Minute inaccuracies in radiocarbon dating may cause a massive overhaul of the historical timeline, researchers studying anomalies in this dating method have found.
By questioning certain assumptions underlying radiocarbon dating, a team of researchers at Cornell University have uncovered 20-year offsets in the calibration of radiocarbon dating used in the archaeologically significant region of the southern Levant, which is composed of Israel, Egypt, and Jordan.
These offsets could markedly alter the calendar dates of significant historical events and could have huge implications for the study of archaeology and history.
How Does Radiocarbon Dating Work?
Radiocarbon dating is a widely used method to establish the age of plant and animal fossils as well as other relics composed of organic material. Researchers use radiocarbon dating to establish the archaeological timescales for certain periods in history and pre-history.
In pre-modern timescales, archaeologists use standardized calibration curves for both Northern and Southern hemispheres to determine the dates of organic material. This method rests on the assumption that, at any given period, radiocarbon levels are similar and stable across all places within a hemisphere.
It is this very assumption that Stuart Manning, director of the Cornell Tree-Ring Laboratory, and his team dared to challenge.
Variations In Radiocarbon Levels Cause Offsets
Analyses of modern atmospheric conditions reveal fluctuating radiocarbon levels over the last 50 years. It is also a given that plants in both Northern and Southern hemispheres grow in different places at different times.
What Manning and his team set out to discover is if radiocarbon levels relevant to radiocarbon dating also varied in different areas during a certain period of time. They also wanted to know if any variations could cause massive changes in how historical events have been placed across the timeline.
To answer their question, the researchers took tree ring samples from plant material aged between 1610 and 1940 in southern Jordan and measured their carbon-14 ages. They found that there was a 19-year offset in organic material compared to the standard calibration curve for the Northern hemisphere.
Implications Of A 20-Year Offset
Applying the 20-year offset to previously established timescales, the researchers found that even a small variation can create changes in the historical calendar, enough to cause heavy implications in historical, archaeological, and paleoclimate debates.
Because studies have been using radiocarbon dating, the 20-year offset could create inaccuracies in the research that could have led researchers to different findings.
The southern Levant region is a historically significant area, where scholars accumulate to study the remnants of the Iron Age and the Biblical period. The sophisticated research projects conducted in the area call for very precise findings, which then go on to become established history.
"Our work indicates that it's arguable their fundamental basis is faulty," Manning says. "They are using a calibration curve that is not accurate for this region."
He is calling for a rethinking of archaeological research, particularly studies that are done in the southern Levant region, and the possible revision of archaeological timescales that may very well alter the timeline of history.
Details of the study are published in the Proceedings of the National Academy of Sciences.