Libby was awarded the Nobel Prize in chemistry for his work in 1960.Carbon dioxide in the atmosphere contains a constant amount of carbon-14, and as long as an organism is living, the amount of carbon-14 inside it is the same as the atmosphere.The older a sample is, the less (the period of time after which half of a given sample will have decayed) is about 5,730 years, the oldest dates that can be reliably measured by this process date to around 50,000 years ago, although special preparation methods occasionally permit accurate analysis of older samples.
But in a dead organism, no new carbon is coming in, and its carbon 14 gradually begins to decay.
However, once the organism dies, the amount of carbon-14 steadily decreases.
By measuring the amount of carbon-14 left in the organism, it's possible to work out how old it is.
Free 5-day trial Ever wondered how scientists know the age of old bones in an ancient site or how old a scrap of linen is?
The technique used is called carbon dating and in this lesson we will learn what this is and how it is used. Carbon dating, or radiocarbon dating, is a method used to date materials that once exchanged carbon dioxide with the atmosphere. In the late 1940s, an American physical chemist named Willard Libby first developed a method to measure radioactivity of carbon-14, a radioactive isotope.