The Large Hadron Collider repurposed an excavation tunnel built for the Large Electron-Positron Collider, which was used until 2000 and whose construction involved the largest civil engineering project in Europe before the Channel Tunnel.

CERN—the European Organization for Nuclear Research—is the world's largest particle physics laboratory, with the Large Hadron Collider serving as its largest tool.

Learn about five of the largest particle accelerators on Earth, which, as of 2026, are led by the Large Hadron Collider at the European Organization for Nuclear Research.

Although built from 1996 to 2008, the Large Hadron Collider relies on accelerators built starting in 1954 to help bring protons to 99.9999991% the speed of light—about 2.73 million football fields per second.

On average, the Large Hadron Collider uses 1.3 terawatt-hours of electricity annually—equivalent to about 124,000 US homes—generated by a French substation.

At the Large Hadron Collider, protons are accelerated so close to the speed of light that they would lag behind a laser by just 10 feet after 14 minutes of travel.

Through 2038, the Large Hadron Collider research program is expected to generate societal benefits of €25.6B, or €3.3B more than operating costs and investments.

The Large Hadron Collider is the world's largest cryogenic system, which uses 10,000 metric tons of liquid nitrogen and 120 metric tons of helium to cool 36,000 metric tons of magnets to temperatures colder than outer space.

The High Luminosity Large Hadron Collider will provide a tenfold increase in particle collisions compared with the initial LHC infrastructure by increasing the number of ions in collision bundles and by concentrating the ion beams.

Watch an animated visualization of how the Large Hadron Collider works, including how particles are accelerated through a series of machines and how collision data is collected and distributed worldwide.

Take a 360-degree tour of ATLAS, one of two general-purpose detectors at the Large Hadron Collider and the largest particle detector by volume ever built. (VR device-compatible)

The first circular particle accelerator was narrower than the average cereal bowl

The 1939 Nobel Prize in physics was awarded to Ernest Lawrence for inventing the cyclotron. By comparison, the Large Hadron Collider is 5 miles in diameter and is the largest cryogenic system in the world, cooling its electromagnets to temperatures colder than those found in outer space.

Each year, the Large Hadron Collider undergoes a winter shutdown—when electricity costs are highest—and bringing it back online requires weeks of tests, including some involving high-energy particles from outer space.

Since 2026, the Large Hadron Collider has provided heat to thousands of French homes and businesses through a system that harnesses hot water from the accelerator's cooling circuits.

Unlike the other major detectors at the Large Hadron Collider, the Compact Muon Solenoid—one of two general-purpose detectors—was built above ground and then lowered underground in sections for reassembly.

Despite fears of creating black holes, the Large Hadron Collider produces collisions with energies of 13.6 trillion electronvolts, about one million times smaller than the energy needed to create the lightest possible black holes.

At the Large Hadron Collider, scientists have transformed lead into gold—a process known as chrysopoeia, which alchemists sought for centuries.

The total length of superconducting wire at the Large Hadron Collider spans about 250,000 kilometers (155,000 miles)—enough to wrap around the equator 6.2 times.

At the CERN Control Center, where the Large Hadron Collider and connected accelerators are managed, champagne bottles from parties commemorating major milestones, such as the first collisions or a new record energy, are collected.

As of 2026, 75 of the 86 particles discovered by the Large Hadron Collider have been found by the LHCb experiment—a detector that explores the decay of particles made of beauty and charm quarks.

Particle accelerators propel matter toward small targets at high speed

Devices like cathode-ray tube televisions were once basic particle accelerators, but modern ones, such as the Large Hadron Collider, use massive magnetic fields and circular tunnels to achieve energies high enough to recreate the conditions just after the big bang.

While constructing the tunnel connecting the UK and France, satellite positioning systems were supplemented by paleontologists on either side of the tunnel, who analyzed fossils to ensure excavation was at the correct depth.

Explore the components of the linear particle accelerator at Los Alamos

Located at the site of bomb design and development for the Manhattan Project, LANSCE features an injector system for hydrogen ions, a series of tanks with alternating electric fields for proton acceleration, and an isotope production facility that creates radioisotopes for medical treatments.

The Worldwide LHC Computing Grid—a distributed system of 2 billion gigabytes of storage across over 40 countries—manages data produced by the Large Hadron Collider.

Before 1932, when particle accelerators were first used for nuclear research, scientists relied on naturally radioactive substances to advance their understanding of the atomic nucleus.

The NSF funded the design and construction of LIGO by MIT and Caltech

The 1992 Cooperative Agreement between the National Science Foundation and both research institutions came twelve years after funding 1.5-meter (4.9-foot) and 40-meter (131-foot) prototypes. With a 1992 budget of $395M, LIGO was once one of the largest NSF-funded projects in history

The wild, early history of the tunnel across the English Channel

Britain and France today are connected by the Chunnel—a tunnel bored roughly 120 feet under the seabed of the notoriously choppy English Channel, which opened in 1994. The dream of integrating Britain with the rest of the continent this way began much earlier, with daring, physically impossible plans proposed as early as the 19th century. Check out the earliest plans here.

As of 2025, LUX-ZEPLIN is the world's most sensitive dark matter experiment, which is designed to indirectly detect a potential candidate for the invisible form of matter.

In 1971, a $35 ferret helped clean the Fermi National Accelerator Laboratory

Lacking cleaning robots, Fermilab scientists purchased a ferret named Felicia when metal slivers obstructing accelerated particles were identified. They trained her to run strings through vacuum tubes more than 90 meters long, and cleanser-dipped swabs were then tied to the strings and pulled through to remove the debris.

The archaeological sites uncovered through London's Crossrail Project

The Crossrail Project is an underground train system in London, which saw 26 miles of new tunnels created over more than a decade. The project provided unique access to long-buried layers of London's history, and a massive parallel archaeological excavation took place.

At CERN's Antimatter Factory, researchers create and guide antiprotons and antielectrons together to form antihydrogen, and all these antiparticles are analyzed to help scientists study the behavior of antimatter.

Leptons do not experience the strong nuclear force that binds quarks together

Particles like electrons can exist in isolation, enabling them to move more freely. Within circuits, this allows electrons to carry energy across wire surfaces quickly. Contrastingly, light created in the sun's core is delayed by a million years on its way to Earth due to collisions with free electrons.

If particle accelerators did create black holes by packing tremendous energy into a small volume, then trillions would be created in Earth's atmosphere daily by cosmic rays.

Between 2002 and 2025, upgrades have increased LIGO's detection range tenfold

After the construction of Initial LIGO was completed in 1999, no gravitational waves were detected during operations between 2002 and 2010. Instrument redesigns and significant technological improvements brought about Advanced LIGO, which began observations in 2015. Continued upgrades between continuous laser runs have improved detection sensitivity and stability.

In 2026, researchers successfully transported antimatter in a truck using a portable trap that employed electromagnetic fields to hold 92 antiprotons.

The Louvre in Paris has its own particle accelerator for art analysis

The Accélérateur Grand Louvre d'analyse élémentaire serves as a noninvasive tool for identifying and quantifying trace elements present in artworks by analyzing how particles backscatter off targets. This information can help detect forgeries and determine a piece's provenance. (Some readers may experience a paywall.)

The most common type of particle accelerator is a linear electron accelerator, which fires particles in a straight line, making them useful for the intense, targeted beams needed in cancer treatment.

Play an incremental game that teaches the history of particle physics

Developed during the CERN Summer Student Webfest 2014, this game tasks you with building the reputation of your particle accelerator as you discover particles and hire staff to collect data. A historical breakdown accompanies each discovery, allowing you to recreate the timeline of the field.

Within ALICE—A Large Ion Collider Experiment—at the Large Hadron Collider, scientists have created quark-gluon plasma—an exotic form of matter present in the moments after the Big Bang.

As of 2023, the world's smallest particle accelerator is smaller than a penny

The prototype is an example of a photonic accelerator, which utilizes tiny lasers to accelerate electrons rather than relying on oscillating electromagnetic fields to move them. It can deliver about 1 electron per second with energies equivalent to those found in cathode-ray tube televisions.

A beam of neutrinos can be created by firing a beam of high-energy protons at a target to produce unstable particles that decay into neutrinos.

The containment apparatus at Chernobyl is the world's largest movable metal structure

Completed in 2016, the "New Safe Confinement" is a €1.5B megastructure—the largest movable structure ever built. It was assembled next to the damaged reactor, then rolled into place along a special track to seal the site for at least 100 years.

The construction of LIGO needed to compensate for Earth's curvature

Across the 4-kilometer (2.5-mile) arms, the height of Earth's surface falls by almost a meter, preventing the lasers traveling within the arms from meeting the mirror at the end of each. Concrete slabs built beneath the arms help keep them level and provide structural support against seismic vibrations.

LIGO is part of the advanced gravitational wave detector network

Like the Laser Interferometer Gravitational-wave Observatory, Europe's Virgo Gravitational Wave Interferometer and Japan's Kamioka Gravitational Wave Detector reflect laser beams down perpendicular tunnels to detect gravitational waves in the patterns created by the recombined waves. Future observatories are expected to contribute to this network, further improving gravitational wave detections.

Watch a time-lapse of the installation of the New Safe Confinement structure

The world's largest movable metal structure was built to contain the radioactive material from the 1986 Chernobyl disaster, which had previously been confined within a structure built to last no more than 30 years. The new structure was slowly rolled along rails over the course of two weeks.

In 2017, a hidden chamber was found in the Great Pyramid of Giza by measuring particles created in the collisions between cosmic rays and atmospheric particles.

The Gasbuggy Project detonated a nuclear bomb to fracture underground rock formations

Part of Project Plowshare—a program aimed at finding peaceful uses for nuclear devices—the 1967 experiment sought to extract natural gas trapped within shale in underground New Mexico. Gas radioactivity was found to be excessively high for use without expensive processing, and the project was deemed an economic failure.

The Curies developed a way to measure radioactivity in an old medical dissecting room

Despite lacking proper laboratory conditions, Marie and Pierre built an ionization chamber and a piezoelectric quartz electrometer to measure the amount of charged particles released by radiation, with a sensitivity of ten-trillionth of an ampere. Substances with different emission rates indicated different elements.

View a timeline of particle discoveries through the Higgs boson in 2012

With few exceptions, the elementary particles that make up the Standard Model were theorized or predicted to exist before their eventual discovery in high-energy environments. These predictions were often the result of inferences drawn from already accepted mathematical models.

Delays in the decay of unstable particles provide evidence for time dilation

Physicists used the muon half-life measured in labs to predict how many should reach detectors on Earth's surface after their production in collisions between atmospheric molecules and cosmic rays. Higher detection rates were consistent with a longer half-life due to slower movement through time.

Explaining the Higgs boson, also known as the 'God Particle'

The Higgs boson is a long sought after fundamental particle that—within the framework of high-energy physics—gives other particles their mass. Having captured public attention when it was discovered in 2012 at the Large Hadron Collider, and its...