And so based on the ratio between the carbon-14 to the carbon-12, and it takes roughly 5,000 years, 5,730 years to be exact, for roughly half of the carbon-14 to decay into carbon-12. So based on this ratio, and I go into much more detail in other videos, you can figure out how old these things are. And you get reasonably precise within a couple of hundreds of years. If you wanna go further into the past, there's things like potassium-argon dating, which is once again taking a radioactive form of potassium and using the idea that it decays into argon, and that when a volcano releases, the argon in that rock is able to go into the atmosphere, but then once it hardens, you have the decay. And so you can see how long since that volcanic eruption are we looking at. And so for example, you can dig, you can do stratigraphic techniques right over here. Stratigraphy, I have trouble saying these words, that's looking at the various layers of the Earth.