Being that I am majoring in chemical engineering and computational chemistry, I find the methods used to date materials found in the archaeological sites fascinating. Obviously, before there were any current scientific methods available, the dating was done logically. Given that Flinders Petrie used his sequence dating on pottery, it ended up that he was fairly accurate. However, with the current methods that are used, a much more accurate date can be assigned to specific sites.
I already knew about radiocarbon, 14C, dating and so it was no surprise to me that it was used to date the materials. I did not realize though, that this method is intended only for organic matter. Now with the variety of artifacts that are dug up in a site, it does seems unlikely that there would be nothing organic that was found on site. Unfortunately, that is not always the case and there has to be other methods involved in calculating an accurate date.
I would have assumed that there was organic material in the pottery that existed because of the pot being made of clay and other natural products. However, it is not the case when the material is placed in the ovens to be baked. That is when I ended up reading about the thermoluminescence,TL, dating. Where radiocarbon dating figured a date by the decaying of 14C in an organism, TL dating works by calculating the amount of radiation in a quartz crystal, which is found in the clay pot. If one understands the quantum mechanics behind how an electron and photon interact molecularly, then it is easy to develop a system of dating. Essentially, at the time of making the pot, energy excited an electron which became trapped in the crystal, thus making an electric charge. When current methods heat the crystal again, the electron is lowered from its excited state emitting a photon as a form of energy. This photon is collected and analyzed, then used to calculate the time that the electron was trapped.
It is all very interesting, but there seems to be some debate as to whether the dates are correct in both and thus an error is typically assigned. Obviously we have to rely on our current methods both scientifically and logically to piece everything together. That in turn will yield to us a fuller understanding of the life in ancient Egypt.