Categories
STEM Education Poetry

Metacognition

Gradually, factually,
Thinking re: thinking; 
These techniques provided
Prove useful routines.  
Learn how to learn: goal of
Metacognition; the
Framework resolved
That remains to be seen.

Back to the modified double dactyl structure for another non-Twitter poem: as I mentioned at the start of July, my plan for the next few months is to alternate my Twitter translations with chemistry-education-focused poems.  I would like to add an intentional focus on metacognition into this year’s General Chemistry coursework, and the first step is to define it.  

Gradually, factually, / Thinking re: thinking; /
These techniques provided / Prove useful routines.  
 
After COVID-19 caused colleges to shift instruction online in Spring 2020, several social media groups and email lists compiled pedagogical resources.  In one such conversation, I was reminded of a wonderful book I had encountered in 2017: Teach Students How to Learn, written by Saundra Yancy McGuire with Stephanie McGuire.  As was the case with “Cubes, Eights, and Dots,” I wish I would have had this book as a student.  The authors clearly explain why learning science at the college level can be challenging; they also introduce several concrete strategies that students can implement immediately.  I have been revisiting their work in preparation for autumn.

Learn how to learn: goal of / Metacognition…
When I teach Gen Chem, it is always with an acknowledgement to myself that the content-area knowledge is not something that will truly last for most of the students enrolled; nor is it something that needs to. Many students are required to take the coursework, but for most, it is primarily content preparation for pre-professional exams, rather than the start of a lifelong endeavor.  An intentional emphasis on learning how to learn would be a welcome addition to the course, since such skills would be transferable into any future curricula and/or career paths!  

…The / Framework resolved / That remains to be seen.  
The poem’s close restates the iterative nature of learning, first highlighted in the “thinking re: thinking” phrasing above (which could easily be heard as “thinking; rethinking”).  A subject’s underlying framework– the bigger picture– is somewhat “resolved” via metacognition.  More accurately, though, that bigger picture is a puzzle that can be “re-solved” multiple times: acknowledging a learner’s expanding perspective each time in doing so, with more insights ever “remain[ing] to be seen.” 

Categories
Science Poetry

Mechanisms

“Schemes mechanistic 
Are useful heuristics 
For learning reactions organic by heart. 
Predicting new pathways, 
Then, novel skills displays: 
Part textbook-learned logic, part chemical art.”

Moving forward, I will plan to alternate my chem-education-focused essays with my Twitter poem translations.  Imprecise as the “pseudo-double-dactyl” form mentioned in the 31 May 2020 post might be, once I had its rhythm in mind, it opened up a range of chemistry words and phrases that fit better there than in the limerick’s anapestic format.  The 9 July 2019 poem highlighted one such “dactylic” topic, examining the concept of organic mechanisms: step-by-step depictions of how a reaction theoretically takes place at the molecular level.  

“Schemes mechanistic/ Are useful heuristics/ For learning reactions organic by heart.” 
“Mechanism” is an intriguingly flexible word that depends greatly on disciplinary context.  An organic chemistry mechanism is one which represents the electron flow that occurs between different reactants to achieve a chemical reaction.  These are sometimes called “electron-pushing mechanisms,” and the electrons in question are represented via the use of curved arrows.  These constitute one of the most common problem-solving types in chemistry: asking students to predict how a given reactant molecule can react to form a target product.  Generally, this is achieved by memorizing how generalized reaction scenarios occur– “learning… by heart”– and applying this knowledge to the specific molecular pathway in question.           

“Predicting new pathways, / Then, novel skills displays: /  
Part textbook-learned logic, part chemical art.”     
“Synthesis” is another word that varies with context but generally refers to putting pieces together to form a larger whole.  In organic chemistry, it refers to the construction of new, larger molecules from smaller ones.   As an educational objective defined by Bloom’s Taxonomy, it represents a higher level of learning, in which someone uses knowledge creatively to advance a new idea.  The last three lines of this poem acknowledge the higher level of learning present in a synthetic endeavor, something advanced by an expert who has moved beyond memorization of disciplinary concepts to fluency with the use of those concepts.  It has been fascinating in developing courses of my own to learn more about how people learn; this poem attempts to articulate some of the differences in skills and objectives between a novice learner and an expert practitioner.   

Categories
STEM Education Poetry

Syllabus Statements

In “Science 1,” our textbooks preach set rules
Established: puzzle pieces that will rest
Quite neatly in their promised outlines.  Schools
Rely on goals predictable to test.  
But what of science practiced?  Whence the books?  
We’ll deem that something else: the effort new
That seeks horizons far and challenge brooks.  
(For purpose here, let’s call it “Science 2.”)
I rarely note this conflict as I teach–  
Since content’s great and time allotted, small–   
And hope that one who will, in future, reach 
Beyond this course can knowledge overhaul.
     I’ll state here bluntly: both have “Science” name, 
     But Versions 1 and 2 are not the same.

I have been reading and listening a great deal in response to the nationwide rallies against racial injustice that have been taking place this summer.  Discussions such as #ShutDownSTEM have highlighted systemic obstacles that Black scholars and students face in academia.   Additionally, research published this summer has emphasized the significant barriers that General Chemistry can create for STEM students, especially Black students and other underrepresented students.  

As a white faculty member, I want to work toward an actively anti-racist learning environment in whatever ways I can.   In resuming my regular posts in this space, in addition to my typical translations of chemistry poetry, I would like to be more deliberate about discussing the challenges of General Chemistry coursework.  Thus, this sonnet is not one I’ve previously posted on Twitter.  Rather than illustrating a specific chemistry concept, it addresses a phrasing that I discovered in the literature early in my teaching career and wished sincerely that I had learned as a student.  I still found it helpful to build my discussion over a poem’s framework.  

In “Science 1,” our textbooks preach set rules /
Established– puzzle pieces that will rest /
Quite neatly in their promised outlines.  Schools /
Rely on goals predictable to test. /
But what of science practiced?  Whence the books? / 
We’ll deem that something else: the effort new /
That seeks horizons far and challenge brooks. / 
(For purpose here, let’s call it “Science 2.”) 
“Science 1” and “Science 2” are defined in an essay entitled “Cubes, Eights, and Dots,” by Robert Kooser and Lance Factor (referenced in an excellent Journal of Chemical Education article that I was fortunate to encounter a few years ago).  The authors blend historical and philosophical perspectives on chemistry “to demonstrate that scientific knowledge is not a cast-iron set of facts, but rather a fluid body of information shaped by the people who use it for specific purposes.”  They describe the development of the octet rule, a guiding principle in drawing Lewis dot structures, which are in turn useful representational tools for chemical compounds.  Notably, their essay tells the story of the rule’s development, rather than its application.  The authors quote physics professor and science historian Gerald Horton, who defines the terms borrowed in today’s poem: 

Science as it appears in textbooks [Science I] and science as it is practiced by researchers into the unknown [Science II] are two different things… Since most of us will never do Science II, we put our energies into learning Science I, but as we have seen, Science II is historically behind and underneath Science I…  We do not dare to tell our students… this would impugn the alleged empirical foundation.

Gerald Horton, quoted in “Cubes, Eights, and Dots”

In other words, textbook chemistry (Science 1) and real chemistry (Science 2) are different; this difference goes beyond simple “theory vs. practice” questions into something more fundamental.  Horton’s final quoted line acknowledges this, with his comment that “[w]e do not dare to tell our students,” in an attempt to preserve disciplinary empiricism.  (Though this is a tangent for another time, I imagine some overlap here with the debate over science “storytelling” that I’ve seen discussed in the literature.)      

What I teach in General Chemistry, with respect to the content covered in “Cubes, Eights, and Dots,” is the use of the octet rule: pure Science 1; application of an established disciplinary concept; simple evaluation via an exam question.  What is the real science– the Science 2– behind the rule?  It is the saga of the stops and starts necessary to devise this useful heuristic for describing chemical compounds: the discussions between Lewis and Langmuir; the refinement of the octet rule and Lewis structures into compelling models for other chemists; science as an investigative, clarifying process.

I rarely note this conflict as I teach– / 
Since content’s great and time allotted, small– /  
And hope that one who will, in future, reach /
Beyond this course can knowledge overhaul.
I have never accentuated this “Science 1 vs. Science 2” tension in teaching General Chemistry, which covers a great deal of disciplinary content in a limited timeframe.  Most Gen Chem students won’t take more than one or two years’ chemistry coursework, so it has seemed like they are better served by a focus on the Science-1-specific objectives that their professional programs (and, more to the point, their largely-multiple-choice qualifying exams) will require.  For chemistry majors, I hope that laboratory work, advanced classes, and independent research will illuminate the differences.  When I talk extensively about the practices and narratives of Science 2, it is either with research advisees, with whom I have far more time, or with general education STEM classes, which do not have stringent content requirements.  

However, I remember my considerable frustration as a student in my own Science-1-centric General Chemistry course, worrying that I was missing some bigger picture, even as I dutifully memorized each chapter’s numerous equations.  I wasn’t able to fully contextualize or articulate that worry at the time.  I am confident that other students, many of whom would not have the support systems that I did, have faced similar frustrations.           

I’ll state here bluntly: both have “Science” name, /
But Versions 1 and 2 are not the same.
Renowned poet and English professor Elizabeth Alexander provides a key to resolving this Science-1/Science-2 conflict, as she writes: “[S]peaking is crucial… you have to tell your own story simultaneously as you hear and respond to the stories of others.”  She adds, “[E]ducation is not something you passively consume.”  Read in a chemistry context, her words inspire the reader to learn the concepts of Science 1 by acknowledging that they, as new learners, are contributing to the narratives of Science 2.    
    
I’ve written in this space on the challenging balance between learning disciplinary vocabulary and employing that vocabulary in one’s own research and creative work.  I’d like to be more intentional, though, moving forward in my professional work: highlighting in my syllabi the existence of the “two sciences” and explaining the challenges their tension creates; quoting Alexander’s essay and encouraging students to explore Science-2-centered narratives (and to consider their own), even as we learn the Science-1 vocabulary and concepts with which to fully describe and understand these narratives.  Although directly acknowledging this complexity is a small step, it is my hope that it will be an initial, constructive one towards a more equitable classroom.     

Categories
Science Poetry

In the Cards

“Patiently, spatially, 
D. Mendeleev 
Arranges the elements by column and row. 
Prescriptive, predictive, 
The table finds favor 
In ‘eur-eka’ moments with space apropos.” 

The 8 July 2019 poem was inspired by a call from Chemical and Engineering News for entries to a Periodic Poetry contest in mid-July.  This poem is a different form of light verse than the limericks that began this project; it is likely best characterized as a modification of the “higgledy piggledy,” or “double dactyl.”  It does not adhere particularly well to the actual rules for that poem format, which are quite specific and numerous.  However, the use of a proper name in line two, its theme regarding a historic event, and the metric feet employed are all aspects that align most closely with the double dactyl form.  

“Patiently, spatially, / D. Mendeleev /
Arranges the elements by column and row.” 
In 1869, Dmitri Mendeleev devised the first form of what we recognize today as the modern Periodic Table of the Elements (PTE).  In 2019, several events marked the 150th anniversary of that innovation.  According to some sources, Mendeleev was a card player who particularly enjoyed the game Patience, similar to Solitaire, in which cards are spatially arranged according to both suit and number.  This provided partial inspiration for his innovation regarding the periodic table’s structure: in the modern PTE, the 118 known elements are arranged according to both atomic numbers (rows) and characteristic properties (columns).        

“Prescriptive, predictive, / The table finds favor / 
In ‘eur-eka’ moments with space apropos.” 
Mendeleev took advantage of known chemical data in creating his PTE precursor, fitting elements into a pattern that placed elements into chemical families with similar properties and reactivities; he also left gaps where there wasn’t an obvious candidate to fit in a space.  The table was thus prescriptive, summarizing known information, and predictive, forecasting the properties and reactivities of newly discovered elements that would fill in the gaps.  

Mendeleev named these yet-to-be-discovered elements according to their chemical relatives.  For instance, he left a gap for an element he deemed “eka-aluminum,” with an expected placement one spot below aluminum (the Sanskrit prefix for “one” is “eka”), expecting that an element with certain properties and reactivities would be discovered and would fit there.  When gallium was isolated in 1875, its properties matched Mendeleev’s predictions for eka-aluminum (and, further, provided a “eureka” moment of scientific discovery!).  This and other “space[s] apropos” played a major role in chemists’ adoption of the periodic table. 

Categories
Science Poetry

Standardized Pentameter

“The SI units, redefined today:
No longer linked to objects in a vault,
But rather fundamental constants’ slate,
To minimize experimental fault.  
The kilogram on Planck will now rely;
The kelvin will use Boltzmann to define
A temp’rature precisely and thereby
Consolidate discussions and designs.  
Five other units likewise are recast–
Candela, second, meter, mole, ampere–
From genesis in revolution past
To standards metric by which STEM coheres.  
With h, k, c, et al., assign true north;
Compare to ever-fixèd marks, henceforth.”

This sonnet, written for World Metrology Day in 2019, provides a useful transition from the April 2019 Limerick Project essays back into my general goals with this website.  Moving forward, I will still aim to post twice a week, and when the substance of a post is a single poem “translation,” I will still aim for 280 words or fewer.  Since this particular poem was spread over multiple Twitter posts, I’ll give myself 560 words as a maximum for the following discussion.   

“The SI units, redefined today: / No longer linked to objects in a vault, / But rather fundamental constants’ slate, / To minimize experimental fault.” 
Metrology is the science of measurement.  World Metrology Day is May 20 and celebrates the anniversary of the definition of the meter as a standardized unit of measurement: one on which the world could agree for purposes of scientific and commercial collaboration.  This occurred at the Metre Convention in Paris on May 20, 1875.  World Metrology Day in 2019 marked the redefinition of the metric system, or the International System of Units (denoted typically as “SI units,” given the French translation of the name: Le Système International), in terms of constants of nature.  Previously formulated in a variety of ways, these important units were redefined to rely on such quantities as the speed of light (abbreviated as c in scientific parlance) that are unchanging and universally known.  This redefinition will allow ever more precise communication and collaboration within the scientific community.    

“The kilogram on Planck will now rely; / The kelvin will use Boltzmann to define / A temp’rature precisely and thereby / Consolidate discussions and designs.”  
The SI unit of mass is the kilogram.  Previously defined by calibration against a specific physical object, one which had been kept in a locked vault, this unit was redefined in terms of Planck’s constant (h).  The SI unit of temperature is the kelvin.  While its previous definition had not relied on a physical object in the same way that the kilogram had, the redefinition linked the kelvin directly to Boltzmann’s constant (k).  Both redefinitions will enable greater cohesion in scientific communication regarding experimental designs and results, as common reference points worldwide.  

“Five other units likewise are recast– /
Candela, second, meter, mole, ampere– ”
Scientists use seven fundamental SI units in total: kilogram (mass), kelvin (temperature), meter (length), candela (luminous intensity), second (time), mole (amount), and ampere (electric current).  With the redefinition presented in 2019, all seven now depend on fundamental constants of nature for their definitions.  

“From genesis in revolution past /
To standards metric by which STEM coheres.”
The metric system was initially devised in the midst of the French Revolution (this is one of those brief statements present in introductory science textbooks that always seems worth an entire seminar course in itself).  The same system now provides a coherent reference for scientists worldwide.  

“With h, k, c, et al., assign true north; /
Compare to ever-fixèd marks, henceforth.”
The closing couplet of this sonnet denotes a few of the fundamental constants of interest to this redefinition (h, k, and c, noted above).  These last lines also allude poetically to constants as they are defined in other disciplines.  Finding true north, in geology, provides an absolute measure of directionality.  In literature, Shakespeare describes steadfast love as an “ever-fixèd mark” in a famous phrase from his Sonnet 116.  It was this last link that provided the inspiration for this particular exercise; I have always been intrigued by the centrality of “the meter” to science and poetry, in such different ways, and the focus on “constants” in different contexts was another fun theme to explore.  Moreover, it was an interesting challenge to adhere to the rules on format and rhyme for an English sonnet, after so many weeks of limericks.

Categories
April 2019 Limerick Project

Routine Maintenance

The Spring 2020 timing of this writing endeavor merits an epilogue of sorts.  The COVID-19 pandemic was in evidence elsewhere in the world from the limerick project’s start but did not affect my day-to-day responsibilities until mid-March.  By that point, I had been working on these brief essays for a while, scheduling each to post a few weeks after its writing.  

It was evident after spring break that my late-semester experience would be significantly different from my early-semester experience.  At the same time, I’d written “ahead” several blog entries, so that posts were scheduled through early April.  I was reluctant to edit those pieces.  I was likewise reluctant to interrupt what had become a diverting writing habit to focus on late-breaking, superfluous reporting on what it was like to shift abruptly to teaching chemistry remotely (in one, unsurprising word: difficult).    

Ultimately, I opted to continue staring resolutely at one STEM-themed limerick at a time, producing 280 (or so) words of explanatory prose about its five lines, with only occasional allusions to the surrounding temporal context.  What may have seemed like obtuse monotony was a considered response; I share here my rationale in case it would ever be useful to anyone else.   

A central theme of chemistry is the link between molecular structure and function.  Generally, chemists consider how adjustments to a molecule’s composition will impact its reactivity, but the same idea echoes across disciplines in resonant, moving ways.  (One such echo is Mrs. Whatsit’s beautiful discussion of the sonnet as a metaphor for one’s life in Madeline L’Engle’s A Wrinkle in Time: “You’re given the form, but you have to write the sonnet yourself.  What you say is completely up to you.”)   

Structure also enables function in terms of my writing.  The three constraints I described in the most recent entry (National Poetry Month, the Year of the Periodic Table, and Twitter’s character limit) together provided my 2019 project’s form, which in turn facilitated its inspiration.  This Spring 2020 exercise was likewise “periodic” in its own structure: returning to each daily theme from April 2019; building on each short poem with a slightly longer explanation.           

Along those lines, I will finish where this particular project began, with the Periodic Table of the Elements.  Mendeleev constructed his periodic table via an understanding of elements in two dimensions, as I wrote about in my initial limerick discussion several weeks ago: what are the elements’ weights (later refined as atomic numbers), and what are their chemical properties?  In this case, function informed structure: understanding the elements’ chemical behaviors helped Mendeleev to build his famous diagram.  

A few years ago, multiple medical emergencies struck my family simultaneously, and it has taken much of the intervening time to regain my equilibrium.  For many years, my academic research didn’t provide much solace; neither did unfocused writing.  But in the overlap of these two “dimensions” of chemistry and poetry, I finally found enough of a framework to yield a creative routine’s structure and purpose: a foothold with which to begin.  That practice has provided stability and function in this historically challenging spring, and I will continue with it in the weeks and months ahead. 

Categories
April 2019 Limerick Project

Theoretical Yield

“A frame for chem concepts, aesthetic, 
Was the goal of my April, poetic: 
A shift in perspective 
Through verses connective. 
Thus ends month’s endeavor, synthetic.”  

The 30 April 2019 limerick was the last in this particular project, which examined specifically the overlap of National Poetry Month and the International Year of the Periodic Table.  Though I’ve written several chemistry poems via the same Twitter account since last spring, this initial month was the most cohesive, both in focus and in form: a set of thirty limericks, examining the overlap of chemistry and poetry, five lines at a time.  

“A frame for chem concepts, aesthetic, / 
Was the goal of my April, poetic…”
This was a daunting project for me to start.  As I mentioned in the first entry on this website, creative writing has always been an interest of mine, but my academic writing, especially as it pertains to my courses, is primarily informative by design.  (Introductory chemistry material is challenging enough when presented in clearly written sentences.)    

However, April is National Poetry Month, and 2019 was UNESCO’s International Year of the Periodic Table.  The confluence of these two events, combined with the constraints of the Twitter format (280 characters maximum), provided enough inspiration and structure to begin: the “frame… aesthetic” alluded to in the first line.  

“A shift in perspective /
Through verses connective. /
Thus ends month’s endeavor, synthetic.”
The through-line of the limerick form— via “verses connective”—was particularly useful for me in this project.  First of all, the limerick is a brief poem: five lines, which never ran close to the 280-character limit (even as my number of hashtags increased!).  Second, since a limerick is by definition a type of light verse, its use helped me highlight these poems as primarily entertaining; this in turn alleviated my worries about their lack of technical precision.  Combined, these effects enabled me to focus on identifying concepts, stories, and techniques that I could describe in this format, looking for “shift[s] in perspective.” 

The concept of an “endeavor, synthetic” is another resonant one, with its complex and intertwined echoes for chemistry, language, and education.  This was a rewarding project, yielding a new understanding of how I can approach my subject, and I’ve enjoyed continuing similar efforts in the year since.  

Categories
April 2019 Limerick Project

Resonance

‘ “We still don’t get ‘renaissance structures,’”
Said the students in moments past lecture.
Their phrasing, inverted,
To me then asserted
Historic’lly wondrous conjectures.’

Since the April 28 limerick was summarized a few days ago for Graduation 2020, this entry returns to the home stretch of my poetic project.  The 29 April 2019 limerick addresses an imaginative misphrasing that I’ve encountered a few times in teaching.

‘ “We still don’t get ‘renaissance structures,’” /
Said the students in moments past lecture…’ 

A common misstatement in General Chemistry is the use of “renaissance structures” for “resonance structures.”  (Presumably, this error would be characterized as some variant of spoonerism or mondegreen!)  

Resonance structures acknowledge the limitations of simple drawings in representing chemical reality.  Chemists use Lewis structures, or electron-dot structures, as a first step towards depicting molecular structures.  In certain cases, a molecule can exhibit resonance, which means that one single Lewis structure cannot fully depict the complexities of the molecule’s bonding.  In these cases, multiple resonance structures are drawn, and a chemist considers the true molecular structure to be an average of the resonance structures, also known as a resonance hybrid.    

Often, resonance constitutes a challenging concept, especially if students have not encountered it previously.  Moreover, I often notice that some of the best discussion in class arises at the close, in the few minutes when students ask questions in passing, before heading out the door.     

‘Their phrasing, inverted, /
To me then asserted /
Historic’lly wondrous conjectures.’

In several years of teaching, I have heard the “renaissance structure” description several times.  I always appreciate the flipped-syllable phrasing, which provides a diverting vision of complex Renaissance architecture… in the midst of my decidedly non-complex molecular drawings.  

“Resonance theory” arises in multiple contexts throughout the curriculum.  As with many scientific phrases, it exhibits an interesting duality: standing alone, it is an evocative phrase; in the chemistry context, it has a specific meaning.  I’ve attempted throughout this project to build on both aspects: balancing the poetic-sounding terms of my disciplinary vocabulary with information about their technical definitions.  

Categories
April 2019 Limerick Project

Dalton’s Theory

“A recurrent theme that’s oft taught in
Gen Chem 1 is the theory of Dalton.
In a chemical change,
Matter will rearrange:
One of key points presented each autumn.” 

In the 27 April 2019 limerick, I returned to discussing common themes of my introductory chemistry lecture course.  In this case, the subject is Dalton’s Atomic Theory.  John Dalton was an English scientist who completed many fundamental studies in chemistry, biology, and meteorology in the late 1700s and early 1800s.  

“A recurrent theme that’s oft taught in /
Gen Chem 1 is the theory of Dalton.” 

General Chemistry 1 introduces three perspectives on chemistry: the particulate-level (what are atoms and molecules in a chemical sample doing?); the macroscopic-level (what can we observe about that sample in the laboratory, as a result of the behaviors of the component atoms and molecules?); and the symbolic (how do we represent both of these levels via equations and other notation, to best communicate with other scientists?).  These three perspectives are summarized as Johnstone’s Triangle (or the chemistry triplet) and learning to translate among the three can be a challenge for students.  Dalton’s Atomic Theory is a common theme in General Chemistry 1 and highlights some links between each of the three “sides” of this triangle.     

“In a chemical change, / Matter will rearrange: /
One of key points presented each autumn.”

Dalton’s Atomic Theory is a set of statements about chemical behavior.  Several of these statements rationalized behaviors about chemical species that had already been observed by other scientists.  Others predicted behaviors that would later be observed, leading to the theory’s acceptance.  The theory rationalizes matter’s behavior (macroscopic perspective) through the concepts of atoms and compounds (particulate perspective).  The theory is generally presented as a set of multiple postulates, one of which states that a chemical reaction rearranges matter but does not create or destroy it.  This idea is a statement of the conservation of mass and is summarized by the last three lines of the limerick; further, it is only one of several “key points.”  These chemical changes are represented (symbolic perspective) with balanced chemical reactions, as described in the 3 April 2019 limerick.

Categories
April 2019 Limerick Project

Timescales

“Within all the plant life arboreal,
Reactions— complex, inventorial—
Cause synthesis (photo);
Roots extending below,
Long relics of time immemorial.”

The last of the poem homages was published on 26 April 2019, a date on which the Friday of Earth Week and Arbor Day overlapped.  It took as its central image the famous setting from the first line of Henry Wadsworth Longfellow’s “Evangeline.” As with most of the poems in this sequence, the allusion was a surface one at best: the “forest primeval” simply seemed a fitting theme for Arbor Day!

“Within all the plant life arboreal, /
Reactions– complex, inventorial– /
Cause synthesis (photo)…”
   
In teaching my classes, I focus on simplified scenarios in which chemical reactions occur one at a time and can be easily tracked and understood.  In any real-world system, the underlying chemistry is multifaceted, consisting of multiple processes occurring in tandem (“reactions– complex, inventorial”).  Photosynthesis is the process by which trees and other plants (“the plant life, arboreal”… and otherwise) can convert the energy from sunlight into chemical energy; it has enormous implications for life on earth, including the generation of oxygen.  Describing photosynthesis comprehensively requires a large number of interconnected chemical reactions. 

“Roots extending below, /
Long relics of time immemorial.”

A reaction’s “timescale” defines how quickly it can occur.  Again, in teaching, I highlight reactions that occur over a scale of seconds to minutes; these can be easily monitored in a classroom environment.  However, reactions can occur much more slowly and much more quickly.  Scientists sum up these timescales with the use of metric prefixes: some processes can take months or years (megaseconds); others can occur in a billionth or a trillionth of a second (nanoseconds or picoseconds, respectively).  

Within a tree like an ancient sequoia, multiple timescales are impressively, simultaneously evident, given the trees’ massive scales and lifetimes through centuries, via these cascades of chemical reactions, continuously occurring in fractions upon fractions of seconds. In her outstanding memoir Lab Girl, Dr. Hope Jahren writes movingly about the chemistry and drama underlying botany: “No risk is more terrifying than that taken by the first root.”  Centuries later, far outpacing our own timescales, these “long relics” can persist.