Carbon dating for kids
Carbon is an element that is found in every living thing on planet Earth.
A type of carbon called carbon-14 decays after an organism dies, so by measuring how much of it is remaining in a dead organism, scientists can figure out how old the organism is. We have over 95 college courses that prepare you to earn credit by exam that is accepted by over 2,000 colleges and universities.
Unlike people, you can’t really guess the age of a rock from looking at it.
Yet, you’ve heard the news: Earth is 4.6 billion years old. That corn cob found in an ancient Native American fire pit is 1,000 years old. Geologic age dating—assigning an age to materials—is an entire discipline of its own.
It’s based either on fossils which are recognized to represent a particular interval of time, or on radioactive decay of specific isotopes. Based on the Rule of Superposition, certain organisms clearly lived before others, during certain geologic times.
This method works because some unstable (radioactive) isotopes of some elements decay at a known rate into daughter products. Half-life simply means the amount of time it takes for half of a remaining particular isotope to decay to a daughter product. Good discussion from the US Geological Survey: geochronolgists just measure the ratio of the remaining parent atom to the amount of daughter and voila, they know how long the molecule has been hanging out decaying. So to date those, geologists look for layers like volcanic ash that might be sandwiched between the sedimentary layers, and that tend to have radioactive elements.
Pretty obvious that the dike came after the rocks it cuts through, right?
With absolute age dating, you get a real age in actual years.
Carbon dating was such an important discovery that American scientist Willard Libby won the top science award called the Nobel Prize for discovering it.
Do you know what you have in common with a tree and a dog? Carbon is an element that is found in every living thing on planet Earth. One form of carbon inside living things is called carbon-14.