So, we rely on radiometric dating to calculate their ages.
Radiometric dating, or radioactive dating as it is sometimes called, is a method used to date rocks and other objects based on the known decay rate of radioactive isotopes.
In order to link the evidence to the accused, the scientists make assumptions, and then they build their interpretations on those assumptions.
You can find many other articles on our website that discuss these issues.
Additional complications come from the burning of fossil fuels such as coal and oil, and from the above-ground nuclear tests done in the 1950s and 1960s.
Geology is the study of the composition and physical properties of rocks, minerals, gems and other related earth materials, including diamonds and crystals.
Scientists gain an understanding of the Earth's history by studying its composition.
Perhaps you have heard of Ice Man, a man living in the Alps who died and was entombed in glacial ice until recently when the ice moved and melted.
The man's body was recovered and pieces of tissue were studied for their C content by accelerator mass spectroscopy.