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

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.

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.

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.

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.

Research shows that cosmic rays may trigger the cascade of displaced electrons needed to produce lightning, which is also enabled by pointed ice crystals that create strong electric fields.

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

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.

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.

Cosmic rays are thought to be accelerated to near the speed of light by repeatedly bouncing across shockwaves produced by high-energy cosmic events, such as supernovae.

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.

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.

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.

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.

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.

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.

Tom Liggett, a Bournemouth University student, sent sealed photographic film into space using a helium balloon, producing photographs from cosmic rays.

Earth's magnetic field, which deflects charged particles, helps protect us from cosmic rays, but the sensitivity of these particles to magnetic fields also makes it difficult for astronomers to determine their sources.

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.

Watch how the machine at the heart of NASA's Cold Atom Lab produces atoms near absolute zero—the coldest theoretical temperature in the universe—for experiments involving quantum phenomena.

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.

As seen in the dark region of the Horsehead Nebula, clouds of space dust can block some forms of light from reaching telescopes, impairing observations and data collection.

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.

Scientists are experimenting with ways to probe the multiverse theory

Researchers are simulating vacuum bubbles—the theorized starting points of universes—using quantum computers, digital models, and exotic lab setups to study how they form, expand, and possibly collide. One experiment aims to "blow" artificial universe-like bubbles inside ultra-cold quantum gases, potentially capturing real-time glimpses of cosmic birth processes in a lab.

Watch lightning strike a building at 40,000 frames per second

When the built-up layer of negative charge at the bottom of clouds is sufficiently high, a network of charge filaments will emerge. If one of the filaments meets a rising strand of positively charged particles, a highly conductive path forms, and charges across all filaments move to the path, generating lightning

Antimatter can be created from dark lightning—high-energy light emitted by deflected electrons after they are accelerated to near the speed of light by thunderstorms.

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

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.

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.

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.

Fermilab's ICARUS experiment is searching for hypothetical sterile neutrinos

Neutrinos are a group of three chargeless, lightweight particles that can transform into one another via a quantum mechanical phenomenon called neutrino oscillations. The rate of these oscillations can be determined by measuring the amount of each type at different distances, where data inconsistencies would suggest the existence of new physics.

Planeterrellas create artificial auroras that mimic the atmospheric displays of light by setting up an electric field between two metal balls in a jar filled with a small amount of air.

Scientists have tested atmospheric models by firing rockets into the aurora borealis

Functioning like components of a CT scan, the missiles transmit signals that can be used to identify charged particles and electromagnetic currents in slices. The slices are then combined to construct a computer-based model of Earth's atmospheric structure, which is used to compare the accuracy of physics-based models.

Lichtenberg figures capture lightning-like patterns within insulators

When high-energy electrons from particle accelerators are fired into materials like acrylic, they form a charged plane before discharging into scarred patterns within the material. By evenly charging a cylindrical bottle through rotation during the irradiation process, a 3D figure of lightning in a bottle can be created.

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.

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

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.

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.

Cloud 9 is a dark-matter-dominated failed galaxy

Identified in 2023, the starless, gas-rich object is the first of its kind seen by astronomers and provides a window into the early stages of galactic formation without observations relying on visible matter as a proxy. The existence of such REHLICs, or Reionization-Limited-H I Clouds, was predicted by cold dark matter cosmological models.

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.

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.

Dilution fridges create the colder-than-space environments needed for quantum computers by successively lowering temperatures across layers plated with gold, which reduces heat transfer via radiation and gives them a chandelier-like appearance.

By measuring them in hot-air balloons during a partial solar eclipse and at night, Victor Hess discovered cosmic rays and concluded they came from beyond the solar system.

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.

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.

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

Cyclotrons move particles in spiral paths of increasing radius

After particles are injected into the center of the device, an alternating electric field and a constant magnetic field energize the particles as they spiral outward toward a target. Cyclotrons are common in hospitals that perform molecular imaging, which relies on radioactive components that decay within hours.

Understanding why charged particles from the sun protect Earth from more dangerous particles

The solar wind engulfs the solar system in a protective bubble called the heliosphere, which was first theorized in the late 1950s based on studies of cosmic rays—high-energy particles traveling through space at near light speed. The heliosphere shields the solar system from much of this ionizing radiation originating elsewhere in the Milky Way.

Dark matter detected in the cosmic web

Researchers from Yonsei University detected dark matter on the cosmic web, a network of filaments that feed gas into galaxies. The detection was made possible by using the general theory of relativity to analyze gravitational microlensing around the Coma Cluster. This article explains the phenomenon and how the detection supports the presence of dark matter throughout the cosmic web.

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.

Cathode rays are beams of electrons that emit light when hitting a fluorescent screen

When these beams are emitted into an evacuated tube containing charged plates or a nearby magnet, deflections are observed due to the electron charge. In 1897, J.J. Thomson's calculations of this deflection led to his discovery of the subatomic particle.