Radioactive and radiocarbon dating
Radioactive and radiocarbon dating - steve o dating single current
One is for potentially dating fossils (once-living things) using carbon-14 dating, and the other is for dating rocks and the age of the earth using uranium, potassium and other radioactive atoms.
Radiocarbon dating has had an enormous impact on archaeology around the world since it made it possible to date carbon and wood could be directly without dependence on characteristic artifacts or written historical records.
The explanation was that the physicists had assumed that the amount of C-14 in the atmosphere had been constant, when in fact it had varied over time.
The solution came using dendrochronology (tree ring dating).
Atoms are made up of much smaller particles called protons, neutrons, and electrons.
Protons and neutrons make up the center (nucleus) of the atom, and electrons form shells around the nucleus.
Radiocarbon decays slowly in a living organism, and the amount lost is continually replenished as long as the organism takes in air or food.
Once the organism dies, however, it ceases to absorb carbon-14, so that the amount of the radiocarbon in its tissues steadily decreases.
But as more dates became available, Egyptologists, who had hieroglyphic records back thousands of years, began to recognize that C-14 dates were generally too young.
They proved this by showing that C-14 dates of wooden artifacts with cartouches (dated royal names) did not agree.
Another problem derives from the “reservoir effect” in which old material, limestone or graphite, has contaminated the samples.
This is particularly true of marine samples and contemporary shells may seem to be hundreds of years old.
C is created in the atmosphere by cosmic radiation and is taken up by plants and animals as long as they live.