Walking along cliffs that were cut by ocean waves or rivers have always made humans wonder how they were formed. The time required to create such majestic towers has created serious debate, both scientific and religious.

Geologic time was very difficult for scientists to "discover." It was not until the mid 18^th century that James Hutton, a Scottish geologist, realized that the Earth was many millions of years old. This was an unimaginable idea because people in his day believed the Earth was only a few thousand years old. Hutton tried to develop scientific methods to determine the time required for every day geologic processes and compare with the past. For example he tried to calculate mud accumulating in the ocean today, to figure out how much time had passed since the formation of the Earth. He used the term "uniformitarism" to compare the present day rock cycle with the past rock cycle. From these comparisons you can interpret how rock layers or strata were formed but not the length of time. You can determine which stratum is younger or older, just by the position of the strata. 

James Hutton wondered about the rocks from the Dorset, United Kingdom coastline

James Hutton