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 bit and how see it affects performance and understand the system better. As a graduate student I was amazed to find with my old VW fastback that there were all sorts of pieces that it didn't 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:

• atmosphere.
• hydrospere.
• biosphere.
• cryosphere.
• lithosphere.

You can think on what are major components of each one of these systems.

Why would one want to learn about the earth?

Specific earth science knowledge is useful:

• as a career and in professional practice ( e.g., geologists, environmental scientists, civil engineers, planners, lawyers).
• in personal endeavors (e.g. avoiding hazards, future problems when purchasing property).
• in civil issues and having an informed citizenry (e.g. voting and being involved in all sorts of issues with a geologic component such as waste disposal and water resources). This aspect is addressed more in our Environmental Geology (GEOL 1010) course.
• Indian Ocean tsunami example.

Development of mental skills:

• will provide experience in and tools for understanding complex problems and systems.
• geoscience is multidisciplinary by nature.

Aesthetic appreciation of the world around you:

• most intangible, but most valued by some.
• this course should literally change what you see as you travel thorugh this world and life.

What is involved in the scientific process?

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

• generation of models, ideas, hypotheses, explanations.
• data gathering, observation, measurement.
• data analysis.
• testing, comparison.
• publication and peer review.
• modeling.

What is the induction method?

Hempel (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 previousl established generalizations. "

This can be distilled to the four following stages:

• "observation and recording of all facts,
• analysis and classification of these facts,
• inductive derivation of generalizations from them,
• further testing of the generalizations."

Induction: generalizations from specific cases.

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

• exemplars: an explanation and the data it explains, training modules for the initiates.
• metaphysics: e.g. historical continuity of basic physical laws.
• language: e.g. statistics.
• values: e.g. honesty.

Chaos - what is it?

• complex behavior from simple systems (e.g. a sand pile).
• long term predictability of system position versus general behavior.
• related concepts are strange attractors, self organization, fractals and scale invariance (some of the jargon).