More than a Lens
By Gabi Hamilton, University of Virginia
Just a simple piece of curved glass. It gave us the power to bend light, and in doing so, to rewrite our understanding of our place in the universe. Lenses are used in cameras, telescopes and microscopes: objects that extend our human capabilities, helping us see and record what our eyes can’t. With the telescope we looked outward, transforming faint smudges in the night sky into galaxies and discovering that our world was not the center of everything. With the microscope we looked inward, revealing the hidden life in a single drop of water. With the camera we had a way to capture and share what we saw, making the invisible visible and permanent to all.
In a way, I build cameras. Not the kind you might take on vacation, but arguably the most complex camera ever conceived. They aren’t designed to capture candid moments, but to help us see deeper into our universe. They do not capture light from distant stars, but something far more fundamental: the echoes of the Big Bang, recreated for a tiny fraction of a second and more than a football field below the surface. We call it the High-Granularity Calorimeter, or HGCAL, for short.
You could also argue I build microscopes. At the Swiss-French border, at the Large Hadron Collider, our subjects aren’t cosmic objects or people, but the elementary particles that form the very fabric of our universe, unleashed in collisions of unimaginable energy and a million times smaller than a grain of sand. To photograph these violent moments of creation, you need more than a lens and a shutter. You need a cathedral of technology, assembled by a global community of modern-day explorers. My workshop is at Fermilab, and my job is to help build its eyes.
Charting the Edge of the Map: The Standard Model of Particle Physics
This global, painstaking work serves a single, profound purpose: to refine the most detailed map of reality ever created, known as the Standard Model of particle physics. A stunningly successful framework describing the fundamental particles and forces that govern the universe, from the atoms in our bodies to the light from distant stars. Its predictions have been confirmed with record precision, culminating in the 2012 discovery of the Higgs boson — the final, crucial landmark on this map. Finding the Higgs was a monumental achievement, the culmination of a nearly 50-year hunt that confirmed the very reason our universe has substance. This particle is the first proof of the mechanism that gives all other particles their masses. Without it, all fundamental particles would be zipping around at the speed of light. In such a universe, atoms could never form. There would be no planets, no stars, and no people. The discovery of the Higgs, was profound because it validated the entire foundation of our map, explaining how our world can exist.
But like the ancient maps of our own world, our map of the cosmos has edges and gaps. Beyond the familiar territory of the Standard Model lie vast, unknown continents. Our map offers no route to understanding the enigmatic ‘dark matter’ that holds our galaxies together, or the ‘dark energy’ that is accelerating the expansion of the universe. The original LHC and its detectors were like the ships designed to find that last known island — the Higgs boson. They did their job brilliantly for more than 10 years. But to explore what lies beyond, we need a new ship, one that takes us further and can withstand the harsh environments that we will brave. By creating an unprecedented number of collisions, we are drastically increasing our chances of witnessing a rare event that could signal new physics. My work at Fermilab’s workshop is about building the next generation of this detector (I mean, camera). A sharper and more resistant eye, allowing us to navigate this overwhelming amount of data and spot the faint glimmer of a new discovery — the first coastline of an unknown land.
My Official Title is Experimental Particle Physicist
But my day-to-day work is far less glamorous than the title might suggest. When I first joined this project, my task was to breathe life into a piece of the camera that no one had ever powered up before. It felt like being handed a map to a hidden country, but the map was written in a dozen different languages. The object itself was just a circuit board covered in seemingly harmless chips, but to make it function, I had to become an explorer. To understand the flow of data, I had to find the expert who spoke the language of the ‘HGCROC’ chip. Then I had to seek out the masters of the “backend electronics.” Each component, some no bigger than my fingernail, had a guardian — a scientist who had dedicated years to perfecting it. My journey wasn’t just through circuits and code, it was through a community. And I wasn’t just assembling a machine, I was connecting people’s life’s work.
My days now are spent in a sterile cleanroom, a brightly-lit space where the air is filtered to be cleaner than a surgical suite. Here, under the gentle hum of the ventilation, lie the structures of our detector, known as cassettes. My work is a blend of microsurgery and intricate puzzle-solving. One moment, I am painstakingly mounting fragile silicon modules — each one a small universe of technology in itself — onto a baseplate and connecting them. The next, I am routing bundles of delicate optical fibers, the neural pathways of our camera, through a labyrinth of electronics, knowing that a single broken connection could render a whole section blind.
This assembly is only half the story. Once a module is built, it becomes my patient. I perform a series of health checks, applying voltages and measuring the electrical currents. Then we place the fully assembled cassette into a specialized chamber and plunge the temperature to -35°C, colder than an Antarctic winter, to mimic the harsh operating conditions inside the LHC. We watch its vital signs, monitoring the faintest flicker of electronic noise or instability. Every test, every measurement is meticulously logged into a vast database, ensuring every component of this camera is fully traceable and certified for its journey into the unknown.
What makes this process even more challenging is that the tools we use for these tests had to be invented alongside the components themselves. We are so far into uncharted technological territory that there is no off-the-shelf equipment to certify our work. We cannot simply buy a ‘cassette tester’. We have to build it. A significant part of my role, therefore, is not just performing the tests, but developing the very procedures for them. This involves writing custom software that can speak the unique electronic language of the modules, designing the hardware interfaces to power and read them out, and establishing the baseline for what a ‘healthy’ signal even looks like. Each new test is a small research project in its own right, a puzzle that requires us to understand the fundamental physics of the device and transform that knowledge into a reliable, repeatable procedure.
My role, I realized, was to be a translator — to take the experience of many, adapt it to our hardware here at Fermilab, and make it our own.
My most recent challenge sounded deceptively simple: read the temperature. In a normal lab, you might use a thermometer. Here, it meant extracting a temperature reading from a tiny resistor, a process that sent me deep into our chip’s technical manual. That document alone felt like an archaeological artifact, a dense compilation of knowledge from dozens of experts I would never meet.
But even with their collective wisdom, I hit a wall. The theory was there, but the practical steps were a mystery. The solution, it turned out, wasn’t on a page. It was in a person.
I found myself on video calls with a scientist from Minnesota, then one from London, then one from Geneva. They hadn’t worked on my exact system, but they had all wrestled with this same problem before. They couldn’t give me the answer, but they could share their maps of the territory. That was the breakthrough. We are so used to hearing about the eureka moments of famous scientists, but we often forget the quiet, collaborative work that makes those big moments possible. My final success wasn’t a dramatic discovery, but a quiet click of understanding, an achievement made possible by an invisible network of collaboration stretching across the globe.
Soon, this camera will open its eyes for the first time
This story is not an exception. It is the rule. A process repeated over and over by hundreds of scientists for thousands of unique components. In the end, what we are building is so much more than a machine. It is a testament to what humanity can achieve when we work together across borders and disciplines. Each tiny component I test, each connection I forge between experts, is a single stitch in a vast tapestry woven by thousands of hands. Soon, this camera will open its eyes for the first time. We have hints of what it might find, but we don’t know for certain what it will see. Perhaps it will reveal new particles that complete our understanding of the cosmos, or perhaps it will show us something so unexpected that it shatters our theories and forces us to begin anew. That uncertainty is the point. We build these cathedrals of science not because we have the answers, but because we are compelled by the questions. And to play a small part in building a new window onto reality is a privilege beyond measure.
Acknowledgements: This essay was written for the Science Policy & Advocacy for Research Competition (SPARC) at the Universities Research Association.
