Examples carbon dating used
But now archaeologists studying, say, the development of agriculture across the continents are able to determine how different societies stacked up against one another throughout the millennia. Climate records from a Japanese lake are set to improve the accuracy of the dating technique, which could help to shed light on archaeological mysteries such as why Neanderthals became extinct.
Two distinct sediment layers have formed in the lake every summer and winter over tens of thousands of years.For example, it makes it possible to compare the ages of objects on a worldwide scale, allowing for indispensible comparisons across the globe.Before this, it was anyone's guess how different digs' timelines compared to one another over great distances.There's also still usually a wide window of time that an object can fall into.And lastly, the ratio of C-14 to C-12 in the atmosphere (and hence the ratio in organic remains) has fluctuated to a certain extent over the millennia, something that can lead to misleading discrepancies that need to be corrected for.Organisms capture a certain amount of carbon-14 from the atmosphere when they are alive.
By measuring the ratio of the radio isotope to non-radioactive carbon, the amount of carbon-14 decay can be worked out, thereby giving an age for the specimen in question.
Also, the larger the sample the better, although new techniques mean smaller samples can sometimes be tested more effectively.
The data can be a little off particularly in younger artifacts, and anything older than about 50,000 years is pretty much too old to be tested because at that point the majority of the C-14 has decayed to practically undetectable levels.
The excavator might employ relative dating, using objects located stratigraphically (read: buried at the same depth) close to each other, or he or she might compare historical styles to see if there were similarities to a previous find.
But by using these imprecise methods, archeologists were often way off.
But that assumes that the amount of carbon-14 in the atmosphere was constant — any variation would speed up or slow down the clock.