Internal-combustion engines convert fuel into motion using controlled explosions

Spontaneous combustion involves an object igniting on its own

Even without matches, sparks, or external flames, exothermic chemical or biological reactions can increase the internal temperature of objects to the point where they reach a threshold temperature that can cause them to catch fire. Running batteries and fermenting bacteria within compressed materials can build this heat and cause combustion.

The hidden engineering of gas stations

Contemporary gas stations are the result of a century of engineering progress. In the early 1900s, only a few thousand cars drove around, and they used kerosene. As vehicles and cheaper gasoline became more popular, fire hazards grew, forcing the invention of fuel pumps, underground storage tanks, and the automatic shutoff valve—all engineering marvels.

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.

Battery and plug-in hybrid EVs can operate with zero tailpipe emissions

Battery electric vehicles only run on electricity, while plug-in hybrids incorporate a small internal combustion engine that recharges the battery or directly powers the wheels to improve driving range. Fuel cell electric vehicles convert hydrogen gas fuel into electricity.

Nuclear-powered missiles replace chemical combustion with energy from nuclear fission

In these systems, energy is added to an airstream, which passes through a nozzle to generate thrust. Because the amount of energy released per unit mass of nuclear fuel is millions of times larger than that of chemical propellants, nuclear missiles can travel faster and farther with less fuel.

How to make your own DIY ionic thruster

In the search for more efficient, sustainable types of propulsive thrust, scientists have dabbled in developing engines using ionic thrust, a type of propulsion using the attractive force of oppositely charged ions. First introduced by a Russian...

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

How metabolism, when cells convert molecules into energy, works

Metabolism is when a cell’s internal network of chemical reactions breaks down food molecules and transforms them into pieces of the cell itself. Sometimes, cells build replacements for worn-out parts. Other times, they build energy molecules that power the cell’s activities.

Heat pumps use an easily boilable chemical to regulate temperature

In air conditioners, warm air is pulled from a home to turn a refrigerant into a gas, which is then compressed, raising its temperature. The gas naturally releases this energy to the comparatively cooler environment when exposed, then expands and is reused in the system. Heaters run in reverse, with the refrigerant picking up energy from the comparatively warmer environment.

Crude oil is the type of oil used to create fuel like gasoline, heating oil, and more

Technically speaking, crude oil is unrefined petroleum. This article dives into the different ways it’s categorized (by density, sulfur content, and origin), and how the combinations of these types of oil are used.

Artificial photosynthesis turns CO₂ into sustainable fuel

Carbon conversion focuses on a central perplexing question: if carbon dioxide is a leading driver of climate change, and fossil fuels are made of carbon-based molecules, can we devise a way to convert CO₂ into useful alternatives efficiently? This video breaks down a potential pathway using artificial photosynthesis, which uses sunlight to convert CO₂ into fuel.

Windmills can be designed to pump groundwater for irrigation or land drainage

A gearbox within the windmill converts the windmill's rotation into the vertical motion of a piston that pushes water up a pipe. It also drives the rotation of an Archimedes screw to move water to higher elevations.

The basic science of rockets

How do rockets work? What is the science behind a rocket launch? How does a rocket go into space? In this short and simple video, we discuss the science of rocket propulsion and what takes to get these vehicles into orbit.

Cathode-ray tube televisions are examples of electron accelerators

CRT TVs work by converting electricity into heat, which causes electrons to be emitted from the rear of the device in three beams responsible for the colors red, green, and blue. Electromagnets direct electrons to phosphor molecules on the screen, which emit light and illuminate the pixels.

How does food move through the body?

Food passes through the digestive system via muscle movement known as peristalsis, during which a rippling contraction slowly pushes content through tubular organs, such as the esophagus and intestines. This is similar to what happens when one squeezes a tube of toothpaste, contracting the tube behind the content and forcing the tube in front of the content to expand, allowing the content to move forward.

Play Infinite Craft, an AI software-powered game

In this browser-based game, users combine the elements of earth, wind, fire, and water to create an infinite number of new elements. Try your best to make as many natural phenomena as you can as you build up to the multiverse.

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.

How fighting wildfires works

Firefighters use sophisticated strategies to control wildfires that sometimes cover thousands of acres. This video breaks down how teams set up fire lines to isolate the fires by cutting down brush and trees around the existing fire, among other...

Pierre Curie found electricity could be generated by compressing certain crystals

Jacques and Pierre Curie discovered the piezoelectric effect in 1880. Pierre incorporated it into an apparatus used by Marie Curie to discover polonium and radium. This phenomenon is seen in barbecue lighter ignition mechanisms, where quartz is struck to create a spark that ignites fuel.

NASCAR automobiles have become significantly more complex over time

The first generation of NASCAR automobiles were nearly identical to on-the-street models, with no modifications allowed to the body or frame. They even raced with doors. Fast-forward 75 years and the cars are 670-horsepower machines designed for racing.

How fusion—which releases energy when two lighter atoms combine to form a heavier atom—differs from fission

Honda and Yamaha have developed motorcycles with self-balancing systems

Honda's "Riding Assist Technology" was introduced in 2017 and maintains the motorcycle's stability by leaning away from the direction of the front wheel and adjusting the front fork's angle at low speeds. Yamaha's system uses actuators to achieve balance during stops and starts.

Pellet grills evenly distribute heat across a grill

Using ignited wooden pellets and fans to evenly distribute the heat across the cooking surface, pellet grills give food deep flavor and grant cooks more control, offering a newfangled take on barbecue.

Watch a goldfish drive a car

Dutch engineer Thomas de Wolf created a car for a goldfish, or a water tank on wheels that is directed by the movements of the creature inside it. Using a motion-sensing camera, when Blub the fish moves to one side of the tank, the camera moves in the same direction.

Compounding, explained

During conversations about personal finance, the term "compounding" gets thrown around—but not everyone understands how compound interest and compound returns work. Broadly speaking, compounding is what happens when you not only earn returns or interest on your original investment, but also on the accumulated returns or interest you receive over time. This article explains how both of these processes function, and what compounding could mean for your wallet.

Photochemical smog forms when sunlight reacts with car and industrial emissions

The hazy phenomenon's name is a combination of "smoke" and "fog" and is composed of chemical pollutants that can cause eye irritation, lung damage and harm to crops. Smog buildup is more common in cities with sunny climates, minimal wind and surrounding mountains that trap these chemicals.

Movement of molten metal around its solid inner core creates Earth's magnetic field

According to the geodynamo process, the rotation of the planet and the looping, convective flow of electrically conductive iron and nickel produce dynamic electric currents, which generate a self-sustaining magnetic field. This is unlike natural, stationary magnets, which possess a static field created when the metal cooled and its atoms aligned with Earth's magnetic field.

Explore a simulation of ideal gas behavior, which can be explained by kinetic molecular theory

The theory describes particles as moving in random directions, with a distribution of velocities determined by the gas's temperature. The particles collide elastically like billiard balls, are negligibly small, and do not exert forces on one another. The gas laws can be derived from these principles using statistics or observed via this interactive.

How Amazon operates a 'flywheel' business model, a self-reinforcing cycle that drives continuous growth

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.

The history of many kitchen appliances involves unexpected discoveries and applications, including wartime radar turned hamster defroster and replacing an 'ice king' with heat-stealing boxes.

In 1984, Operation Smash Hit intentionally crashed a 239-ton train into a nuclear waste canister at 100 miles per hour to prove the canister's safety, which remained completely intact and lost just 0.29 of its 100 pounds of pressure.

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.

Hurricanes, which rely on air consistently spinning in the same direction, cannot cross the equator because air curves in opposite directions north and south of it.

The use of fungi to detoxify land and water—a process known as mycoremediation—has been used to clean up natural resources affected by the 2025 California wildfires.

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.

Visualize how CRISPR-Cas9—a type of immune system used by single-celled organisms to attack invasive viruses—targets and makes precise changes to a gene's DNA.

An initial public offering or 'IPO' is the process of a private company becoming public by putting shares of the company on the stock market for purchase.

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.

When you complete a CAPTCHA on a website to prove you are human, you may be unknowingly training algorithms for self-driving cars, whose systems require training data to help identify crosswalks, bicycles, and other outdoor objects.

Volcanic activity may have triggered the Black Death by spewing gases that led to crop failures in Europe, thus forcing the import of grain ships with plague-infested fleas.

Sony set the standard for cylinder-shaped batteries when it repurposed manufacturing equipment used to make rolls of magnetic recording tape.

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

Some Pokémon have been named after real and fictional organisms, while some real-world species have been named after Pokémon, such as Chilicola charizard and Binburrum zapdos.

Explore an interactive map of battles from the American Revolution, along with detailed summaries of each engagement

Memecoins are a type of cryptocurrency—a form of digital currency with a wide variety of uses—created around popular 'memes,' or viral internet jokes.

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

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.

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

'Saturday Night Fever,' the 1977 film that introduced disco to the mainstream, was based on a fabricated magazine story.