Tuesday, April 14, 2020
Alone in Albuquerque: Walking through the Covid-19 Isolation
Part 1: The Isolation
Social distancing is what we do when shopping in person. It's keeping six feet from other shoppers, wearing face covering, and, for me, it is also avoiding certain store aisles. Those are the junk food aisle, with its myriad of temptations, and the first aid aisle, for hand sanitizer and isopropyl alcohol, not to forget toilet paper, have long since been hoarded away by our neighbors. With sufficient public compliance, social distancing will slow the viral spread. This I believe. But social distancing is hardly the whole story.
Social isolation, a harsher term less frequently heard, is the daily reality of those of us who live alone and are without jobs deemed "essential". It is the other face of covid-19 illness. In the last month, I estimate that I have averaged, per week, no more than 20 minutes of face-to-face, person-to-person conversation. My most sustained conversation came when donating blood two weeks ago. Not only did I answer important questions about my medical history and verify the spelling of my name and the date of my birth, I also exchanged tone of voice, body gesture, facial expression, and other nonverbal cues with the nurse, a fellow human, seated only a few feet from me. With a hemoglobin count testing out to 15.6, I was cleared to donate. She nodded and smiled at me in approval. This was a physical interaction that, until a month ago, I took for granted and rarely noticed.
Initially I expected New Mexico Governor Lujan-Grisham's wise stay-at-home order against coronavirus spread to be a boon. That solitude I cherish would become even more abundant! Instantly I would become less distracted and more productive. This blog would be receiving new posts daily!
It has not turned out that way. Solitude now maroons me. Sure, there is the internet and online classes mediated by Zoom. I use them, and they do help, but only in the way that aspirin helps when one has a toothache. In this virtual stand-in community of ours, something significant is absent.
What has helped -- indeed, what has become essential to me -- is the rigid routine of my afternoon walk, taken six days a week, always the same route, always 14 miles in length, typically taking three and a half hours. West down Lomas to UNM, north and then east along the spillways, passing by the Big-I, finally south down Pennsylvania, and soon back at home. Maybe it is the mindless routine or the repetition, but whatever it is it assuages my isolation. In it, something significant is present.
Superficially, each day's ramble is predictable. Day to day the scenery changes little, and yet, like the weather, every walk, in its details, is different. It is those details and how they link to the land, the sky, the wind, and the weather that I want to write about. They are what connects this post, and ones to come, to this blog's theme of geology and the human condition.
Part 2: The Walk
Spring afternoons here commonly take on a brightness leaving me squinting like Charles Bronson in a Spaghetti Western. Sunscreen clogs the pores of my face, returning them to the state of my adolescence. Lip balm likewise leaves a waxiness on my lips, and a taste of peppermint in my mouth. The hat I wear is broad-brimmed to shade my face and neck. Its once-shapely contours have slowly dissolved away by the Florida downpours it has endured. It too protects against the elements, until I have carry it in hand against the unrelenting winds of this first Albuquerque spring. Those winds, how they desiccate, stripping moisture, rendering this land upon which I walk a thirsty tan and yellow, domed by deepest blue and meandering white wisps of clouds. Beside me barren tumbleweeds roll along in their breeze, spewing seeds upon the poured concrete that will wait and wait until rain at last comes. "Sirocco" and "Santa Ana" -- winds elsewhere in the world have names. Surely these must be named as well.
Last week, afternoon relative humidity fell to about 15 percent. Compared to an air temperature of 73 F, the dew point temperature was just 12 F. Is it any wonder that the cracking and chapping of my skin extends from my lips down to my feet? All of this is unprecedented in my life. Last July I escaped a home on the hot, humid, and hurricane-prone Gulf Coast of Florida. I came here seeking change, a geologically dynamic landscape, and, most of all, relief from humidity. Evidently I have succeeded.
As I walk past the Big-I, that is, the interchange of Interstates 25 and 40, the dire state of our economy, free falling now into recession, is nowhere heard. Instead, what I hear is a ceaseless low drone of traffic steadily flowing, a parade, without beginning or end, of tractor trailer rigs, emblazoned with names and logos like C.R. England and Saia LTL, hauling freight -- toilet paper even -- to empty store shelves across the Southwest. "Keep Calm and Carry On", the Brits say, and they, the truckers, do. One need only listen. It is the lull that I like. I keep pace with it, as if it were a metronome, and I, too, carry on and walk on. Fourteen miles is too far to tarry long.
For miles I follow the North Diversion Channel. It is an engineered spillway of enormous volume, said to dispose of as much as two Olympic-sized swimming pools of water per second. Within a city receiving only nine inches of rain per year, such a beast might seem unusual. But it, like the other spillways crisscrossing the city, is not. The Sandia Mountains immediately to the east receive two to three times that precipitation near the summit. Albuquerque is built on an incline, falling about 1200 feet from the Sandia foothills down to the Rio Grande. For the urban pedestrian that I am, spillways are the alternative to the streets. Most come with paved bike paths. Passing behind junk yards and back lots, spillways are home to feral cats, liquor-swilling vagrants, and daredevil skateboarders. Here, in these channels, collects the city's graffiti and detritus, its cast-off clothing, like a single sneaker still in good shape, its Circle K and 7-Eleven fountain drink plastic cups that never decompose, and its broken, derelict furniture. If the urging of my bladder is strong enough, I can seek relief beside a skimpy, windblown bush, unafraid of being collared by a cop for urinating in public. Here resides the wildlife I know: pigeons roosting beneath the interstate overpass, trilling road runners pecking the hardened soil for lizards, and the occasional coyote prowling for backyard chickens.
Thus, this land that I walk is my wilderness, an Arcadia for those of us confined -- not by law but simply by lack of a car -- to the city for the duration of the pandemic. Walden Pond it is not, nor is it the virgin wilderness portrayed in Ansel Adams calendar photos. I leave that world to the ecological purists, those who, in their dedication, will drive for days on end questing after the pristine, in the process converting untold gallons of Permian petroleum into heat-trapping atmospheric carbon dioxide.
As this city is my place of exile, it is also, when the wind blows right, my paradise upon the earth. Down the channel sometimes blows, from the General Mills plant at Paseo del Norte, the luscious aroma of coffee cake baking, of cereal grain, and of crusty, flaky shortening sweetened with caramelized sugar, and adorned with pieces of walnut. It is something to die for.
Part 3: The Self of Flesh and Blood
What is that significant thing absent in this isolation? And what is that other significant thing present during my walks? These are the questions motivating this essay. A single answers suffices for both: it is my body. It is my physical self, that self of 129 pounds that is moving, metabolizing, and mortal. Maybe too this self is manufacturing malign coronavirus particles, though, surely, the marrow of my bones is readily replacing my recently donated blood. It is also a sensual self that knows the world by sensing it, and a carnal self acting in and on the world. I smell the coffee cake, I salivate, and I want some. Desire drives me. Are you any different?
Eastern gurus, old time Bible preachers, and New Age metaphysical celebrities lecture us instead about the spiritual. It is claimed to be immortal, uncorrupted, free of desire, and all the rest. Well, at least it is in theory and in our hopes. In contrast, I celebrate the opposite: the physical self that I know because I live through it. This life, threatened as it is by viral infection, and this earth, with its trash in the spillways, are enough for me. It is the world that inhabits me.
posted 2020-04-14, updated 2020-04-14
Monday, March 9, 2020
Abyss of Time
As a child, the deep end of the swimming pool terrified me. At the shallow end, I could stand on the bottom with my head still safely above the surface. I swam with confidence and pleasure. The deep end, however, was a different matter. Lettering painted on the rim of the pool -- say, 9' 6" -- filled me with dread. Down by more than double my height, the pool drain possessed, I imagined, a gravitational sucking force. Were I to swim over it, surely, it would drag me under, as irresistibly as if pulled beneath by the tentacles of an octopus. A watery death awaited, my toes caught and entangled in the drain's grates. Of that, the child I was had no doubt.
The pool's deep end was for me an abyss. In its etymology, the word "abyss" derives from Greek words "a-" (without) and "byssos" (depth), thus bottomless and limitless. Usually it refers to watery, oceanic depths, but it might also suggest a crevasse, chasm, or other terrestrial void. Abyss has a connotation of terror, one coming, I suspect, from the implication that what is bottomless must also be inescapable. Moreover, it is a bottomless below, suggesting a grave, the underworld of Hades or Tartarus, and the oblivion coming with death. Few who visit there ever return to the world of the living on earth's sunny surface [1]. The related word "abysmal" has had, since the early 19th century [2], the additional connotation of a wretchedness into which one falls, for example, "the abysmal conditions of those living on the street." For the Chinese, abyss appears as an interpretation of the water over water, or Pit, hexagram of the I Ching. Other interpretations of that hexagram involve darkness, risk, and concealed danger. Fear of bottomless depths is, evidently, not strictly Western.
I am now reading Claude C. Albritton's book, The Abyss of Time (WH Freeman, 1980). A geologist, Albritton provides a history of the geological discovery of the vastness of earth's time. We might simply call such vastness "deep time". The discovery came slowly, in the successive discoveries made by geologists and others over several hundred years. Time gathered its depth (or, expanse) as these discoveries pushed out estimates of the age of the earth from 6000 years (a date derived nonscientifically by analysis of the Jewish scriptures, Genesis in particular) to today's estimate of 4.6 billion years. This increase of more than 750,000-fold has required adjustment in how we, as mortal humans, understand ourselves as existing in the matrix of time.
Albritton's title, "the abyss of time", originates in the discoveries of James Hutton, one of geology's founders. Hutton came to understand geological processes as slow and inexorable. Given sufficient time, these processes -- no different from those active at this present time -- can raise mountains and cut vast canyons. No Biblical floods or other catastrophic events are needed [3]. Instead, only time, in vast amounts, is required. Consequently, "we find no vestige of a beginning - no prospect of an end," wrote Hutton (Albritton, p. 96). Moreover, "the mind seemed to grow giddy by looking so far into the abyss of time" (Albritton, p. 103) wrote John Playfair, Hutton's collaborator and biographer. Playfair wrote this at Siccar Point, Scotland, the site of a geological unconformity that provided Hutton with his most important insights. But why describe time with the word "abyss" considering it terrifying connotation?
In its new-found vastness, geological time seems to deny our stories of time's beginning, be it the Genesis story or the Big Bang, as well as of time's ending, say, the return of Christ or nuclear winter. Time without beginning and without end consequently loses its unfolding progressive character, becoming more nearly circular and repetitious. Sisyphus, eternally rolling his boulder up the mountain only to have it roll back down, graduates from mere metaphor and mythology. He is a man punished by the gods with futility and imprisoned in the realm of circular time. His fate and its futility are what makes understanding geological time an abyss [4].
Endnotes
1. Greek and Roman mythology give special attention to those few mortals who have visited and later returned from the Underworld. These special mortals include Odysseus, Aeneas, Sisyphus, and Orpheus. (Eurydice, beloved by Orpheus, almost made the list.)
2. See "abysmal" in The Oxford Dictionary of Word Histories, edited by Glynnis Chantrell, 2002.
3. This doctrine now goes by the name Uniformitarianism.
4. Albert Camus, for one, disagreed. In his essay "The Myth of Sisyphus" (ca. 1942), he presented Sisyphus as the modern absurd hero, ending his essay with the words "one must imagine Sisyphus happy". His Sisyphus defies both the gods and the circularity of time. He knows time but not the abyss. I wonder how much Camus knew about geological time.
posted: 2020-03-09, last edited: 2020-03-10 (rewritten)
The pool's deep end was for me an abyss. In its etymology, the word "abyss" derives from Greek words "a-" (without) and "byssos" (depth), thus bottomless and limitless. Usually it refers to watery, oceanic depths, but it might also suggest a crevasse, chasm, or other terrestrial void. Abyss has a connotation of terror, one coming, I suspect, from the implication that what is bottomless must also be inescapable. Moreover, it is a bottomless below, suggesting a grave, the underworld of Hades or Tartarus, and the oblivion coming with death. Few who visit there ever return to the world of the living on earth's sunny surface [1]. The related word "abysmal" has had, since the early 19th century [2], the additional connotation of a wretchedness into which one falls, for example, "the abysmal conditions of those living on the street." For the Chinese, abyss appears as an interpretation of the water over water, or Pit, hexagram of the I Ching. Other interpretations of that hexagram involve darkness, risk, and concealed danger. Fear of bottomless depths is, evidently, not strictly Western.
I am now reading Claude C. Albritton's book, The Abyss of Time (WH Freeman, 1980). A geologist, Albritton provides a history of the geological discovery of the vastness of earth's time. We might simply call such vastness "deep time". The discovery came slowly, in the successive discoveries made by geologists and others over several hundred years. Time gathered its depth (or, expanse) as these discoveries pushed out estimates of the age of the earth from 6000 years (a date derived nonscientifically by analysis of the Jewish scriptures, Genesis in particular) to today's estimate of 4.6 billion years. This increase of more than 750,000-fold has required adjustment in how we, as mortal humans, understand ourselves as existing in the matrix of time.
Albritton's title, "the abyss of time", originates in the discoveries of James Hutton, one of geology's founders. Hutton came to understand geological processes as slow and inexorable. Given sufficient time, these processes -- no different from those active at this present time -- can raise mountains and cut vast canyons. No Biblical floods or other catastrophic events are needed [3]. Instead, only time, in vast amounts, is required. Consequently, "we find no vestige of a beginning - no prospect of an end," wrote Hutton (Albritton, p. 96). Moreover, "the mind seemed to grow giddy by looking so far into the abyss of time" (Albritton, p. 103) wrote John Playfair, Hutton's collaborator and biographer. Playfair wrote this at Siccar Point, Scotland, the site of a geological unconformity that provided Hutton with his most important insights. But why describe time with the word "abyss" considering it terrifying connotation?
In its new-found vastness, geological time seems to deny our stories of time's beginning, be it the Genesis story or the Big Bang, as well as of time's ending, say, the return of Christ or nuclear winter. Time without beginning and without end consequently loses its unfolding progressive character, becoming more nearly circular and repetitious. Sisyphus, eternally rolling his boulder up the mountain only to have it roll back down, graduates from mere metaphor and mythology. He is a man punished by the gods with futility and imprisoned in the realm of circular time. His fate and its futility are what makes understanding geological time an abyss [4].
Endnotes
1. Greek and Roman mythology give special attention to those few mortals who have visited and later returned from the Underworld. These special mortals include Odysseus, Aeneas, Sisyphus, and Orpheus. (Eurydice, beloved by Orpheus, almost made the list.)
2. See "abysmal" in The Oxford Dictionary of Word Histories, edited by Glynnis Chantrell, 2002.
3. This doctrine now goes by the name Uniformitarianism.
4. Albert Camus, for one, disagreed. In his essay "The Myth of Sisyphus" (ca. 1942), he presented Sisyphus as the modern absurd hero, ending his essay with the words "one must imagine Sisyphus happy". His Sisyphus defies both the gods and the circularity of time. He knows time but not the abyss. I wonder how much Camus knew about geological time.
posted: 2020-03-09, last edited: 2020-03-10 (rewritten)
Friday, February 28, 2020
Freeman Dyson, RIP
Freeman Dyson died today, Friday, 28 February 2020, age 96, at a hospital in his longtime home of Princeton, NJ. A thoughtful obituary by George Johnson just appeared (Friday night, 28 Feb 2020) on the New York Times website.
Dyson was a mathematical physicist who knew the greats -- Feynman, Oppenheimer, Bethe, Teller, and the rest -- and became great himself by contributing the theory of quantum electrodynamics. He was one of the final living members of the World War II generation of scientists who invented cryptography, radar, and, of course, nuclear weapons and who later wrote about and lobbied vigorously for their safe and controlled use. These scientists saw themselves also as humans, citizens, and small-d democrats who knew the essential need for public discussion of issues raised by the technology they created.
Dyson reminds me of Jacob Bronowski. Both were Englishmen, both mathematicians, and both authors of books overlapping science and the humanities. Bronowski is best known for his public television series The Ascent of Man (1973). Dyson, likewise, wrote many popular books, though in an unpopular way. He dared to bring in Johann Wolfgang von Goethe, Bertold Brecht, Ingmar Bergman, T.S. Eliot, and other nonscientist people of culture.
One of those books, his 1979 memoir Disturbing the Universe, I read over a cross-country Greyhound bus trip in January 1983. What I discovered in it was not science, nor memoir, but humanity. Dyson, for example, compared Richard Feynman to Jof the Juggler in Ingmar Bergman's film, The Seventh Seal (1956). That film, central now to my understanding of life, I did yet know, but Dyson's book sent me out to see it when it finally caught up to me. Thank you, Professor Dyson. One does not expect to learn such things in a scientist's memoir! (Feynman, of course, I have long known. Like so many of my generation, I learned physics partly by perusing all three volumes of The Feynman Lectures on Physics.)
Dyson was technological optimist. Problems on earth -- be they overpopulation or climate change -- either were not as serious as claimed or could be overcome by even more technology, such as space colonies somewhere else in the universe. One would travel there by spaceships powered by nuclear explosions. It is here I lose touch with Dyson. Perhaps I lack his imagination. Certainly I lack his faith in technological solutions to problems of human nature.
Disturbing the Universe introduced me as well to Goethe's Faust, particularly this favorite line from its Part I. It is a fitting quotation to a remembrance of Freeman Dyson: "All theory is gray, / But the tree of life, my friend, is green."
posted 2020-02-28, edited 2020-02-29
Thursday, February 20, 2020
How old is old?
What is the oldest thing found on earth?
Rocks, right? Some of the oldest rock formations are found in northern and eastern Canada and date back about four billion years. Immensely, unimaginably old they are, and yet the earth itself is older, dated to about 4.54 billion years. On earth, rocks are continuously recycled, broken down by weathering and erosion, and moved by water, wind, and gravity. And rocks are also built back up, reformed by sedimentation and remelting, pushed up again by our earth's ever-moving crust. Original rocks, present when our newly-created, molten planet had cooled and solidified, are likely long since recycled and remade by our dynamic living planet.
So how about meteorites, the rocky remains of "shooting star" reaching the earth's surface still intact? They are older still. At the local New Mexico Museum of Natural History and Science is found an iron-nickel meteorite collected from South America and dated to 4.55 billion years ago. "PLEASE TOUCH" says the sign by the meteor. Awed, I place my hand on its rusty metallic surface and try to feel the vastness of time that my rational mind cannot comprehend. "This may be the oldest rock you will ever touch" suggests the sign. Indeed.
Earth, sun, and the seven planets [1] of our solar system all originated together about 4.57 billion years ago. Originally part of rocky objects smaller than Earth but still part of the solar system, rocks that would become meteorites cooled faster and solidified sooner than Earth. Thereby they are older.
But can we go even farther back in time? Can we find even more ancient mineral-based substances on earth? Until recently I thought not. But now, I stand corrected.
Older matter ought to exist somewhere. Old as Earth and the solar system are, we are but recent arrivals. As the Big Bang creation is dated to about 13.7 billion years ago, some two-thirds of the universe's history had already passed before our solar system was created. Generations upon generations of stars and galaxies predate us and our sun. The vastness of earth's history therefore contacts to something termed "recent". Absurd! My mind rebels at this absurdity and this monstrosity. I am a trained experimental scientist. I do believe these ages. Still, I need something solid, something tangible, something to touch and feel, if only with scientific instruments, so that I can also believe in my heart and marrow as I believe in my brain. I need more evidence.
Late last month a scientific paper [2] appeared providing some of that evidence. The paper's title is instructive: "Lifetimes of interstellar dust from cosmic ray exposure ages of presolar silicon carbide". The words "presolar" and "interstellar" suggest matter older than the solar system and originating outside of it. "Dust" suggests solid matter, and "silicon carbide" is a particular type of mineral, one of the first minerals to form in the history of the universe [3]. Presolar grains are not new. What this paper contributes is a new method of dating them. The grains they dated are derived from the Murchison meteorite that landed in Australia in 1969. While most of the meteorite's matter dates from just after the formation of the solar system, embedded within it are trace grains of far older matter, matter containing the mineral silicon carbide (SiC). The oldest grains date to 1 to 5 billion years prior to the solar system's formation, or 5.6 to 9.6 billion years ago. As I touched the meteorite at the local museum, might my hand have come into contact with similar ancient presolar grains [4]?
Should we believe this paper? Key to answering that question is considering carefully the methods used. The authors face two challenges: (1) convincing us that the SiC grains came from outside the solar system and (2) establishing a date for their formation. For (1) the authors relied on a well-established method: demonstrating by mass spectroscopy isotopic anomalies characteristic of matter originating outside of the solar system. For (2) the authors developed a new dating method based on cosmic ray exposure. They had to. As they note in their paper, "Dating of interstellar dust directly with astronomical methods is not possible. Neither is dating based on the decay of long-lived radioactive nuclides, due to current analytical limitations and unknown initial isotopic compositions."
But can we go back even further in time?
Yes, we can go almost all of the way back, back more than 13.6 billion years, if we relax one key assumption. Up to this point, this blog post has been written from a geologist's point of view. What counts to the geologist are minerals, those underlying chemical components of terrestrial rocks, meteorites, and presolar grains. Key to the definition of mineral is the requirement that atoms continuously exist in an intact, regular, and solid structure. Recycling of rocks on earth's surface, for example, reshuffles this structure, thereby resetting a mineral's age to the most recent episode of (re)mineralization.
Chemists, in contrast, see things differently. They are more willing to let go of the requirement that dating apply to elements in their mineral form. What matters is only the elements themselves, and not their chemical neighborhood and bonding partners. All hydrogen, some helium, and traces of lithium were created in the Big Bang and predate even the first stars. Cosmologists estimate that by 379,000 years after the Big Bang, the expanding universe had cooled enough for the nuclei of the hydrogen, helium, and lithium to combine with electrons forming the first atoms.
I sip some tea, and in the water composing it, I taste and consume hydrogen dating back nearly to the Big Bang 13.7 billion years ago. Oh the places that hydrogen has been!
NOTES
1. Missing from the list of eight planets (Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune) is Pluto. Based on its small mass and the aberrant characteristics of its orbit (specifically, its eccentricity and large deviation from the ecliptic), Pluto was reclassified in 2006 from a "planet" to a "dwarf planet", the same status shared by Ceres, one of the larger known asteroids.
2. The article is by Philipp R. Heck et al. and was published on 28 January 2020 in the Proceedings of the National Academy of Science, 117(4): 1884-1889. The original article is available here at no cost.
3. See Professor Robert Hazen's course, "The Origin and Evolution of Earth" (The Great Courses, 2013), especially lectures four and five. See also the Wikipedia entry on "presolar grains".
4. I am doubtful. The Murchison meteorite, a carbonaceous chondrite, has a composition distinctly different from iron-nickel meteorite displayed at the NM Museum of Natural History and Science.
ACKNOWLEDGMENT
Professor Carol Hill, her course "Planetary Geology" (now being taught at the University of New Mexico), and my fellow classmates motivated and informed this blog post.
posted: 2020-02-20, last modified: 2020-02-20
Rocks, right? Some of the oldest rock formations are found in northern and eastern Canada and date back about four billion years. Immensely, unimaginably old they are, and yet the earth itself is older, dated to about 4.54 billion years. On earth, rocks are continuously recycled, broken down by weathering and erosion, and moved by water, wind, and gravity. And rocks are also built back up, reformed by sedimentation and remelting, pushed up again by our earth's ever-moving crust. Original rocks, present when our newly-created, molten planet had cooled and solidified, are likely long since recycled and remade by our dynamic living planet.
So how about meteorites, the rocky remains of "shooting star" reaching the earth's surface still intact? They are older still. At the local New Mexico Museum of Natural History and Science is found an iron-nickel meteorite collected from South America and dated to 4.55 billion years ago. "PLEASE TOUCH" says the sign by the meteor. Awed, I place my hand on its rusty metallic surface and try to feel the vastness of time that my rational mind cannot comprehend. "This may be the oldest rock you will ever touch" suggests the sign. Indeed.
 |
| Iron-nickel meteorite at the New Mexico Museum of Natural History and Science |
Earth, sun, and the seven planets [1] of our solar system all originated together about 4.57 billion years ago. Originally part of rocky objects smaller than Earth but still part of the solar system, rocks that would become meteorites cooled faster and solidified sooner than Earth. Thereby they are older.
But can we go even farther back in time? Can we find even more ancient mineral-based substances on earth? Until recently I thought not. But now, I stand corrected.
Older matter ought to exist somewhere. Old as Earth and the solar system are, we are but recent arrivals. As the Big Bang creation is dated to about 13.7 billion years ago, some two-thirds of the universe's history had already passed before our solar system was created. Generations upon generations of stars and galaxies predate us and our sun. The vastness of earth's history therefore contacts to something termed "recent". Absurd! My mind rebels at this absurdity and this monstrosity. I am a trained experimental scientist. I do believe these ages. Still, I need something solid, something tangible, something to touch and feel, if only with scientific instruments, so that I can also believe in my heart and marrow as I believe in my brain. I need more evidence.
 |
| Timeline of the Universe |
Late last month a scientific paper [2] appeared providing some of that evidence. The paper's title is instructive: "Lifetimes of interstellar dust from cosmic ray exposure ages of presolar silicon carbide". The words "presolar" and "interstellar" suggest matter older than the solar system and originating outside of it. "Dust" suggests solid matter, and "silicon carbide" is a particular type of mineral, one of the first minerals to form in the history of the universe [3]. Presolar grains are not new. What this paper contributes is a new method of dating them. The grains they dated are derived from the Murchison meteorite that landed in Australia in 1969. While most of the meteorite's matter dates from just after the formation of the solar system, embedded within it are trace grains of far older matter, matter containing the mineral silicon carbide (SiC). The oldest grains date to 1 to 5 billion years prior to the solar system's formation, or 5.6 to 9.6 billion years ago. As I touched the meteorite at the local museum, might my hand have come into contact with similar ancient presolar grains [4]?
Should we believe this paper? Key to answering that question is considering carefully the methods used. The authors face two challenges: (1) convincing us that the SiC grains came from outside the solar system and (2) establishing a date for their formation. For (1) the authors relied on a well-established method: demonstrating by mass spectroscopy isotopic anomalies characteristic of matter originating outside of the solar system. For (2) the authors developed a new dating method based on cosmic ray exposure. They had to. As they note in their paper, "Dating of interstellar dust directly with astronomical methods is not possible. Neither is dating based on the decay of long-lived radioactive nuclides, due to current analytical limitations and unknown initial isotopic compositions."
But can we go back even further in time?
Yes, we can go almost all of the way back, back more than 13.6 billion years, if we relax one key assumption. Up to this point, this blog post has been written from a geologist's point of view. What counts to the geologist are minerals, those underlying chemical components of terrestrial rocks, meteorites, and presolar grains. Key to the definition of mineral is the requirement that atoms continuously exist in an intact, regular, and solid structure. Recycling of rocks on earth's surface, for example, reshuffles this structure, thereby resetting a mineral's age to the most recent episode of (re)mineralization.
Chemists, in contrast, see things differently. They are more willing to let go of the requirement that dating apply to elements in their mineral form. What matters is only the elements themselves, and not their chemical neighborhood and bonding partners. All hydrogen, some helium, and traces of lithium were created in the Big Bang and predate even the first stars. Cosmologists estimate that by 379,000 years after the Big Bang, the expanding universe had cooled enough for the nuclei of the hydrogen, helium, and lithium to combine with electrons forming the first atoms.
I sip some tea, and in the water composing it, I taste and consume hydrogen dating back nearly to the Big Bang 13.7 billion years ago. Oh the places that hydrogen has been!
NOTES
1. Missing from the list of eight planets (Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune) is Pluto. Based on its small mass and the aberrant characteristics of its orbit (specifically, its eccentricity and large deviation from the ecliptic), Pluto was reclassified in 2006 from a "planet" to a "dwarf planet", the same status shared by Ceres, one of the larger known asteroids.
2. The article is by Philipp R. Heck et al. and was published on 28 January 2020 in the Proceedings of the National Academy of Science, 117(4): 1884-1889. The original article is available here at no cost.
3. See Professor Robert Hazen's course, "The Origin and Evolution of Earth" (The Great Courses, 2013), especially lectures four and five. See also the Wikipedia entry on "presolar grains".
4. I am doubtful. The Murchison meteorite, a carbonaceous chondrite, has a composition distinctly different from iron-nickel meteorite displayed at the NM Museum of Natural History and Science.
ACKNOWLEDGMENT
Professor Carol Hill, her course "Planetary Geology" (now being taught at the University of New Mexico), and my fellow classmates motivated and informed this blog post.
posted: 2020-02-20, last modified: 2020-02-20
Wednesday, January 8, 2020
Sandia Granite and the Abyss of Time
[Listen to this post read by its author.]
Granite. Ordinary granite. Its heft weighed in my hands. I rotated the muddy chunk with numb fingers to better examine the clear quartz within. "Intrusive igneous rock", I thought. No magnifying glass was required to make out the hexagonal prisms of quartz's crystals. "Slow-cooling too", I reasoned, for otherwise the crystals would be invisibly tiny to my unaided eye.
In geology, I am a novice, a mere child for whom the slightest glint or sparkle suffices to delight. In my specimen, quartz seems to float in an amorphous matrix of feldspars -- salmon-pink colored orthoclase and white plagioclase -- with black rectangular chunks of biotite, or maybe hornblende, mixed in [1]. With a steel rock hammer, I had just chipped it out of a road cut. That road is the "Old 66", as locals call it, or "NM 333", as the highway department designates it.
Just east of Albuquerque, Old 66 traverses the geologically-rich Tijeras Canyon. Stretching, rifting, and faulting of the earth's crust in these parts 10 to 20 million years ago uplifted that slow-cooling, subterranean granite, repositioning it overhead as the Sandia Mountains, and opening this Canyon. Here history, both geological and cultural, lurks.
"Along this very road", I thought, imagining Steinbeck's Joad family escaping the Oklahoma Dust Bowl in their overloaded, westbound jalopy. "Salt of the earth, as much as this rock in my hand." Conflating the movie version with the novel, I saw in my mind's eye a young Henry Fonda at the wheel, hungry, lean, and desperate. Old 66 symbolizes America and our restless drive, whether to escape, like the Joads, or instead to celebrate. "Get your kicks on Route 66." I hear that now, in Nat King Cole's cool baritone. And here I was literally walking the very road, rock hammer in hand, collecting specimens, and, yes, getting my kicks.
Wind blew wet and cold for this bleak October day of 2019. Chilling it further was the damp wake of occasional, fast-moving traffic as we worked from the road's narrow shoulder. "Grab your specimens and go", I reminded myself. "Keep focused, keep moving, stay warm, this is only the first of several scheduled stops. Others in the group are already in the car waiting for you." For Professor Carol A. Hill's class "Geology of the Sandia Mountains and the Rio Grande Rift", this was the optional field trip for the hardcore enthusiasts.
"One point four billion years old?", I asked aloud, knowing the number from books [2], as well as from her lectures, yet not quite ready to accept it. "Yes", Professor Hill replied. It is a matter of fact. Granite. Mundane granite, quite literally mundane, removed from the earth with a whack of the hammer. This chunk in my hand is enormously, unimaginably old. That much I understood.
America, our America, in contrast, repels the cling of history, or so it seems. Everything is always changing, wrecked or improved, opinions differ, in any case superseding what came before. Nearby Interstate 40, for instance, has made Old 66 a relic of a former, forgotten era. Long gone are the Art Deco motor lodges and sleek filling stations servicing streamlined cars. And these days, who still remembers Nat King Cole? As our culture forever morphs, these rocks and this earth remain, mute witnesses to it all, biding their time.
I have long worked with unimaginable numbers. Is there anything larger than Avogadro's constant of chemistry, or anything smaller than Planck's constant of physics? Just key them into your calculator using scientific notation. Easy, right? But 1.4 billion years is more than a number. It is also history, geological history, and as history it is a human creation. I ought to be able to feel it in order to fully know it.
One way to comprehend is to temporarily put aside the units -- years -- and only consider the magnitude. America has many billionaires. Can I comprehend their wealth? (Not really. I am satisfied simply to pay off my credit card balance each month.) Instead, as we are concerned with time, what about 1.4 billion seconds? How long might that be? About 44 years, according to my 33 year old HP-15c calculator. That's human middle age. Already, I've lived more than 1.4 billion seconds. That duration I know viscerally. I feel it as aches in my joints and muscles after several hours of hiking.
The relevant quantity, however, is 1.4 billion years. Because there are about 32 million seconds in a year, the age of my granite chunk is equivalent to 32 million middle-aged human lives, stacked end to end. No, I can't comprehend that either.
Another technique is to ignore the number's size and instead locate it in the context of what is already understood. In 2003, I visited the ancient bristlecone pines high in the White Mountains bordering California and Nevada. Immediately, as I walked among these scraggly Methuselahs of trees, I comprehended -- I felt in my marrow -- their 3000 year old age. Younger than the Trojan War I reasoned [3], yet also older than Homer's singing about the War in his epics, the Odyssey and the Iliad. I could understand because the Odyssey I have known and loved since childhood. Some stories of our cultural history evidently endure unchanged.
Earth's history has analogous mileposts. Life emerged on earth between 3.8 and 3.5 billion years ago and, much later, by 0.54 billion years ago life had evolved hard shells that preserved well as fossils. Somewhere within this three billion year span between life and fossils my chunk of granite cooled and solidified from magma. But, unlike the bristlecone pines, I still have no intuition or feeling for the age of the rock in my hand. The distance between the mileposts is just too great.
I am trained as an experimental scientist. I approach geology in that way. On another field trip, to a remote location near Socorro, NM in December 2019, I found a hefty chunk of glassy, translucent crystal [4]. It formed in sheet-like layers, almost like ice. Could it also be quartz? I tried, and succeeded, at scratching it with a knife. No, it definitely was not quartz. Then I watched and listened for what a drop of hydrochloric acid would do. I neither saw nor heard fizzing, so what I had was likely not calcite either. Perhaps unwisely, I licked it. Not salty, so not halite. Using established tests and guide books, using simple instruments like a knife and acid, using my five senses, and using my fallible reasoning, I tentatively conclude that what I found was selenite (crystalline calcium sulfate).
Making 1.4 billion years troublesome to me is its unapproachable abstraction. I can't taste it or try to scratch it. I cannot relate that age to my favorite stories, whether by Steinbeck or by Homer, much less to the voice of Mr. Cole. Sandia granite is found in America but seems not to be of America. I can hold a chunk of it, but I can't fully understand it, not its age. Here, my understanding hits its limits.
Footnotes
1. Sandia "granite" is, more precisely, the granite subtype called granodiorite.
2. For the geology and rock ages, see Jayne Aubele et al., "Geology of the Sandia Mountains", chapter 5 of Field Guide to the Sandia Mountains (edited by Robert Julyan and Mary Stuever), University of New Mexico Press, 2005. For background, Halka Chronic, Roadside Geology of New Mexico, Mountain Press Publishing Company, 1987, pp. xii-xiii, 27-31, 169-173, is helpful.
3. As I have understood it, the Trojan War was fought between 1200 and 1150 BCE. Homer, if he existed, travelled the Aegean in roughly 750 BCE and, over the course of several long nights, sang the epics to enthralled audiences.
4. This field trip is recounted in an earlier blog post, Land Beneath My Feet.
Posted: 2019-01-08. Updated: 2019-01-08.
Granite. Ordinary granite. Its heft weighed in my hands. I rotated the muddy chunk with numb fingers to better examine the clear quartz within. "Intrusive igneous rock", I thought. No magnifying glass was required to make out the hexagonal prisms of quartz's crystals. "Slow-cooling too", I reasoned, for otherwise the crystals would be invisibly tiny to my unaided eye.
In geology, I am a novice, a mere child for whom the slightest glint or sparkle suffices to delight. In my specimen, quartz seems to float in an amorphous matrix of feldspars -- salmon-pink colored orthoclase and white plagioclase -- with black rectangular chunks of biotite, or maybe hornblende, mixed in [1]. With a steel rock hammer, I had just chipped it out of a road cut. That road is the "Old 66", as locals call it, or "NM 333", as the highway department designates it.
 |
| Sandia Granite, formed 1.4 billion years ago, from a road cut on NM 333 between Albuquerque and Tijeras, NM. |
Just east of Albuquerque, Old 66 traverses the geologically-rich Tijeras Canyon. Stretching, rifting, and faulting of the earth's crust in these parts 10 to 20 million years ago uplifted that slow-cooling, subterranean granite, repositioning it overhead as the Sandia Mountains, and opening this Canyon. Here history, both geological and cultural, lurks.
"Along this very road", I thought, imagining Steinbeck's Joad family escaping the Oklahoma Dust Bowl in their overloaded, westbound jalopy. "Salt of the earth, as much as this rock in my hand." Conflating the movie version with the novel, I saw in my mind's eye a young Henry Fonda at the wheel, hungry, lean, and desperate. Old 66 symbolizes America and our restless drive, whether to escape, like the Joads, or instead to celebrate. "Get your kicks on Route 66." I hear that now, in Nat King Cole's cool baritone. And here I was literally walking the very road, rock hammer in hand, collecting specimens, and, yes, getting my kicks.
Wind blew wet and cold for this bleak October day of 2019. Chilling it further was the damp wake of occasional, fast-moving traffic as we worked from the road's narrow shoulder. "Grab your specimens and go", I reminded myself. "Keep focused, keep moving, stay warm, this is only the first of several scheduled stops. Others in the group are already in the car waiting for you." For Professor Carol A. Hill's class "Geology of the Sandia Mountains and the Rio Grande Rift", this was the optional field trip for the hardcore enthusiasts.
"One point four billion years old?", I asked aloud, knowing the number from books [2], as well as from her lectures, yet not quite ready to accept it. "Yes", Professor Hill replied. It is a matter of fact. Granite. Mundane granite, quite literally mundane, removed from the earth with a whack of the hammer. This chunk in my hand is enormously, unimaginably old. That much I understood.
America, our America, in contrast, repels the cling of history, or so it seems. Everything is always changing, wrecked or improved, opinions differ, in any case superseding what came before. Nearby Interstate 40, for instance, has made Old 66 a relic of a former, forgotten era. Long gone are the Art Deco motor lodges and sleek filling stations servicing streamlined cars. And these days, who still remembers Nat King Cole? As our culture forever morphs, these rocks and this earth remain, mute witnesses to it all, biding their time.
I have long worked with unimaginable numbers. Is there anything larger than Avogadro's constant of chemistry, or anything smaller than Planck's constant of physics? Just key them into your calculator using scientific notation. Easy, right? But 1.4 billion years is more than a number. It is also history, geological history, and as history it is a human creation. I ought to be able to feel it in order to fully know it.
One way to comprehend is to temporarily put aside the units -- years -- and only consider the magnitude. America has many billionaires. Can I comprehend their wealth? (Not really. I am satisfied simply to pay off my credit card balance each month.) Instead, as we are concerned with time, what about 1.4 billion seconds? How long might that be? About 44 years, according to my 33 year old HP-15c calculator. That's human middle age. Already, I've lived more than 1.4 billion seconds. That duration I know viscerally. I feel it as aches in my joints and muscles after several hours of hiking.
The relevant quantity, however, is 1.4 billion years. Because there are about 32 million seconds in a year, the age of my granite chunk is equivalent to 32 million middle-aged human lives, stacked end to end. No, I can't comprehend that either.
Another technique is to ignore the number's size and instead locate it in the context of what is already understood. In 2003, I visited the ancient bristlecone pines high in the White Mountains bordering California and Nevada. Immediately, as I walked among these scraggly Methuselahs of trees, I comprehended -- I felt in my marrow -- their 3000 year old age. Younger than the Trojan War I reasoned [3], yet also older than Homer's singing about the War in his epics, the Odyssey and the Iliad. I could understand because the Odyssey I have known and loved since childhood. Some stories of our cultural history evidently endure unchanged.
Earth's history has analogous mileposts. Life emerged on earth between 3.8 and 3.5 billion years ago and, much later, by 0.54 billion years ago life had evolved hard shells that preserved well as fossils. Somewhere within this three billion year span between life and fossils my chunk of granite cooled and solidified from magma. But, unlike the bristlecone pines, I still have no intuition or feeling for the age of the rock in my hand. The distance between the mileposts is just too great.
I am trained as an experimental scientist. I approach geology in that way. On another field trip, to a remote location near Socorro, NM in December 2019, I found a hefty chunk of glassy, translucent crystal [4]. It formed in sheet-like layers, almost like ice. Could it also be quartz? I tried, and succeeded, at scratching it with a knife. No, it definitely was not quartz. Then I watched and listened for what a drop of hydrochloric acid would do. I neither saw nor heard fizzing, so what I had was likely not calcite either. Perhaps unwisely, I licked it. Not salty, so not halite. Using established tests and guide books, using simple instruments like a knife and acid, using my five senses, and using my fallible reasoning, I tentatively conclude that what I found was selenite (crystalline calcium sulfate).
Making 1.4 billion years troublesome to me is its unapproachable abstraction. I can't taste it or try to scratch it. I cannot relate that age to my favorite stories, whether by Steinbeck or by Homer, much less to the voice of Mr. Cole. Sandia granite is found in America but seems not to be of America. I can hold a chunk of it, but I can't fully understand it, not its age. Here, my understanding hits its limits.
Footnotes
1. Sandia "granite" is, more precisely, the granite subtype called granodiorite.
2. For the geology and rock ages, see Jayne Aubele et al., "Geology of the Sandia Mountains", chapter 5 of Field Guide to the Sandia Mountains (edited by Robert Julyan and Mary Stuever), University of New Mexico Press, 2005. For background, Halka Chronic, Roadside Geology of New Mexico, Mountain Press Publishing Company, 1987, pp. xii-xiii, 27-31, 169-173, is helpful.
3. As I have understood it, the Trojan War was fought between 1200 and 1150 BCE. Homer, if he existed, travelled the Aegean in roughly 750 BCE and, over the course of several long nights, sang the epics to enthralled audiences.
4. This field trip is recounted in an earlier blog post, Land Beneath My Feet.
Posted: 2019-01-08. Updated: 2019-01-08.
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