They used pottery and other materials in sites to date 'relatively'.They thought that sites which had the same kinds of pots and tools would be the same age.
The radiocarbon method was developed by a team of scientists led by the late Professor Willard F.Libby of the University of Chicago after the end of World War 2.Libby later received the Nobel Prize in Chemistry in 1960 for the radiocarbon discovery.Welcome to the K12 section of the Radiocarbon WEBinfo site.The aim here is to provide clear, understandable information relating to radiocarbon dating for the benefit of K12 students, as well as lay people who are not requiring detailed information about the method of radiocarbon dating itself.
I have tried here to answer some of the frequently asked questions that I receive from students via email, as well as providing some basic information about scientific dating methods."Everything which has come down to us from heathendom is wrapped in a thick fog; it belongs to a space of time we cannot measure.We know that it is older than Christendom, but whether by a couple of years or a couple of centuries, or even by more than a millenium, we can do no more than guess." [Rasmus Nyerup, (Danish antiquarian), 1802 (in Trigger, 19)].The person who wrote these words lived in the 1800s, many years before archaeologists could accurately date materials from archaeological sites using scientific methods.Rasmus Nyerup's quote reminds us of the tremendous scientific advances which have taken place in the 20th century.In Nyerup's time, archaeologists could date the past only by using recorded histories, which in Europe were based mainly on the Egyptian calendar.