By: Tracy V. When paleontologist Mary Schweitzer found soft tissue in a Tyrannosaurus rex fossil , her discovery raised an obvious question -- how the tissue could have survived so long? The bone was 68 million years old, and conventional wisdom about fossilization is that all soft tissue, from blood to brains , decomposes. Only hard parts, like bones and teeth, can become fossils. But for some people, the discovery raised a different question.
How Carbon-14 Dating Works
How Do Scientists Determine the Age of Dinosaur Bones? | HowStuffWorks
Seventy years ago, American chemist Willard Libby devised an ingenious method for dating organic materials. His technique, known as carbon dating, revolutionized the field of archaeology. Now researchers could accurately calculate the age of any object made of organic materials by observing how much of a certain form of carbon remained, and then calculating backwards to determine when the plant or animal that the material came from had died. An isotope is a form of an element with a certain number of neutrons, which are the subatomic particles found in the nucleus of an atom that have no charge. While the number of protons and electrons in an atom determine what element it is, the number of neutrons can vary widely between different atoms of the same element. Nearly 99 percent of all carbon on Earth is Carbon, meaning each atom has 12 neutrons in its nucleus. The shirt you're wearing, the carbon dioxide you inhale and the animals and plants you eat are all formed mostly of Carbon
Radiocarbon helps date ancient objects—but it's not perfect
By: Marshall Brain. A child mummy is found high in the Andes and the archaeologist says the child lived more than 2, years ago. How do scientists know how old an object or human remains are?
Over time, carbon decays in predictable ways. And with the help of radiocarbon dating, researchers can use that decay as a kind of clock that allows them to peer into the past and determine absolute dates for everything from wood to food, pollen, poop, and even dead animals and humans. While plants are alive, they take in carbon through photosynthesis.