A Physicist Abroad

  • Cargèse

    Part 7

    Tucked into my daypack was my camera and snacks, a high-fat selection with a sleeve of the gloriously light and crisp Petit Beurre biscuits by LU and a small net of Babybel cheese, and I picked up six 1.5 liter bottles of water to share.  Our volunteer hiking crew consisted of seven students: myself and two others who were experienced hikers, my roommate Alejandro who hadn’t hiked much but was in great shape, and three inexperienced hikers including the two flatmates from Korea.  As I had suggested this trail and organized our departure, I carried most of the responsibility for the latter three, and passed the water around to them, but conveniently ignored their small, but significant, red flags.  These were just minor things, like wearing denim jeans for a strenuous hike in high summer, or flat-soled skater shoes for walking on a rocky, uneven trail, or slinging a camera with a long, heavy zoom lens over a shoulder.  Everyone was all smiles posing with the trailhead marker, but all we had done so far was walk about half a mile along paved streets rising out of Cargèse.

    Evidence of civilization in Corsica stretches back more than 8000 years, to the late Stone Age, with the most famous archeological site at Filitosa, a hamlet at the southern end of the island.  Scattered throughout the site are numerous carved statue-menhirs, tall, thin stone pieces with detailed faces, weathering and watching beyond the past 80 centuries.  From its terminus, the Mare e Monti trail quickly gained elevation along the northern face of a hill, generously granting views of the jagged coast and interior mountains topped with bare granite, until it reached a grassy plateau, skirting fences that divided private property.  Before diving back down the hillside into a deep valley, the trail kissed a road at a hairpin turn through the driveway of a farmhouse or chambre d’hôtes, ringed by manicured hedgerows, and where, now an hour into the hike, we enjoyed a brief hydration break.  Framed by four large protective timbers, each solidly planted in the ground for the practical purpose of preventing farm equipment from driving over it, was one of these statue-menhirs, unadorned by any informative signage and standing about eight feet tall, simply set out in the middle of the front yard and I, oblivious to its provenance, casually snapped a picture.

    The cacophony of a rural menagerie filled the valley, goats, sheep, horses, and dogs all making their presence known.  The trail had followed the descent of a broad, dried stream bed from the farmhouse, thankfully marked by orange blazes that prevented us from wandering off into a field, and now coincided with a dusty dirt road on the valley floor.  The livestock were all securely pastured behind fences, but otherwise able to graze freely.  The oddest sight was dozens and dozens of dogs tied to trees in a clearing just off the road, their terrible yelping and the clattering chains casting a foreboding pall like something out of a horror movie.  I had thought they might be hunting dogs and tying them up ensured that wildlife wasn’t frightened away, but as we walked closer and could see through the space in the trees, these dogs were in no shape to hunt.  Mangy, emaciated, and exposed bare to the fiery sun in the heat of the day, we could only hope that they were somehow cared for.  The barking continued clawing at our backs long after we had passed, only mercifully drifting away with the zephyr as the trail veered off and cut uphill.

    I grew up on CCC trails in the American West, diligently planned and carefully chiseled from the sweat of millions of men that supported their families during the Depression.  In general, there had been no maintained historical trails, and starting fresh, the Forest Service and other government organizations designed switchbacks in trails during sections of significant elevation gain on a sheer slope which both reduced erosion and the pitch of the trail.  By contrast, if you needed to climb up an incline for whatever reason, it seems only natural that you would simply walk directly, and not meander back and forth.  Indeed, that is what this trail, an ancient path to homesteads in the mountains, now did.  Hundreds of meters up it went, and the loose, cascading gravel made the going even slower as we were constantly losing our footing.  Only years later did I gain the perspective that this was the norm, with trails in Appalachian New England, for example, venturing straight up thousands of feet to the peaks of the White Mountains, and not even diverting for massive boulders or rock faces, and that I had been spoiled by paths for summiting that were born out of recreation, and not necessity.

    The smiles in the group photo at the top, looking down at the valley that slides into the bay from over 2000 feet above, were demure, fewer sets of teeth visible through ear-to-ear grins and much more sweat than at the trailhead.  Closing in on noon, we paused for lunch here, and spotted the few ocher clay-tiled roofs of Revinda, our destination, peaking out of the trees across the valley.  Our naked exposure to the sun as it rose higher accelerated eating, but rendered the scenery that much more spectacular, the sapphire zenith yielding to a cirrus haze at the horizon and then inverted until broken by the verdant tans of dried fields that stretched up the hills until the slope became too much and the oak shrubs dominated all the way until the boulder field in which we sat, so we all took the necessary pictures and moved on in hopes that we could find more pleasant and shaded rest soon.  Revinda was hardly more than a handful of buildings indeed, mostly for animal husbandry, with one store-front business run by a hardy woman who live in these rugged hills.  She seemed to do it all, offering beds for the night, preparing lunches for the day, and harvesting pure Corsican honey, the prized maquis d’été, proudly advertised by a sign aside the entrance to the modest dining room.  We settled under a broad chestnut tree just above a stone wall, drinking down the diminishing bottles and petting the lone donkey who was also escaping the midday sun.  

    That much water and walking challenges the sturdiest of bladders and I was asked by one of our group if I knew where the bathroom was located.  While I was far from fluent, a couple years of French in college easily pushed me to the most conversant among us and I approached the proprietress, who was intermittently chatting with the two men eating.  “Excusez-moi, où est la toilette?” I asked, with the reasonable expectation that she would point through the open door and say something like “À la gauche” and then it would be simple to relay the message and we would line up patiently waiting to use the facilities.  Instead, she spread her arms wide, seemingly embracing the earth from which all is taken and to which all must be given, and raising her head toward the heavens replied in a sort of mystic prayer, chanting “Pas de toilette; la nature est votre toilette.”  We each searched for our own altar of micturition among the widest-trunked trees set a bit further back from houses and roads, but only slowly through the fog of mild dehydration did her solution become more obvious.  We were patently foreigners forcing ourselves upon this tiny village and our group outnumbered its entire exterior population by more than a factor of two, not including the donkey, and anyway he pissed outside all the time.  With a couple more sips of water, we came to admire the generosity of her poetry when she was well within rights to stare me down, eyes boring into my soul, and bluntly say “Va chier derrière cet arbre”.

    The fellowship began to crumble on the slog back.  One of our group thought that we were going too slow, and decided to run the miles that remained to Cargèse.  The inexperienced hikers fell further and further back from the rest of us, now burdened by useless plastic bottles, and I shared what I could to maintain both morale and their health.  The shade returned as the trail transformed into the stream bed, but lacked any reprieve due to the climb.  I was becoming legitimately scared; this was the only way back, three of us were suffering from dehydration, and the Petit Beurre biscuits and a shoulder to grasp I could offer were rendered effete.  Foot planted in front of foot purely from the feeble motivation that at the top was that chambre d’hôtes and the promise of water, water, water.  With the trees thinning and the crest approaching, I ran ahead, passing by the hedgerows, crying out “Avez-vous de l’eau?” and luckily the woman tending the flowers looked up and gestured me to the house, filling bottle after bottle with water from the hydrant.  “Merci, merci beaucoup!” I called over my shoulder sprinting back, and her confused look changed to concern as she could now see the reason for my haste, three people crumpled over in her driveway and two others doing their best to calm and comfort.  Their first sips were like fresh breaths of life, averting total disaster.

    Bearing several bottles of Powerade in my arms, I passed them around, demanding they be drank here, in the supermarket parking lot, in my presence.  5 pm was already long in the past, and the hike was ultimately more than 17 miles and close to a full mile of gross vertical elevation gain on a trail whose quality varied enormously.  I had both severely underestimated its arduousness and had been irresponsible in advertising the hike, very nearly paying a dear price for it.  With the Powerade down, one of my flatmates excused themselves from our circle, and passed back into the supermarket.  He returned a few minutes later, wearing a fresh, wide grin, and cradling a liter of vodka.

  • Cargèse

    Part 8

    We had settled into the rhythm of the school during the second week.  Morning lectures, then lunch with a bit too much wine, then in and out of consciousness for the afternoon lecture in the warm auditorium with the pleasant buzz of the booze, and then student talks after waking up with a shot of espresso during the break.  Tim was finally able to present that tutorial without interruptions and the other lectures skewed to new, hypothetical physics ideas, their motivation, how to predict them with sufficient precision, and how to find them in collider physics experiment, assuming, of course, that they actually exist.  That boat excursion had merely been postponed, and thankfully the plan now was just a short trip after lectures were over on Tuesday evening.  However, our emotions were thrown around like a landlubber on the deck in rough seas, with the decision Tuesday morning that the weather was too dangerous, but by Tuesday afternoon, everything was calm and the trip was back on.  Injecting a bit more spontaneity into the day, I walked to the harbor with other students, after quickly changing into swim trunks and leaving all of my valuables in my apartment, save my key.

    Our destination was the Gulf of Porto, about 10 miles north along the coast and where the boat would anchor near a calanque or cove where we were promised some free time to swim in the sea.  However, we discovered the first surprise at the harbor, where we were joined by numerous others, not part of the school.  While we were never explicitly told, we had assumed that the boat would be our private charter, and instead it was just a regular tour boat, which diminished some of the charm.  Thankfully, I was early enough to board that I found a seat on the open-air deck, absolutely necessary for avoiding motion sickness on the slightly choppy water.  After the captain had welcomed us aboard and the organizers of the school translated to English for the students seated nearest to them, the second surprise was revealed.  Géraldine asked the captain how long the ride would be before stopping to swim, but the response was negative, apparently a liability that the tour company could no longer afford and a recent change as swimming had been permitted at a prior school.  All that us stripped-down students could do was watch the coast undulate back and forth as a bay waxed or a cape waned, or pick out Revinda, miles away in the hills that appeared less impressive from below, but had no way to photograph it.

    The French Riviera and Corsica are blessed with dramatic cliffs that plunge into the sea, a consequence of erosion of soft minerals for millennia.  The calanque we approached now was a partially-submerged cave hardly wider than the boat, and the captain cut the engine so we coasted quietly parallel to land.  With the captain at the helm, the two others in the crew stationed themselves halfway toward the stern at both railings and would yell back to the bow as rocks encroached on the hull.  The novelty of this tour was for the boat to enter the calanque, with the bow now in the shadow of the cave, then slowly more and more, while the waves lapped in the inches separating floating from capsizing.  We paused, the boat about half in shadow, still bobbing with the water and just avoiding the sharp walls.  The captain reversed the engines and back into the sun we went, cheerfully announcing over the intercom that that maneuver was called a “French kiss.”  For everyone on the boat to get the calaque experience, next we backed into the cave, now the stern immersed in shadow but this time, no announcement was made on our way out.  A line of tour boats in the Gulf had formed in the meantime, engines turned back on, and we sped away, back to Cargèse when someone called to the bow what that move was called.  The response, a bit more grim than before, was “Tu ne veux pas savoir.”

    As is tradition at conferences, a banquet for all attendees is hosted the night before the final day of physics, and this school honored that tradition with a dinner at the Institute on Thursday.  Grilled swordfish caught directly from the Mediterranean was served while the camaraderie and infinite wine made up for any shortcomings in the food.  Long since having forgiven me, I chatted with the three students who had needed more water on the hike until well after the sun set, and the cool pastel rainbow of twilight had sunk into the sea, replaced by twinkling stars.  With lectures starting as usual in the morning, little carefree partying took place, with most people working their way back up to Cargèse well before midnight.  With understanding nods from across tables over the bluff, my flatmates and I planned our exit simultaneously and walked to our apartment.  The iPhone 4 had been released just a couple of months earlier and one of our flatmates wielded his like Gandalf entering Helm’s Deep on the third day, pointing the overbrightened screen toward the ground, illuminating the pitch-black, rutted gravel road made even darker by the overhanging, creeping trees.  We sobered as the distance along the highway grew, and arrived at our apartment with clear minds, anticipating receiving the final pieces for a puzzle that no one yet knew how to complete, nor even if all had been identified.

    The first picture on the web was a photo of four women, dressed like a ’60’s doo-wop quartet with the elbow-length satin gloves and everything, under a banner with their group’s name, Les Horribles Cernettes.  By the time of this school, this image was nearly 20 years old, and its initialism coincided with the next particle collider experiment at CERN, itself conceived over five years prior to Tim Berners-Lee uploading the photo to info.cern.ch.  The complete physics program of the Large Hadron Collider had been planned to collect data for about 25 years, until the mid-2030s, so now, just months into the first proton collisions, was the time to think about the machine that would succeed it.  Fittingly, the final lecture of the school looked toward the far future, to the problems that the LHC would address, and to problems that would require a bigger collider at even higher energies.  For the LHC, it was widely understood that it would be the experiment to discover or invalidate the existence of the Higgs boson, named after one of its proposers and the fundamental particle responsible for the masses of other particles.  Previous experiments had established lower bounds on its mass, while mathematical consistency of our theory of particle physics forced a strong upper bound, and the LHC had been designed to be maximally sensitive to the allowed range.  All we could do now, sitting in the auditorium, was wait and salivate for more and more data to be collected, that eventually a signal would pop up over the noise.  All we could do now was hope that Nature heard and requited the Cernettes pine  “Hey Mr. Higgs do you wanna do the twist?”

    The filled bus waved to Alejandro, who sipped un café at a cafe and who wasn’t departing until tomorrow, while driving off to the Ajaccio airport.  I had taken an early seat and so was positioned near the back of the bus and at an inland window, which I would soon learn was doubly undesirable for the drive.  The rocking of the bus and the rolling of the hills harmonized at vertigo resonance, my vision narrowed and muddled, and my stomach turned over and over.  I wasn’t alone as several students throughout the bus went bent over, working with all their might to keep their breakfast private, but with abundance of caution, the secretary passed around emesis bags from the driver’s vast collection.  Thankfully, my neighbor was unaffected, so changing seats to the aisle with a clearer view to the front helped, as well as an offered stick of gum to chew.  Ajaccio arrived not a moment too late, and as we pulled into the lot my peripheral vision returned, and the sight of the bright, midday harbor washed away the nausea.  Thankfully no changing clothes or mopping of aisles was required.

    While the destination of most of the students on the bus was the airport, others dispersed in search of their next travel stage, so it was time for goodbyes.  Goodbyes to my flatmates who would be ferrying to Nice, though during the day and so my advice about reserving a cabin was less necessary.  Goodbyes to the first students I met in Ajaccio, two of whom would be staying on the island, either continuing hiking or road-tripping.  Goodbyes to the European students whose flights were departing in minutes, rushing into the terminal to check in.  The airport was my final destination on Corsica, traveling next to Nice and then on to London, but had several hours to wait until my flight in the early evening.  In this wait, I had a few compatriots, people traveling ultimately to the US or east Asia and so their flights were also later in the day.  After security and Duty Free, European airports, especially small ones like Ajaccio, are rather austere, so we found a clearing near a wall and slumped over our luggage for a brief nap before the long journey through the night ahead of us.

    Pinned into our corner as the density of people grew with the progression of the afternoon, we were helpless to defend ourselves from the repulsive actions of our fellow humans.  One of our group, Ryan, was stuck next to a row of seats on which a young family had established as their own private base camp.  Still in diapers, the youngest member of this family had relieved themself and was apparently exuding a stench that stimulated the parents to action.  A good, say, two feet from Ryan’s facial sensory organs was the south end of the child, on their back on the seat, heels to the sky, soiled diaper making way for their bare bottom.  I could only spare a couple of quick glances otherwise I would have been overwhelmed by complete, uncontrollable laughing fits myself, but that was enough see Ryan’s wide-eyed, slack-jawed shocked disgust as wipe after wipe pulled the mustardy substance off and was gathered in a crumpled pile in mom’s left hand, revealing pink, plump flesh underneath.  The coup de grâce, though, was yet to come as once baby and bum were cleaned, but prior to a fresh diaper, mom pulled a thermometer from the changing bag and in it went.  With a few exchanged words in French, the parents were apparently now satisfied, the family packed up and moved along, vacating their defiled seats, and ever so slowly and deliberately Ryan turned his head to me, wearing a thousand-yard stare.

    Heathrow after 10 pm is silent.  I had landed on British Airways but would takeoff to the US on United Airlines, so I would have to transfer terminals on the airport’s shuttle bus.  I apparently found nothing odd about following signage to the bus, down escalators, completely alone in one of the busiest airports on Earth, until spotted by a member of the janitorial staff who snapped that I wasn’t supposed to be there. Confused and apologizing profusely, I was reassured that no blame lay on me, but rather on security for not closing the area, and was kindly lead back to the correct path to the open areas of the airport toward the border crossing.  I sat alone and uninterrupted in the vast, vacant luggage hall prior to customs for long enough to access wifi, write an email or two, and then be yelled at again this time by a border agent that I would have to move along, and actually leave this secure area.  Finally past any security were rows of seats and a few souls scattered around already sleeping under the fluorescent lights, with the intermittent announcements, the distant screams of a vacuum, and the incessant advertisements strobing and shouting from the wall-mounted televisions.  Here I was again, presented with my bed made by my miserly decision to forgo a hotel room, but at least my nest of luggage, jackets, backpacks, and pillows tucked into the hard molded plastic chairs would lay undisturbed by any sort of breeze.

  • Why Can We Trust Our Memories?

    Introduction from lecture notes on introductory mechanics taught in 2019 and 2020

    Why can we trust our memories? This has a lot more to do with physics than you might think. What do we mean by “trusting memories”? We mean that our previous experiences can be used to inform future situations. This means that what we learned in the past must be applicable to the future; that is, there is a continuity through time of our experiences. A hot stove you touched yesterday hurt, therefore you know that if you touch a hot stove tomorrow it will also hurt. We can make this more physically precise by stating that experiences exhibit a time-translation symmetry. This means that our learned experiences are always the same (a symmetry) throughout translating or moving through time. This is obviously extremely important for conscious beings like us, otherwise we could never learn.

    Even more grand a statement that follows from this is that the laws of physics do not change in time. Now, I don’t mean that individual objects to not change in time; I mean that the way and rules for how objects interact with one another are always the same. For example, the rules of Monopoly are always the same, but any given game can have different outcomes. If the laws of physics do not change in time (they exhibit a time-translation symmetry), there ought be a concrete quantity whose value is unchanged, or conserved, in time. This is energy: that the laws of physics do not depend on time means that energy is conserved, and vice-versa. This relationship between a symmetry and a conservation law is called Noether’s theorem, after Emmy Noether, a German mathematician.

    Noether’s theorem is perhaps the most important result in all of theoretical physics and provides extremely strong constraints on the interactions of objects. However, depending on the system you are studying, energy may or may not be conserved. We only believe that energy is conserved for the entire universe, the only truly closed system we can imagine. The energy of an object can change if work is done on that object. Work is necessarily a concept that is outside of the object or system that you are studying. Because you can’t go outside the universe, no work can be done on it and so energy is conserved.

    However, not only do the laws of physics not depend on time, but they don’t depend on where you are or how you are oriented. That the laws of physics are independent of your position means that they exhibit a spatial translation symmetry. Just like with time translations, Noether’s theorem states that there is a conserved quantity: momentum. Momentum only changes if a force acts on your system or object. Further, the laws of physics don’t depend on your orientation: throwing a ball to the north or to the west exhibits the exact same phenomena. Thus we say that physics is rotationally-invariant: everything (i.e., the laws of physics) is the same if you rotated the system. For rotations, Noether’s theorem tells us that the corresponding conservation law is angular momentum. Angular momentum, a measure of an object’s rotation about a fixed axis, can only change if there is a torque on an object.

    These three conservation laws, energy, momentum, and angular momentum, will be the central components of this course. We will describe systems under which they are conserved, and use that to our advantage when making predictions for future behavior given current data. We will also discuss how work, forces, and torques break conservation laws for open systems (systems that interact with an external environment). Fortunately and powerfully, this breaking of conservation is not arbitrary, and we will construct powerful relationships fitting it all together.

    Though this class and topics are often referred to as “classical mechanics,” connoting “classical” in the Greco-Roman sense, the physics you learn this semester underlies all phenomena that we know. Conservation laws are the way that modern particle physics is formulated, and so these ideas are used throughout my own research. Though it may seem pedestrian or even pedantic at times, there is an amazingly rich structure lurking just beneath the surface. This semester, I’m thrilled to be your guide exploring Nature from this profound perspective.

    Link to complete lecture notes and videos: https://www.physics.ucla.edu/~larkoski/Phys101.pdf

  • Miracles of Science

    An excerpt on an essay on my first trip to Florence, Italy, for a two-week workshop.

    My Ph.D. advisor was a highly cultured, worldly individual, known far and wide by his universally-adopted textbook on quantum field theory, often telling a story of visiting a women’s college in Tokyo where he was to be met at the subway station by his hosts, but not informed how he would recognize them.  Off the platform and up the stairs he went, and there were three young women, broadly smiling, each proudly bearing a copy of his book.  After physics, it seemed the one thing of which he was most knowledgable was opera, often making obscure allusions to some egregious betrayal in aria during a physics seminar that was typically met with silent confusion.  I had accompanied him on a number of conference road trips up and down the West Coast, and one particularly memorable drive was on the 9 hour trek to Eugene, weaving up Siskiyou Pass in a pounding late winter rainstorm, his lead foot accelerating his VW Golf past 85 miles per hour, and Aida blasting at near pain volumes, hands off the wheel conducting the orchestra, and explaining the minutiae of the stage and how the tenor and soprano were finally together, forever.  Though not in Florence for this conference, he had visited the Institute a number of times previous, and before I left his only recommendation was that I climb the dome.

    Out of the apartment before 7:30 am, my flatmate and I walked downhill, backs to the Institute, for a small adventure before we set to work.  The physicist desires to explain the universe in a limited set of mathematical equations, which require a logical structure and repeatability, but such a strict reductionist approach, confining the universe to a box with a pretty bow, is but a few hundred years old and for millennia prior, people still erected buildings and bridges that yet stand, though Newton’s laws were never employed.  Some structures are perhaps not so impressive from our modern view, while others, such as the pyramids or the henges, are miracles though only because we implicitly and unfairly limit the intelligence and ingenuity of our predecessors.  A dome is another wonder, masses on masses that curve and extend over nothing, and as the size of the dome grows so do the lateral forces, until beyond some point where it would collapse, the sides exploding outward and the crown crashing inward.  A simple modern solution would be to provide extra support, trusses underneath or buttresses outside, but both significantly undermine the awe, which is an especially crucial quality if you are contracted to build the world’s largest cathedral.  After the eighth bell’s toll, the small wooden door at the side, under a mosaic of the Annunciation, a genuflecting Gabriel and the dove presenting to Mary, opened and we started the climb up and into Brunelleschi’s cupola.

  • Hoisted by Their Own Petard

    Excerpt from an essay on a visit to the Kavli Institute of Theoretical Physics in Santa Barbara.

    Long, long ago, there had been a dream by a particularly enthusiastic subset of theoretical physicists that essentially everything you could hope to know about particle physics could be inferred from some set of reasonable physical principles or axioms.  It was therefore referred as a bootstrap, because you could, the hope was, use those physical principles to make some predictions, but then those predictions could themselves form axioms from which more predictions could be made, and continuing, you could pull theory predictions up from seemingly nothing by their own bootstraps.  The most vociferous of these bootstrappers believed that the techniques that had been developed by Feynman, Julian Schwinger, Freeman Dyson, and others that had been so successful in marrying special relativity and quantum mechanics and applied to understanding electromagnetism, would be completely useless in understanding the force responsible for the zoo of particles, collectively called hadrons, discovered through the 1960s.  So they pushed and pushed, clawing their way up the mountain of predictions and many of those who were not as keen on the idea out of the field itself, but there were some victories, with perhaps the most influential on the future being Gabriele Veneziano’s discovery in 1968 of the function that described the probability that strings interacted.  However, the bootstrap program and its dreams were thoroughly killed in 1973 with the discovery that, actually, this force is entirely analogous to electromagnetism, and those same techniques developed by Feynman, Julian Schwinger, Freeman Dyson, and others were indeed effective and infinitely more powerful and direct than the bootstrap.

    As these old techniques were dusted off and explored more and more by a larger and larger fraction of the field, some of those old bootstrap ideas sneaked back in.  The final form of a calculation that would evaluate to thousands of terms with these old rules could be compressed into a single term written on half a line and what’s more, you could prove, circumventing the old rules completely, that this simple form was completely general using an inductive step that bore that eery smell of the bootstrap.  These techniques were generalized to broader classes of predictions through the 1990s and by the early 2000s, it was realized that all of these miraculous relationships and simplifications were due to making the right axioms, the right assumptions that were necessarily and sufficiently maximally symmetric, the spherical cow of theoretical physics.  The field rightfully exploded, the few who toiled for decades before this revolution but continually demarked progress with novel relationships and new calculational methods hailed as the heroes of the field, and the bootstrap had returned, but in a form that worked and improved the way that things were done, not with rhetoric, but with results.  I was here for two weeks of a workshop on this New Bootstrap, close enough to my research that I could understand the language, but far enough away that I would merely quietly sit the back row during a talk, the flow of information strictly going one way.

  • Out of Touch

    Thoughts after attending a recent conference.

    What’s the first sign that you are getting old? Is it the grunt and getting up from a chair more deliberately? Is it a slowing pace up a hill you used to run? Is it thoughts, now deeper and buried among decades of useless knowledge, harder to access and tripping your tongue? Is it that the tools you designed and forged are rusting and the welds weakening? Is it trying a new tool but getting lost and your mind muddled by merely the instructions? Is it in watching others, youthful, vigorous, demonstrate mastery of something you do not know, can’t understand, and can hardly interpret their language? Is it the memories of the problems and solutions and newer problems and almost solutions and the generations on generations of friends that you fought alongside, brothers and sisters in arms against ignorance, that have all left for greener pastures and more favorable winds, leaving you nearly alone? Is it watching history repeat or rhyme or alliterate because there are really only but a handful of stories to tell, isolated yelling at the sky at the claimed novelty and innovation of now, that you had witnessed decades earlier? Is it losing the sense of awe and gaining cynicism at the new ideas, though truly something on the verge of a revolution, a paradigm, but devolved into simply shouted louder and more persistent and more annoying? Or is it just being tired, tired all the time, tired to sleep, tired to think, tired to argue, tired to excite, to never truly be awake again?

  • Self-Aware Imposter

    Excerpt from an essay on a visit to Japan in February, 2020.

    Have you ever had those experiences when, looking back, you feel embarrassed for your past self?  I seem to have a lot of those, and in some cases even realize in the moment that I’m totally blowing the current social interaction.  I recognized very few people from the conference, for at least two reasons.  Even though everyone there was a theoretical particle physicist, the specific topic of the conference was not a field that I work in, and was distanced enough that my knowledge of the theme of the conference was very elementary.  Further, naturally most of the attendees were from institutions in Japan as attending a conference that could be accessed by a morning commute high-speed train and return home each night is vastly more convenient than traveling across the world.  I did recognize one famous physicist, with whom I have crossed paths a few times.  One night while at a conference in Aspen, Colorado, I joined his group for dinner, and at another time I had given a talk at his home institution and it seemed to me at the time that he was very engaged.  Working up the courage to talk while walking across the room during the conference’s coffee break, my mind raced with the first words to say to re-introduce myself.  Finally, I get close, and say “Hi, I’m Andrew Larkoski,” and a blank stare greets me back.  “Hi,” dribbles out of his mouth, and I backpedal a bit to provide context.  “I gave a talk at your institution a few years ago,” which is of course an essentially content-free statement as there will be dozens of talks each year, so he volleys back the natural question, “What did you talk about?” but by then it is too late and my brain has wiped itself spotlessly clean of any useful information.  “Uh, I can’t remember,” and with a knowing giggle that this conversation isn’t going anywhere he replies “Okay,” and mercifully moves on to talking to someone else nearby.  Years later, while staring at myself in the mirror, doing some mundane activity like shaving, flossing, or brushing my teeth, this interaction will flood my memory and my cheeks will redden and I will hope against all hope that no one else remembers.

  • The View From Below

    Excerpt from an essay about lecturing at a summer school in Puerto Rico and visiting Arecibo.

    I took a seat in the nose-bleed section of the auditorium, a few rows past the last students, and worked on my laptop and watched the lectures out of one eye.  I was scheduled as the second lecturer of the day, to begin after a mid-morning coffee break, and so I attempted to divine what worked with this audience and, more importantly, what did not.  The school was completely set up for lecturers to display slides on a projection screen and talk through the formulas and plots in an attempt to teach the eager students.  There simply don’t exist very simple, compact mathematical expressions that are relevant for particle physics, and so lecturers had the tendency to casually show a slide with a formula in microscopic font extending from the left margin to the right, say a sentence about it, and move on to the next slide representing the next step in a logical progression, expecting that students caught all of that.  I have never been satisfied with this style of lecturing, as all of these students can read all about the most complicated mathematical formulas in some dense, weighty tome.  What a book cannot provide is the energy, enthusiasm, and excitement of the everyday micro-discoveries that abound in physics and ultimately make doing it so fun.  I had requested to the organizers that I would like to present my lectures on a blackboard, writing important terms and equations at the same pace that students could digest them.  The organizers had obliged, expressing their gratitude that I had a grand plan for my lectures.  So, off to one corner of the stage, opposite the podium, they had provided a compact, rolling whiteboard.

    The lack of slides untethered me from the podium, and I could walk around the stage discussing the physics I was entrusted to teach, quasi-scale invariant objects called jets that are manifestations of the strong nuclear force.  The story and motivation was easy to describe verbally augmented with hand gestures for emphasis, and I would occasionally write important points on the whiteboard for later reference.  Though increasingly becoming rare, large auditoria in physics departments would have a few to several columns of blackboards, with each column consisting of two or three boards that could be pushed around vertically.  This set up ensured that the past hour or so of notes would be visible to students at all times, and was easy for the lecturer to call back to earlier calculations by simply pointing at the appropriate board.  The whiteboard I was supplied was a mere six feet wide, though two-sided, so I could only write a few phrases or equations on each side, then flip it over for more on the back.  The precious space encouraged me to limit both what was written and what was erased, but the inevitable questions about the previous board degenerated my lecture into a near slapstick comedy of whirling the entire thing around and around and around.

  • One of the Many

    Excerpt from an essay on attending a summer school in Cargèse, Corsica, France.

    As an undergraduate, I had worked with two professors and two graduate students on a fledging research direction motivated by the new realms that the LHC would probe and the exquisite precision of the data it would produce.  This was fall 2006, still a few years before the LHC would turn on in earnest, but unfortunately progress on the project suffered from several competing destructively-interfering effects.  The senior professor was highly-esteemed but had little time for day-to-day work, the junior professor was engaged, but was secretly hunting for jobs elsewhere, and us three students were very young, and lacked perspective or a broad picture of the project.  I did some simple calculations and others performed some simulations, but nothing materialized into something worthy of a paper by the time I graduated, and I moved on, distracted by all of the trappings of graduate school.  Then, early in 2008, a group of researchers from the UK and France published a short, simple paper presenting a novel technique for analyzing the data of the LHC, a method for discovering undiscovered particles.  This was it, this was the paper that we had been trying to write, but failed because we were out of sync or inexperienced.  This paper changed the playing field, re-imagining what could be possible at the LHC.  Searches for new particles that had been abandoned were now re-evaluated and an entirely original research direction was initiated that eventually infiltrated every aspect of the scientific program at CERN.  It was humbling to realize that in some sense I had been so close to being a key player in a major revolution, but at the same time acknowledging that there had still been so many pieces I had missed that there was no way I could have assembled the puzzle.

  • Land of Confusion

    Excerpt from an essay about a trip to a conference in South Korea and the content of the talk I presented.

    Buried in the weeds of the third footnote of a short paper on an unrelated topic was a claim that just felt wrong, that a quantity was incalculable within the context of the standard predictive framework of particle physics.  Technically, their claim was correct, but it simply made no sense from the results of thousands of prior studies that had demonstrated that everything behaved as expected, so there must be some underlying reason that both these things could be true.  This irritant lead my post-doc advisor and myself to establish its consequences in other situations, to slowly rise above this isolated example and map out the islands of confusion that bobbed in the sea of what we had, until recently, thought we knew.  Higher up, we could see that those islands were not islands, but connected by causeways and sandbars and isthmuses and all related to one another, and with some more general understanding, I set to deep dives in dusty math textbooks in the dark aisles of the loneliest stacks in the library, but tool after tool merely churned the waters, failing to break through the surface.  More chats at lunch and staring at equations on blackboards lifted us higher yet, and then, through the clouds, beyond the horizon, the tiniest glimpse of something peeked out, that we had been trapped on a two-dimensional surface like Square in Flatland, and that the answer spanned three, four, five, or more dimensions.  Once we had ascended high enough, the solution was trivial: calculate in higher dimensions and then project down to answer the specific question of interest, and we demonstrated that it worked over and over and over in every situation we encountered.  So we wrote up a paper.