Tuesday, April 2, 2013

Geology’s founding father: James Hutton

It is 225 years since Scottish farmer-scientist, James Hutton, published his seminal paper on the “Theory of the Earth”. Hutton was the first to introduce the idea of “deep time”. He realised that the Earth was enormously old, and that its formation and evolution can be understood in terms of processes occurring today such as volcanism, erosion and sedimentation. He published his paper as a kind of extended abstract, read out at a meeting of the Royal Society of Edinburgh. Hutton’s own words best explain his ideas:

“The purpose of this Dissertation is to form some estimate with regard to the time the globe of this Earth has existed, as a world maintaining plants and animals; to reason with respect to the changes which the Earth has undergone; and to see how far an end of termination to this system of things may be perceived, from the consideration of that which has already come to pass.

As it is not in human record, but in natural history, that we are to look for the means of ascertaining what has already been, it is here proposed to examine the appearances of the Earth, in order to be informed of operations which have been transacted in time past. It is thus that, from principles of natural philosophy, we may arrive at some knowledge of order and system in the oeconomy of this globe, and may form a rational opinion with regard to the course of nature or to events which are in time to happen.”

With this, Hutton put geology onto a scientific footing. He says that predictive models depend on careful observations and understanding current and past processes. This is exactly the scientific method that experimental Earth scientists follow today, treading the path that Hutton pioneered. Hutton began studying rocks in the hope of improving his farming, but in doing so he uncovered ideas far more significant for the wide understanding of our planet. There is a lesson here, too. Immediate societal or business problems may drive much of our scientific activity but they can miss the bigger picture. Occasionally, however, our pursuit of them may inadvertently (and fortuitously) lead to more accurate interpretations of the way the universe works, transforming our view of our environment and ourselves.

Hutton’s ideas were a radical leap from the previous faith-based views of the age and origins of the Earth, to ones based on physical evidence and reason. But he was very careful to define what could not be deduced from his evidence. Towards the end of his abstract he states, “that with respect to human observation, this world has neither a beginning nor an end”. Simply put, he had found no physical evidence for either. This is summed up more poetically in the most famous Hutton sound-bite “no vestige of a beginning, no prospect of an end”.

Hutton’s work defines the scientific method. He tested received wisdom against careful observations, when necessary building a better model based on those observations. He admitted with honesty the limits of his data.

In a future post, I will describe some of the outcrops and rocks that led Hutton to his conclusions, but in the meantime I must return to my own enquiries of the world around us. I wish you well in yours.

Image: James Hutton (1726-1797). Detail from a portrait by Sir Henry Raeburn in the Scottish National Portrait Gallery.




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