Videos radiometric dating
Segment from A Science Odyssey: "Origins."Geologists have calculated the age of Earth at 4.6 billion years.But for humans whose life span rarely reaches more than 100 years, how can we be so sure of that ancient date? Even the Greeks and Romans realized that layers of sediment in rock signified old age.Herschel’s “many thousand million years” and Lyle’s uniformitarianism shaped the cornerstone of Darwin’s theory.In the first paragraph of the Introduction in The Origin of Species, Darwin highlighted the centrality of Lyle’s and Herschel’s influence of on his theory: “to throw some light on the origin of species — that mystery of mysteries, as it has been called by one of our greatest philosophers.” Herschel had used this signature phrase, “that mystery of mysteries,” in a letter to Lyle endorsing his Principles of Geology.Here is an easy-to understand analogy for your students: relative age dating is like saying that your grandfather is older than you.
Radioactive elements break down over time into another element at a known rate, called a "half-life." The "half-life" is the amount of time it takes for half of the radioactive element to change into another element.
DR CHRISTINE PRIOR In conventional radiocarbon dating, you’re measuring the presence of the C-14 when you measure the radioactive decay.
The C-14 decays with the beta particle, and you have some detection equipment and you count the C-14s one by one.
Radiometric dating is a process of measuring radioactive isotope decay rates of unstable atoms that loses energy by emitting radiation.
The chemical element Argon (Ar) formed from the radioactive isotope Potassium-40 (U) are the most common types of elements studied in rocks for the radiometric dating of the rock.AMS is faster and needs a much smaller sample, but is more expensive.