Geologic Time • Reasoning responds to the demands characteristic of disciplinary problems. • In the discipline of geology, time’s vastness is a characteristic of many problems. • Understanding the meaning of “time” is central to geologic reasoning. • Ordering events in time is crucial to geologic explanation.
Geoscientists use time as Place, Length, Number, Clock, & Referee
“In order to time something, you have to compare it to something else that always goes at the same speed. But to know it goes at the same speed, you have to time it. It’s kind of confusing.” --John in 4th Grade, 1979
Clock Time as
Measuring Time with the “Popcorn” Clock: What to count? Equal intervals of time derived from the randomness of decay (analogous to kernels popping).
For example, Correlation Charts illustrate: Before and after (sequence) At the same time (synchroneity) For the same time (duration)
Visual forms in geoscience picture time artfully.
Visual depictions of temporal relationships include: Correlation Charts Cross-sectional Diagrams Stratigraphic Columns Block Diagrams Cartoons and Animations Contour Maps Geologic Maps
Selected elements of reality, in vivid, coherent form that adhere to Elliot Eisner’s criteria of artistry.
What is the value of understanding geologic time?
. . . fostering deep respect for the present moment.