CT scanners at airports take images across energy bands to identify baggage contents

Computed tomography scans use X-rays to create 3D internal images

Just as shadows can reveal the shape of obstacles blocking visible light, the donut-shaped CT scanner measures how X-rays are blocked, revealing the shape of bones, organs, tissue, and other matter along a cross-section. As it rotates, the scanner combines these cross-sections to build a model of the internal structure.

Ultrasound machines emit and collect high-frequency sound waves to construct images

Before its use in medical imaging, the technology was employed in World War I for submarine detection, the same way bats use sound for echolocation of obstacles. Differences in the penetrating power of different frequencies allow medical professionals to detect different structures in the body.

Many airports have dedicated stores for luggage, despite most passengers having luggage with them already

This podcast episode argues that airport luggage stores exist due, in part, to the security measures implemented after 9/11, creating capitve audiences of travelers. Some argue that airport luggage store shoppers coming from places where luggage is more expensive could be purchasing luggage in international airports. Specifically, the episode traces airport history from the very beginning to today's luggage store in your local Terminal B.

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.

Scientists use ground-based radar data to detect turbulence within clouds

NCAR developed the NEXRAD Turbulence Detection Algorithm and the Graphical Turbulence Guidance system to provide forecasts up to 18 hours ahead using ground-based Doppler radar data. Software systems also utilize an automated observation and reporting package—the EDR system—found on Delta, United, and Southwest Airlines aircraft.

Dogs smell a lot of stuff we can't, including bed bugs and chemicals in electronic devices

In addition to identifying medical smells and tiny insects like bed bugs, dogs can also detect electronic storage devices. These tools often contain triphenylphosphine oxide, a chemical used to prevent overheating.

A composite of telescope images of the sun, which each reveal unique solar features

While traditional cameras can reveal sunspots—cooler regions on the sun's surface—in visible light, x-ray detectors can highlight explosions of high-energy plasma and magnetic fields known as coronal mass ejections. Hydrogen-alpha filters can reveal clouds and filaments of material suspended in magnetic fields above the sun's surface.

A list of five everyday products that rely on radioactivity, including exit signs and gemstones

Like some glow-in-the-dark wristwatches, some exit signs contain sealed tubes of tritium—radioactive hydrogen gas—which emit low-energy beta particles that react with surrounding elements to produce light, making them visible without batteries. In smoke detectors, smoke particles disrupt the steady flow of ions generated by americium-241.

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.

How lasers have become a go-to in archaeology

Archaeological teams now have another item to pack with their trowels: Lasers. Researchers' approach to unsurveyed land has been transformed by light detection and ranging technology. LiDAR has helped archaeologists break new ground and uncover...

Can brain scans help with processing trauma?

MRIs and brain monitoring therapies are becoming increasingly popular for those looking to process trauma and address mental health conditions, including PTSD and depression. This article details how these therapies quantify mental health, giving users another way to measure and manage their mental and emotional needs through brain mapping and other methods.

Can AI revolutionize cancer detection?

Scientists have developed a tool to evaluate the risk of lung cancer, the most deadly form of the disease. Named "Sybil," this AI program was trained using CT scans with clear cancer signs, followed by scans where cancer wasn’t obvious. The tool is able to review CT scan data to predict a patient's of developing a lung cancer within six years. See how it works here.

Environmental DNA monitoring can help detect the presence of invasive species

Genetic material that organisms deposit into water, soil, or air can be identified by analyzing samples from each environment, allowing land managers to more reliably detect and track organisms than visual surveys alone. eDNA has been used to develop early warning surveillance systems for various invasive marine species.

Alternatives to polygraphs, which correctly identify innocent people only 57% of the time

Lie detector polygraphs have been standard in law enforcement for a century despite being based in unproven science. Researchers are exploring brain-scanning and eye-tracking alternatives, though some suggest there's no reliable lie-detection process at all.

Objects can be 3D printed with light by projecting 2D computerized tomography (CT) scans onto rotating cylinders of resin, which solidify upon exposure.

During flights, cell phones can act like signal jammers as they search for service

When farther from cell towers, these devices expend more energy to emit more powerful signals, which can overwhelm any ground-based tower or radio telescope they fly past. Rather than protecting the flight, airplane mode conserves a cell phone's battery.

Why Japan builds airports on water

Some of Japan's roughly 100 airports are built on water—that is, engineers have created new land in bodies of water specifically to construct airports. This six-minute video explains why the country is doing so despite the higher cost of such airports.

Chip technology replaced magstripes to stop easy card cloning and fraud

The magstripe on bank cards always gives the same data, making it simple to copy using a device called a grabber. In contrast, embedded chips create a unique code with every transaction, making it much harder to clone or steal card information.

View the electromagnetic spectrum and the properties of different types of light

All forms of electromagnetic radiation, from radio waves to gamma rays, travel at the speed of light in a vacuum, but their wavelengths decrease as their frequencies increase. The light-sensitive nerve cells in the human eye are sensitive to a narrow range of values, which we observe as the spectrum of visible light.

Watch a former CIA deputy director rate spy gadgets from movies and television

Dawn Meyerriecks, former CIA deputy director of science and technology, examines the realism of gadgets, including James Bond's weaponized Aston Martin, climbing gloves from the Mission: Impossible franchise, and the briefcase and listening device from "The Americans."

US Customs and Border Protection traditionally operates at ports of entry and along US borders

CBP manages security at official border crossings and patrols areas between ports of entry to prevent unauthorized crossings. View details of the agency's mission, organizational structure, and approach to managing the United States' physical borders.

Space trash could be cleaned up using a giant inflatable bag

California-based TransAstra has developed and tested a device called Capture Bag, intended to catch anything from small rocks to house-sized boulders. The company claims its system could also be adapted for asteroid capture and mining.

Calculate your estimated yearly dose of ionizing radiation

This calculator from the EPA provides a value in millirems—the US unit for effective dose—based on a variety of exposure parameters, including the state a user lives in and travel-related sources of ionizing radiation, such as passing through screening machines.

Radioactive elements can introduce software errors because the ionizing radiation they produce can detach electrons from atoms, and computer code relies on the distribution of electrons.

Carrier screening enables individuals without symptoms to see if they carry a gene for disease

Some conditions are autosomal recessive—meaning a person may carry a gene for that condition, but not have symptoms. Cystic fibrosis, sickle cell disease, and Tay-Sachs disease are examples of autosomal recessive diseases in which a person must inherit two copies of a nonfunctioning gene—one from each parent—to develop disease.

Removal of different color tattoo inks may require multiple lasers

Light needs to be absorbed by ink particles to break them down into small enough pieces for the immune system to eliminate. Color ink reflects, rather than absorbs, lasers of the same color, while black ink absorbs all colored lasers.

Infographics explaining global terrorism trends

Our World in Data’s terrorism page details global trends in terrorism. Through interactive infographics, the site shows how the number of terrorist acts varies around the world and how it has changed over time. Sections investigate common definitions of terrorism, trends in global terrorism deaths, and the global distribution of terrorism. Additional segments highlight airline hijackings, public opinion, and media coverage of terrorism. Explore this website for an array of infographics on terrorism.

Stars appear to twinkle because turbulence in the motion of molecules in Earth's atmosphere causes light to bend and wiggle rapidly on its way to the surface—a phenomenon called scintillation.

Power lines are dotted with large, brightly colored balls to improve the visibility of these thin wires to helicopters and small planes and help prevent potential crashes.

An investigation suggests a Scottish island became awash in forever chemicals via seafoam and seaspray—raising questions about what that means for the safety of other coastal areas.

See images of medical cases of firework injuries shared on this 'Instagram for doctors.' (Warning: Graphic content)

When you complete a CAPTCHA on a website to prove you are human, you may be unknowingly training algorithms for self-driving cars, whose systems require training data to help identify crosswalks, bicycles, and other outdoor objects.

The history of many kitchen appliances involves unexpected discoveries and applications, including wartime radar turned hamster defroster and replacing an 'ice king' with heat-stealing boxes.

Tattoos remain visible on your skin thanks to immune cells called macrophages

In 1984, Operation Smash Hit intentionally crashed a 239-ton train into a nuclear waste canister at 100 miles per hour to prove the canister's safety, which remained completely intact and lost just 0.29 of its 100 pounds of pressure.

Visualize how CRISPR-Cas9—a type of immune system used by single-celled organisms to attack invasive viruses—targets and makes precise changes to a gene's DNA.

Hotels in Cannes, the glamorous city on the French Riviera, hire hawks to ward off seagulls during the city's famous film festival.

Art theft is the third-largest source of criminal revenues worldwide, thanks in part to the subjective nature of valuing a work of art.

The 2026 Ebola outbreak is hampered by a lack of vaccine against the species of the virus, heightening the need for rapid tests to aid in disease control.

Sony set the standard for cylinder-shaped batteries when it repurposed manufacturing equipment used to make rolls of magnetic recording tape.

Doctors differentiate between a phobia and fear by asking patients whether their fear interferes with their day-to-day activities.

To reduce wrinkles in clothing, research recommends gentle wash cycles with more water and tumble drying with smaller loads and longer times.

Some coin denominations have ridges etched on their sides, partly to prevent counterfeiting, in a practice called 'reeding.'

When caught in the mouths of cardinal fish, seed shrimp release glowing, bioluminescent chemicals, which alert predators of the cardinal fish, prompting the shrimp's ejection.

US intelligence allegedly pursued more than 600 schemes to assassinate Cuban revolutionary Fidel Castro.

Browse a detailed visual analysis of over 200,000 similes—comparisons that often use 'like' or 'as'—from popular fiction to see how frequently writers the same idiomatic expressions.

While the first exchange-traded fund (a 'basket' of different assets that can be bought and sold on a stock exchange) in the US only launched in 1993, the global ETF market has grown to more than $10T in the short time since.

Apollo astronauts left items in the moon's 'toss zone,' including golf balls, family photos, and bags of human waste, to make room for lunar rocks.

The American Society of Civil Engineers' infrastructure report card gave the US a C in 2025, its highest grade since the project launched in 1998.

The price of gas is a composite made up of several different factors, with the federal gas tax making up less than 20% of what drivers pay at the pump.