(1 of 11 in a series)
The author of this blog is a geophysicist. Geophysicists study the physical properties of the geo, the earth, and make predictions about the composition, structure, and geologic attributes of the earth based on our observations. With the entire earth (and beyond) as our “data set” to study, geophysicists are taught to think big picture. Geophysicists are trained to develop both global and local theories based on sparse and sometimes conflicting data.
We measure. We study. We evaluate. We postulate. We theorize. We do algebra in our heads. And we test our theories against the facts. The theories that hold up become principles and laws of nature. In essence, it is the job of the geophysicist to discover the truth about the earth and its form that we cannot see through careful measurement and observation of what we can see.
Let me give you an example. Have you ever thought that the continents of South America and Africa look like they fit together like pieces of a puzzle? Well, maybe they do. In the 1960’s, geophysicists discovered the “Mid-Atlantic Ridge”; a north-south trending ridge that bisects the Atlantic Ocean and based on magnetic measurements of the sea floor is thought to be a “spreading center” where new earth’s crust is being formed and “pushed out” such that South American and Africa were indeed being “pushed” apart. At the same time, a new world-wide array of seismic monitors revealed that the Pacific Ocean is surrounded by a narrow band of active earthquake epicenters.
Putting these two ideas together, new crust being formed in the Atlantic and a narrow band of earthquakes around the Pacific, the theory of Plate Tectonics was born. That is the idea that the earth is is like a giant, moving jigsaw puzzle with new crust being formed at “spreading centers” and being devoured in “subduction zones” along the margins of the continents where these earthquakes are occurring. The east coast of Japan, home of last spring’s devastating earthquake is one example of these “subduction zones.” Since its initial suggestion in the 1960’s, more spreading centers and subduction zones have been identified and many more geophysical observations have been taken that fit and confirm the Plate Tectonics model.
The story of the Plate Tectonics model fits the pattern of discovering truth about the world we can’t see from measurements of what we can observe. Most geophysicists work on a much smaller scale such as identifying a single fault plane in the earth’s crust that serves as a focal point for a local set of earthquakes or finding subterranean geologic structures where oil and natural gas have accumulated. Whatever the specifics of an individual practicing geophysicist’s job, the overarching task is always the same: discovering truth about what we cannot see through observation of what we can.
Discovering truth through observation is what this next series of posts is about. Can we take our scientific training and experience and our knack for observation and apply them to the broader questions of life? Can we discover the truth that sets us free?