Carbon dating has a limitation in how many years back it can date something like a bone for example. There are many examples of how people bring in something to be dated, something that is only a few decades or centuries old in many cases, in most cases. The people end up dating these things and will generally say they are thousands or even millions of years old. When dating things, it's important to understand the rate of decay that certain elements may have in the present. Now, in the past, however, things may have been different. We assume that the past was the same as the present. That delves more into historical science as opposed to observational science.
RE: The End Of Reason: A Glimpse Behind The Curve