Some possible answers to questions posed - Physical Geology introductory lecture.

Physical geology as a discipline is evolving into earth system science. What does that mean?

We can start with a simple metaphor. If you want to understand how a motor or clock works you take it apart, study the parts and their character, then note the arrangement of the parts, and then put it back together. You change one part and then see how it affects performance and thereby understand the system better. As a graduate student I was amazed to find with my old and rusty VW fastback that there were all sorts of pieces that it didn't seem to need. Other pieces were critical.

Natural science is similar. Focusing on and studying one part is a reductionist approach. Studying one mineral in a rock would be an example. Putting parts together to understand the operations of the larger system is an integrationist approach. Both are necessary in natural science, but often you start with a reductionist approach and move on to integration of the components you understand. With new tools and driving questions geoscience is embarking on more of an integrationist approach. If you want to understand what happens inside the earth's crust it turns out that not only are the rocks important, but the fluids that move through them, and the life that lives in them. Fluid dynamics, biology and geology begin to merge into earth science. Here are some of the large system bits we now are integrating:

On the image in the upper right can you identify each of these components? Image source: http://visibleearth.nasa.gov/view_rec.php?id=1597

Why would one want to learn about the earth?

Specific earth science knowledge is useful.

Such knowledge helps develop useful mental skills:

Aesthetic appreciation of the world around you:


What is involved in the scientific process?

Below is a list of some of the components that people often include.

The next question might be as to how they fit together.


What is the induction method?

The following is from Hempel (a historian of science):

" If we try to imagine how a mind of superhuman power and reach, but normal so far as logical processes of thought are concerned, .... would use the scientific method, the process would be as follows: First all facts would be observed and recorded, without selection or a priori guess as the their relative importance. Secondly, the observed and recorded facts would be analyzed, compared, and classified, without hypothesis or postulates other than those necessarily involved in the logic of thought. Third, from this analysis of the facts generalizations would be inductively drawn as to the relations, classificatory or causal, between them. Fourth, further research would be deductive as well as inductive, employing inferences from previously established generalizations. "

This can be distilled to the four following stages:

Induction: generalizations from specific cases, that can be applied elsewhere.


What is shared by a scientific community? Kuhn's suggestion as to four critical components are given below.

Note that there can be significant overlap, shared exemplars, metaphysics, language and values between different scientific disciplines.



How can we understand complexity?

This is image of the lower part of the Niobrara River in Nebraska. It is a good example of a braided river system. Think of the myriad of factors that contribute to why this river has the pattern and behavior it does. Precipitation patterns, vegetation, the amount and type of sediment, the slope, river ice in the winter, groundwater interaction, and much more. It is a good example of a complex system.


Chaos - what is it?


Basically, one sees a mountain side. Often insights come from asking questions. How did this mountain form and is being shaped at present. What features are exposed in the mountain side, and how did they form. Here are some more specific thoughts that might come to mind when viewing this image with some training in geology:

This is a start. The textures, colors, patterns, and even smells of rocks vary widely, and provide information on the history and the how and why of what can be seen. This course will help you begin to read that record.

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