> [!summary] Progressive Summary # Structured Notes ## Definitions cosmochemistry - study of the stellar origins of the elements geochronology - the science of dating the earth igneous rocks - rocks made from the cooling of larva metamorphic rocks - rocks transformed by heat or pressure petrology - study of igneous and metamorphic rocks ## Chapter Summaries ### Chapter 1 - A Call for Timefulness We are time illiterate, having no sense of geological time scales. The West places a low value on "process, development, and maturation." Physics and chemistry achieve their precision by purifying themselves of the messiness of time, whereas the heart of geology and biology "lies in the idiosyncratic profusion of organisms, minerals, and landscapes that have emerged over the long history of this particular corner of the cosmos." Geology gives us a lens in which to view Deep Time, just as microscopes and telescopes extend our sense of space. Rather than just a blip appearing before midnight, our extended family goes back as far as 6 am. As earthlings, we've been around for a long time. --- Supporting quotes from the book: > As a species, we have a childlike disinterest and partial disbelief in the time before our appearance on Earth. With no appetite for stories lacking human protagonists, many people simply can’t be bothered with natural history. We are thus both intemperate and intemporate—time illiterate. Like inexperienced but overconfident drivers, we accelerate into landscapes and ecosystems with no sense of their long-established traffic patterns, and then react with surprise and indignation when we face the penalties for ignoring natural laws. This ignorance of planetary history undermines any claims we may make to modernity. We are navigating recklessly toward our future using conceptions of time as primitive as a world map from the fourteenth century, when dragons lurked around the edges of a flat earth. > As exasperating as professional Young-Earthers, creationists, and apocalypticists can be, they are completely forthright about their chronophobia. More pervasive and corrosive are the nearly invisible forms of time denial that are built into the very infrastructure of our society. For example, in the logic of economics, in which labor productivity must always increase to justify higher wages, professions centered on tasks that simply take time—education, nursing, or art performance—constitute a problem because they cannot be made significantly more efficient. Playing a Haydn string quartet takes just as long in the twenty-first century as it did in the eighteenth; no progress has been made! This is sometimes called “Baumol’s disease” for one of the economists that first described the dilemma. That it is considered a pathology reveals much about our attitude toward time and the low value we in the West place on process, development, and maturation. > Academe, too, must take some responsibility for promulgating a subtle strain of time denial in the way that it privileges certain types of inquiry. Physics and chemistry occupy the top echelons in the hierarchy of intellectual pursuits owing to their quantitative exactitude. But such precision in characterizing how nature works is possible only under highly controlled, wholly unnatural conditions, divorced from any particular history or moment. Their designation as the “pure” sciences is revealing; they are pure in being essentially atemporal—unsullied by time, concerned only with universal truths and eternal laws. Like Plato’s “forms,” these immortal laws are often considered more real than any specific manifestation of them (e.g., the Earth). In contrast, the fields of biology and geology occupy lower rungs of the scholarly ladder because they are very “impure,” lacking the heady overtones of certainty because they are steeped through and through with time. The laws of physics and chemistry obviously apply to life-forms and rocks, and it is also possible to abstract some general principles about how biological and geologic systems function, but the heart of these fields lies in the idiosyncratic profusion of organisms, minerals, and landscapes that have emerged over the long history of this particular corner of the cosmos. > > Biology as a discipline is elevated by its molecular wing, with its white-coat laboratory focus and its venerable contributions to medicine. But lowly geology has never achieved the glossy prestige of the other sciences. It has no Nobel Prize, no high school Advanced Placement courses, and a public persona that is musty and dull. This of course rankles geologists, but it also has serious consequences for society at a time when politicians, CEOs, and ordinary citizens urgently need to have some grasp of the planet’s history, anatomy, and physiology. > Fathoming deep time is arguably geology’s single greatest contribution to humanity. Just as the microscope and telescope extended our vision into spatial realms once too minuscule or too immense for us to see, geology provides a lens through which we can witness time in a way that transcends the limits of our human experiences. > Since the birth of the discipline in the early 1800s, geologists—congenitally wary of Young-Earthers—have droned on about the unimaginable slowness of geologic processes, and the idea that geologic changes accrue only over immense periods of time. Moreover, geologic textbooks invariably point out (almost gleefully) that if the 4.5 billion-year story of the Earth is scaled to a 24-hour day, all of human history would transpire in the last fraction of a second before midnight. But this is a wrongheaded, and even irresponsible, way to understand our place in Time. For one thing, it suggests a degree of insignificance and disempowerment that not only is psychologically alienating but also allows us to ignore the magnitude of our effects on the planet in that quarter second. And it denies our deep roots and permanent entanglement with Earth’s history; our specific clan may not have shown up until just before the clock struck 12:00, but our extended family of living organisms has been around since at least 6 a.m. Finally, the analogy implies, apocalyptically, that there is no future—what happens after midnight? > Understanding the reasons for the morphology of a particular landscape is similar to the rush of insight one has upon learning the etymology of an ordinary word. A window is opened, illuminating a distant yet recognizable past—almost like remembering something long forgotten. This enchants the world with layers of meaning and changes the way we perceive our place in it. > I’ve written this book in the belief (possibly naïve) that if more people understood our shared history and destiny as Earth-dwellers, we might treat each other, and the planet, better. At a time when the world appears more deeply divided than ever by religious dogmas and political animosities, there would seem to be little hope of finding a common philosophy or list of principles that might bring all factions to the table for honest discourse about increasingly intractable environmental, social, and economic problems. > > But the communal heritage of geology may yet allow us to reframe our thinking about these issues in a fresh new way. In fact, natural scientists already serve as a kind of impromptu international diplomatic corps who demonstrate that it is possible for people from developed and developing countries, socialist and capitalist regimes, theocracies and democracies to co-operate, debate, disagree, and move toward consensus, unified by the fact that we are all citizens of a planet whose tectonic, hydrologic, and atmospheric habits ignore national boundaries. Maybe, just maybe, the Earth itself, with its immensely deep history can provide a politically neutral narrative from which all nations may agree to take counsel. ### Chapter 2 - An Atlas of Time It took a lot of different minds to build an atlas of deep time: - visionary thinkers like Hutton and Lyell who were not obsessed with details - fossil hunters like William Smith - polymaths like Darwin and Holmes who saw connections across disciplines - fastidious instrumentalists like Nier and Patterson - bureaucracies like the International Commission on Stratigraphy - legions of field mappers who knew how to turn rocks into verbs The concept of "Deep Time" was coined by John McPhee in 1981 in his book Basin and Range to describe prehistorical and prearchaeological time. **Geology is unique among all the sciences in having direct, tangible access to the objects that have witnessed Deep TIme**. Geology reads the Earth like a palimpsest, a text that is constantly being erased and written over, leaving faint traces each time. In 1789, James Hutton was at Siccar Point, Scotland and noticed two different layers of sedimentary rock. He made two brilliant leaps of thought. First, he recognised that the bottom layer was a former mountain range with marine strata. Second, he recognised that the top layer had eroded the mountain over vast stretches of time, and that the rocks on top were sediments that had accumulated during this time. That year, he wrote a treatise called *Theories of Earth*, in which he presented the foundational idea of geology. **Uniformitarianism is the idea that present-day processes are the same as those that operated in the geoligic past.** This broke with the prevailing Biblical worldview, which said that only catastrophes could have created the diverse forms that were observed in the world. Charles Lyell would rigorously promote this idea a generation later, with his book *Principles of Geology*. Darwin brought this book with him on the HMS Beagle, and it contributed to his insight that time could shape organisms through natural selection. In the early 1800s, a canal digger named William Smith noted that certain fossil shells occurred in the same sequence in strata throughout England. These **index fossils** became ways of drawing connections between layers that were not physically continuous. Although there are no fossil records from Precambrian times, this represents 90% of earth's history. Progress stalled in the 2nd half of the 19th century. Lord Kelvin felt that Hutton's ideas about the age of the earth was a threat to the 2nd law of [[thermodynamics]]. Starting from the 1860s, he published a series of papers that calculated the age of the earth from the rate of conductive cooling of the planet and the lifespan of the Sun. Between 1864 and 1897, his estimate of the earth's age shrank from hundreds of millions of years to 20 million. Darwin died in 1882, with the age of the earth still in doubt. His entire theory rested on this foundation. He called Lord Kelvin his "sorest trouble". A rift between geologists and physicists arose, which set geology back by decades. Geologists did not take the ideas of meteorologist Alfred Wegener seriously. He proposed the theory of continental drift in 1915, but it wasn't accepted until the 1960s. When Henri Becquerel discovered radioactivity in 1897, it set the stage for the dating of rocks. By 1902, Marie Curie and Ernst Rutherford showed that elements could transmute into other elements through radioactive decay. In 1905, Rutherford discovered that this occurred at an exponential rate and could be used as a natural clock. In 1908, Arthur Holmes, an 18-year-old physics student at Imperial College, figured out how to date zircon rocks. --- Quotes from the book: > To my surprise, I found that geology demanded a type of whole-brain thinking I hadn’t encountered before. It creatively appropriated ideas from physics and chemistry for the investigation of unruly volcanoes and oceans and ice sheets. It applied scholarly habits one associates with the study of literature and the arts—the practice of close reading, sensitivity to allusion and analogy, capacity for spatial visualization—to the examination of rocks. Its particular form of inferential logic demanded mental versatility and a vigorous but disciplined imagination. And its explanatory power was vast; it was nothing less than the etymology of the world. I was hooked. > > An apt way to describe how geologists perceive rocks and landscapes is the metaphor of a palimpsest—the term used by medieval scholars to describe a parchment that was used more than once, with old ink scraped off to allow a new document to be inscribed. Invariably, the erasure was imperfect, and vestiges of the earlier text survived. > Among the sciences, geology is something of a late bloomer. The motions of the planets were explained in the seventeenth century, the laws of thermodynamics and electromagnetism were worked out in the nineteenth, and the secrets of the atom were known in the early twentieth, all before we knew the age of the Earth or had any clear idea about its planetary-scale behavior. This does not mean geologists have been dullards but rather that Earth has been an elusive subject to study—simultaneously too near and too far away to get into clear view. When other sciences were making great strides toward describing nature using telescopes, microscopes, beakers, and bell jars, Earth could neither be viewed through one lens nor reduced to a laboratory-sized experiment. > The discipline of geology is akin to an optical device for seeing the Earth text in all its dimensions. To think geologically is to hold in the mind’s eye not only what is visible at the surface but also present in the subsurface, what has been and will be. > On the 200th anniversary of Darwin’s birth, I organized an all-day reading of On the Origin of Species at our university library, with dozens of faculty, staff, and students each taking a turn reading aloud for 20-minute stints, with breaks every hour for brief discussion. # Quotes # References