Stimulating electrons to emit identical photons produces lasers

This effect was predicted by Albert Einstein in 1917, and requires all excited electrons in a material to exist in the same excited metastable state within their atoms. Pumping all atoms through the same mechanism, such as electricity or flash lamps, can create this environment.

Particle accelerators have been used to reveal detailed ant anatomy

Using a synchrotron facility at the Karlsruhe Institute of Technology in Germany, a pair of X-ray beams swept across about 2,200 ant specimens to create over 200 terabytes of projection images from multiple angles. The images were compiled into micrometer-resolution 3D reconstructions of 792 species, which are freely accessible on the Antscan platform.

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.

Watch the motion of an individual photon using a high-speed camera

Although light travels over 3 million football fields per second, cameras that capture trillions of frames per second can observe individual particles of light as they interact with atoms in materials they travel through. Such observations can be used to determine the speed of light in different materials.

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.

Synchrotron radiation has revealed the fur color of creatures millions of years old

When electrons are accelerated in the loop, they produce intense X-rays that can reveal properties of a sample struck by them, just as X-rays can be used to show bone structure in humans. Studying the reflected light from fossils can uncover the presence of known pigmentation compounds.

Through sonoluminescence, concentrated sound waves can produce short, high-intensity flashes of light by rapidly collapsing microscopic bubbles to temperatures up to twice that of the sun's surface.

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.

Lasers, semiconductors, medical imaging, and atomic clocks rely on quantum mechanics

Semiconductors, crucial in electronics, operate based on quantum superposition. Lasers use stimulated emission, a quantum process, and MRI machines leverage the quantum spin of hydrogen atoms for imaging. Atomic clocks measure time with unprecedented precision using quantum transitions.

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.

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.

Photons emitted via stimulated emission have identical characteristics

When confined to a pair of mirrors, a single photon passing a region of population-inverted atoms can produce a chain reaction of monochromatic light. This chain reaction amplifies the initial photon, from which lasers get their name: light amplification by stimulated emission of radiation.

Lasers can be used to reduce the motion of atoms because particles of light—photons—can collide with particles of matter, as billiard balls do, to slow them down.

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.

Watch a crystal undergo X-ray diffraction to determine its internal geometry

In the early days of X-ray crystallography, getting photos of a single sample could take dozens of hours, followed by months of mathematical analysis. Today, automation and computer software can complete such tasks in a few hours.

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.

Photo 51's distinct 'X' pattern and spacing provided data to validate DNA's model

Rosalind Franklin and Raymond Gosling captured the photo after bombarding DNA fibers with X-rays and observing how the beams were deflected. The photo had a 62-hour exposure time and indicated a helical structure for DNA.

Explore a 3D model of the experimental setup Rosalind Franklin used to take Photo 51

To capture the X-ray diffraction image of DNA from the thymus of a calf, Franklin built a humidity-controlling camera to isolate the B form of DNA. The exposure lasted 60 hours and produced a cross pattern, indicating a helical structure.

Bioluminescent reaction enzymes are often used in biomedical research

Near-infrared luciferase systems allow researchers to image and analyze cellular activity in living animals because they penetrate tissue more deeply than visible light. This provides a means of studying gene expression and protein interactions without harming the animals.

X-ray diffraction reveals atomic structures by analyzing how crystals scatter X-rays

X-ray diffraction involves rotating a crystal in an X-ray beam while a detector captures the resulting diffraction patterns, which depend on the crystal’s internal structure. The mathematical principles behind the technique won the 1915 Nobel Prize and improved crystallography.

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.

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.

How radioactive isotopes are created and used for medical diagnostics

In particle accelerators, protons can be accelerated into other atoms to create radioactive isotopes, which can be attached to specific molecules to create radiotracers that are taken up by specific cells. Radiotracers can emit particles that produce light once they collide with an electron, and this light can be captured by a PET scanner to diagnose specific ailments.

A nuclear reactor's characteristic blue light is produced from superluminal particles

When light travels through water, its effective speed is 25% lower than its speed in a vacuum. Just as sound waves bunch up and produce a sonic boom when objects move faster than the speed of sound, particles moving faster than this reduced speed generate a shock wave of light, visible as a blue hue.

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.

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.

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.

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.

More than 97% of the world's particle accelerators are used for commercial purposes

Only a few hundred of the over 30,000 particle accelerators worldwide are used for research. Most are involved in medical imaging and treatment, food sterilization, semiconductor processing, cargo screening, and radioisotope production. They're also used to modify the properties of polymers.

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.

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.

Some scientists hypothesize that stressed rocks can discharge built-up static electricity in the form of lightning—a phenomenon known as fracto-luminescence, or earthquake lights.

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

Random lasers can be created from biomaterials, such as peanuts and birch leaves

Rather than creating a narrow beam of light via amplification in an optical cavity, the random laser produces a red glow by scattering photons created in the natural pores of a peanut kernel after it has been injected with a solution of light-generating carbon dots derived from birch leaves.

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.

X-rays earned the very first Nobel Prize in physics for revealing hidden worlds

In 1895, Wilhelm Conrad Röntgen discovered X-rays, which could pass through solid objects and make unseen structures visible. Today’s X-ray tools continue to advance science and medicine, including capturing real-time images of proteins.

Microchip fabricators create light by heating tin droplets to over 220,000 Kelvin

Every second, lasers strike 50,000 droplets moving at 250 kilometers (155 miles) per hour, vaporizing the tin in supernova-like miniature explosions that produce ultraviolet light. Knowing this light will spread via diffraction as it passes through a filter during manufacturing, designers reverse-engineer the filter design based on the required final microchip pattern.

Thunderquakes—seismic waves created when lightning strikes the ground—have enabled scientists to image underground environments near Earth's surface by detecting vibrations along subterranean fiber-optic cables.

Some materials can absorb low-energy light and emit high-energy radiation

Through anti-Stokes cooling, incoming energy is combined with vibrations in a material's crystal lattice to produce a net reduction in its temperature. Using this effect, lasers can be directed at microchip hot spots to help keep data centers cool.