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. And you might use some dating techniques, for example, potassium-argon, say, okay, this is that, a certain amount of age, that is a certain amount of age, these were maybe, this was volcanic rock from a volcanic eruption. And then you can look at the fossils. You could say, okay, a fossil that I found here is going to be newer than the stuff here, and it's gonna be older than the stuff here.