Carbon 14 dating system
Willard Libby (1908–1980), a professor of chemistry at the University of Chicago, began the research that led him to radiocarbon dating in 1945.He was inspired by physicist Serge Korff (1906–1989) of New York University, who in 1939 discovered that neutrons were produced during the bombardment of the atmosphere by cosmic rays.Over the second half-life, of the atoms remaining decay, which leaves of the original quantity, and so on.In other words, the change in numbers of atoms follows a geometric scale as illustrated by the graph below.other carbon isotopes in the same ratio as exists in the atmosphere. But what's interesting is that a small fraction of carbon-14 forms, and then this carbon-14 can then also combine with oxygen to form carbon dioxide.And carbon-14 is constantly doing this decay thing. So over the course of 5,730 years, roughly half of them will have decayed. Well, if you know that all living things have a certain proportion of carbon-14 in their tissue, as kind of part of what makes them up, and then if you were to find some bone-- let's just say find some bone right here that you dig it up on some type of archaeology dig.Dedicated at the University of Chicago on October 10, 2016.
Libby, a Professor of Chemistry at the University of Chicago, predicted that a radioactive isotope of carbon, known as carbon-14, would be found to occur in nature. And we talk about the word isotope in the chemistry playlist. But this number up here can change depending on the number of neutrons you have. And every now and then-- and let's just be clear-- this isn't like a typical reaction. So instead of seven protons we now have six protons. And a proton that's just flying around, you could call that hydrogen 1. If it doesn't gain an electron, it's just a hydrogen ion, a positive ion, either way, or a hydrogen nucleus. And so this carbon-14, it's constantly being formed. I've just explained a mechanism where some of our body, even though carbon-12 is the most common isotope, some of our body, while we're living, gets made up of this carbon-14 thing. So carbon by definition has six protons, but the typical isotope, the most common isotope of carbon is carbon-12. And then that carbon dioxide gets absorbed into the rest of the atmosphere, into our oceans. When people talk about carbon fixation, they're really talking about using mainly light energy from the sun to take gaseous carbon and turn it into actual kind of organic tissue.Working with several collaboraters, Libby established the natural occurrence of radiocarbon by detecting its radioactivity in methane from the Baltimore sewer.In contrast, methane made from petroleum products had no measurable radioactivity.