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.

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.

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.

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.

View a collection of sound animations, which depict how a source of sound waves pushes against particles to carry energy away without matter being displaced.

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.”

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

Fulgurites are glass sculptures made by lightning vaporizing sand

Sometimes referred to as fossilized lightning, these tube-like structures are formed when high-temperature electrical currents fuse mineral grains into crystals, which can feature branching patterns resembling filaments of current. Their name derives from "fulgur," the Latin word for lightning.

Explore a visual and auditory guide to wave properties and waveforms to learn how every sound imaginable can be created by combining multiple vibrations of air.

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

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.

A person's voice sounds different when breathing helium, sulfur hexafluoride, or gases other than air because the speed of sound varies with the properties of the material through which it travels.

Scientific applications of bubbles include logic gates, laser production, and medical imaging

Microbubbles of nonreactive gas can be administered to improve the reflection of sound waves and the resulting imaging during an ultrasound. Bouncing light waves within a bubble can stimulate emission of light from a trapped chemical, just as occurs within a laser, and bubbles can act as valves that control the flow and reaction rates in microfluidic systems.

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.

In 1880, Jacques and Pierre Curie discovered that electricity could be produced by striking certain materials—the piezoelectric effect—a phenomenon that is seen in barbecue lighters.

Visualizing a synaesthetic soundscape

Artist Michal Levy has chromesthesia, a subtype of synesthesia in which sounds and music trigger involuntary associations with and sensations of color. This condition gives Levy a unique artistic perspective and ability to interact with and interpret music. In this short animation, Levy tries to capture her audiovisual experience of 'Giant Steps," considered a landmark composition in jazz history by musician John Coltrane.

Will-o'-the-wisps may be the result of microlightning between bubbles

Methane and air bubbles moving through water can generate small sparks between them, which can ignite gas. The above-ground phenomenon may have historically been the result of passing travelers igniting swamp gas with their lanterns. (Some readers may experience a paywall.)

Listen to the 'sounds' of the universe with this sonification library, where astronomers have transformed certain astronomical data sets into audio for broader engagement.

Interacting sound waves can create regions where the pressure from each wave combines, allowing objects to levitate in place against gravity or be manipulated for touch-free construction.

Listen to samples of 'sounds' produced in the sun's interior, created from the sonification of internal vibrations detected by the Parker Solar Probe.

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

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.

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.

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.

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.

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.

If a source of music traveled past someone at twice the speed of sound, assuming sufficiently sensitive hearing and powerful equipment, they would hear the music backward.

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.

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.

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.

Before the invention of transistors, vacuum tubes made radio possible

Discovered by Thomas Edison, vacuum tubes allow electrical currents to travel through empty space. Later modified into a diode—keeping current flowing in only one direction—vacuum tubes allowed electronics to turn alternating current into direct current.

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.

Explaining the Leidenfrost effect, where water can hover and move against gravity

Water droplets can glide across surfaces whose temperatures are well above water's boiling point. This heat instantly vaporizes the bottom of the droplet, creating a layer of steam that the rest of the droplet rides and bounces upon. This can be seen when sprinkling water on skillets to determine if the surface is hot enough to cook on.

A tube-and-diaphragm system tells gas pumps when to stop providing fuel

As long as air passes freely through a small hole at the end of the nozzle, the diaphragm is inflated, and fuel flows normally. Once fluid reaches the hole, the change in pressure from the difference in air and fluid densities collapses the diaphragm, which cuts the flow of gas.

Glow sticks feed energy released in chemical reactions to fluorescent dyes

When bent, the glass tube inside the stick breaks, releasing hydrogen peroxide into the surrounding solution. The ensuing reaction creates unstable molecules that decompose and release energy, which is then absorbed by molecular dyes that emit light when their excited electrons return to lower energy states.

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.