Copper is responsible for turning blonde hair green in swimming pools

Bright blue fireworks are the most difficult color to create

Copper chloride emits blue light when heated, but breaks down at the temperatures created when fireworks explode. Pyrotechnicians continue to search for an ideal mixture that provides a temperature high enough for copper chloride to shine brightly without being destroyed.

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.

Stress-induced hormones contribute to gray hair

When the body experiences stress, the sympathetic nervous system releases the hormone norepinephrine. This hormone prematurely activates pigment-producing cells (melanocytes) in hair follicles, which depletes the hair's ability to retain color over the long run.

During the fall, chlorophyll breakdown in leaves produces color changes

With shorter days and less sunlight, the concentration of the green pigment diminishes, revealing yellow and orange pigments. Red leaves result from trapped sugars, producing new pigments called anthocyanins, which weren't present in leaves during the growing season.

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

We can get food poisoning from spending time in swimming pools, lakes, rivers, and ponds

Some of the same pathogens that may sicken us in food or water may also sicken us in recreational swimming environments. Bacteria can rub off of people’s (or animal’s) bodies or contaminate the water through a diarrheal episode. Washing your hands for at least 20 seconds before eating food if you are at the beach, pool, or other similar environments and being sure not to swallow the water are ways to help keep safe.

Beyond critical minerals, copper is emerging as a bottleneck to clean energy

Copper remains invaluable for the transmission of electricity needed in energy infrastructure projects, with 90% of the average circuit board made of the element. However, limited smelting capacity and low ore quality amid increasing demands are stressing global supplies.

How sunlight helps chlorofluorocarbons destroy the ozone molecules that block solar radiation

CFCs, which are used in old refrigerants, air conditioners, and aerosol sprays, do not react with atmospheric molecules. Once they reach the stratosphere, ultraviolet radiation breaks chlorine atoms off of them, which can each break apart more than 100,000 ozone molecules, thinning Earth's protective layer against ultraviolet radiation.

Watch how coral bleaching resembles an organism's immune system attacking itself

Microorganisms called zooxanthellae are in a symbiotic relationship with coral polyps and provide them with food created through photosynthesis. When ocean temperatures or sunlight exceed an optimal range, zooxanthellae release harmful chemicals that irritate coral cells. To protect themselves, corals sacrifice their food source and expel the colorful microorganisms, becoming white.

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.

How goldfish cause significant environmental damage when released

Researchers have found that goldfish cause "regime shifts" in habitats as they search for food in places like lake beds, kicking up sediment that muddies the water and disrupts small invertebrates. They can also outcompete native species to further destabilize existing food webs.

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.

Scientists turn alchemists, transforming transform lead into gold

Fulfilling alchemists' dreams, scientists at the Large Hadron Collider (LHC) transmute lead into gold. While the 86 billion gold nuclei produced were short-lived, the experiment sheds light on how electromagnetic fields can play a critical role in nuclear transmutation.

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.

Breaking down the different types of drinking water, from alkaline to sparkling

While tap water is regulated by the EPA, environmental and infrastructural factors can introduce contaminants, which filtering can help to remove. Distilled water has had all of its mineral contaminants removed and may be used in laboratory settings, but mineral water has them added in for taste or to promote health.

Alkaline hydrolysis—dissolving the body—is one 'green' burial option

This approach, which is sometimes called flameless cremation, involves dissolving the body with water and chemicals. The remaining bone fragments can then be spread like ashes. It was reportedly incorporated into the funeral industry in 2011.

Coral reefs get their colors from zooxanthellae—microorganisms that line corals' digestive tracts and provide them with sugars in exchange for a home within this protective tissue.

Research has shown that bioengineered algae can help remove microplastics

Scientists at the University of Missouri found that, like microplastics, some algae are particularly hydrophobic—they repel water—and that both can clump together to form a microplastic-algae sludge, which can then be collected to remove microplastics from water. Researchers believe this algae provides a scalable solution for microplastic removal that can be employed in wastewater treatment processes.

Conditioners can help unshrink garments by lubricating fibers

Textile fibers relax and shrink due to heat and moisture, disrupting hydrogen bonds. While loosely knitted fabrics are more prone to shrinkage than tightly woven ones, synthetic fibres like polyester resist shrinkage due to their crystalline structure.

Ancient Greek and Roman sculptures were likely colorful, not white

Archaeologists stumbling upon statues from ancient Greece often found weathered creatures, their faces and figures marred by age and conflict. But evidence of polychromy—painting sculptures with color—has continued to mount.

No medical evidence suggests collagen drinks or supplements will improve your hair

Marketing claims that collagen supplements or drinks will make your hair shiny, thick, and improve hair growth are not backed by scientific evidence.

Sunflowers have long been a symbol of nuclear disarmament because they can extract large amounts of radioactive cesium from soil.

Scientists testing how climate change affected plants found in a years-long simulation study that poison ivy grew 70% faster than it did without extra carbon dioxide

The experiments in the 1990s were designed to simulate potential 2050 conditions, using carefully controlled circular forest plots with gas pumped into them.

Why professional tennis players are so picky about balls before serving

Just as swimmers shave their bodies before competitions to swim faster, experiments show that tighter, less fluffy balls experience less drag forces when moving through the air and thus produce faster serves at the cost of less control. Players may select a fuzzier ball in scenarios that call for safer, more cautious play.

Vitamin D supplement pills are linked to rising cases of vitamin D toxicity in the US

Vitamin D deficiency is common. But taking Vitamin D supplements in doses exceeding 4,000 IU/day (a measurement of vitamin biological activity) for prolonged periods can raise bodily concentrations of this vitamin to dangerous values. US National Poison Data indicates that the annual average of vitamin D poisonings from 2000-05 was 196, but this rose by 1,600% to 4,535 per year for the period of 2005-11.

Hippocratic doctors treated severe mental illness with the poisonous plant hellebore

Since symptoms like hallucinations were believed be due to an imbalance of black bile, yellow bile, blood, and phlegm, the treatment at the time was to bring those humors back into balance. That meant standard treatments could include bleeding a patient or using substances like hellebore to induce vomiting or diarrhea.

Pure water does not conduct electricity because this flow of energy requires the movement of charged particles, and water is a neutral molecule.

Boost your Wi-Fi with aluminum foil

A surprising hack using aluminum foil can potentially improve Wi-Fi signals, to many readers' surprise. Check out the science with this brief article. Wi-Fi signals spread like radio or light waves from a router's antenna, often leading to...

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.

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.

"Plaques" and "tangles" are top potential causes of Alzheimer's—but questions remain

The exact causes of Alzheimer's—and how to treat it—continue to be the subject of intense research. Two leading factors are amyloid beta plaques and tau protein tangles, which effectively pile up in the brain and interfere with neurons and cause cell death, which manifests as memory loss and other symptoms.

Urushiol, the oily toxin in poison ivy, can remain allergenic on clothing for years.

Radioactive elements can introduce software errors because the ionizing radiation they produce can detach electrons from atoms, and computer code relies on the distribution of electrons.

Sunflowers have long been a symbol of nuclear disarmament because they can extract large amounts of radioactive cesium from soil.

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.

Alzheimer's can lead to brain shrinkage, with an average of around 2% of volume reduction per year

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.

Hotels in Cannes, the glamorous city on the French Riviera, hire hawks to ward off seagulls during the city's famous film festival.

The US first hosted the World Cup in 1994, a tournament that lives in soccer infamy for its poor planning and the murder of Colombian player Andres Escobar, who'd accidentally scored on his own net.

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

Hookworm infection, though risky, may help fight certain autoimmune conditions by tamping down the immune system's inflammatory response.

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.

Apollo astronauts left items in the moon's 'toss zone,' including golf balls, family photos, and bags of human waste, to make room for lunar rocks.

After her fellow cult members tried to kill her with an LSD-infused hamburger, one member of the Manson Family, the murderous cult led by Charles Manson, decided to testify against the group's leader.

70 years ago today, city officials in Santa Cruz, California, banned rock 'n' roll to protect its youth from corruption after witnessing a 'provocative' concert the night before.

While El Niño moves warm Pacific Ocean waters east along the equator, La Niña moves them west, shifting where rainfall will become more common for months.

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 Brothers Grimm were lawyers before they were storytellers, and became interested in fairy tales as they began investigating how rules and customs had been passed down through cultures.

American short story writer Flannery O'Connor raised 40 peacocks, which became potent symbols for her fiction's elegant violence

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.