What the Hell is... Radio Carbon Dating?
Ever wondered how scientists figure out the age of ancient bones or artifacts? Enter the superhero of dating methods: Radio Carbon Dating
Every living thing on Earth is carbon-based: All known life forms are composed of carbon, which is a key element in the biochemical compounds that make up all cells.
When any living thing dies, it stops taking in carbon-14. From that moment on, the carbon-14 starts to decay. This decay happens at a steady rate, known as a half-life, which is about 5,730 years. So, if you want to know how long it’s been since someone or something passed away, just measure how much carbon-14 is left.
By comparing the carbon-14 levels in a sample to what you'd expect in a living organism, scientists can estimate when that organism bit the dust—up to about 50,000 years ago. Any measurement of, say, rock are only based on the lifeforms formed on or in it, with this carbon-14 ehausted. If you try to date something older than that, you might run into problems since the carbon-14 levels get super low.
You might ask--if a diamond is 99.9% carbon, how do we date them? Well, we can't date diamonds using carbon-14 because they weren't "alive" and exchanging this "radioactive isotope"(—if that sounds scary, think of your breath as a flame. Plants absorb the carbon dioxide (CO₂), we humans and animals breath out!) So, diamonds don't contain the right type of carbon for that method. Instead, scientists estimate a diamond's age by studying the rocks around it (and using fascinating methods like uranium-lead dating.) Diamonds typically formed 1 billion to 3 billion years ago deep in the Earth, so we use geological techniques to figure out when they were created.
Radio carbon dating is like a cosmic time machine that helps us unlock the secrets of our past. Science fiction has played with intelligent life and aliens that are possibly silicon-, or otherwise, based on a different blueprint. But in the steps to the easiest evolution of elements in the universe, carbon is the best bet for alien lifeforms to take, at least at the start of their civilization-building.