What is the principle of uniformitarianism?

The principle of uniformitarianism posits that the processes we observe shaping the Earth and its features today have operated in the same manner throughout geological history. This concept suggests that the same natural laws and processes that govern current geological activity—such as erosion, sedimentation, and volcanic activity—have been consistent over long periods of time. By understanding the ongoing processes, scientists can make inferences about the Earth's past and how its landscape has evolved.

This principle is foundational in geology, allowing scientists to interpret the geological record and understand the Earth's history through the lens of ongoing processes. It contrasts sharply with theories that suggest dramatic, catastrophic events are solely responsible for Earth's geological features, as these would imply that the past was governed by different rules than those we observe today.