radiocarbon

Imagine an archaeologist carefully brushing dirt off an ancient piece of wood found beside a pottery shard. How do they know how old it is? Often, it's thanks to radiocarbon. Radiocarbon is a form of carbon, specifically carbon-14, that is unstable and slowly decays over time. All living things take in radiocarbon from the atmosphere while they are alive. When they die, this process stops, and scientists can measure how much radiocarbon remains to work out the age of the material.

This technique, called radiocarbon dating, is important for understanding history, archaeology, geology, and even climate change. It's like a tiny clock ticking inside things that once lived. You'll often hear about it when people are finding the age of bones, wood, cloth, charcoal, and other organic materials.

Radiocarbon, also known as carbon-14 (¹⁴C), is a radioactive isotope of carbon that forms naturally in the upper atmosphere. Unlike the more common and stable carbon-12 and carbon-13, radiocarbon is unstable and decays at a predictable rate. That steady decay is the key to its usefulness.

All living organisms—plants, animals, even you—constantly take in carbon from their environment, including a small amount of radiocarbon. As long as an organism is alive, it keeps taking in more, so the level stays fairly steady in its tissues. However, when the organism dies, that process stops. From that moment on, the radiocarbon begins to decay, turning back into nitrogen-14.

Scientists can measure the amount of radiocarbon left in organic materials, such as wood, bone, charcoal, or shells, and compare it to the known rate of decay. Its half-life is about 5,730 years. This lets them estimate how long ago the organism died and date the material.

Radiocarbon dating is a key technique in archaeology, geology, and environmental science. It's used to date ancient artifacts made from organic matter, reconstruct past climates, and sometimes help check the authenticity of historical documents. It works best for materials up to around 50,000 years old, though advances in technology keep improving what scientists can do with it.

So, radiocarbon isn't just a scientific term; it's a window into the deep past, helping us understand the story of life on Earth and our place within it.