Then they look for pieces of dead wood which are older than the specimen which they started with and whose tree-ring patterns match up with and overlap those of the first specimen (tree-rings can vary greatly in width due to environmental factors and thus produce a pattern by which we can match specimens which grew in the same environment).Scientists then look for more pieces of dead wood to match and overlap the second specimen and on and on.
This is called a "long chronology." By dating the oldest piece of wood using the Carbon dating method and comparing the two dates, scientists can make the necessary adjustments to their calculations. Aardsma, "Myths Regarding Radiocarbon Dating," Impact, No.If you know how pure your block of radium originally was, it's relatively simple to calculate how old it is by measuring how much radium is left.This is a very useful tool if you have solid blocks of radium that need dating, but if you don't know how much radium was there in the first place, the job is a lot harder.Furthermore, the presumption that radiocarbon dating is an "exact science" is erroneous and in all fairness few scientists make this claim anyway.The problem is that the many individuals across many disciplines that employ radiocarbon dating as a dating device do not understand its nature or purpose. References: William Frank Libby and his team developed the principles of radiocarbon dating during the 1950s.