How do the different ways we perceive time influence how we think (and learn to think) about deep time? As I mentioned in a post last week, a goal I have in 2021 is to read and learn about how humans perceive time with a specific focus on connecting that to how geoscientists develop ‘timefulness’. I’ll get into how Marcia Bjornerud explains timefulness, and my own reflections about what it means, in a future post. For now, consider timefulness as a mindset that is not just ‘deep time’ thinking, but the ability to connect multiple timescales, spanning the continuum from human experience to geological, to the present and with an eye on the future. In his book Deep Time Reckoning, cultural anthropologist Vincent Ialenti puts it this way:

“Learning to hop more nimbly around these timescales can inspire a more refined multiscale, multiangle, or multiperspective sensibility. This kind of multidimensional thinking must, I suggest, be cultivated during the Anthropocene.”

Yes, to hop around timescales — or, put another way, the ability to temporally zoom in and out. I’m interested in how geoscientists develop this skill and how we can more effectively facilitate others — students, each other, our communities — to learn and apply timefulness to the big challenges we face.

For this post, I wanted to briefly explore the related ideas of clock time and event time. In a social/cultural context, this is typically thought of as cultures and societies that tend towards operating by the clock versus measuring time primarily by social events. Both are, of course, in operation depending on the context. Work-related meetings are very much on clock time in my world — they start and (hopefully) end at specific times. Those running the meeting will even say things like “We only have a couple minutes left and I want to respect everyone’s time, so let’s stop here.” In contrast, a social gathering may have a clock-time beginning (although communicated with some looseness; e.g. “Come by anytime after 6pm”) but in many cases does not have a clock-time end. People leave at different times depending on their circumstances and, at some point, the event (the party) ends because it “feels” over.

“090421 Watch” by steeljam is licensed under CC BY-NC-ND 2.0

We can apply this notion to geology and Earth history and to the thought processes that goes into reconstructing past conditions and events. The geologic timescale itself is a combination of event time and clock time. Boundaries between the named divisions of the timescale are, in most cases, based on the “event” that is the disappearance of notable fossils. While we have incorporated clock time (absolute ages), a task that is seemingly never ending as our geochronological tools improve, it’s important to remember that the geological timescale stands on event time. Marcia Bjornerud has an interesting passage in Timefulness about this idea in the context biologists applying molecular clock approaches to Earth history and how those findings are not always consistent with conclusions from paleontologists:

“The disagreement reveals interesting cultural differences between field-based paleontologists, who, inured to the idiosyncrasies of fossil life, are willing to embrace the idea of nonsteady rates of evolution, versus lab-based molecular biologists, who see mechanism in cellular structure and are more orthodox uniformitarians than their geologic counterparts.”

Event time and clock time is embedded in much of the research I do and am interested in. For example, we’ve been working on the sedimentology and stratigraphic architecture of outcropping Cretaceous deep-marine deposits in southern Chile for almost two decades now. Some of the work is clearly using an event-time framework in that the objectives of the research don’t require clock time to make a contribution and provide insight into, for example, fundamental processes. Indeed, a lot of physical stratigraphy research is perfectly comfortable in a relative timescale that reconstructs the order and character of events but need not assign ages to them.

But then there’s other research that does require clock time. For example, testing hypotheses about how specific tectonic or climatic events (that are well established in clock time) requires knowledge of the absolute ages. We published a paper a couple years ago that was singularly focused on sharing with the community a refined ‘clock time’ for this specific place and time in the geologic past (the phrase ‘chronostratigraphic framework’ is arguably just jargon for ‘clock time’).

And if the science is rooted in understanding the rates of processes then, of course, we need to be thinking in clock time. Numerous disciplines in geoscience have elevated questions related to rates — whether it’s landscape change, biological evolution, climate transitions, tectonic processes, and more — among the most important questions for the community to address.

I’ll close with a final thought: What is an ‘event’? The example of the party mentioned above is fairly clear cut — it has a beginning and an end and would be a discrete ‘thing’ in your memory. But, what about when an event is stretched out over time? As I write this (January 2021) we are still in the midst of a pandemic that, in the U.S., will soon be a year long. Our future memory of this may think of it as an ‘event’, but when exactly did it begin? And the ‘end’ of it will certainly not be a single moment or day on the calendar. However, historians a century from now will likely talk about what feels like forever to us as a discrete event. Events in the geologic past, whether it’s a few thousand years ago or hundreds of millions of years ago, aren’t so different. I’ll explore this idea of events in the context of temporal reasoning more in a future post.