Variations in rapidly expanding gas and mechanical elements produce fireworks sounds

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

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

This shockwave is caused by the rapid release of energy and is one of the key characteristics of fireworks, alongside the bright light show. The colors result from chemicals that absorb light at different wavelengths in the spectrum, with higher-energy compounds leading to darker colors and lower-energy compounds—like strontium chloride—producing colors like orange and red.

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.

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.

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.

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

Though not really silent, the displays are quieter than traditional fireworks. They may offer an attractive alternative for people who have sensory sensitivities or for pet owners. The sound from these options can be less loud than standard fireworks due to changes in chemical composition and the inclusion of a smaller lift charge that doesn't carry the fireworks as high into the air, reducing the initial bang.

The sound of thunder can vary based on your distance from lightning

The rapid flow of electricity heats and pressurizes air, causing it to expand and produce a shockwave at each point along the bolt at multiple frequencies. As these shockwaves overlap, higher-frequency sounds, which produce a sudden crack, dissipate more quickly, while lower-frequency sounds—long booms and rumbles—travel farther.

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

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

While mishandling fireworks can cause severe burns and loss of appendages, there are also risks for viewers of displays. Released particulate matter can cause the surrounding air to resemble wildfire smoke, and the explosions can cause hearing loss and damage to the corneas.

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

Crackling, popping, and rustling sounds have been reported during auroras

At the altitudes where auroras take place—between 100 and 300 kilometers (62 to 186 miles)—air is not dense enough to efficiently vibrate and carry sound waves to the ground. However, one theory suggests that the geomagnetic energy behind auroras can trigger electrical discharges near the surface, which may be the cause of reported sounds.

See how fireworks are made and learn how metals like magnesium and copper are responsible for different colors.

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

Concentrated sound waves can collapse microscopic bubbles, creating light

The phenomenon, known as sonoluminescence, can generate extremely short, high-intensity flashes from the sudden focusing of sound energy, which can drive the temperature within the bubbles to values over twice that of the sun's surface.

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.

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

Another memorable tradition takes place in Vrontados, Greece, with people in two rival churches firing bottle rockets at each other's bell towers in an event known as the Rocket War. Yet another tradition occurs in Tainan City, Taiwan, fifteen days into the Chinese lunar calendar, with celebrants donning protective gear and attempting to get hit by fireworks—a tradition dating back to the late 1800s when residents asked the god of war for help with a raging cholera epidemic, with a similar display.

Sound can shatter glass if its frequency matches the material's natural vibrations

The sound made by an object when struck is its resonant frequency, which is the sound made when energy is dissipated. Providing energy at that frequency amplifies the vibrations, rather than allowing them to dissipate, which can deteriorate the object's structural integrity.

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.

Internal-combustion engines convert fuel into motion using controlled explosions

Gasoline engines mix fuel and air, compressing it and igniting it to create thousands of tiny explosions that push pistons up and down. This movement spins the crankshaft, which moves a vehicle's wheels.

Firework or sparkler burns, even if they cover a relatively small area of skin, can significantly affect our range of motion.

Why breathing helium, sulfur hexafluoride, and other gases changes your voice

The speed of sound varies depending on the properties of the material it travels through, including its density. Because helium is less dense than air, sound travels faster, altering the timbre of one's voice to be squeakier by enhancing its higher frequencies. In molecules that are heavier than air, low-frequency sounds are enhanced, producing a deeper voice.

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.

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 pulsars, which emit radio pulses up to hundreds of times a second

Just as figure skaters spin faster by tucking in their arms, these celestial objects acquire high rates of spin from the collapse of the cores of massive stars. The star's rotation spins its magnetic field, generating beams of radio waves from its magnetic poles. If either of these poles faces a detector, the signals can be picked up and converted to audio signals.

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.

See this overview of the firework rules across all 50 states, ranging from a complete ban on non-professional fireworks in Massachusetts to states with more lax rules like Indiana.

Metal fragments can create glowing rings when sand chips them off helicopter blades

The Kopp-Etchells effect—named after two soldiers who died in action in Afghanistan—may occur when kicked-up material shaves off fragments from a helicopter blade's abrasion strip. Due to a property called pyrophoricity, the fragments react with air and ignite, producing halos.

Audi spent over three years developing engine sounds for its electric vehicles

Unlike the sounds made by combustion engines in gas-powered vehicles, electric cars produce no motor sounds. The company's acoustics team worked with composer Rudolf Helpmier to craft an electric-inspired revving sound for its R8 e-tron supercar.

A pickleball's loud 'pop' sound can reach 120 decibels, which is equivalent to a hammer hitting a nail

Oscillating matter in the early universe left behind patterns detailing cosmic expansion

As gravity tried to bring matter closer together in the early universe, its high temperature produced an outward pressure that caused it to expand. These competing forces caused matter to vibrate and produce the equivalent of sound waves, which spread outward as the universe expanded and cooled, serving as relics of dark energy's history.

The deadliest aspect of volcanic eruptions is often not lava, but pyroclastic flows—avalanches of ash, gas, and rock that can move more than half the speed of sound.

Pickleballs' loud 'pop' sound can reach 120 decibels

That's about the same level as a hammer striking a nail. Luckily, it's not quite as loud for a player on the receiving side of the net, at about 80 decibels, though that's still quite loud—it's equivalent to heavy traffic.

Mechanical watches measure the passage of time via the vibration of a quartz crystal

When electricity from a battery passes through the crystal inside a watch, the crystal vibrates, creating an electrical signal with a precise frequency of one vibration per second. This signal moves the hand of the watch so that it ticks once per second, allowing it to track the passage of time.

A history of raising the alarm, from rattles to 911

Because fires spread so quickly, communities around the world have deployed many tactics to raise the alarm to get help. This history from the Museum of Natural History dives into the use of rattles, bells, and brigades to gather help to fight fires, showing just how far we've come since 911 was introduced in 1968.

What makes food crispy, and how science can be used to maximize this property

The fracturing texture experienced when biting into vegetable tempura, fried chicken, pastry crusts, and other foods comes from having a dehydrated, porous surface. When frying food in hot oil, trapped water vaporizes and escapes, creating tunnels and pores in the food as it dehydrates. Breading, particularly with the large, irregular shapes of panko, and leaveners can help create more air spaces.

Explore chaos in this simulation of two double pendulums, where small differences in the release angles produce wildly different outcomes.

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.

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.

Massive 3D printers have been used to build homes by stacking layers of 'concrete toothpaste,' a fire-resistant material that effectively insulates against outside noise.

The word 'jazz' evolved from 'jasm,' 19th-century American slang for 'energy'

For centuries, Niagara Falls has been a magnet for daredevils seeking to conquer one of nature's most powerful wonders, with its 200-foot drop and water rushing at 32 feet per second with 280 tons of force.

One disco producer saw 'Star Wars' four times on its opening weekend and was so inspired that he recorded the album 'Star Wars and Other Intergalactic Funk,' which produced a chart-topping single.

Some renewable energy sources may weaken the resiliency of electric grids by removing outage buffers provided by coal- and natural gas-fired plants, which provide the system with more time to find a new power source if a plant goes down.

See these 16 pieces of art evoking phobias of snakes, flying, spiders, and more. 

Gerrymandering works through two techniques: cracking opposing voters across districts to dilute their power, and packing them into a few to waste their votes in lopsided majorities.

Fast-casual restaurant Chili's is experiencing a resurgence, with its parent company recently reporting a nearly 32% increase in sales, thanks to passionate Gen Z fans on TikTok.

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.

SpaceX's S-1 or 'prospectus' revealed many previously unknown details about the company, including its unprofitability despite doing $18.7B in revenue in 2025, exactly how many voting shares Elon Musk will have in the company (roughly 85%), and more.

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

Elk Cloner, the first computer virus to spread in public, was written as a practical joke by Richard Skrenta, a Pittsburgh high school student.