A Physicist Abroad

  • Olde CERN

    Excerpt from an essay on visiting CERN during the week of July 4, 2012.

    The automatic door to the canteen, Restaurant 1 or R1, rotated open with its unmistakable swish, and I walked from the far end through the rows of empty tables, passing the lone cashier on my way to picking a tray and some cutlery at the entrance to the breakfast buffet.  I quickly learned during my previous visit that the ornais aux abricots were fantastic, two soft, ripe apricot mounds like a fresh egg yolk on a light and crunchy puff pastry, and added some fruit and juice to round out the meal.  My head still hurt and I had stared at the ceiling much longer than expected after my alarm, but I was here now, slowly shaking off Pacific Daylight Time, with a few old timers who arrived at work early in the morning for coffee and bavarder.  Soon, I was back toward the buffet, placed my tray on the conveyor, and continued on, past the convenience store, bank, and travel agent, up the stairs to the main entrance of the auditorium.  This was also at a threshold where the floor changed, and a line of tiles in the center of the hallway gestures one past the library around a corner through a corridor of offices and up another flight of stairs to the administrative office for the theory division.  It is joked that theorists can’t remember how to get to R1, but all they have to do to find food is to keep their nose down and follow the line.

    Theoretical physics at CERN is as storied as its experiments, with Felix Bloch and Victor Weisskopf early Directors-General of the entire laboratory, and Niels Bohr himself the first director of the theoretical physics group.  All members of the current group were luminaries in their respective disciplines, and it seemed like every other famous theorist throughout the world visited for a sabbatical year.  In no way was this esteemed tradition more tangibly manifest than in the theory building itself.  I had a friend describe the habitat of CERN theorists as an “East German Mental Hospital,” with flickering fluorescent lighting, wooden doors warped by humidity, the plastered walls covered with posters from decades of yore or cabinets stacked with piles of folders, books, or teetering sheets of paper, reaching above my head and rendering the hallway dangerously narrow if a quick escape was required.  Some of the offices of the oldest members in the group had been occupied for 50 years by a sole resident, and 50 years of papers covered every open space, leaving just a small cave around their computer screen.  This was perhaps one of the oldest places in the entire CERN site, at the time not remodeled since its construction, and simply by turning a corner one received an instant and fully-immersed baptism into the theoretical particle physics of the latter half of the 20th century.

  • Bumps in the Data

    An excerpt on an essay about a trip to China for two conferences in summer 2016.

    On the previous December 15, seven months earlier, the experiments at the Large Hadron Collider provided an early Christmas present to the salivating hordes of theorists who had, from their perspective, too long been deprived of excitement and intrigue in the data.  The experiments saw a bump on a plot that should be smoothly falling and these emaciated theorists went berserk.  Every possibility was tried, and most impossibilities as well, as models of new physics to explain this deviation from the null hypothesis, with a deluge of more than 500 papers of tenuous scientific merit written over the following weeks.  As more was written, more confusions arose because these bumps seemed at odds with other, boring, data, and the experiments continued to collect events, update the plots, and provide additional context with the picture transitioning from grainy and obscured to much sharper and clearer.  Alas, this bump deflated with the enthusiasm of the masses and was officially declared dead by June, simply an unfortunate collection of statistical coincidences that evaporated with more data.  Conferences, of course, must be planned months in advance, so that invitations can be made, plane tickets purchased, and rooms reserved to ensure healthy participation, and along with these logistics, a theme is also established to focus the conversations and questions to be answered.  Now, in July, a group of 30 or so of us were gathered at the Chinese Academy of Sciences for a workshop under the auspices of discussions and updates and brainstorming about hints of new physics in the data collected by the Large Hadron Collider.

    Theorists, especially those whose livelihood depends on their unwavering ability to dream of a signal in the noise, are nothing if not eternal optimists.  So this once exciting deviation now swept into the bottomless dustbin of what Nature is not, was not mentioned at all, and instead new but baroque ideas about the older, canonical problems in particle physics were presented.  How can one solve the hierarchy problem, the discrepancy between the mass scale of the Higgs boson and the Planck scale at which gravity dominates the fundamental forces?  Simple, just add a billion billion new degrees of freedom to your theory.  Where are all these new particles that were promised that the LHC would find?  Just out of reach, hidden because of innumerable convenient numerical accidents amongst parameters in your theory.  Not all talks were so quixotic, though perhaps only a quarter addressed practical improvements to predictions, for example, and dreaming the most extravagant dreams serves the purpose of exploring and mapping the space of possibilities even if Nature is none of them.  The collective amnesia was both impressive and depressing with nearly the entire field mere months earlier frothing at the mouth, following a statistical fluctuation to the edge of logic and beyond, and when that well dried up just returned to business as usual.  With a deep breath, healthy skepticism, and patience to wait for the data to let statistics do their thing this could have been avoided, but where’s the fun in that?

  • Party on the Beach

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

    We only had time to run to our apartment for a quick dinner before getting back to the Institute.  Exploiting the lack of a schedule for tomorrow, students throughout the school had planned events to fill it, from sunning and swimming at Plage de Péru, the main beach in Cargèse, to short hikes around fortified Genoese towers that dotted the coastline.  A group of Spanish students realized that no schedule implied that there was no need to wake up before, say, 3 pm, so tonight they had planned an extravagant party on the beach, buying up the booze and finger foods from the supermarket and hauling it down the slope, distributing them over the tables.  AV equipment was carried from the auditorium and arranged in front of the canteen, casting the Euro techno beats curated by the hosts out to the sea.  Even the school organizers partied in solidarity with all of us students, who had clearly been overworked for the week, and needed a release. 

    Among the relatively small group of American students, we had privately and quietly complained about the music and the deejaying of the Spaniards.  Diplomacy was not an option because we were vastly outnumbered, so we opted for a direct attack, wresting control of the speakers by plugging in an iPhone that was pre-loaded with hits.  Dead air and bated breaths occupied the bluff while we huddled to decide on the best selection for wowing and winning over these skeptical and discriminating Europeans, well-trained to associate song with nationalistic pride from Eurovision.  Now settled, one of us scrolled through the phone and tapped the song that was so quintessential Americana that everyone else hated it: “In the day we sweat it out on the street…” grated The Boss while we rocked out on air guitar and Max Weinberg’s drumming.  However, it was clear that we were on a very short leash and were nearing mutiny when the final fermata of “Baby, we were born to run” stretched to silence, so we switched it up to something that everyone could at least dance to.  On came Miley Cyrus and her dream of making it big in LA, which we were generously allowed to play to completion, but further American meddling in the music was strictly forbidden and associated with the harsh punishment of being subjected to it.

  • The Cost of Open Science

    Overheard in discussions at a recent conference I attended.

    Sneaking out of the auditorium during a less engaging talk for the bathroom, I was surprised to find the pair chatting in the foyer, and though they quickly hushed when they saw me, I assumed they were digesting the additional complaints and criticism heaped on top of the now year-old pile.  While our previous interaction had ended rather heated, I was quick to introduce myself and thank them for the great talks, reemphasizing that I was rather curious to know the reasoning behind their publication choice.  Leads on an experiment that had been shuttered for over a decade, they remained among the few that continued to analyze and probe the data and had some three or four years ago, begun the endeavor of measuring the mass of the W boson, whose value governs the rate of radioactive decay, for example.  The analysis and validation was impressive, details checked and doubled checked, detector misalignment identified and corrected through cosmic rays that sliced through the electronics, and all done blind to reduce human bias.  Then, when the blinds were removed, out came the result, more precise than any measurement before, but an inconceivable 7 standard deviations from expectation, representing a probability of less than one in 300 billion that they were actually consistent.  These two had, after I had asked during their talks, collectively remembered that their Lab had demanded that this result be sent for publication in Science, while perhaps the most prestigious journal throughout the rest of physics, was met with extreme skepticism in particle physics.  Excusing myself after this exchange, a senior physicist long noted for his candor and abrasiveness stepped up and just outright told them, “It seems like you’re hiding something.  That’s the optics.”

    Claims and results like this, while rare, do happen, but Occam’s razor, the mantra that extraordinary claims require extraordinary evidence, and diligent prodding by others in almost all cases find that fatal flaw.  Further, as experiments in particle physics grew in size, there was less possibility that results could be scooped as there may be but a single experiment at the time that could perform the measurement.  The advent of the internet lowered barriers to collaboration and communication and long had there been a tradition of open science in particle physics, with preprints posted for the world to read sometimes months or a year before a formal publication.  During that time, battles would be fought, confusions addressed, sometimes new studies performed, but by the end of it what was submitted to a journal was always stronger and more rigorous than the raw product.  Long too had traditional particle physics journals, the Physical Reviews, the Journal of High Energy Physics, the European Physics Journals, subscribed to this form of open science, with all publications, under the umbrella of particle physics at least, to be accessible to all.  Science and Nature, never very popular with particle physicists and neither was particle physics very popular with these journals, explicitly prevented open science, enforcing an embargo on all submitted papers to have never been public anywhere else.  The first time that the rest of the particle physics world learned about this implausible 7 sigma measurement was once Science published it, and in some sense by then it was too late.

  • Informal Physics in Aspen

    Excerpt from an essay on visiting the Aspen Center for Physics in winter.

    The slew of talks that welcomed evening framed the focus for the week: what is the future of particle physics and what experiment shepherds the field into the middle of the 21st century?  The dreams had at least become concrete conversations within the the past year, and several conferences hosted throughout the world at the great historical particle physics laboratories, SLAC, CERN, or KEK, had scientific programs that encouraged more dreaming and, hopefully, action.  In this sense, the conference at Aspen was nothing special, more or less the same crowd I had seen many times before, though as time had passed, the arguments for a collider that would probe a distance scale 10 times smaller than that of the Large Hadron Collider had sharpened.  At the top, the ultimate question to be answered by such a machine were the compounding mysteries of the Higgs boson, not yet three years post-discovery, but an outlier in the mathematical language of particle physics that seemed to require ad-hoc buttressing to make it fit.  Then, as others had suggested, if we would learn more from a collider ten times the size of the LHC, why not even larger, like Enrico Fermi’s vision of a “globaltron” that encircled the Earth that could probe distances ten times smaller yet?  Yet others had strayed further from legitimate scientific discourse and constructed a counter-conference in the snow, a dozen miniature snowmen enraptured by a near-human size specimen, who, with a finger of its woody arm, pointed at a rough-drawn figure of the ultimate collider that could probe distances yet a thousand times smaller, colliding particles that were accelerated in a machine just within Earth’s orbit, encircling the Sun.

    Dying claps at 7:30 pm invited us to percolate from the auditorium, some pausing at offices to gather a bag, but most clustered in the kitchenette quickly leading to a severe traffic jam.  However, we all had the same question to ask and the high density allowed for fast diffusion of information on dinner, both the where and with whom.  A certain class of physicist who was in Aspen to play, who seemed to seek fame, television spots, and gala banquets over understanding Nature, had already reserved a table at some 5-star restaurant.  My skiing group had found a few others and starting walking into downtown, guided only by frugality, and small clusters would splinter if they spotted a place with cuisine that intrigued or matched their dietary restrictions, and after a few blocks of this, I remained with a few other junior people, post-docs or grad student stragglers that lacked the backbone to make a firm decision in these situations, and one of perhaps the top three or so most famous physicists in our entire field, director of the premier theoretical physics institute in Japan, a spokesperson and advocate for the future collider effort there, distinguished professor at the top public university in the US.  Naturally, he chose the restaurant and the rest of us followed, but devoted no energy to the decision and just ducked into a place around the next corner that served standard pub fare, craft beers, and an extensive selection of cannabis offerings.  So seated there, while we waited for our food and the others listened in, I animatedly described a paper I had recently finished, the old problem we had attacked and insight we developed, at the back of the dim dining room, his face only faintly illuminated by pharmacist’s neon green.

  • A Scientific Cathedral

    Excerpt from an essay on a tour of the ATLAS experiment at CERN.

    An entire lifetime thinking, dreaming, breathing physics isn’t sufficient to prepare you; pictures on a screen are flat and shrunken, and that person in frame in the corner is as useful for the scale as would putting a LEGO mini-figure there, and while words on a page can faithfully transmit some of the awe and mystery, they still fit in your hand, trapped on the page.  The final door was unlocked indicating sufficient oxygen concentration, so our guide held it open and ushered us in.  Across the railing was the largest experiment on the largest machine ever created, completely occupying its voluminous cavern save the narrow paths and stairs that hugged the walls, the size of a five-story building but thousands of tonnes heavier, a near-solid mass of billions and billions of pieces of silicon and iron and liquid argon channels and cables and supports and which every piece had descended the shaft from 100 meters above and then was meticulously constructed underground.  The view at this first position was overwhelmed by its entirety and only a part of the end of the experiment, a silicon wheel framed in iron on its cylindrical shape, could be discerned, so we were led single-file to a steep, narrow staircase, gripping the railing and avoiding low-hanging scaffolding, down to the main visitor platform, and looked up.

    Despite and precisely because of its size and density, ATLAS was designed to be taken apart perhaps easier than to put together, and we could now see the tracker, usually obscured by 10 meters of metal, slid out of its housing and exposed for maintenance, and framing it on the left was that wheel, 20 marigold wedges of silicon fanned out from the center like rays of the sun, and to the right were those ring electromagnets that produced the toroidal magnetic field, appearing to float around the tracker core, carrying with it the rest of the experiment, ladders, catwalks, and tunnels.  Thousands of cables cascaded from ports on the detached component in front of us, neatly color-coded and orderly strung in streets that merged into boulevards that merged into dense superhighways of lines lashed together with zipties, that, as made of plastic, were immune to the whims and whiles of the magnetic field that drenched the experiment, ensuring that cables always stayed in place.  Craning up our necks, the access shaft continued out of view, a vacuous hole through which everything we could see had to pass, with a dozen pipes along its wall, the largest of which carried all of the air we were breathing at the bottom with fresh air at the top, mixed and circulated by the roaring fans.  It was as if Michelangelo had carted out and was buffing the Pietà in the nave of St. Peters.

  • Telescope in the Jungle

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

    Pulling up out of the lowlands, on the winding drive into the mountains, a pearly-white tower pointed skyward, punctuating the verdant, lush jungle.  Then, as you continued closer, a second distant tower appeared, then small satellite dishes, and buildings perched along a ridge, all of which were the sole non-greenery since turning off the highway three miles earlier.  I arrived amongst a few other cars in the parking lot, in front of the still firmly closed entrance gate and tall, solid metal wall made more inviting by the banners acknowledging funding support and a broad planetary and galactic mural welcoming you to Arecibo Observatory.  At 10:00 am, the gate creaked open and the guard motioned to the few of us standing around that we could enter the site.  This access road leads you on for another quarter mile through more jungle, purposefully isolating the telescope as best as possible from all of the stray electromagnetic fields that carelessly emanate from car radios or pocket cell phones.  It seemed that every few steps there was sign pock-marked with rust-colored lichen bearing the no symbol over a drawing of an artifact from the ‘80s stating “Prohibido El Uso Del Celular.”  As the first to reach the visitor center and the observation platform, the view, isolated and alone, was like I was opening a present wrapped exclusively for me today, on my birthday.

    The first thing I noticed about Arecibo wasn’t its size.  Though that was astoundingly impressive at 1,000 feet across, completely covering a 20 acre limestone sinkhole in the mountains, with three 300 foot towers supporting high-tension cables from which a catwalk and the receiver are suspended.  Neither was its technological precision, with 38,000 panels arranged in a spherical cap to reflect electromagnetic waves in the radio band originating from directly above onto the receiver, and then ultimately onto computers to be analyzed.  The first thing I noticed was that it looked tired, like an ancient, scarred warrior who was finally stumbling and pawing, losing their first battle against that enemy that always ultimately wins.  Decades of rains had leached rust from the rails along which the receiver moved, and a dark streak stained its white housing where the water had streamed and dripped down to the dish.  The visitor center building was relatively new, but the paint on the railing of the observation deck was chipped, exposing the bare metal underneath to the elements.  Hurricane Maria had ripped off the light grey surfacing of about a third of the aluminum panels, which I knew had no effect on the reflectivity of the telescope, but sobered my enthusiasm and excitement with a dose of realism. Though we believe that Arecibo has broadened and deepened our view of those timeless questions, it itself cannot escape the slow, ever-tightening, strangling grip of time.

  • Coffee in Italy

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

    As the mid-afternoon doldrums hit, we filtered up to the dining room again, and the few that had arrived before us were already deep in lively debate of the politics of one country or another.  This was Italy and this was espresso time, and I joined out of external social pressure rather than a love or need of coffee, which, before this week, I had drank of very little.  The air of the room was heavy with the stench of burnt beans atomized into steam and expelled from the machine into beige plastic demitasse, and I joined the queue, then walked to an open seat bearing the drink and a stick packet of sugar, the only way that I could stomach it.  A whole packet of sugar for one shot of espresso rendered what was in the cup thick and syrupy and I was able, just, to maintain a straight face while I sipped, but needed the strength of all my faculties to do so, and did not engage in the conversation.  Every day I did this, and every day about 30 minutes later, jitters would take over and I would crash, humorous head-on-keyboard style, slumped in my chair for a nap before I could wrest control from this vile drink.  Convinced that this was the fault of the coffee, I swore off the stuff when I returned home, ordering a hot chocolate while my girlfriend ordered a latte, and only minimally engaged with it when I would return to Europe.  Years later, when I had come to adore black, unadulterated pour-over coffee for its therapeutic properties to children screaming at hours of the day I had previously been unaware existed, it finally dawned on me that my issues with Italian espresso had not been the espresso at all, but the sugar.

  • First Impressions of Beijing

    An excerpt on an essay about a trip to China for two conferences in summer 2016.

    The countdown began as soon as I was on the ground.  So far, my flight had landed on time, my passage through customs and the Chinese border was as smooth as I could imagine, and now I rifled through my backpack to find the travel directions written in Mandarin that our hosts had prepared to present to a cab driver.  90 minutes remained for the ni hao while passing the paper to the driver and settling into the back seat; 70 minutes remained as we passed the toll at the intersection with the fifth ring road with lanes and lanes of stopped traffic during rush hour; 50 minutes remained as the Bird’s Nest Olympic stadium came in and then out of the frame of my window; until finally 30 minutes remained as the cab rounded the fourth ring road and settled due west of the Forbidden City at the valet stand while I exchanged a xie xie accompanied by hundreds of Yuan for the ride.  Bounding two or three at a time up the stairs, then past the buffet with the first early risers shuffling from hot plate to pastries to coffee stand, to my room on the mezzanine level, ready for me though only a shade after 7:00 am.  Backpack stripped of non-essentials, just my camera and passport remained, I stepped out the front door of the hotel, with less than 15 minutes remaining to catch the tour bus before it departed from the Center for Future High Energy Physics.

    I set off on a run on the pedestrian path parallel to Fuxing Road, an eight-lane boulevard slicing through the tall, narrow apartment buildings with each flat’s balcony bearing a rug on the railing and a UHF antenna bent like a divining rod toward open sky, for the mile that separated me from the buses.  Morning in Beijing’s high summer created a haze that was not quite either fog nor smoke, muffling the heartbeat of the city, its rumbling breath of traffic, and deliberately revealing the path only a hundred feet ahead while I pounded on, cradling my rocking backpack from behind, out of phase with my feet.  Hundreds of meters above the pavement was clear, hot sky and the further I ran the wetter and wetter I became, collecting both humidity and undried sweat, while my hands moved from my backpack to wiping my brow to peeling off the shirt stuck to my chest in hopes some fresher air might circulate through.  The path was still mostly absent of people, but a statue of Mao glared disapprovingly from across a vacant lot while approaching the intersection beyond which lay the Center.  The conference website had stated that the buses would be parked near the guest house, of which the only information I had received was a low-resolution map and my own coordination with Google, so I veered right, sprinting through the main lawn, around a line of tan brick buildings, to an alley lined with cedars where I finally slowed.  The drivers of the two buses had just started engines, but the door of the first bus was open and I boarded, saying hi to the two organizers seated in the front row while making a dignified attempt at decreasing my heart rate and hyperventilation, but completely giving up on the drowned state of my clothes, and flopped into an open seat.