The Secrets of the World’s Largest Particle Accelerator
Beneath the peaceful fields on the border between Switzerland and France, just outside Geneva, lies one of the most ambitious scientific projects in human history — CERN, the European Organization for Nuclear Research.
Hidden 100 meters underground stretches the Large Hadron Collider (LHC), a 27-kilometer ring where scientists investigate the deepest mysteries of the universe.
But what is really happening in this subterranean labyrinth of magnets, detectors, and cables? And why do scientists smash particles together at nearly the speed of light?
How the LHC Works
The LHC is a particle accelerator — a machine that propels protons (tiny particles found inside atomic nuclei) to extreme energies using powerful electromagnetic fields.
When they reach 99.9999991% of the speed of light, the beams are sent racing in opposite directions through two parallel tubes before colliding at specific points inside enormous detectors.
Each collision releases tremendous energy in an infinitesimal space, allowing physicists to observe the fundamental components that emerge from these high-energy events.
It’s like recreating, on a microscopic scale, the first instant after the Big Bang, when the universe itself was born.
Why Smash Particles at All?
Colliding particles may sound destructive, but it’s actually the most precise way to study the forces and building blocks of nature.
By examining the fragments created in these collisions, scientists can learn how matter formed, why particles have mass, and what unknown phenomena might still exist.
The goal is to understand why the universe contains more matter than antimatter, how mass arises, and whether dark matter — the invisible substance that makes up most of the cosmos — can be explained by new physics.
Discoveries So Far
CERN’s greatest triumph came in 2012, when researchers confirmed the existence of the Higgs boson — the elusive particle that gives mass to other particles.
Predicted in the 1960s but unseen for decades, it was finally detected by the giant ATLAS and CMS experiments, each the size of a multi-story building with millions of sensors.
The discovery validated the Standard Model of particle physics, a framework describing how matter and forces interact. Yet it also raised new questions — because many mysteries, like dark matter and gravity, remain unsolved.
The Power of the Collisions
To put things into perspective: protons in the LHC collide at energies up to 14 tera-electronvolts (TeV) — an almost unimaginable amount on the subatomic scale.
It’s not dangerous, but it’s enough to reveal quantum-level phenomena and test physical laws at unprecedented precision.
To achieve this, the LHC relies on superconducting magnets cooled to –271°C, just above absolute zero.
Its cooling system is one of the largest ever built, using liquid helium to maintain perfect stability.
Is It Dangerous?
When the LHC began operating in 2008, rumors spread that it might create mini black holes capable of swallowing the Earth.
Scientists quickly dispelled the myth: while tiny black holes could theoretically appear, they would decay instantly, posing zero threat.
Similar high-energy collisions occur naturally all the time, when cosmic rays hit the Earth’s atmosphere — and the planet is still here.
CERN as a Model of Global Cooperation
CERN is not just a laboratory; it’s a symbol of international collaboration.
More than 10,000 scientists from over 100 countries work together, sharing data, developing new technologies, and building bridges across cultures.
It was this spirit of openness that also led to the invention of the World Wide Web in 1989, by British scientist Tim Berners-Lee, right here at CERN.
Why It Matters to Us
Though its research may seem distant from daily life, CERN’s discoveries have profound practical impacts.
Technologies developed there power medical imaging (MRI, PET), computing networks, data science, AI, and even new materials.
CERN reminds us that curiosity is not just a scientific trait — it’s a human one.
When we peer 100 meters underground to study the building blocks of existence, we’re really looking for answers to the oldest question of all:
What are we made of, and where did we come from?