The Mayan calendar used 3114 BC as their reference.More recently is the radiocarbon date of 1950 AD or before present, BP.Atoms of the same element that have different numbers of neutrons are called isotopes. Most carbon on Earth exists as the very stable isotope carbon-12, with a very small amount as carbon-13.Here’s an example using the simplest atom, hydrogen. Carbon-14 is an unstable isotope of carbon that will eventually decay at a known rate to become carbon-12.Radiocarbon dating uses isotopes of the element carbon. Cosmic rays – high energy particles from beyond the solar system – bombard Earth’s upper atmosphere continually, in the process creating the unstable carbon-14. Because it’s unstable, carbon-14 will eventually decay back to carbon-12 isotopes.Because the cosmic ray bombardment is fairly constant, there’s a near-constant level of carbon-14 to carbon-12 ratio in Earth’s atmosphere.Scientists tried to determine Earth’s age via our planet’s layers of rock, which must have been built over time.
Today’s scientists believe that answer is incorrect, but Kelvin’s calculations were in being based on logical thinking and mathematical calculation.
Follow the links below to learn more about radiocarbon dating. Radiocarbon dating uses carbon isotopes A special kind of radiocarbon dating: Bomb radiocarbon dating What is an isotope?
To understand radiocarbon dating, you first have to understand the word Although an element’s number of protons cannot change, the number of neutrons can vary slightly from each atom.
Meanwhile, Arthur Holmes (1890-1964) was finishing up a geology degree at the Imperial College of Science in London where he developed the technique of dating rocks using the uranium-lead method.
By applying the technique to his oldest rock, Holmes proposed that the Earth was at least 1.6 billion years old.