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

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.

Variations in rapidly expanding gas and mechanical elements produce fireworks sounds

Chemical compounds designed to vibrate rapidly when ignited produce whistling, screeching sounds, while crackles and pops are created by small star pellets inside the firework, which explode one after another quickly. Fluttering and chirping sounds are produced by spinning elements that rotate rapidly as the firework ascends.

Explore the chemical compounds found in fireworks

Besides the various salts and metals used to produce fireworks colors, shells are also filled with gunpowder and oxidizers to help fuel and accelerate reactions. Chlorates help strengthen colors, while dextrin, a starch, helps hold mixtures together.

Watch over a dozen fireworks effects

Adding pellets of salt to gunpowder within a fireworks shell causes them to explode with different colors, but the type of gunpowder used also has an effect. Finely ground gunpowder burns quickly, producing streaks that swiftly burn out.

'Silent' fireworks are not entirely noise-free

By using a reduced amount of flash powder—the ingredient responsible for the loud explosions that fireworks make—"silent" fireworks produce displays between 70 and 90 decibels, rather than the approximately 175 decibels heard in professional displays.

Visualize the components of fireworks

This article provides animated diagrams depicting how different parts of fireworks function. The elements work together through timed mechanisms to produce desired effects.

Fireworks contribute to air, water, and soil contamination and disrupt wildlife

Fireworks displays have far-reaching environmental consequences, including acid rain from displays during storms and microplastic pollution in water supplies. Wildlife has also been seen abandoning sites during fireworks and never returning.

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.

Learn how your body is, scientifically, like a firework with its own slow, controlled burn.

See how fireworks are made and which metals are responsible for different colors.

'Silent' fireworks have gained more interest in recent years as a quieter celebratory option.

Fireworks usage on Independence Day comes from their celebratory use in ancient China

Burning bamboo stalks produces a small explosion that was believed to ward off evil spirits. As knowledge of fireworks, which initially used these stalks, carried over into other cultures, so did their use to promote good luck and celebration.

Thunder occurs when fast-flowing electricity heats and pressurizes air, causing it to expand and produce a shockwave at each point along the bolt at multiple frequencies.

Watch a drone flight through a fireworks display

This video explores the history, construction, and preparation of modern fireworks displays, including creating gunpowder from scratch. Experimentation with fireworks underwater is also featured, but they require special materials to prevent water from infiltrating the fireworks shell.

Beyond burns, fireworks can harm respiratory, auditory, and visual health.

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.

Learn more about the history of fireworks, which date back to an accidental invention during an alchemist's quest for information about immortality.

Fireworks-related ER visits in 2024 increased by 52% as compared to the prior year.

The different energy levels of each element result in unique colors when burned

When heated, electrons absorb energy and move to excited states within an atom. They promptly drop back down and release light energy corresponding to the size of the drop, which is unique to each element.

Firework-related celebrations include an annual summer celebration in El Salvador, where residents throw kerosene-soaked balls to commemorate a 1658 volcanic eruption.

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.

Objects that move faster than the speed of sound—Mach 1—create shockwaves called sonic booms by building up and forcing sound waves to combine as they lag behind the object.

Watch a pyromusical display to AC/DC’s “Thunderstruck”

The same principles behind fireworks also power the types of pyrotechnic displays in some live events. Here, you can see an application of the technology in a pyromusical set to rock band AC/DC’s iconic song, “Thunderstruck.”

Fun family fireworks turn ballistic

The American Pyrotechnics Association estimates that over 10,000 injuries result each year from fireworks, close to three-quarters of which occur around the Fourth of July. This video shows just one rather explosive miscue.

China makes 90% of the world's fireworks, with Liuyang as its production capital

Fireworks were invented in China, but their predecessor, the firecracker, was discovered in Liuyang upon burning bamboo. Pyrotechnics have since become part of the city's culture. Liuyang has won many international fireworks display competitions.

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.

The surprising science behind Pop Rocks

Have you ever wondered why Pop Rocks makes tiny explosions in your mouth? Well, there's actually pressurized carbon dioxide bubbles trapped within the sugary candy. This 19-second video shows you what Pop Rocks look like under a microscope.

Watch a pyrotechnician answer questions about fireworks

Professional pyrotechnician Patrick Cyrana answers the internet’s most curious questions about fireworks, from designing ghost effects and exploring how electronic firing systems work to explaining what it takes to create displays in the rain.

By igniting flammable gas in a tube filled with holes and playing music into it, the fire will take the shape of the sound waves, enabling the visualization of audio.

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.

The bullwhip was the first human-made object to break the sound barrier, producing a small sonic boom heard as a crack when flicked quickly.

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.

The most fireworks launched from a pyrotechnics suit is 642

Frenchman Laurent Nat, a pyrotechnics artist and performer with over 10 years of experience, set the world record on June 13, 2014. The suit, inspired by clothes worn by professional firefighters, is made out of 100% cotton and incorporates stilts to allow fireworks to be fired in all directions.

When struck, objects vibrate at unique rates called resonant frequencies, which makes tapping wood sound different from tapping metal, but providing objects with sound at their resonant frequency can cause them to shatter.

11 people died from firework injuries in the US in 2024, with most of those deaths involving misuse of the explosives and device malfunctions or misfires.

The composition of magma affects the explosivity of volcanic eruptions

Silicate-rich magma contains extensive molecular chains that trap dissolved gases like water and carbon dioxide. These gases build pressure until they violently escape, creating explosive eruptions. Low-silica magmas produce gentler eruptions categorized as effusive.

In the early 1900s, Fourth of July celebrations were so dangerous that a reform movement emerged to make them safer.

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.

View an animation of how certain chemicals fluoresce—that is, emit visible light after having absorbed higher-energy light, such as ultraviolet radiation.

Light echoes are expanding shells of reflected starlight

Just as sound waves reveal the location of obstacles by reflecting off them, pulses of light emitted by stars illuminate rings of interstellar dust, giving the appearance of ejected material as the light travels outward.

The Ruggieri family of pyrotechnicians innovated on European fireworks displays

The Ruggieri family transformed fireworks from military to theatrical displays by focusing on artistry. Claude Ruggieri's knowledge of chemistry allowed him to produce vivid green fireworks, a first in Europe.

Disney Research developed a haptic interface where you can feel a fireworks display

Disney’s “Feeling Fireworks” uses water jets and a latex screen to replicate fireworks for blind individuals. Such technology may also provide inclusive experiences for the deaf community, though as of 2024, there are no plans to implement them in Disney parks.

Firework or sparkler burns can have large effects on our hands' range of motion.

Massachusetts is the only state that bans all nonprofessional fireworks.

One Chinese businessman controls 70% of the fireworks entering the US

A warehouse explosion in 2008 forced all pyrotechnic shipments to travel through the Shanghai port under three special permits Ding Yan Zhong was given. Since then, he has established a near-monopoly over the global fireworks distribution chain, with logistics and shipping hubs in China and California. (Some users may experience a paywall.)

Every day, lightning releases several Hiroshima bombs' worth of energy into the atmosphere

If all this lightning struck one location at once, the bolt would be the diameter of the center circle of a basketball court, turning the entire court into a crater. Its heat would ignite surfaces for miles around, and its shockwave would demolish buildings.

Tiny water droplets can blur a rainbow's colors into a foggy white

When sunlight enters water droplets, it can reflect from the inside and spread out into different colors, producing a series of colorful arcs—supernumerary bows—which we refer to as rainbows. For droplets a few hundredths of a millimeter in size, these arcs overlap onto each other, producing fogbows of white light.

Visualizing the chemistry of nuclear weapons

Nuclear weapons have devastating effects, but the science of how they work is atomically small. There are two main types of nuclear reaction: fission and fusion. The fission bomb produces immense energy by splitting an atom, the result of firing a...

The deadliest fireworks accident in history was Marie-Antoinette's wedding

In 1770, a fireworks display in Paris celebrating the marriage of Marie-Antoinette to the Dauphin, later known as Louis XVI, resulted in as many as 3,000 deaths. Most casualties were caused by trampling from a panicked crowd of thousands rushing away after some fireworks were blown into the spectators.

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.