Final answer:
Uniformitarianism is a principle in geology that states that the same natural laws and processes that operate today have always operated in the past and will continue to operate in the future.
Step-by-step explanation:
Uniformitarianism is not the study of the interior of the Earth. Instead, it is a principle in geology that states that the same natural laws and processes that operate today have always operated in the past and will continue to operate in the future. This principle is often summarized as 'The present is the key to the past.'Uniformitarianism was proposed by geologists such as Charles Lyell and Charles Hutton in the 18th and 19th centuries. It suggests that geological features, such as mountains, rivers, and valleys, were formed by gradual and consistent processes over long periods of time.In summary, uniformitarianism is a principle in geology that emphasizes the continuity of geological processes throughout Earth's history.