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.

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.

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.

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.

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.

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.

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

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.

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.

The three smallest bones in the human body—the malleus, incus, and stapes—amplify the vibrations of sound waves by almost 20 times to help enable hearing.

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.

Studying 'sonic' black holes

If a fish screams as it falls down a cascading waterfall accelerating to ridiculous speeds, will his fish friends above hear him scream? This analogy, odd as it is, has become an essential tool in the astrophysicists kit for learning how enigmatic black holes operate. Lab experiments mirroring the so-called sonic black hole have achieved insights for their cosmic counterparts. Read how it works in this brief piece.

Listen to the pair of colliding black holes detected by LIGO

As ripples in spacetime, gravitational waves do not produce sound, which is the perception of specific vibrations in matter (e.g., vocal cords vibrating air molecules). The "chirp" of gravitational waves comes instead from converting the spacetime ripples into sound waves that the human ear can hear.

An Aztec skull whistle discovered in the 1990s was mistaken for a toy

In the late 1990s, archaeologists unearthed a sacrificed man clutching two skull-shaped clay whistles at a Mexico City temple to the wind god Ehecatl (eh-HEH-kahtl). Initially dismissed as toys, the instruments produce a scream-like sound that modern brain scans show triggers fear and urgency responses in listeners. This podcast explores the discovery.

'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.

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.

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.

Tornadoes produce inaudible signals to humans hours before forming

Researchers at the National Oceanic and Atmospheric Administration have found that tornado-producing storms generate specific sounds below the range of human hearing, much like the infrasonic signals produced by earthquakes and avalanches. Although difficult to distinguish from wind noise, scientists hope to build systems that use these signals to improve tornado forecasting.

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.

A sound's pitch will seem to change if the listener or the source moves toward or away from the other because motion changes the time it takes each successive sound wave to reach the listener.

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.

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

If the Earth stopped spinning, 85% of the world's population would experience supersonic winds

The planet's equator moves about 470 meters per second—over 1,000 miles per hour—and air there would continue moving at this speed for several minutes if the ground stopped rotating. These conditions would cause tsunamis, global storms, and fling debris fast enough to destroy nearly all human-made structures.

Pickleballs' loud 'pop' sound can reach 120 decibels, equivalent to the sound of a hammer striking a nail.

Cosmic rays are thought to be accelerated to near the speed of light by repeatedly bouncing across shockwaves produced by high-energy cosmic events, such as supernovae.

View the 18 vehicles that broke the land speed record

The battery-powered "La Jamais Contente" was the first car to exceed 100 kilometers (62.1 miles) per hour, achieving the feat in 1899. By 1997, advancements in aerodynamic understanding and engineering led to the Thrust Supersonic Car, a jet-powered vehicle that reached a speed of 1,223.6 kilometers (760.3 miles) per hour.

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.

Squeaky toys mimic prey sounds, appealing to dogs' hunting instincts

Squeaky toys provide instant feedback and gratification, and they can also prevent boredom and improve canine dental health. Some toys contain seemingly silent squeakers that use ultrasonic technology to emit sounds only audible to dogs.

Wave tanks can be used to create and study the impacts of tsunamis by building tension in an underwater object before allowing it to slip and rapidly displace water.

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.)

Unlike the roars in movies, dinosaurs likely cooed, rumbled, and boomed

Fossil evidence and CT scans suggest that many dinosaurs produced low-frequency sounds using resonating crests, closed-mouth vocalizations, or organs similar to those of birds and crocodiles. Larger sounds would not have been helpful for sneakily hunting prey.

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.

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

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.

The collapse of gas bubbles in the joint synovial fluid causes 'cracking' knuckles.

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.

Once whale songs were discovered, conservation efforts boomed

Until the 1950s, humans believed whales were mute. Once American underwater surveillance systems caught their sounds during the Cold War, the perception of the creatures changed, leading humans to campaign for whaling bans and long-term conservation efforts. These captivating whale songs can be heard throughout the ocean.

Phil Spector's 'wall of sound' revolutionized girl groups—and pop music

The method captured a room of live musicians and transmitted the sound into a basement outfitted with more speakers and microphones. That sound was then sent into the central control room, producing a massive recording that sounded unlike anything else in pop music.

Some earthquakes can produce smaller tremors called boomerang earthquakes, which travel in the opposite direction and ripple back to the original earthquake's source.

The most popular drum sound of the 1980s was discovered by accident

You know it when you hear it: the distinct snare drum of songs like Phil Collins' "In the Air Tonight" or Bruce Springsteen's "Born in the USA." It's called "gated reverb," and it's something most people associate, for better or worse, with the sound of the '80s. This Vox explainer breaks down how it was discovered by accident, thanks to a microphone typically used for communication that picked up additional sounds.

The decibel scale measures sound intensity, with hearing damage occurring after prolonged exposure to sounds above 85 decibels—equivalent to a noisy lawnmower.

Some animals possess sensitive hearing to help pinpoint prey and map the world

Bats and dolphins produce sound to reflect off surfaces and create a mental image of their surroundings. Owls' faces are dish-shaped to help funnel sounds to their ears, including that of mice moving along leaves or snow. Pinnipeds, such as seals and walruses, hear in both air and water.

Listen to what a forest in the Jurassic Period may have sounded like with this reconstructed soundscape, which was created by analyzing the fossilized wings of 165 million-year-old insects.

Stonehenge may have functioned as an echo chamber designed to keep ceremonies secret from outsiders.

Acoustics researcher Trevor Cox discovered that Stonehenge acts like a concert hall, reflecting and amplifying sound. This video shows Cox demonstrating the effect using a scale model inside a soundproof studio.

Simulate the buildup and discharge of static electricity through friction by dragging the arm and leg of 'John Travoltage' along surfaces.

See this graphic describing what different decibel levels mean for hearing loss.

Likened to a car backfiring or a faraway cannon fire, skyquakes have been reported worldwide in Earth's atmosphere without any obvious cause.

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.

50 years of research has focused on unraveling the relationship between music and frisson

One insight reveals that musical passages with surprising volume changes or unexpected harmonies and beauty are more likely to trigger frisson, perhaps because they upend listeners' expectations.

High-frequency sound waves have been used to brew espresso with room-temperature water and about one-fourth the energy of a traditional espresso machine, which relies on hot water and pressure.

Champagne’s fizz used to be considered a flaw

The bubbliness that we love now was once considered a winemaking failure. In fact, Dom Pérignon probably would have referred to it by its common nickname at the time, "vin du diable," or devil’s wine. The wine’s volatility often caused bottles to explode, which was both dangerous and costly. It wasn’t until the development of sturdier bottles and more consistent winemaking techniques that popularity truly soared.