O-rings contain fluid within a system

Low temperatures led to the equipment failure that caused the Challenger disaster

The polymer chains that make up an O-ring give it the ability to quickly deform and fill in gaps to seal fluids, including the hot gases from the Challenger's rocket boosters. Cold weather on the day of launch stiffened the O-rings, reducing their flexibility and sealing properties.

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.

Friction is the force that resists the sliding of surfaces along one another

Friction always acts to resist movement and is determined by how rough the surfaces are and how hard they are pressed together. In the case of fluids, friction arises from the relative motion between adjacent fluid layers, which act like sliding surfaces.

What's inside an Oreo?

If you look at the ingredient list on your Oreo packaging, you may discover that you don't recognize—or can't even pronounce—some of the listed ingredients, let alone know what they're used for! For instance: Did you know that soy lecithin helps makes oil and water mix? Or that cocoa processed with alkali becomes darker and less acidic? A food scientist breaks down what's inside an Oreo in this seven-minute video.

Adhesion molecules and intercellular junctions allow cells to connect together

While some organic structures are mostly composed of non-cellular components (e.g., collagen and calcium phosphate minerals in bones), tissues and organs composed of connected cells rely on specialized proteins and connections to create watertight seals that protect cells within the interior from environmental molecules.

Some marine life can survive the extreme pressure of the deep ocean because of specialized molecules that strengthen proteins, enzymes, and cellular membranes.

In osmotic power systems, the natural movement of water from regions of low to high salt concentration is used to generate electricity from pressurized water.

Manholes connect underground sewer and water drain pipes

Wherever a portion of sewer is connected to another, a manhole is built. These serve both as access points for maintenance and as connectors for the system. This video shows how crucial manholes are for proper sewer functioning.

Iron rusts in the presence of water and oxygen because these ingredients enable the metal atoms to release energy and enter a more stable state.

Understanding why suction cups rely on Earth's atmosphere to work

When pressed against a surface, air is squeezed out of a sealed volume, causing the internal pressure to drop below the surrounding atmospheric pressure, and this imbalance creates the "sticking." For this reason, astronauts do not use suction cups or related technologies to stay on spacecraft during spacewalks.

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.

Oxygen is produced in the International Space Station from recycled water, which is split into hydrogen and oxygen gases using an electric current.

O'Neill cylinders are free-space habitats that spin to create artificial gravity

Popularized in the 1970s by Princeton physicist Gerard K. O'Neill, the 15-mile-long structures would be manufactured from lunar and asteroid materials and house human colonies. His space colony ideas have since influenced works of science fiction.

Odor blockers use nonpolar oils to trap smelly polar molecules

In the case of feces, gut bacteria produce compounds such as skatole and hydrogen sulfide, which the brain registers as unpleasant. Because oils do not dissolve in water, they can be used to create a layer on the surface that prevents smelly compounds underwater from escaping into the air.

Fire engines are among the most complex vehicles on the road

These vehicles are purpose-built to carry water, foam, hoses, ladders, and lifesaving equipment to a scene in minutes. This animated video pulls apart every system inside a pumper truck, showing exactly how the machinery that fights fires actually works.

When experiencing turbulence, fluid elements undergo stretching and folding

Simulations show patches of fluid particles, such as splashes of milk, bend under turbulent flow, creating curvature that grows linearly then exponentially. This accelerated deformation enhances folding and mixing faster than other methods, such as stirring or beating.

The ins and outs of oil refining

The oil industry is broken up into the upstream, midstream, and downstream segments, and oil refining is part of the latter. “Downstream” refers to companies like Standard Oil that are converting crude oil into a finished product.

Enhanced geothermal power systems can trigger earthquakes by injecting fluid into rock, increasing subterranean pressure.

Fracking provides access to fossil fuel reserves locked in underground rock

Using a pressurized fluid mixture that is over 90% water, cracks are created in shale about 2 miles deep to release trapped oil and natural gas. The process uses an average of 3 to 6 million gallons of water per well, which can strain local water supplies.

Watch a server submerged in a fluid continue to run and stay cool by boiling the liquid away.

Ring galaxies, the rarest kind in the universe

Galaxies come in different sizes, but when it comes to shapes there are just four kinds: spiral, elliptical, irregular, and the rarest kind, ring. Ring galaxies only form in the event of a small galaxy passing through a large one, but there's more to them that that. This page explores these rare and beautiful heavenly bodies.

OPEC often intervenes to influence the price of oil

This guide explains how investing in oil works with in-depth explanations of each of the forces that control oil’s price. Oil is unique as a commodity in part because of OPEC’s role in regulating its price.

What does blood do?

Blood's primary purpose is to ferry oxygen and nutrients to cells in need while collecting cell waste and byproducts for removal. It also enables the body's repair and immune systems to traverse our internal landscape to address cell damage or external invaders, such as viruses and parasites. Zooming out from the exact roles of blood's various cells, the fluid connective tissue also assists with maintaining homeostasis via temperature regulation and pH balance.

Mid-ocean ridges are underwater volcano systems where tectonic plates diverge

New ocean crust is formed at these ridges as magma rises from Earth’s mantle and fills the space between the spreading plates. The speed of divergence influences ridge shape, with slow spreads forming rugged valleys and fast spreading creating smooth, wide slopes.

A guide to crude oil and natural gas extraction, from rig site preparation to land restoration

Requirements for traffic plans, access roads, and noise barriers vary by state and local laws, but once the rig site is prepared, the rig is assembled and digs a well that is then encased in steel and cement to protect groundwater reservoirs. After drilling and testing the extraction pipe, fracking fluid is injected into the rock to create cracks where crude oil resides, allowing it to be pumped out.

How water pressure affects the body

The extreme conditions of the deep sea include increasing amounts of pressure as explorers and organisms descend into its depths. The major danger for both fish and humans is the way pressure changes how body tissues absorb chemical molecules...

Some geothermal power plants make electricity using a secondary fluid

Direct dry-steam systems pull underground steam into a turbine-generator system, while flash and double-flash cycle systems spray extracted liquid water into a low-pressure tank, causing it to rapidly vaporize—"flash"—before moving to the turbine. Binary cycle systems use the extracted steam and water to flash a second fluid that easily boils, which then drives the turbine.

The Ring of Fire, which spans 40,000 kilometers (24,900 miles) around the Pacific Ocean, is the most geologically active region on Earth.

Are there any planets in the universe that aren’t round?

We think of all planets as spheres, but do they have to be spheres? To be classified as a planet, an object has to be sufficiently massive to reach a spherical shape through gravity. However, this doesn't mean they're perfectly round; for example, Earth has a slight equatorial bulge caused by centrifugal force from its rotation. Other observed planets feature tear-shaped formations while theorists posit donut-shaped planets. Read more here.

How fighter jet ejections work

One of the most complex pieces of equipment in a fighter jet is the pilot's ejection apparatus, and the process of ejecting is far more challenging and violent than its depicted in film. This six-minute video breaks down the protocol step-by-step.

'Breather holes' in airplane windows help manage cabin pressure

Airplane windows have three layers of acrylic: the super durable outside layer, the inner pane which acts like a "scratch" surface, and the middle pane with the tiny hole. This bleed hole allows pressurized cabin air to be borne by the strong outer pane while preventing the inner pane from breaking.

Why Water Towers Are Built This Way

Beyond a certain pressure and temperature, matter can become a supercritical fluid—an exotic state of matter that simultaneously exhibits properties of gases and liquids.

Earth's magnetic field can trap high-energy charged particles produced by the sun and distant cosmic events in doughnut-shaped rings called Van Allen belts.

Why roller coaster loops are never circular

The beloved looped roller coaster rides used to be shapes as perfect circles and constructed with wood, resulting in wobbly machinery that gave people whiplash. After the invention of steel and further scientific understanding, Six Flags debuted The Great American Revolution—a modern, oval loop with steel that offered a safer and smoother experience.

Infants are particularly at-risk for ear infections

The Eustachian tubes, which connect the middle ear to the upper throat and help to drain fluids and equalize pressure, are relatively flat at birth, making it hard for gravity to assist with drainage. The angle of these tubes changes and becomes steeper as we age, making fluid buildup in the ear canal less common.

A breakdown of gelling agents used to modify a liquid's texture

Gelatin, agar, and other substances form a structural network that traps liquid, making it appear solid and enabling chefs to create stable layers in pastries and confectionery products. In different concentrations, they can also be used to thicken liquids into gels or encase them in gelatinous spheres.

The Oort cloud, our solar system's theoretical icy shell

Recurring comets lead astronomers to believe they originate from an extremely distant, icy shell encapsulating the solar system. They call it the "Oort cloud," and this giant swarm of icy objects is as fascinating as it is is massive. Home of comets and a tremendous number of planetesimals, this NASA site introduces you to the Oort.

The Navier-Stokes equations include the fluid version of Newton's second law

The first equation is the fluid version of the conservation of mass, which prevents incompressible fluids from gaining or losing matter. The second equation replaces acceleration and inertia, which is resistance to acceleration, with fluid pressure and viscosity.

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.

A human joint is any place in the human body where two bones connect, providing structure and stability.

Nearly all natural rubber comes from cloned trees in Southeast Asia

Synthetic rubbers have been unable to mimic the strength and tolerance to heat and pressure provided by natural rubber. This makes rubber trees essential to major global infrastructure, despite being vulnerable to disease due to a lack of genetic diversity.

To prevent floating away from others while sleeping, sea otters may wrap themselves in kelp or hold paws, using physical contact to form groups known as 'rafts.'

Oxygen and nutrients are circulated in tardigrade bodies through physical movement

Rather than having a circulatory system, oxygen is directly absorbed through their skin and spreads through a fluid called hemolymph as tardigrades crawl. When molting to grow, they shed their outer skin and stylets—sharp mouth parts used to pierce prey—which are regrown in their salivary glands.

In 2013, an astronaut's helmet began filling with water during a spacewalk

A leak in the cooling system of Luca Parmitano's spacesuit caused water to obscure his vision and silence his radio as the International Space Station entered Earth's shadow, forcing him to feel his way back to the airlock in darkness.

The Office of Water protects the nation's rivers, lakes and drinking supplies

The office develops national standards for safe drinking water, regulates wastewater treatment, and enforces the Clean Water Act. It partners with states and tribes to monitor pollution, protect wetlands, and restore aquatic ecosystems across the United States.

The marvels of mucus

Mucus—otherwise known as snot or phlegm—has a gross reputation, but the substance is actually of vital importance, lining the moist surfaces of our nose, intestines, lungs, and more. It plays a constant role in keeping our tissues from drying out and acts as a line of defense, but if it gets too sticky or thick, it can cause problems. Read about the marvels of mucus here.

Space-bound rockets contain four major systems—structure, propulsion, payload, and guidance—and operate in stages, with different sections burning through their fuel before breaking off, to reduce dead weight and improve efficiency.

OPEC can roll out production cuts among its members to control oil’s global supply and price

The Organization of the Petroleum Exporting Countries (OPEC) was created to coordinate and unify petroleum policies to secure fair and stable prices. During the pandemic, for instance, the organization pushed through production cuts in an attempt to stabilize prices.

Explore OPEC’s official webpage

OPEC’s official website offers a comprehensive hub for its core work—featuring press releases, monthly and statistical reports, digital publications like the World Oil Outlook and Annual Statistical Bulletin, and other research center materials.