View the rainbow effect on the waters at First Landing State Park

Tiny water droplets can blur a rainbow's colors into a foggy white

When sunlight enters water droplets, it can reflect from the inside and spread out into different colors, producing a series of colorful arcs—supernumerary bows—which we refer to as rainbows. For droplets a few hundredths of a millimeter in size, these arcs overlap onto each other, producing fogbows of white light.

Watch underwater photosynthesis make water look like champagne

In shallow waters where sunlight can reach, photosynthetic reactions absorb water and dissolved carbon dioxide, producing bubbles of oxygen at the surface of plants. As these bubbles rise to the water's surface, a fizzy appearance is created.

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.)

All rainbows are 'raincircles' caused by water droplets separating white sunlight into a spectrum of colors, but Earth's surface blocks the bottom half of the circle from our line of sight.

Massive blooms of microscopic plankton called dinoflagellates produce the neon blue light seen in glowing tides.

Water is naturally tinted with a slight blue, but sediments and organics can alter its color

The innate coloration comes from water absorbing red light in the visible spectrum more than green or blue, giving shallow waters in some parts of the Caribbean their turquoise hue. If sand is light, it can be churned up by turbulent water, clouding its appearance. Plankton and other organisms can color water by affecting how the rest of the spectrum is absorbed or reflected.

View a gallery of bioluminescent organisms, including jellyfish and mushrooms

Some species produce a quick flash of light, while others glow steadily with an eerie glow, often to seek attention or in response to being disturbed. Snails, worms, fungi, and other organisms highlight that this ability evolved independently, rather than from one common ancestor.

Aerial photos of red tide off the Gulf Coast

The toxic algae grows naturally in warmer oceans in small amounts and is typically harmless. With extended warm periods and unusually-high additions of nutrients from run-off, the algae blooms extensively, posing health risks to wildlife and humans...

Wood that changed the color of water was the earliest recorded example of fluorescence

Lignum nephriticum, a tea used to treat kidney and urinary illnesses, was described in the 16th century as derived from white wood that turned water a bluish hue. However, in the 17th century, accounts described the wood as reddish and creating a kaleidoscope of colors in water. In 1915, the sources were identified as two different woods, which absorb UV radiation and emit visible light.

View the transition from laminar to turbulent flow

Using a dye released in the water, streamlines, which are parallel to one another and consistent at low flow velocities, become visible. As the water moves more quickly, viscosity cannot suppress the velocity change, and streamlines become chaotic, creating turbulence.

An investigation suggests a Scottish island became awash in forever chemicals via seafoam and seaspray—raising questions about what that means for the safety of other coastal areas.

See an anamorphic illusion of a massive crashing wave in South Korea

An enormous aquarium with perpetually crashing waves has popped up amidst an urban landscape in South Korea, but don’t expect to hear the water sloshing around if you walk by. Designed by District, the elevated tank is actually a massive anamorphic illusion. The digital media company created the pub

The history of soap and how it forms bathtub scum and white spots in old oil paintings

Soap has been produced since at least 2,200 BCE via a chemical reaction between fats or oils and a base. This creates salts that act as molecular bridges, helping water lift dirt and grease from surfaces. The same chemistry produces scum when metals in hard water bind to soap molecules, as well as white spots in paintings when metal ions in pigments react with fatty acids in the oil binder.

How a polluted New York City waterway created extremophiles hungry for 'black mayonnaise'

In the 19th century, coal processing plants, oil refineries, a tannery, and other industries lining the Gowanus Canal contaminated its waters with coal tar, sewage, and other pollutants, forming the toxic sludge. Samples taken from the site before clean-up efforts revealed over 450 species of microbes with metabolisms adapted to break down these contaminants.

How a Scottish island became awash in forever chemicals—and what it means for other coastal areas

Utility data from 2024 indicates that Fair Isle, Britain's most remote inhabited island, has Scotland's highest level of toxic PFAS—forever chemicals—in its public drinking water. The level is still below Scotland's safety threshold, yet the high levels have confounded scientists and communities because there are no obvious industrial sources on the island. An investigation by The Guardian suggests those chemicals are arriving from thousands of miles away via seaspray and foam. PFAS are persistent pollutants that are chemically attracted to the interface between water and air—meaning there will likely be more of them in seafoam than there may be in the seawater itself.

Scientists discover what looks like an underwater road

Crew aboard the Exploration Vessel Nautilus discvered a “yellow brick road” that looks it leads to Atlantis. Climage change may affect future ocean studies.

Rain-catching tubes provide new hydropower source for tropical regions

An experiment in Singapore showed that charge separation could be established by rainwater flowing through narrow tubes. The separation, which creates a voltage, could be scaled up in regions of high rainfall to provide a clean energy source.

Explore the animals that populate the depths of the ocean, from fish and coral in the first few hundred feet, all the way down to the bottom of the Mariana Trench.

Rainfall and lush vegetation make the Great Smoky Mountains smoky

The national park is a rainforest that receives significant rainfall. When the vegetation on the mountains gets wet, it releases a gas that is smoky, and sometimes even appears blue, a phenomenon that gave the mountains (and the park) its name.

When Niagara Falls stopped flowing

In 1969, engineers stopped Niagara Falls for the first time in 12,000 years to prevent erosion revealing hidden coins, boulders, and a rare dry view before restoring its roa

The Great Salt Lake's distinct dual coloration results from high-salinity organisms that only live in the northern portion and produce a purple protein.

Fish populations in the Great Barrier Reef have increased after installing waterproof speakers on the ocean floor that played recordings of sounds from healthy coral reefs.

How one biologist drew a national park's definitive map

Long before GPS, biologist John Cely mapped the swampy terrain of South Carolina's Congaree National Park by hand, and mostly from memory. The map was so accurate, it became the preferred resource for the park's rangers. This Atlas Obscura article explores how Cely acquainted himself with the park's particulars and how the map grew from an unofficial peculiarity into the park's definitive guide.

The fish doorbell letting people help spawning fish

Utrecht, a city in central Netherlands, has implemented an innovative "fish doorbell" system at a river lock to assist migrating fish during their spring journey to spawning areas. This unique setup allows online viewers to participate in helping fish navigate through the locks. An underwater camera is installed at the Weerdsluis lock, streaming live video to a dedicated website, where viewers may press a digital button when they see a fish.

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

River dolphins manhandle an unlucky anaconda

The natural world around us is endlessly inspiring, and fascinating, and often very odd too: like when researchers snapped a photo of Bolivian river dolphins swimming around with a Beni anaconda snake in their mouths, for example.

Physiological changes to the brain on LSD can be captured via MRI

Psychedelics like LSD often take users on novel experiences that can result in lasting shifts in perspective and behavior. See how LSD affects brain activity in this video that details how scientists visually captured the psychedelic's effect for the first time.

The 19th-century painters of the Hudson River School were among the first American romantics, with portraits that displayed the natural beauty of the young country.

The 19th-century painters of the Hudson River School were among the first American romantics, with portraits that displayed the natural beauty of the young country.

Symmetric patterns of magnetic stripes seen on either side of mid-ocean ridges

The symmetry provides evidence of seafloor spreading, where new oceanic crust is created at mid-ocean ridges, which pushes older ocean crust away on either side. Matching the pattern to magnetized material in rocks on Earth’s surface provided a timeline of ocean floor recycling.

Why does that bag look like a face?

If you've ever spotted a face hidden in an inanimate object, you've engaged in a timeless phenomenon known as pareidolia. This three-minute video explains why and how it happens.

Watch a lightning storm from the International Space Station

While passing over the Alabama and Georgia regions, NASA astronauts photographed passing thunderstorms from the ISS. The illuminated clouds are described as "nebula-like formations."

Stunning shots of a singing red-winged blackbird

Photographer Kathrin Swoboda visits Huntley Meadows Park to photograph red-wing blackbirds singing. In 2019, she captured them emitting smoke-like rings from their beaks due to visible condensation in the cold. This serendipitous shot won the top prize at the Audubon Photography Awards that year, highlighting the unique phenomenon of birds' breath visible in chilly temperatures. Check out the photos here.

The original copy of the Declaration of Independence is not a pristine document, and even features a smudged anonymous handprint in the bottom left corner.

This poison ivy knowledge quiz—accompanied by photos of the plant's varied forms—may help you identify this common rash-inducing growth.

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.

In 1915, workers recovered a submarine-like vessel from the Chicago River, prompting fears of German espionage

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.

Dorothy's famous entrance into Oz in 'The Wizard of Oz' relied on analog tricks, including a body double and sepia-toned paint, as much as it did on technology

Fear or disgust related to clusters of holes and cracks, called trypophobia, may stem from evolutionary processes to help us avoid pathogens.

See the most iconic photos from four decades of LIFE magazine

The boiling temperature of water decreases with increasing elevation because the molecules need less energy to overcome the lower atmospheric pressure associated with thinner air.

When a Paris department store hesitated to sell Estée Lauder's perfume, she 'accidentally' broke a bottle, causing the smell to spread throughout the store and shoppers to start asking to buy the scent.

After 25 people used virtual reality headsets to practice flying with virtual wings—flapping their arms—their visual cortex responded to the wings almost as if they were real arms, treating them as body parts.

Ebola infects and disables immune cells, triggering a cascade of events that leads to small blood clots throughout the body, weakening blood vessels and interrupting blood flow to key organs.

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

Learn how to read a prospectus, the juicy document that any company must file with the SEC before going public.

SpongeBob exemplifies Aristotle's philosophy for living well because he understands that happiness doesn't come from external factors like money, recognition, or power.

See how Budweiser's famous Clydesdales spend their days at Warm Springs Ranch, where roughly 70 to 80 of the beer brand's giant horses can be found at any given time.

44% of Americans say they pray at least once a day—discover how your state's religiosity stacks up against the rest of the country.