Figure 1: Regression between the log-transformed water retention time (WRT) and decay rates of organic carbon (OC). Figure 2: Comparison of the relationship for inland waters and marine sediments.

One of the coolest (OK, maybe the coolest) is using radioactive carbon to determine the age of old bones or plants. To understand this, you must first understand radioactivity and decay.

That process is called radioactive decay. And scientists know exactly how long it will take for half of any amount of carbon-14 to decay away. Scientists call that time its "half-life." ...

“Carbon-14 dating has an exponential decay ... this equation that kind of squeezes it to zero has an exponential decay equation that includes e to some negative constant times time.” ...

By reducing such litter decay to a simple mathematical equation, researchers can better understand how carbon and nitrogen cycle through terrestrial systems—and thus improve climate change models.