Scientists have developed calibration techniques to adjust for these fluctuations.While alive, all plants and animals take C14 into their bodies.We thought that it was unlikely that the pyramid builders consistently used centuries-old wood as fuel in preparing mortar.
In spite of this discrepancy, the radiocarbon dates confirmed that the Great Pyramid belonged to the historical era studied by Egyptologists. Koch Foundation supported us for another round of radiocarbon dating.
We broadened our sampling to include material from: We also took samples from our Giza Plateau Mapping Project Lost City excavations (4th Dynasty), where we discovered two largely intact bakeries in 1991.
We then compared our results with the mid-point dates of the kings to whom the monuments belonged (Cambridge Ancient History, 3rd ed.).
The average radiocarbon dates were 374 years earlier than expected.
We wanted to use science to test the accepted historical dates of several Old Kingdom monuments.
One radioactive, or unstable, carbon isotope is C14, which decays over time and therefore provides scientists with a kind of clock for measuring the age of organic material.
Ancient baking left deposits of ash and charcoal, which are very useful for dating.
The 1995 set of radiocarbon dates tended to be 100 to 200 years older than the dates, which was about 200 years younger than our 1984 dates.
Four of the Senwosret II dates were only off by 30, 24, 14, and three years.
Significantly, the older date was on charcoal (see “old-wood problem” below).
For Khufu’s Great Pyramid, they scatter over a range of about 400 years.