Brett Samantha Dooley, Department of Arts, Science, and Business Technology, Patrick Henry Community College
I teach physical and historical geology at a community college in south-central Virginia. The college is in a small city of around 14,000 people in a region formerly known for textile and furniture manufacturing; we currently have over 11% unemployment. A challenge this creates for me is that generally half of my students are non-traditional students on Trade Act or another vocation rehabilitation program and have gone over a decade (maybe two) since they were last exposed to a math or science course. Even the traditional students tend to be very weak in math and lack confidence in their ability to perform well in a science class. The fear of science, combined with the weak math skills, makes this already abstract concept all the more difficult. An additional problem I face is the hesitance of students to believe that the Earth is more than 6,000 years old. While they don't often argue directly with me about this, it is clear that a gap exists between what they have been taught to believe and what they are learning in class, and many are simply not willing to, as Godfrey (2005) would put it, shift paradigms, thus making a concept that, at its core, is difficult to comprehend even more difficult because of a lack of willingness even to attempt to grapple with it.
I have not developed any unique approach to teach this concept, but have relied on the visual and kinesthetic techniques others have used and adapted it for my students. To limit the amount of math my students need to do I have used the online software developed by Morris (2000) at his Athro, Limited website. My students can choose an analogy with which they are most comfortable (a day, a month, their lifetime, a distance) and have the program tell them the decimal equivalence within the model. They do this as a homework assignment and we discuss it in class the next class period. I also bring visual analogies into class with examples I've seen other's use like an arm (Jenn, 2008) or the Washington Monument (Bentley, 2008).
To provide additional support for the concept, I bring my students to the Virginia Museum of Natural History and we begin by doing a 30 m walk off of time. We mark off eon, era, and period boundaries, along with some key events (oxygenation of the atmosphere, first prokaryotes, first eukaryotes, ...). They next go around and answer questions based on the exhibits. As they go around the exhibits they write down what fossils they are seeing and from which Paleozoic period they were found. After answering the questions, the students go back to the time line we made and put down the occurrence of fossils in the museum to tie it back in with the idea of when these different species were around.
This has met with varied success. The students generally enjoy the trip to the museum, but it does not seem to make an impact on their understanding of deep time.
Bentley, C. (9 October 2008) My favorite analogies. NOVA Geoblog. Retrieved January 25, 2012.
Godfrey, S. J. and Smith, C. R. (2005) Paradigms on Pilgrimage: Creationism, Paleontology and Biblical Interpretation.
Jenn, F. (8 November 2008) Geological Time-Arm. EffJot: Geology, stupidity, cooking, and more. Retrieved January 25, 2012 from http://blog.effjot.net/wp-content/uploads/2008/11/geo-arm.jpg
Morris, P. (2000) Comprehending Geologic Time. Athro-Limited. Retrieved January 27, 2012 from http://www.athro.com/geo/hgfr1.html.