Geologic Time Reasoning responds to the demands characteristic of disciplinary problems .

1. 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.

2. Meaning is use..

3. How do geoscientists use the concept of time?

4. Geoscientists use time as Place, Length, Number, Clock, & Referee

5. Time as Place

6. Time as Place

7. Place substitutes for time.

8. Lengths represent durations.

11. Comparing durations requires clocks.

12. “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

13. Clock Time as

14. Measuring Time with the “Popcorn” Clock: What to count? Equal intervals of time derived from the randomness of decay (analogous to kernels popping).

15. Time as Referee

16. Sequence and synchrony in time referee arguments.

17. For example, Correlation Charts illustrate: Before and after (sequence) At the same time (synchroneity) For the same time (duration)

23. How do geoscientists represent time?

24. Visual forms in geoscience picture time artfully.

25. Visual depictions of temporal relationships include: Correlation Charts Cross-sectional Diagrams Stratigraphic Columns Block Diagrams Cartoons and Animations Contour Maps Geologic Maps

33. Selected elements of reality, in vivid, coherent form that adhere to Elliot Eisner’s criteria of artistry.

34. What is the value of understanding geologic time?

35. .004% of timeline?

36. Place in Time

37. Place in the Mind

38. The past reaches into the present . . .

39. . . . fostering deep respect for the present moment.