Do We Need Orbitals?

Do we need to discuss orbitals in General Chemistry? They are a standard part of G-Chem textbooks. With the “Atoms First” approaches, orbitals show up quite early in the semester. In my G-Chem class, they typically show up at the beginning of Week 4, so my class has been immersed in them all of this week.

As a quantum mechanic, I enjoy talking about orbitals and other aspects of quantum chemistry that show up in G-Chem. This is a topic in which I am probably more knowledgeable than your average chemistry instructor. I can comfortably field student questions on the weird and wonderful world of electron behavior. However, I also see the pitfalls in the simplified presentation at the G-Chem level, often leading to student misconceptions that I then have to correct in physical chemistry and/or inorganic chemistry. After many years of teaching, I can state that the topics surrounding the notion of an orbital are for the most part confusing to G-Chem students. Do we need them at that level?

Why do we ‘think’ we need orbitals? Here are some things an instructor might say.

(1) Writing electron configurations is one of the key ‘outcomes’ in a G-Chem course. By that, I’m referring to the 1s² 2s² 2p⁶ 3s² variety, rather than the 2.8.2 Bohr model variety.

(2) Students need to know s and p orbitals so we can discuss hybridization, and this sets up a discussion of resonance/delocalized-pi systems and all sorts of language used in Organic Chemistry (the course that comes after G-Chem).

(3) How else will we cover that Molecular Orbital diagram in the G-Chem text book so we can show the superiority of MO theory and its prediction that O₂ is paramagnetic?

(4) The “simple” picture of electron sharing in covalent bonds is wrong. Students need to be able to describe bonds using orbital overlap.

(5) How else will you explain why the Periodic Table has the unique shape that it does (with the s-block, d-block, p-block, etc.)?

Here’s how much time I typically take on orbitals (and leading up to them), as represented by titles of each hour-long class period.

·      Waves and Photons

·      Interaction of Light & Matter, and the Bohr Model

·      Photoelectric Effect and Wave-Particle Duality

·      Quantum Numbers and Orbital Shapes/Sizes

·      Photoelectron Spectroscopy and Orbital Energies

·      Electron Configurations

Three other class periods that relate to orbitals are:

·      Periodic Trends

·      The Covalent Bond (introduction)

·      Hybridization

Most years I don’t cover the standard Molecular Orbital “mixing” Energy Diagram involving the 1s, 2s, 2p orbitals, but I do discuss the overlap of two 1s orbitals to form a bonding and anti-bonding molecular orbital, and relate this to the Pauli repulsion, when introducing the covalent bond. Most of the discussion in Periodic Trends uses the simpler shell model, and orbitals are explicitly invoked only to discuss the two kinks in the trend of increasing ionization energy across a row in the periodic table.

If I didn’t concern myself with orbitals, I would be able to dispense with a swath of material in my current G-Chem class and use that time to tackle other topics in-depth and perhaps introduce other relevant important concepts in chemistry. But first I must consider if they can be dispensed with. Let’s consider responses to the five listed objections.

(1) Do we need really need orbital-based electron configurations? Bohr’s shell model is sufficient to explain both ionic and covalent bonding. It’s more intuitive to understand in both cases. One can draw Lewis structures, discuss molecular shape, determine polarity for intermolecular forces, all without the orbital-based electron configurations.

(2) Do we really need hybridization? We don’t need it to draw resonance structures, and if students remember that being able to draw resonance structures contributes to stability, that’s likely good enough at the G-Chem level. Delocalization can be qualitatively discussed without hybridization through resonance structures. Many O-Chem books cover hybridization in their introduction, just enough to cover what is needed. Much of sophomore-level O-Chem doesn’t require orbitals. Geometric/steric/resonance arguments can cover a lot, and even simple nodal theory could stand in for “frontier orbital” symmetry explanations.

(3) The success of predicting the paramagnetism of O₂ comes at the cost of a whole bunch of things the students don’t understand and get seriously confused by. And frankly, the result is hardly used. Simple geometric reasoning combined with VSEPR theory can explain the anomalously weak F–F and O=O bonds. One doesn’t need paramagnetism to discuss the reactivity of O₂.

(4) Yes, the simpler model might be “wrong” but how does the orbital picture enhance student understanding of chemical reactivity? In my experience, it just adds to confusion and the students actually rely on the simpler heuristics to get them through. Again, this is at the G-Chem level. We discuss bonds breaking and forming, but viewing it through an orbital lens doesn’t confer a particular advantage.

(5) A Bohr shell/subshell model coupled with photoelectron spectroscopy can do this sufficiently without getting into the orbitals explicitly.

Now, I’d certainly want to tell students the limitations of the Bohr model (along with its strengths). Chemistry is peppered with models. We’re trying to describe the unseen. We’re forced to use models all the time. All models are wrong. Some are useful. It’s something I tell my students as we move from model to model. Goodbye, quantum numbers and orbitals. We would use Bohr electron configurations with a shell/subshell model as a foundation to bonding. So that’s roughly six hour-long class periods that could be devoted to something else.

If orbitals were not mentioned, I would still discuss atomic emission/absorption spectra and the Bohr model, and I would still discuss the strangeness of Bohr’s magic wand in the context of the Bohr model. (I could even try my Orbital Azkaban analogy!) I would only need to use a part of my “Waves and Photons” class and not worry about diffraction and interference and the quantum nature of a photon (although I would still mention the idea of a standing wave.) I could skip the photoelectric effect, wave-particle duality, the deBroglie relation, and Heisenberg’s Uncertainty Principle. I think Pauli repulsion is important, but this can be discussed without the four quantum numbers definition and talking about “space and spin” properties of fermions in simple terms. Shorter multiple bonds compared to single bonds can be attributed to Lewis-ish geometric considerations.

All that being said, I don’t expect to jettison orbitals in my G-Chem class. For one thing, our department teaches multiple sections so I might be one of ten instructors. We decide on a common textbook and coverage of topics for both semesters. I’m unlikely to win an argument to skip them especially since all of us are used to teaching G-Chem with orbitals, not to mention we also learned it that way. I also genuinely enjoy talking about it in class. I think electrons and chemical bonds are weird and wonderful – I suppose that’s why I’m a chemist. And while some students find it difficult and confusing, others enjoy delving into the “whys” – a fresh breath of air compared to the way chemistry was taught in their high school.

Just yesterday after class, a student came up to say she really enjoyed class because she experienced some gain of understanding compared to what she saw and memorized in her high school A.P. chemistry class. We had discussed ionization energy of H, He¹⁺ and He, and the effect of electron screening. We then delved into how the 1s electron differentially shields the 2s and 2p from the nucleus, and how it splits up the energy levels of orbitals with the same n quantum number. (We had previously covered the limitations of the Rydberg equation.) Then, we looked at photoelectron spectroscopy data and talked about the interplay between theory and experiment. I felt gratified for going into those details that had also excited me about chemistry when I was an undergraduate!

I leave you with a picture from one of my opening slides from this past week: the orbitron gallery. Check out the WebElements store if you want to get your own!

Interview with the Professor

It’s been over 20 years since I watched Interview with the Vampire, so I no longer remember the story. I haven’t read the Anne Rice book on which the movie is based, but it surely must have been interesting enough for a movie to be made with a bunch of famous actors. Interviewing a vampire could be quite dangerous to one’s health. This is true even if you’re a wizard, as Harry Dresden finds out in the first book of the Dresden Files.

In today’s post, I present to you, without a hint of danger, the much-less-interesting Interview with the Professor. I occasionally get interviewed by students who have some sort of writing assignment. Last year, a student interviewed me for a project canvassing opinions of chemists and non-chemists on renewables. And I honestly don’t remember what the topics were in previous years. That’s what happens when you fail to document, and your memories fade. Yesterday I was interviewed by a student in my general chemistry class on a project related to another of his classes. I’ve decided to document my response before memory fades. Just for fun, I also decided to make a book cover mimicking the 1^st edition cover of Rice’s book (although I was too lazy to get the font and dimensions just right).

No movie will be made out of this interview since I have no magical or paranormal powers that I’m aware of. Neither is the story dramatic or tension-filled. It might even have clichés, since I’m simply not that interesting of a protagonist. It does reveal what students might be interested in knowing or writing about, and how I responded. In any case, I record this as an aid to fading memories. I wrote this up half a day after the in-person interview. I did not record myself, so I’ve likely edited my responses to make it more readable. The student sent me the questions 24 hours in advance so I did have some moments to think about them.

Why did you want to become a teacher?

Since young, I’ve realized I have a knack for it. I enjoyed helping people learn something that I (hopefully) knew or understood. My parents were both schoolteachers when I was growing up. I think they provided positive role models. I don’t recall them complaining about their students or the teaching. (On the other hand, as in most places, the public school system was problematic.) I helped grade multiple choice questions starting at the age of maybe nine. I also thought how wonderful it would be to continue having lots of school holidays! (Now, that I’m a teacher I’ve been slightly disabused of the notion.)

What do you like most about teaching?

I enjoy talking about something that I know. (As an introvert, I keep quiet when I don’t.)

Helping students and seeing the aha! moment continues to be gratifying to me as a teacher. I learn when I teach. One might argue that I’m the one learning the most. And teaching is

never dull – students are different every year!

What do you like most about chemistry?

There’s a beauty to it. All of matter and its interactions can be explained by the structure and behavior small entities that you can’t see. Understanding chemistry requires words, numbers, pictures, equations, and imagination! At first glance, it seems there’s a grand system – but it’s actually full of idiosyncracies. The Periodic Table looks organized, and is a fantastic organizing principle – your first encounter usually hides the particularities, but as you learn more chemistry, it makes you appreciate the uniqueness of each element, and how its chemical behavior can change in different environments.

How do you see the value of grades in schoolwork? What do you think would change if work was not graded?

I think grades provide a measure of what and how much students have learned, although imperfectly since we use proxies such as exams to measure what we cannot see – the learning going on inside someone’s brain. For example, if someone knew over 90% of the material, as demonstrated on an exam, I might say the student’s knowledge in that area is excellent. That would be an ‘A’. Knowing two-thirds of the material means there are still many holes. Not so great. That might be a ‘C’.

The second thing it does is motivate students to learn. For a small number of students who are internally self-motivated, whether or not there are grades would make no difference. But for many others, knowing one will be graded provides some (external) motivation.

Do you find readings from textbooks, lab experiments, or class lectures and discussions to be most important? Or, how do they each present value for learning?

They’re all important, but for different reasons. The textbook is useful to read before class because it gives you a sense of where things will be going. If you read the text ahead, even if you don’t understand everything, you’ll be much better able to follow along in class. The textbook is also useful as a comprehensive reference. It provides additional worked examples and lots of problems to try. Learning chemistry requires practicing problems!

Lab experiments provide hands-on experience. There is no other way to learn lab techniques than to actually do things in lab. Simply watching a video just doesn’t cut it. In lab, you get to see and experience how science actually works in all its glory and messiness. Many students who become chemistry and biochemistry majors actually do so because they enjoy the lab experience.

Sometimes difficult to figure out things on your own. That’s where the lecture and class discussions are useful. One role of the teacher is to pre-digest harder-to-learn or complex material. An expert can also provide context and alert you to common errors. Being co-located in the classroom also allows learning interactively. Students can ask questions immediately. Teachers also ask questions to probe student thinking. The interaction also allows the teacher to tailor/adapt to student learning needs in real time and space.

Does your teaching style change depending on how advanced a class you’re teaching is?

Yes, it depends on the nature of the class, how challenging the material might be, but also background knowledge of students. If the students do not have much background, it is important (at least in chemistry, and likely in the natural sciences) to tell the student the key things. Lecturing therefore works well. Also working through examples of problem solving is helpful to the novice learner. So in general chemistry, part of my class is lecture, part is discussion, and sometimes there are worksheets where you work both alone and in groups to solve problems in chemistry. In a special topics class where I want the students to dig into the primary literature, the class is much more discussion-based. Students lead some of those discussions. In a mathematically heavy class like physical chemistry, I have to go through some of the math more slowly. So yes, I try to adapt my style to the topic at hand, to the background of the students in the class, and what we are trying to accomplish in class.

Epilogue. After the student left my office, I was reminded how much I enjoy the teaching part of my job as a professor. That was more than worth the time taken to think about the interview questions and write up this post!

P.S. Maybe I should also read Interview With The Vampire at some point.

The Dresden Files: A Different Magical Harry

Harry Dresden has outed himself as a wizard in the Yellow Pages. He’s the only one self-advertising, mind you. But he needs clients to pay rent and so offers to investigate incidents involving the paranormal or finding missing objects. Naturally, the Chicago Police Department has him on retainer for when something bizarre comes up, but they don’t pay well and some of the cops think he’s a fraud. It turns out he is an actual wizard, living in a dilapidated basement apartment. At least those are his current humble beginnings in the first book in the Dresden Files series, Storm Front, written by Jim Butcher. 

The story follows the lines of a detective noir novel, but with supernatural bits included. There’s a police officer ‘partner’, a journalist, and a supportive grunting neighborhood bartender. For TV-watchers Dresden might be a combination of Grimm and The Mentalist. There is magic involved, but much depends on being observant and keeping one’s wits in tricky situations. In that sense, there’s nothing too special about Storm Front. Harry Dresden is not like Harry Potter, in case you were wondering. There is something akin to a Statute of Secrecy among the wizarding folk in Dresden’s world, but he’s willing to breach it for cash. But he has principles. He won’t appear at parties, provide endless purses or make love potions. He really is a detective at heart, and seems to want to do his bit to help others. Dresden thinks there’s a need, even though most people don’t believe he’s a ‘real wizard’. Here’s his justification.

The end of the twentieth century and the dawn of the new millennium had seen something of a renaissance in the public awareness of the paranormal. Psychics, haunts, vampires – you name it. People still didn’t take them seriously, but all the things Science had promised us hasn’t come to pass. Disease was still a problem. Starvation was still a problem. Violence and crime and war were still problems. In spite of the advance of technology, things just hadn’t changed the way everyone had hoped and thought they would. Science, the largest religion of the twentieth century, had become somewhat tarnished… People were looking for something – I think they just didn’t know what. And even though they were once again starting to open their eyes to the world of magic and the arcane that had been with them all the while, they still thought I must be some kind of joke.

Storm Front is written entirely in the first person – Dresden’s perspective of course. This has two advantages. One, the action moves quickly and doesn’t split into several parallel threads. Two, the reader gets a glimpse of how a wizard thinks internally. This latter point is what I find interesting. Dresden drops interesting tidbits along the way about how magic works. I see the potential for a systematic (perhaps even ‘scientific’) building of magical theory in the author’s approach; it’s at least enough for me to put the next book in the series on my reading list.

Unlike in Harry Potter, where the interference of magic and Muggle electricity is only mentioned in passing, this link is experienced explicit by Dresden. Here are a couple of passages.

The phone rang again almost the instant I put it down, making me jump. I peered at it. I don’t trust electronics. Anything manufactured after the forties is suspect – and doesn’t seem to have much liking for me. You name it: cars, radios, telephones, TVs, VCRs – none of them seem to behave well for me. I don’t even like to use automatic pencils. … The music continued for a few seconds more, and then it began to skip over a section about two seconds long, repeating it over and over again. I grimaced. Like I said, I have this effect on machinery. It has something to do with being a wizard, with working with magical forces. The more delicate and modern the machine is, the more likely it is that something will go wrong if I get close enough to it. I can kill a copier at fifty paces.

Driving a car can sometimes be a challenge. Dresden also avoids elevators, for good reason. I have previously speculated that the link is via electromagnetic radiation. He calls the science of magic ‘quasiphysics’ – which seems appropriate. When investigating what seems like a magical crime, Dresden concludes.

There just weren’t all that many people who could get enough power into that kind of spell to make it work – unless there was some flaw in the quasiphysics that governed magic that [redacted for spoiler]; and I wouldn’t know that until I had pursued the forbidden research.

Dresden has a lab in the sub-basement of his apartment. From his description, it sounds like a chemistry lab. He discusses the essence of making potions – providing a rudimentary theory of sorts – but the explanation seems weak or underdeveloped to me. He also has a lab assistant in the form of a spirit that he has trapped in a skull named Bob. It turns out Bob is like Alexa. But instead of being connected to the Internet, he’s connected to a treasure trove of magical information down the ages. Bob is helpful with remembering potion recipes and adapting them to the brewer. There seems to be some uniqueness between the efficacy of the objects used and who brews the potion and for what purpose, i.e., potion recipes are dynamic and must be adapted. It isn’t clear yet exactly how or why. There is however a mention of lab coats and wizarding robes!

I took my off my duster and got out my heavy flannel robe before I went down into the lab. That’s why wizards wear robes, I swear to you. It’s just too damned cold in the lab to go without one. … [Bob] made his residence inside the skull that had been prepared for him several hundred years ago, and it was his job to remember thing. For obvious reasons, I can’t use a computer to store information and keep track of the slowly changing laws of quasiphysics. That’s why I had Bob. He had worked with dozens of wizards over the years, and it had given him a vast repertoire of knowledge – that, and a really cocky attitude.

Dresden considers the energy required before he attempts to cast a spell. Energy efficiency is crucial. I think a sensible theory of magic requires you to expand a proportional amount of energy for the changes you are making to the material world, so I applaud this effort. This is why one needs powerful objects to store magical energy. Dresden makes a direct connection when he discusses ‘violet’ light that he senses in a place full of magic energy that he can potentially access. In the electromagnetic spectrum, violet is at the edge of visible light and carries the most energy compared to other colors of the rainbow. (Is there a magical color?) There is also an interesting discussion of the tension between dark magic and light magic – I think this is something that could be explored in subsequent books, and there might be an underpinning magical theory to this.

I close with his description of ectoplasm. Yes, there is an occasion where Dresden gets covered in the goo. But there’s now a direct connection when matter is summoned.

Both of us were coated in dust that was stuck to the stinking, colorless goo, the ectoplasm that magic called from somewhere else whenever generic mass was called for in a spell. The goo wouldn’t last long – within a few more minutes, it would simply dissipate, vanish into thin air, return to wherever it came from in the first place. For the moment, it was just a rather disgusting, slimy annoyance.

It’s enough to keep me interested in reading the next book.

Carving Nature at Its Joints

What’s the difference between a butcher and a hack?

The expert butcher efficiently carves up a carcass in seemingly effortless motions. I’m much more the hack. Cutting up meat is tiring. I’m slow and inefficient. One might say I lack practice. I blame this on the convenience of modern day supermarkets. Meat comes prepackaged in easy to cut pieces. I much prefer this to childhood visits to the ‘wet’ market. Buckets of water were constantly splashed on the floor to wash away the blood from chickens and other assorted hunks of meat. I’m not squeamish. Seeing fowl being slaughtered in front of me isn’t a problem. But I’m lazy.

Why does the butcher’s knife-work seem effortless? In an old Taoist story, a king asks an expert butcher what his secret is. “Ordinary butchers hack their way through the animal Thus their knife always needs sharpening. My father taught me the Taoist way. I merely lay the knife by the natural openings and let it find its own way through. Thus it never needs sharpening.” This quote comes from the introductory chapter of Carving Nature at Its Joints, a collection of essays on Natural Kinds in Metaphysics and Science. The introduction, written by Matthew Slater and Andrea Borghini, is aptly titled “Lessons from the Scientific Butchery”. The book’s title alludes to Plato’s discussion of his theory of the Forms in Phaedrus. How we classify things, how we distinguish kinds from each other, is akin to “carving nature at its joints”.

Carving is a philosophy book, or rather a collection of essays by philosophers. I don’t often read philosophy. It feels like hard work with lots of definitions and seemingly twisty language. I’m more of a hack when it comes to philosophy, although I do find many of the questions posed by philosophy interesting to ruminate, particularly when they overlap with the natural sciences. So I try to hack my way through the complicated (to me) prose in the hope of learning some nuggets. I also feel humbled by my lack of knowledge in this area, and it is good for me to reminded what a struggle it can be for my students to whom the vocabulary of chemistry seems obtuse – with seemingly obscure definitions and its own twisty language.

I’ve only worked my way through the introductory chapter of Carving, but chemistry makes an appearance in several instances. The authors quote a philosopher named Nagel who writes: “The statement that something is water implicitly asserts that a number of properties (a certain state of aggregation, a certain color, a certain freezing and boiling point, certain affinities for entering into chemical reactions with other kinds of substances, etc.) are uniformly associated with each other.” Another philosopher, Quine, asserts: “Comparative similarity of the sort that matters for chemistry can be stated outright in chemical terms, that is, in terms of chemical composition. Molecules will be said to match if they contain atoms of the same elements in the same topological combinations.”

Is water H₂O, commonly depicted as a Mickey-Mouse-head-shaped molecule? A single water molecule does not have the properties that Nagel describes. A large collection of water molecules might, although those might change depending on the ‘environment’. Can you even find a sample of pure water? Students in the lab think that the deionized (dI) water is “pure” although it isn’t. Thankfully, I have never caught a student trying to chug down dI water for ‘health’ reasons. Do the different impure natural samples of water point to the Platonic Form of Water? There’s a whole book titled Is Water H₂O? by philosopher Hasok Chang. I started reading it several years back, and then got bogged down about a third of the way through. Maybe reading Carving will motivate me to get back to it. Interestingly both books have similar nondescript covers dominated by a single color. I assume red for butcher’s blood and blue for water, although these are just representations. Is blood red? Is water blue? What is color anyway?

The introduction to Carving discusses a number of philosophical definitions and positions. The concept of essence is discussed with respect to Aristotle, Locke and more contemporary philosophers such as Bealer, Kripke and Putnam. It’s been a long time since I read Aristotle or Locke, but I was reminded about the difference between primary and secondary qualities, and between nominal and real essences. I was also reminded that Aristotle wrote something called Metaphysics, which I haven’t read but probably should. (I read Nicomachean Ethics in college.) I didn’t know that Aristotle had written something called Posterior Analytics, a title which might sound naughty in this day and age.

It was interesting to learn from the authors of Carving that “chemical kinds have long been a favorite example of essentialists… it seems that quite plausible that the sort of similarity that would matter for this domain would be molecular structure: the arrangement of certain kinds of atoms.” However, the authors discuss the difficulties associated with this position and how it can be tricky to define properties. In the first week of my introductory chemistry courses, we discuss how the atom – the philosophically indivisible particle – turns out to have subatomic particles, and how the scientists discovered these particles through their properties. It’s especially ironic that the firm establishment of ‘matter is made up of atoms’ thanks to Einstein’s theory and Perrin’s painstaking experiments occurred simultaneously as Thomson, Rutherford, and others, took the atom apart.

I’m looking forward to learning more lessons from the Scientific Butchery. From the table of contents of Carving, it looks like there will be some interesting articles on fundamental physics and classifications in biology. The reading will be slow, but I’m newly motivated to put myself in the shoes of a student, and so be in solidarity with my chemistry student. Besides general chemistry, I’m also teaching quantum chemistry this semester. And no one really understands quantum mechanics. It’s a strange world with a mathematical vocabulary that many students are uncomfortable with. My comfort level with comprehending mathematical equations also has its limits, and I try to avoid the hairy parts. With strange ideas such as wave-particle duality, it becomes increasingly difficult to separate things into kinds.

Twilight of the Third Age

I’ve enjoyed playing several games of War of the Ring this past month. I played 72 games in the first four years, but since then it has slowed to a trickle. There was even quite a stretch of years where it did not see the light of day. I broke the dry spell last year, getting in four games during the summer. I’ve exceeded that count slightly this year. Most of my plays have been with the base game (I have the 2004 first edition) but a number of games have included the Twilight of the Third Age expansion (released in 2006 with Battles of the Third Age).

I enjoy considering What If scenarios, and being a Tolkien fan, War of the Ring allows me to ‘replay the tape’. Multiple times. With different strategies. So, here’s a recent session report with one version of that tale. This one includes Twilight of the Third Age. It includes an actual Balrog character, and more!

The Balrog makes an early appearance in Moria just as the Fellowship starts off from Rivendell. Forces of Shadow begin to mass in Moria and Dol Guldur. The Elves are quickly roused to war, and Galadriel takes military command of Lorien which is assailed by the two orc armies from east and west. Lothlorien comes under siege.

Meanwhile, six members of the Fellowship of the Nine Walkers arrive in Fangorn stealing through Moria unawares. The remaining three (Gandalf, Frodo and Sam) however are finally spotted at the Goblin’s Gate, having braved the High Pass. Shortly after, a tamed Smeagol joins the group as a guide, but proves not to be helpful in avoiding the spies of Sauron. Gandalf sacrifices himself to protect Frodo, but Sauron’s hunt for the ring proves a heavy burden for Frodo and takes its toll. Frodo, Sam and Smeagol divert their original plan and take refuge in the Woodland Realm for Frodo to recover.

Saruman reveals himself as an ally of Sauron, stirring up the Dunlendings to war. Saruman splits his forces. A small army of orcs and Dunlendings marches north and east through Moria to aid the siege against Lorien, where Galadriel has been holding out after eliminating the Balrog, but Elven reinforcements are depleted. The Witch King reveals himself, and his Nazgul circle Lothlorien. A second small yet potent army of the White Hand, with orcs and wolfriders, storms the Fords of Isen and quickly besieges a lightly garrisoned Helm’s Deep marshaled by Gimli. Legolas has ridden to Edoras and the armies of Theoden are marshaled. In the meantime, Boromir, arrives in Minas Tirith to shore its defences while Pippin and Strider arrive in Pelargir. Merry remains in Fangorn but Saruman’s quiet mustering of his armies does not rouse the Ents to anger.

Lorien finally falls after a protracted siege and the Nazgul fly towards Helm’s Deep. Gimli and the small defense is no match for Saruman’s orcs. Helm’s Deep falls quickly. Meanwhile, two large armies of orcs pour out of Minas Morgul. The Haradrim march west and Strider, having been crowned King of Gondor in Pelargir, arrives in Dol Amroth with Merry. They have heard word of ships massing at Umbar. Although Frodo is not fully healed, the fall of Lorien and Helm’s Deep, and movements in the south mean that there is no time to lose. Frodo and Sam, still guided by Smeagol strike South for Mordor. Gandalf, now clad in the White, reappears in the Woodland Realm for defence. The Northmen have been roused to war and muster troops in Dale and Carrock.

The Mordor orcs spill into Osgiliath and besiege Minas Tirith just as the Haradrim strike Pelargir. Siege towers are built around Minas Tirith even as Boromir tries to shore up the defence of the city. The Witch King, commanding the Shadow forces, slowly wears down the defences of the city. The Haradrim meanwhile push towards Lamedon where they are joined by the Southrons from Umbar. Dol Amroth comes under siege but Aragorn is well-prepared with a strong defence. Meanwhile the ring quietly moves south. However, the spies of Sauron are effective in forcing Frodo to use the ring repeatedly. Tame Smeagol seems to be of no help.

Minas Tirith finally falls and the Nazgul shift their focus to Dol Amroth. Frodo and Sam are found by the spies of Sauron in the Dagorlad, in the presence of an army of orcs. They are able to escape, hide and steal through the Black Gate into Mordor, steal guided by Smeagol. While Legolas and Theoden hold Edoras in force, Saruman’s orcs move closer. At the same time, a second army of Morgul orcs moves into the Druadan forest from Osgiliath. Edoras is about to be assailed on both sides.

In the pits of Gorgoroth, Frodo succumbs to the power of the ring, thus removing the last hope of the Free People. Who knows? They might have stood a better chance if malicious yet cunning Gollum was the guide instead of tame Smeagol.* Although Aragorn holds Dol Amroth against a massive siege, he will not be able to stand against the might of Sauron who has regained his One Ring. (The Shadow player won this time, but in two other recent games of Twilight, the Free Peoples won – one by a considerable margin, and the other was a nail-biter to the very end.)

*After the game, I realized I made a rule error. If the Fellowship is declared by the Free Peoples, tame Smeagol should have left the Fellowship, and thus Gollum should have become the guide with Gandalf’s demise.

Here’s a picture of the board at game’s end showing the large besieging army at Dol Amroth. The smaller inset at the edge of the board is where defending armies are placed when they retreat into a stronghold. I’ve annotated some features of the game. Those familiar with War of the Ring who have not seen the Twilight expansion will notice some game pieces not found in the base game: siege towers, trebuchets, corsair ships and the Ents. In this session report I’ve also highlighted new characters: (tame) Smeagol, Galadriel, the Balrog, and the Dunlendings.

I’ve now played close to a hundred games over almost fifteen years. (That’s some 200-300 hours by my estimate, but it’s time enjoyably spent.) In my opinion, the base game favors the Shadow player slightly (even with the recommended extra elite unit in Erebor during setup). Maybe about 20% of my games have included Twilight, and I think it favors the Free Peoples slightly, but my sample size is much smaller. While there is a chunk of strategy involved, the luck of the dice and the card draw allows fortunes to sway back and forth. It keeps things interesting and exciting!

Hoyle's Top Ten

Six months ago, a colleague shared with me this post by Joe Hoyle. (I don't know Hoyle personally but my colleague does.) At first, it might seem like just another of those Top Ten lists, but this one has stuck with me. I’ve revisited it several times, and have been thinking about my own top ten things I’ve learned from teaching. But the more I’ve pondered this, the more I see myself aiming towards Hoyle’s reflections. He’s been teaching for 47 years, that’s more than double the amount of time I’ve been at it. If you’re a teacher, I highly recommend this list.

Instead of coming up with my own top ten (still a work in progress), I will reflect on some of the items on Hoyle’s list.

Coming in at #10: You always have to prepare for class. In particular, Hoyle says “you simply have to be the best prepared person in the room”. This truism holds even as you work to have your students come to class prepared (a constant challenge). I’m pleased to say that #10 is something I’ve continuously worked on. I’m constantly revamping and rehashing my course material to make class better! I hope I’m still doing that after forty years of teaching, but I’m not quite there yet.

#8: Students rarely change over the years. This has mostly been true to my experience as a teacher, at least in terms of academic ability and basic intellectual skills. If I look at the grades students have earned in my class over the years, the distribution hasn’t changed much although I’ve made my classes a tad more challenging over time – adding a tiny bit more depth and nuance to my exam questions, problem sets and in-class exercises. If I were to hazard a guess, I’d say my class I’ve upped the ante about 5% over the last couple of decades. It’s not much, and maybe students have coped just fine because I’m improving as a teacher (or at least I hope so). The one thing that I think has changed is that students today are more stressed and I am seeing a larger proportion of mental-health related issues. I think technology and the quickening pace of everything in their lives is a contributing factor, and that they fight a harder battle against distraction.

Of the ten, I’ve pondered #4 the most over the last six months: Helping students understand that they leave each class with Swiss cheese knowledge – it looks solid but it is full of holes. Maybe it’s the Swiss cheese analogy that is easily visualized, but this one made me think about how to help my students avoid self-deception, thinking they know the material when they don’t. While I’ve been tempted to be a tad more confusing to force them to grapple more, I’ve instead steered towards thinking about helping them build conceptual context. It’s only been two weeks of the new fall semester but I feel like I’ve spent more time than usual in my classes providing context for how what they’re learning today fits with what they’ve learned earlier, what is coming up, what the big picture looks like, and why they should care. But I need to improve assessing my approach to see whether I’m making headway. Striking a balance of asking questions directly of my students without being too intimidating is tricky (for me).

Hoyle’s #1 would also be my #1: Great teaching starts when you can convince your students to be adequately prepared when they walk into class. I wish there was a magic bullet to this. I’ve tried many things over the years and I have a set of practices that sort of work. Regular quizzes, highlighting things from the problem sets in class, annotating detailed syllabi, reading questions, etc. I try to balance this with treating them as adults, i.e., not too much hand-holding, but also giving them the opportunity to make their own choices. If a student doesn’t read beforehand, that student will find it more difficult to follow along in class, and hopefully it acts as a wake-up call.

One thing Hoyle does is e-mail his students very regularly in a way that conveys he cares about their success and learning, and that he’s working to help them succeed. This is something I’m not good at doing outside of class and office hours. I have tried not to overburden my students with e-mails, because I’m not sure I would like receiving lots of e-mail from my instructor if I was a student. Maybe I’m projecting, and that I think the university sends me and the students way too much that it starts to get tuned out. But Hoyle’s examples suggest that the quality of the messages is a crucial factor. Maybe I’m lazy, and have not been willing to put in the extra work this would take. Something for me to think about.

Sabbatical Planning

The word sabbatical has roots in Hebrew, Latin and Greek. It carries the biblical connotation as “resting from work”, although in the academic context there’s still lots of work going. Jewish and Christian sources connect the Sabbath rest, typically to the creation story, loosely paraphrased as “God worked for six days and rested on the seventh.” The book of Leviticus includes a commandment to refrain from working the fields every one year out of seven.

At my institution, tenure-line faculty members and administrators can apply for a sabbatical following six year of service, i.e., you can “go on sabbatical” once every seven years. In most institutions, the options are a half-year sabbatical at full pay or a one-year sabbatical at half pay. I’ve been thinking about sabbaticals because I was working on my sabbatical request the past month or so. The request includes an application and a proposal, so I spent some time thinking about what I would like to do on my sabbatical and how I would go about accomplishing my goals.

As someone who enjoys history, I dug up an old article about sabbaticals in academia. Back in 1962, the AAUP (American Association of University Professors) published a summary article titled The Origin and Early History of Sabbatical Leave by Walter Crosby Ellis. (You can access it on JSTOR.) According to the Dictionary of Education, the sabbatical is “a plan for providing teachers with an opportunity for self-improvement through a leave of absence with full or partial compensation following a designated number of years of consecutive service.” From this definition, Ellis list three essential elements: purpose, compensation, time-eligibility from prior service. However, he thinks there is a fourth that’s lurking – “an investment in the future of the institution”. Arguments are made about the sabbatical being “an intellectual and practical necessity” but what is self-improvement and why is it important?

In answer to this I can only speak for myself. In my last sabbatical, I was able to immerse myself in a new field of study. I did this by visiting other labs (for several months at a time) to learn new things. That’s what got me into origin-of-life research! The summer at the end of my sabbatical was spent writing up a grant proposal that charted a new course of my research. (It was funded!) I was able to construct multiple projects for my undergraduate student researchers. Since then, I’ve had the opportunity to present my research at multiple conferences, serve on a grant review panel, and our group has published multiple papers in my narrow area of research expertise relevant to the field. I also spent part of the sabbatical prepping for an elective course on the Chemical Origins of Life, which I taught the fall semester when I returned. A year later I was team-teaching an origin-of-life-themed non-majors science class. I’ve since developed a number of origin-of-life related discussion activities and problem sets for my general chemistry courses.

I would not have been able to do any of this if not for the sabbatical. Being able to have a large stretch of time to focus on learning something new and complicated is important to me, for both my teaching and research/scholarship. Challenging myself to learn something unfamiliar and (potentially) difficult also puts me in the shoes of a student. It reminds me to appreciate how confusing it is to read something where you understand less than half of what’s going on. It reminds me to persevere and keep working, as I make progress inch-by-inch, and eventually understanding dawns. I think of the sabbatical as both diving deep and stepping back for a larger view. I have the time and space to think about my teaching and research in a broader context, but I can also drill down to solve a particular nagging research problem or design a new class assignment.

So what am I planning for my upcoming sabbatical? I identified three aims. There’s some unfamiliar-to-me methodology I would like to learn that could transform the direction of my research group, and also make significant headway in origin-of-life research. That’s my “stretch” goal. High-risk, high reward, but difficult. More mundanely there are a couple of ‘problems’ in my current area that I’ve been putting off. They aren’t as suitable for undergraduates because a lot of experience is needed to do trial-and-error troubleshooting. I suppose I could try hiring a postdoc, but I’ve stayed away from this approach for various reasons. A sabbatical would be a good time to tackle these. Finally, there are some things I’ve been reading about in cognitive load theory that I think could make an impact to approaches in chemical education. I would need to learn a bunch of new things outside my field of expertise, but isn’t that what a sabbatical is for?

But a sabbatical shouldn’t be all-work all the time. I’m also looking forward to feeling refreshed and taking time to smell the flowers! I’ve submitted my request and now I just have to wait to see if it gets approved. Fingers crossed.

First Week Fall 2018

Looking back at my blog, I see that I’ve regularly reflected on my first week of class – at least most semesters. So here’s the Fall 2018 edition!

I started to feel tired this afternoon now that I’m at week’s end. It’s not even a full week because Monday was a holiday (U.S. Labor Day). However, I do expend more energy when I’m actively teaching during the semester compared to the summer. So maybe my body is just getting used to the regime. We’ll see how I fare next week when I have to make it through a full week.

One thing I’ve noticed about Day One of class in both general chemistry and physical chemistry (the two classes I teach the most regularly) is that I cover less “content” every year. I spend 5-10 minutes of class highlighting the syllabus because I’ve e-mailed the students a link to the full detailed syllabus a week beforehand. I incorporated my ideas from the summer into the syllabus, and students seemed fine with it. That still leaves me the better part of an hour to dive into chemistry – which I do! However, I find that I am increasingly discussing big picture context-type things with less time on nitty-gritty details of Chapter One stuff. On Day Two of class I’m back to my densely-packed plan, although in my Quantum Chemistry class, I still made more big-picture statements while cutting out a few ‘sidebar’ details as we went through deriving the Rydberg equation from the Bohr model of hydrogen.

On Tuesday morning, I met my new academic advisees – all first-year students who had indicated some interest in a science major when they filled in their questionnaire after being admitted to the university. A chunk of time is helping them make any needed changes to their class schedules. I’m pleased to say that this year very few of them needed to make changes, and for the most part their initial schedules were in good shape. I also spend some time talking about the liberal arts and our college’s version of the core curriculum. This year I decided to preface my discussion with having the students spend 5-10 minutes drawing freehand a map of the U.S. in as much detail as possible. (One international students drew her home country.) Then I paired up the students such that no two students were from the same state and had them compare and contrast their drawings. The idea was to have them see that they tend to know what their home state looks like and maybe several of the neighboring states, but things get hazy further from home. This indeed proved to be the case although I had a couple of students who did pretty well – one with 30-ish states and the other close to having all 48! The subsequent discussion was about learning new things in one’s classes and from each other, with overtones of the-parts-form-a-whole speech.

On Tuesday afternoon, I sent a “welcome back” e-mailed to all my returning academic advisees (rising sophomores, juniors and seniors). This is mainly to let them know where to find my timetable and my office hours and to encourage them to stop by to say hello! I’m pleased that several of them stopped by this week to ask me about my summer and tell me about what they were up to! I’m also pleased that a few students in my classes have already come to office hours this week to get some help on homework or to ask me about studying strategies. A good start!

My new research students seem to be off to a good start too! I’ve encountered fewer questions than in previous semesters about Unix, vi, and using the computational chemistry software. We’ve talked more about the chemical reactions they’re modeling and they’ve gotten their first few ‘results’ although there are many more computations to be run. I’d like to think this is because my revamped two-day training with updated tutorials and focusing on certain key skills has helped. But it also might be the fact that when three of them were together training they also helped each other. And they might all simply be quick learners! Anyway, this is all to the good.

The bad part of this week was having three technology-related snafus on Thursday. We are using a new general chemistry textbook this year, and thus a new online homework system. When I logged in on Thursday morning, one of my three assignments – the one that students were actively working on – had disappeared! I was also unable to see any edits I made to assignments and when I tried to create and ‘save’ a new assignment, it didn’t show up! After some moments of frustration trying different things (including several different web browsers and refreshing), I gave up and submitted a help ticket. The problem was fixed and my assignment reappeared. The second snafu was when one of my advisees noticed a problem on her degree audit system; a class which should have counted towards her major was showing up as an elective instead. After a little more investigation I realized that a bunch of other students had the same problem (although they hadn’t noticed yet), and I’m in the process of getting it fixed working with the registrar’s office. The third snafu showed up in the afternoon. I tried submitting a calculation to our computing cluster only to get an error that it couldn’t contact the license server. This was odd because one of my students had been running fine in the morning. It took me a bunch of troubleshooting tests to narrow down the problem, and was able to then clue the sysadmin into how to fix it. Took an hour but problem resolved.

Other than those three issues, I’ve had a good first week. But now I’m looking forward to the weekend!

I enjoyed browsing my previous ‘first week’ posts:

·      Spring 2018 (technically I was in week 2)

·      Fall 2017

·      Spring 2017

·      Fall 2016 (it's gold!)

·      Fall 2015

·      Spring 2015

Oddly, I didn’t post anything for Spring 2016. Not sure why.