Temporal Thinking in the Geosciences
This summary was compiled by Carol Ormand,SERC.
Two key features of geoscientists' temporal thinking distinguish them from the general population: They take a long view of time, and they expect low-frequency, high-impact events. Geoscientists have internalized the vastness of the age of the Earth and the relative brevity of human history. They can envision Earth in states drastically different from the planet they have personally experienced.... In the long view of time, exceedingly slow processes such as erosion or evolution can effect huge changes, such as the removal of a mountain or the establishment of new species. Infrequent but powerful processes, such as floods, volcanic eruptions, landslides, and asteroid impacts, are routine rather than aberrant when considered across the whole of Earth's history.
Developing this kind of temporal thinking is essential for geoscience majors -- but could also change humanity's impact on our planet.
Thinking about time the way geoscientists do is cognitively challenging. It requires thinking about time intervals and rates of change that are well beyond the human experience. To conceptualize these intervals and rates, geoscientists make use of extremely large numbers (with magnitudes ranging into the billions) as well as proportional reasoning, both of which pose cognitive challenges for many students (e.g. Kastens et al., 2009; Cheek, 2011). Moreover, the history of our planet includes time scales and events far beyond the human experience. To understand Earth history, one has to be able to imagine a planet without humans, without animals, without plants, without life of any kind... with vastly different arrangements of landmasses, and with very different climatic conditions. One has to be able to imagine mountain chains forming and eroding, many times, prior to the formation of today's mountain belts around the world. One has to be able to imagine continents forming and breaking apart. Since we don't have any direct experience with such a world and such events, the history of our planet is extremely non-intuitive.
If we could help all students -- not just the geoscience majors -- to understand geologic rates and time, that understanding could have a profound impact on our political choices and policies (Kastens et al., 2009):
Geoscientists' long view of time could provide a crucial counterweight and support decision making with a time horizon of decades to centuries. A society in which a long view of time is pervasive could plan more effectively for infrequent events such as hurricanes or earthquakes and might take more seriously the prospect that tiny but cumulative forcings leveraged over long intervals of time can cause profound changes to the planet.
This shift in thinking, altering humanity's perception of our place and significance in the history of our planet, could be as revolutionary as Copernicus' discovery that the Earth is not the center of the universe (Kastens et al., 2009; Dodick, 2012).
Cheek, K. (2011). Students' Understanding of Large Numbers as a Key Factor in Their Understanding of Geologic Time: International Journal of Science and Mathematics Education, v. 10, n. 5, pp. 1047-1069.
Dodick, J. (2012). Supporting students' cognitive understanding of geological time: A needed "revolution" in science education, in Kastens, K.A. and C.A. Manduca, eds., Earth and Mind II: A Synthesis of Research on Thinking and Learning in the Geosciences: Geological Society of America Special Paper 486, pp. 31-33.
Kastens, K.A., C.A. Manduca, C. Cervato, R. Frodeman, C. Goodwin, L.S. Liben, D.W. Mogk, T.C. Spangler, N.A. Stillings, and S. Titus (2009). How Geoscientists Think and Learn: EOS, Transactions, American Geophysical Union, v. 90, n.31, pp. 265-266.
Manduca, C.A. and K.A. Kastens (2012). Geoscience and geoscientists: Uniquely equipped to study Earth, in Kastens, K.A. and C.A. Manduca, eds., Earth and Mind II: A Synthesis of Research on Thinking and Learning in the Geosciences: Geological Society of America Special Paper 486, pp. 1-12.