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.

How black boxes made flying safe

Black boxes—which are actually orange—were not universally present in airplanes until roughly 1967, a process which grew out of frustration over frequent, unexplained crashes in the industry's first few decades. This piece tells the origins of...

Fluorescent bulbs can be illuminated by overhead power lines without making contact

The electromagnetic fields produced by the alternating current in transmission lines can induce the motion of charges in nearby objects. This motion yields electric currents that can light up bulbs but are too small to harm humans.

Tennis balls are yellow, partly thanks to a suggestion by British naturalist and broadcaster Sir David Attenborough.

Understanding ball lightning remains an area of active research

Observations of glowing orbs of light that appear during or after thunderstorms have been documented since at least the 12th century, but their rarity and short lifetimes have made their study challenging. Some theories suggest they form when lightning vaporizes pockets of gases in the air or certain materials on the ground.

Most commercial planes get struck by lightning multiple times a year

This piece explains why commercial aircraft rarely crash in thunderstorms, detailing how pilots use onboard radar, shared reports, and strict avoidance protocols to navigate storms that look far more dangerous on screen than in reality.

Lightning rods provide a conductive pathway to safely steer massive electric currents

The device is positioned higher above the ground to "catch" one of the many branching filaments of electrons from clouds before they make contact with other surface structures, which have been induced to have a positive charge by overhead storm clouds. The current is then sent to a conductive grid buried underground.

Turbulence is needed to make airplanes more stable and golf balls fly farther

Vortex generators—small fins placed along airplane wings—create small eddies that prevent airflow separation, maintaining lift and preventing stalls. Golf balls have dimples that create a turbulent boundary layer on their surface, minimizing drag forces.

View a gallery of whimsical transmission tower designs from around the world

Despite their importance to the functioning of the electric grid, these structures are often considered aesthetically unpleasant. To remedy this, some have been transformed into art installations featuring stained glass and colorful lighting, or built with whimsical designs, such as clown faces or giant bodies.

Colored paint lines on new tires mark different types in the factory

Each stripe helps warehouse workers and distributors identify tire types at a quick glance. This innovation became important a century ago as manufacturers scaled operations and developed distinct product lines.

How David Attenborough's work in color television gave tennis balls their color

As controller of BBC Two, Attenborough wanted the BBC to achieve the first full-color broadcast in Europe and saw Wimbledon as the perfect event to make it happen. Noticing that the white tennis balls used then would stain green and become less visible on color broadcasts as matches progressed, he suggested fluorescent balls, which were eventually adopted.

Fireflies light up to provide mating signals and warnings to predators

Variations in the illumination patterns and flight paths while emitting light have been observed across firefly species. Some species instead rely on pheromones if they are primarily active during the day or have lost the ability to illuminate.

Spy balloons. UFOs. What else is up there?

The appearance and downing of a Chinese surveillance balloon brought the concept of high-altitude floating aircraft into the public consciousness. While sparking a diplomatic row, it also revealed how many objects—nefarious or benign—are...

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.

The quarterback cadence is a unique quirk to the game of football

Only the offense knows when the ball will be snapped, giving the team with the ball the advantage. Common combinations of colors and numbers (like "blue 42") were codes for plays early in the sport, but are now used arbitrarily.

View major global infrastructure, including power plants, fuel lines, and water pumping stations

The Open Infrastructure Map displays data from the OpenStreetMap database, which aggregates information from freely licensed geodata sources, surveys, and photographic and satellite imagery. It also displays power lines, generators, substations, various chemical pipelines, telecommunications towers, data centers, and more in daytime and nighttime maps.

When helicopters fly near sandy surfaces, these granular particles can strip off fragments from a blade's abrasion strip, which then quickly react with the air and ignite, producing rings of light.

On average, every in-service airplane is struck by lightning once a year

The average strikes per surface area per year on Earth suggest that aircraft should only be struck once every 1,000 years, based on their size, but proximity to storm clouds' high electrical fields increases strike rates. Aircraft are designed as continuous conductive shells, causing electricity to flow along their exterior and preventing internal damage.

Atmospheric composition and temperature impact the color of lightning

Just as fire ranges from red to blue with increasing temperature, lightning's blueish-white comes from the superheating of air. The emission of light from the predominantly nitrogen- and oxygen-rich atmosphere produces a purple tint, with additional color caused by light scattering from humidity, hail, dust, and ash.

The engineers proposing massive airbags for airplanes

Though they are famously rare, airplane crashes are some of the most shocking catastrophes when they occur. These researchers are dreaming up an implausible safety feature to help crashing planes land safely.

Blacklights can illuminate certain biological materials, including blood, teeth, and fingernails, because they contain fluorophores—molecules that visibly glow immediately after exposure to higher-energy light.

Shooting stars are streaks of light produced by meteoroids

As these rocks enter Earth's atmosphere at high speeds, friction causes them to burn up, briefly leaving streaks of light. The color of these fireballs can be used to determine the composition of the meteoroid, if it does not reach the ground and become a meteorite for analysis.

Biofluorescent animals—those that absorb light, such as ultraviolet rays, and re-emit other types of light, such as neon green—include some flying squirrels, scorpions, sea turtles, and platypuses.

Dead birds are often the warning sign health officials look for as a sign of West Nile danger.

High solar activity can produce pink and purple auroras

Although less common, energetic enough charged particles from the sun that descend to an altitude of about 100 kilometers (62 miles) can strike a mixture of ionized and neutral nitrogen molecules, causing them to emit red and blue light, which our eyes perceive as purple.

Why professional tennis players are so picky about balls before serving

Just as swimmers shave their bodies before competitions to swim faster, experiments show that tighter, less fluffy balls experience less drag forces when moving through the air and thus produce faster serves at the cost of less control. Players may select a fuzzier ball in scenarios that call for safer, more cautious play.

Solar activity and the density and chemical composition of the air affect auroral colors

Oxygen atoms can emit red and green light when energized by collisions with the solar wind, but red takes longer to be emitted and is disrupted by bumping into other molecules. This causes red light to appear at higher altitudes, where the air is less dense. Higher-energy solar wind can penetrate to lower altitudes and collide with more abundant ionized nitrogen, which produces blue light.

Virtually all plants are biofluorescent because their photosynthesis is powered by chlorophyll, a pigment that glows red as a way to get rid of excess energy when exposed to ultraviolet light.

Explore a visual history of Air Force One.

Examining the causes of power outages, from system damage to preventative measures

Stray balloons, contact with trees, malfunctioning equipment, and severe weather are among the causes of failures that can cause widespread, unplanned blackouts. Although contingency options that rely on alternative transmission pathways to deliver electricity from generators to consumers may be possible, some shutoffs, brownouts—available power is reduced—and cycles of repeated outages may be intentionally implemented to protect public safety.

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.

Rising satellite numbers pose increased risks of planes being hit by falling debris

Projections of more than 100,000 satellites in space by the 2030s—eight times the number in 2025—highlight a growing threat to aviation. Experts suggest the odds could reach seven in 10,000 annually by 2035, alongside higher risks to people on the ground.

Rayleigh scattering of light gives the atmosphere its blue skies and red sunsets

Light is deflected from its original path by atmospheric particles, where bluer light is scattered more than other colors. When the sun is at its highest point in the sky, it travels through the thinnest part of the atmosphere, scattering some blue light across the sky. A greater atmospheric path length at sunset scatters more colors, leaving only red, yellow, and orange.

The agricultural origins of paintball guns

The paintball field industry—where players compete in pseudo-battle using the (minimally) harmless guns—is worth over $1 billion annually, and it continues to grow. This fun piece breaks down the relatively recent history of the industry by...

Fireworks make a loud booming sound after explosion due to air expanding faster than the speed of sound.

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.

Visualizing the symbols and history of world flags

More than 200 world flags feature high-intent designs, projecting ideals and values to the world through archetypal symbols, colors, and shapes. This page effectively depicts the data behind symbol and shape usage, how much each country's flag has changed over time, the most popular colors used, and more in a series of elegantly simple charts.

Bright blue fireworks are the most difficult color to create

Copper chloride emits blue light when heated, but breaks down at the temperatures created when fireworks explode. Pyrotechnicians continue to search for an ideal mixture that provides a temperature high enough for copper chloride to shine brightly without being destroyed.

Spikes of light around stars are artifacts of light bending around the mirror supports

Through diffraction, electromagnetic waves can bend around obstacles, as observed in the silver linings at the edges of clouds, where light should be blocked. Within reflecting telescopes, starlight diffracts around struts—beams holding a secondary mirror in place—and spreads perpendicular to them, creating pairs of spikes.

What happens to golf balls after they're used?

With over 1 billion golf balls produced annually, an estimated 300 million to 1.5 billion are lost worldwide. On average, thousands of balls are left behind on each course, often ending up in ponds, forests, and beaches. While many golf courses recover and reuse some of these balls, studies suggest countless remain unretrieved.

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.

Radio waves are used in broadcasting, weather radar, telecommunications, and GPS

Its ability to bend around obstacles and reflect off the ionosphere—an electrified layer of Earth's upper atmosphere—allows this type of light to travel long distances without damaging living things due to its low energy. MRI scanners, WiFi, and Bluetooth technologies are also applications of this form of light.

Fireworks' chemical composition and internal layout produce their unique displays

The burning of different metal compounds, facilitated by combining fuel with oxidizers, results in explosions of varying colors. The timing and pattern are engineered through the arrangement of pellets and fuses.

Airports at high elevations, like Denver International Airport, have longer runways than most airports because airplanes cannot take off or land as quickly in thinner air.

In the 1940s, pilots flew into thunderstorms to learn about their formation and properties as part of the Thunderstorm Project, the first multiagency meteorological study mandated and funded by Congress.

Colorful thunderstorm phenomena can be viewed from the International Space Station

Transient luminous events are lightning-related phenomena that occur in the atmosphere above storm clouds. These events often look like columns of red light resulting from electrical discharge, but may also appear as purple tendrils or long blue jets.

Lightning bolts are about as thick as a garden hose

The conductive filament ranges from about 2.5 to 5.0 centimeters (1 to 2 inches), though its extreme brightness makes it appear much thicker and visible from miles away. Scars on individuals who suffer a direct strike produce Lichtenberg figures with similar maximum thickness.

By separating light with tools such as prisms, scientists can reveal the presence and composition of celestial matter by identifying color fingerprints unique to specific elements and molecules.

Bioluminescence provides organisms with a method of hunting, defense, or mating

Unlike glow sticks, bioluminescent reactions use renewable resources like oxygen and ATP. This ability allows fireflies to mate and deter predators, anglerfish to confuse and attract prey, and deep-sea shrimp to defend themselves by vomiting glowing slush.

Red and blue election maps are a modern media invention

The red–blue color scheme used on election night maps emerged in the 20th century as television networks adopted color graphics to make results easier to follow. The association of red with Republicans and blue with Democrats later became standardized.

Besides allowing patients to see how much medication they had left, transparent orange pill bottles were introduced in 1968 to protect medications from degradation caused by ultraviolet radiation.