Deep Time and And Awe-Inspired Learning
Modern humans have existed on this planet for an incredibly short time compared with other life forms and particularly with the world itself. It took a long time for people to realize just how old the Earth is. The evidence was there but it took time to process, particularly in a world where so many felt compelled to force it through a religious lens.
It also took time for science to discover and use the tools that provided clear evidence of the age of the planet. Fossils appear to have been known about since ancient times. Early in the development of modern approaches to geology it was recognized that certain layers of rock often had typical fossils. These allowed relative dating and comparison with similar rock layers in other locations. It was only following the discovery of radioactivity and radioactive decay that more precise dating methods became available.
Now it became possible to develop the concept of ‘deep time’, a time so vast in comparison with human life spans that many people find it hard to imagine. There have been times in Earth’s history when most of the planet was ice-bound, other times when greenhouse gas levels were twice what they are today. These episodes continued for many times the life spans of humans, often extending over thousands or hundreds of thousands of years. The greenhouse gases humanity is currently pouring into the atmosphere will also bring about changes that exceed many human lifetimes. That, however, is a topic for a different discussion.
My hope in this blog post is that introducing a better understanding of deep time will bring about a new way of looking at humanity’s place in a much larger context. Sharing my sense of awe at the depth and complexity of the many forms of life that have come and gone over vast reaches of time will, I hope, inspire a sense of awe and drive a new curiosity driven form of interest and learning.
It takes hard work and persistence to master any subject. However, you don’t need to be an expert to share in the wonders that an understanding of deep time brings. And, in a rapidly changing planet, it is critical to understand something of the past if we are to be fully functioning members of society.
My educational background lies in the Earth Sciences, including several years teaching at a university before going on to work in environmental regulation. But, while I enjoy having an understanding of the science nothing brings home the reality of deep time more than picking up a 500 million year old piece of rock that holds a well preserved trilobite.
I have been collecting trilobites for some time but my obsession with them goes back much further. Trilobites were one of the types of complex life to show up in rocks of the Cambrian Period that spanned roughly 541 to 485 million years before present (BP). With over 20,000 types known, trilobites were present for at least 250 million years and survived two mass extinctions though the number of species were diminished before they finally became extinct.
Trilobites are indeed fascinating and much has been written about them (see suggested reading below) but the point here is to use them as just one example of how handling real artifacts of the past can stimulate curiosity and a desire for learning, particularly in the young. Real artifacts help make the past more accessible and help us develop a better understanding of deep time.
Why is knowing about deep time so important? Among other reasons it shows that species have come and gone in vast numbers. In the current climate change crisis facing humanity there is much talk about species extinction. It rarely seems to occur to people to consider that humans are one of those species and have no special exemption from possible extinction. There have been five known mass extinctions in the Earth’s past. Humans in their current form have existed for an incredibly short time in geologic terms. Our short life spans make it hard to view the larger picture.
But a happier reason for embracing deep time is that it gives us a much better understanding of our planet, its history, and the great variety of life forms that have existed throughout the millennia. I have chosen to focus on trilobites but there are so many other fascinating fossils that I could have selected. Dinosaurs continue to be popular attractions in museums but perhaps more interesting is the search for the earliest manifestations of life on the planet. Why did life seem to suddenly expand in the fossil record of the Cambrian Period? What was happening in the 4 billion years before that? What more awe-inspiring question could we ask than that? I hope this brief discussion encourages your curiosity to learn more.