Radiocarbon helps date ancient objects—but it's not perfect
For nearly 70 years, archaeologists have been measuring carbon-14 levels to date sites and artifacts.
Nothing good can last—and in the case of carbon-14, a radioactive isotope found in Earth’s atmosphere, that’s great news for archaeologists.
Over time, carbon-14 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. Humans and other animals ingest the carbon through plant-based foods or by eating other animals that eat plants. Carbon is made up of three isotopes. The most abundant, carbon-12, remains stable in the atmosphere. On the other hand, carbon-14