Particles produced in cosmic ray showers that would normally decay long before they reach Earth's surface are observed in ground-based detectors because they experience time more slowly when moving near the speed of light—a phenomenon predicted by special relativity.

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.

Scientists have determined the properties of cosmic rays by analyzing their trajectories in bubble chambers—containers filled with a vapor that clings to charged particles.

A particle accelerator allowed researchers to noninvasively examine a mummy

The mummy hailed from the Faiyum oasis, where Egyptian and Roman cultures intersected, and was analyzed using the Advanced Photon Source at Argonne National Laboratory. The device used high-energy X-rays to probe the material composition of numerous objects embedded deep inside the mummy without damaging its remains.

Learn how to build your own cloud chamber to detect cosmic rays—particles from space that move near the speed of light—at home.

Particle accelerators detect subatomic particles using millions of sensors

Calorimeters measure the energy of particles. Tracking devices can measure momentum and charge from the trajectory of particles, which is determined by recording tiny electrical signals. Time-of-flight detectors provide particle velocities directly and particle mass indirectly, giving physicists a suite of properties to compare with those of known matter.

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.

Antimatter was discovered by examining debris from collisions between atmospheric gases and cosmic rays—high-energy matter particles from space.

Particle detection has evolved from cloud and bubble chambers to digital 3D displays

As invisible particles passed through cloud and bubble chambers, they disrupted supersaturated vapor and superheated liquid, respectively, creating trails that served as proxies for cosmic rays. The transition from photographed events to digital sensors enhanced data collection and accuracy.

What it's like to go inside the Great Pyramid of Giza

Tourists can actually enter the ancient wonder, taking a 15-minute jaunt through tight spaces some describe as uncomfortable. The focal point of the journey is the chamber of the dead pharaoh, historically significant but not always visually compelling. The author describes it as a cool bucket list item but wouldn't repeat it.

Scientists can map Earth's shape and structure by measuring the ratios of certain particles arriving from different directions in space, as these ratios change with the density of the material particles travel through.

View a ranking of the masses of fundamental particles, from the massless photon to the top quark, and a timeline of their discoveries.

Cosmic rays can be detected using cloud chambers—containers where alcohol vapor condenses around trails of ions created by these high-speed particles from space.

Cosmic rays are evidence of incredibly powerful astronomical events—solar cosmic rays provide information about eruptions and flares on the sun's surface, while galactic cosmic rays shed light on dying stars.

In 1997, the Compton Gamma Ray Observatory identified 'positron geysers'—fountains of antimatter particles—emerging from near the center of the Milky Way.

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.

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.

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.

While atoms are normally made of protons, neutrons, and electrons, exotic ones have been built with antimatter—alternate versions of normal matter that live for fractions of a second.

Some cosmic rays possess energies as high as 100,000,000 teraelectron volts—more than 10 million times the energy of particles accelerated in the Large Hadron Collider.

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 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.)

It may be possible to create dark matter in particle accelerators

In high-energy collisions, exotic forms of matter can be produced by directly converting energy into mass according to *E = mc*². Even though a dark matter particle would not be directly observable, its creation would result in unaccounted-for mass, which can be compared to potential dark matter candidates for indirect detection.

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.

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.

As of 2025, LUX-ZEPLIN is the world's most sensitive dark matter experiment

The experiment is designed to indirectly detect WIMPs—weakly interacting massive particles and a candidate for what dark matter is made of—by looking for light produced when they collide with xenon atoms. Such collisions would also release electrons, which are then manipulated to produce a secondary light signal that helps rule out background effects.

After photons—particles of light—neutrinos are the most abundant particles in the universe.

Cosmogenic nuclide dating reveals how long a surface has been exposed to air by measuring the abundance of rare isotopes produced when cosmic rays interact with minerals.

The Higgs boson is a quanta, or discrete piece, of the Higgs field, which gives elementary particles, such as quarks and electrons, mass as they travel through it.

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)