Teaching About Time

Pete Berquist, Geology, Thomas Nelson Community College

I teach Physical and Historical Geology courses at a community college in Virginia. Many, if not most of my students have very little concept of geology and are questionably science-literate. I have always been fascinated about the application of time to solving geologic problems of any age, and in graduate school, I used zircon geochronology to decipher the extent and location of micro-continents during the Grenville Orogeny and the subsequent assembly of the supercontinent Rodinia. I see the element of time implicit in all topics of geology and I believe addressing time can lead to a deeper understand of, and appreciation for virtually all topics within the earth sciences.

I recognize that I have a unique perspective of time, compared to my students, and that my perspective has been molded over years of studying and research. I accept that comprehending and applying principles of geologic time is difficult, and perhaps that's one reason my I find the aspect of time so intriguing. Regardless, I truly believe that my students can learn to grasp the enormity of deep-time and use their understanding as a way to better understand Earth.

Acknowledging that geologic time can be abstract, and that many of my students are skeptical about science, I feel that the best approach is to teach about time from an applied perspective and to use analogies relevant to their every-day world. One simple example I use to stress the validity of radiometric dating is to show that the same principles that allow us to harness nuclear power are the same principles that fundamentally describe parent-to-daughter decay: to eschew radiometric dating, therefore, is to reject that the lights come on when you flick the switch and get a stream of electrons created from the nuclear power plant 30 miles down the road. An example of a more applied assignment stems from a problem that I encountered with my research when I discovered corrupt data within an important part of a spreadsheet calculating hundreds of ages from zircons analyzed on an ion micro-probe. I adapted the data into an assignment where students use Excel to calculate the ages, and then they look at pictures of the individual zircons that were analyzed and plot the age data to draw interpretations about the rock's history. Students have commented on how they enjoy working "real data" and to be able to actually calculate ages and explore the meaning of those ages.

Apart from the more technical example above, I believe that solving some geologic time problems can rely on intuition, observation, and very basic math. I like to incorporate as many examples of these simple applications of time throughout the core topics in my Physical geology course and find that these problems can help increase student's confidence in doing geology and using simple math to describe complex ideas/concepts.

While some of my efforts are successful, I am compelled to search for more techniques and examples. I anticipate that this workshop will be a fruitful experience to learn how to teach about time more successfully and in a more engaged manner. I look forward to working with, and learning from you all!