understand radiocarbon dating, you first have to understand the word isotope. An isotope is what scientists call two or more forms of the same element. But they still have the same chemical properties. Atoms of the same element that have different numbers of neutrons are called isotopes. Radiocarbon dating uses isotopes of the element carbon.

Radiocarbon dating uses carbon isotopes. Radiocarbon dating relies on the carbon isotopes carbon and carbon Scientists are looking for the ratio of those two isotopes in a sample. Most carbon on Earth exists as the very stable isotope carbon, with a very small amount as carbon Carbon is an unstable isotope of carbon that will eventually decay at a known rate to become carbon Carbon is considered a radioactive isotope of carbon.

They have the same ratio of carbon to carbon as the atmosphere, and this same ratio is then carried up the food chain all the way to apex predators, like sharks. But when gas exchange is stopped, be it in a particular part of the body like in deposits in bones and teeth, or when the entire organism dies, the ratio of carbon to carbon begins to decrease.

The unstable carbon gradually decays to carbon at a steady rate. Scientists measure the ratio of carbon isotopes to be able to estimate how far back in time a biological sample was active or alive. This plot shows the level of carbon in the atmosphere as measured in New Zealand red and Austria green , representing the Southern and Northern Hemispheres, respectively.

Aboveground nuclear testing almost doubled the amount of carbon in the atmosphere. The black arrow shows when the Partial Test Ban Treaty was enacted that banned aboveground nuclear tests. Image via Hokanomono via Wikimedia Commons.

A special kind of radiocarbon dating: As we mentioned above, the carbon to carbon ratio in the atmosphere remains nearly constant. Among the significant events that caused a temporary but significant spike in the atmospheric carbon to carbon ratio were above-ground nuclear test detonations in the two decades following World War II.

Bomb radiocarbon dating is a term for radiocarbon dating based on timestamps left by above-ground nuclear explosions, and it is especially useful for putting an absolute age on organisms that lived through those events. The only major fluctuation [in carbon] we know of occurred when we began detonating nuclear weapons in the open air, back in the midth century.

If you ever wondered why nuclear tests are now performed underground, this is why. Most radiocarbon dating today is done using an accelerator mass spectrometer , an instrument that directly counts the numbers of carbon and carbon in a sample. A detailed description of radiocarbon dating is available at the Wikipedia radiocarbon dating web page. Radiocarbon dating is a technique used by scientists to learn the ages of biological specimens from the distant past.

The EarthSky team has a blast bringing you daily updates on your cosmos and world. We love your photos and welcome your news tips. Earth, Space, Human World, Tonight.


Radiocarbon dating has transformed our understanding of the past 50, years. Professor Willard Libby produced the first radiocarbon dates in and was later awarded the Nobel Prize for his. Radiocarbon definition, a radioactive isotope of carbon with mass number 14 and a half-life of about years: widely used in the dating of organic materials. See more.

Total 2 comments.
#1 06.11.2018 в 23:01 Kamnox:
What should be expected, the author wrote sadly!

#2 14.11.2018 в 16:28 Jinsogood:
In general, successful work