Understanding Complex Issues: Lessons from the Life of a Pebble

By Gary Berg-Cross

Recent posts have addressed some complex issues including free will (and fine tuning) as well as the psychology of religion. Often complicated issues are dumbed down to make them more acceptable and digestible to a broad swath of folks. But this is often done disingenuously using fallacious arguments and/or false data to lead people to targeted conclusions and opinions. See for example, Mathew Goldstein’s blog Theists' defense against atheism and human invention fails.

Presidential campaigns, like chit-chat, often tend to avoid difficult issues. Appealing to preconceptions, using simplifying language and binary thinking frames are all part of a dumbing down to fit the narrative styles of contemporary life. Complex social and natural phenomena like climate change just aren’t sexy items and get discussed in bumper sticker phrases. This telegraphic style comes despite that fact that most of us would acknowledge that there nuances and shades of gray on issues. We just don’t routinely take them into account.

It is plausible that complexity emerges from multi-causal factors and the fact that many issues are composite being made up of several parts. Further such parts are often in conflict. National security, for example, is composed of many factors supposedly organized in defense of our concept of freedom.

But national security polices can be in conflict with some established ideas of freedom and liberty. And what about a seemly distant concept like climate change? As some have noted the world-wide costs and consequences of changing climate (increases in global average air/ocean temperatures, widespread melting of snow & ice and rising global average sea level) is one strong factor influencing how the 21st century will unfold. The totality of such effects they will have serious implications for U.S. national security interests, as well as global stability. Defense analysts talk about a range of problems from the mundane of coastal military installations more sustainable to the supporting the stability of “friendly” nations that lack the suite of resources, good governance, & resiliency needed to respond to the many adverse consequences of climate change. The subtleties and depth of understanding needed for such things tens to get thrown aside in political campaigns as they put issues into neatly categorized little boxes often for ideological ideas. Such is the case with things like climate change denial which often seems based on a mis-uderstanding of the underlying science. It's just too hard to unscramble the egg of deep time and understand our current circumstances in earth historical time.

But science is quite different and complex phenomena, such as evolution, get their due. It’s a contrasting pleasure to read an exposition of complex issues by a scientist to a talking point snipptet of a gabby politician like Newt Gingrich. It was therefore a great joy to run across a guided trip through geological complexity in a book The Planet in a Pebble: A Journey into Earth's Deep History by geologist Jan Zalasiewicz. There is an online copy of much of it including pictures!

If you or I pick up a rock at the beach we might see some small beauty and a portion of the composite nature. But Zalasiewicz know how to pick a special rock whose existence is entwined with the history of the whole Earth. He picks a pebble “of gray slate from a Welsh beach - perhaps from somewhere like Aberystwyth, or Clarach, or Borth on the west Wales coast." But Zalasiewicz knows about the inherent complexity in the pebble which he compares to a dense computer chip –“ tightly packed with more information than one could ever surmise from gazing on its smooth surface." It’s the unpack of this information with modern techniques that makes such an interesting story.

It does take Jan a while to elucidate the complexity in 13 chapters, each exploring a different stage in the history of the material from which the pebble is made and ways we have of dating these events and what happened in them. Along the way we learn geologist’s lingo and come to love ‘strata” and such.

He starts all the way back with a cosmological view Big Bang expansion at a time before there were elements for a pebble is be composed of. This is followed by plenty of violence periods including exploding stars to product the elements from which the slate-based pebble emerged. Then there is the formation of the sun and the planets followed by the formation of continents and seas.

Today, almost everything that happened to the pebble and its constituent parts can be inferred from lab measurement. One of the most interesting is zircon, a high-density accessory mineral that often turns up in trace quantities in rocks such as granites and quartzes. Zircon crystals aren’t pretty to a layman or a jeweler, but they were born 4.4 billion years ago - only a hundred million years or so after the Earth was formed, and are our oldest terrestrial material. Besides they are geologically adventuresome and have unique chemical properties that allow geologists to reconstruct their birth in ancient landscapes. Zircons act as eerily accurate atomic clocks with small amounts of radioactive uranium and thorium that they contain decaying constantly to provide a radiometric clock that can tell us when as well as where they first appeared. This gives earth scientists access to what Zalasiewicz calls a virtual “time machine” to Earth’s beginnings” nearly four and half billion years ago. Zalasiewicz’s isotopic tales of ancient continents and explanations of how geologists have learned to unravel such complex geochemical matrices are just as gripping as his detailed accounts of the pebble’s eventful history. For example, Neodymium isotopes tell when the stuff that makes up the pebble was released from the Earth's mantle.

Among the intertwined topics showing the complex processes that lead to a small pebble we follow the formation of ancient continents. Runoff from these provides the sediment that made the pebble’s slate was derived. When this sediment was deposited in ancient oceans it included hydrocarbons formed from buried organic matter. Biology is a surprisingly powerful part of the story. It turns out that Jan’s pebble contains fossils of graptolites, animals that date the rock with fine precision. There is even lichenometry, a method by which the stubbornly slow,steady growth of lichen gives us clues about how long its rock-host has had a surface for its growth. Such events leave traces that can now be dated from isotopic methods. This allows Zalasiewicz to tell not only us a story of various aged components of the pebble but also how we know this. This is not a story on faith, but one of scientific method and the resulting understanding. Unlike religious mysteries these are painstakingly uncovered. And each part encodes and reveals a different part of commensurate fabric. Truly a wonderful experience and a lesson in knowing.

Note, the title is a bit of a take on William Blake rhapsody about the possibility of seeing “ a world in a grain of sand." Where Blake was poetic and a bit mystical in Auguries of Innocence Zalasiewicz is being more like the Newton that Blake feared and seeing the beauty of a rainbow that is not decreased by natural understanding, but is heightened. I wish that more of our thought leaders would take on such a project and educate the public in the honest possibilities After John McPhee’s works it is one of the most accessible works on geology that can be enjoyed by a layman.