Chromium contaminants in a ruby crystal gave the world's first laser its red color

Several birthstones play key roles across modern technologies

Diamonds are used in drills and quantum computing, while peridot and zircon help in steelmaking and carbon capture. Rubies, sapphires, and alexandrite enable several varieties of lasers found in medicine and advanced optics. Garnets are found in water filtration systems and radiation detectors. Sapphires are used as substrates in semiconductors.

Some materials can absorb low-energy light and emit high-energy radiation

Through anti-Stokes cooling, incoming energy is combined with vibrations in a material's crystal lattice to produce a net reduction in its temperature. Using this effect, lasers can be directed at microchip hot spots to help keep data centers cool.

Random lasers can be created from biomaterials, such as peanuts and birch leaves

Rather than creating a narrow beam of light via amplification in an optical cavity, the random laser produces a red glow by scattering photons created in the natural pores of a peanut kernel after it has been injected with a solution of light-generating carbon dots derived from birch leaves.

A diamond's color comes from impurities, defects, and unique formation processes

While most diamonds are transparent and sparkly, the presence of nitrogen and boron during formation can make them yellow, orange, or blue. Radiation can produce green diamonds, and structural deformities can introduce red hues.

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.

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

Synchrotron radiation has revealed the fur color of creatures millions of years old

When electrons are accelerated in the loop, they produce intense X-rays that can reveal properties of a sample struck by them, just as X-rays can be used to show bone structure in humans. Studying the reflected light from fossils can uncover the presence of known pigmentation compounds.

Radioactivity was accidentally discovered when uranium left marks on photographic plates

In 1896, Henri Becquerel had been exploring phosphorescence—the emission of light of one color after an object is exposed to another color. He expected these emissions to come from objects exposed to sunlight, but he observed emissions after an overcast day.

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.

Red is deeply symbolic in Chinese culture

Since the bold hue warded off the mythical Nian, the color red has come to represent luck, prosperity, and celebration. If you come across a home or neighborhood preparing for new year celebrations, you'll see red lanterns, wall hangings, clothing, and more.

View examples of luciferin, the light-emitting molecule behind bioluminescence

Bioluminescent marine organisms rely on various unique luciferins, including Cypridina-type luciferin in seed shrimp and chlorophyll-based dinoflagellate luciferin, to react with oxygen to produce light. These chemicals require unique catalysts to help them bind with oxygen.

Scientists create the first CRISPR-modified spider to enhance its silk proteins

A research group at the University of Bayreuth used CRISPR-Cas9 to genetically modify spiders to produce glowing red silk. Spider silk is five times stronger than steel by weight, and this research paves the way for developing new silk functionalities.

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.

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.

Where does your glass come from?

Glass is created from silica sand, soda ash, and limestone. The more transparent you want your glass to be, the higher the purity you need from your silica—a rarity. Colorless, low-iron glass featured in skyscraper windows and Apple's cube-shaped showrooms has increased demand for such pure silica.

The 1939 film changed Dorothy's slippers from silver to ruby

Baum’s original book listed the slippers as silver, but the filmmakers wanted the shoes to pop on film—and highlight their use of Technicolor—so they turned them ruby. The slippers wound up becoming one of the movie’s most iconic elements.

Why it's so hard to end the use of toxic lead

Lead was one of the earliest metals mined on Earth, desired for its soft malleability and used in cosmetics, pipework, gasoline, and more. But even though researchers demonstrated its toxicity in the 20th century, much of the world still uses it.

The history of chemistry, from alchemists to probing atoms before World War I

Those involved in the predecessor of the modern scientific discipline engaged in experimentation to develop recipes that would transform ordinary matter into gold and to create medicines, cosmetics, dyes, and alloys. Over the course of centuries, scientists identified unique elements, organized them based on their properties in the periodic table, and eventually developed the technology to discover the internal structure of atoms.

How lasers have become a go-to in archaeology

Archaeological teams now have another item to pack with their trowels: Lasers. Researchers' approach to unsurveyed land has been transformed by light detection and ranging technology. LiDAR has helped archaeologists break new ground and uncover...

When processing light, the brain can perceive colors with no natural wavelength

While some animals are sensitive to many forms of light, humans possess receptors that are sensitive to red, green, and blue wavelengths. These receptors send signals to the brain, which are processed and mixed to produce the array of colors we observe, including magenta, pink, and "supercolors" that lack a corresponding natural wavelength in the visible spectrum.

Red blood, skin, hair, and nail cells destroy their DNA upon maturing

To maximize the amount of oxygen they carry and more easily alter their shape to fit into narrow blood capillaries, red blood cells destroy their own nuclei. Cornified cells found in hair, nails, and the outermost layer of skin destroy their nuclei and other cellular contents to make room for keratin, which provides durability and structural support.

Credit for inventing the laser was fought over for nearly three decades

Although Theodore Maiman built the first working laser in 1960, Gordon Gould coined the term earlier. Charles Townes and Arthur Schawlow of Bell Labs filed a patent after Gould came up with the idea and name, but before Gould filed his patent.

The centuries-old history of titanium white goes back to the Inca

Titanium white can be found in items ranging from paint to pills. Though it was created in New York in 1908, the pigment was first used hundreds of years earlier by the Inca, according to this article.

See a dying star in different wavelengths

The Crab Nebula is the remnants of a dying star that went supernova . First spotted a thousand years ago by Chinese and Japanese astronomers, and likely Native Americans as well. Its original bright light has long since faded, but you can see it in different light wavelengths through this interactive website.

Britain’s bottle innovation saved Champagne

Champagne wouldn’t be where it is today without a surprising partner: 17th-century British glassmakers. An energy crisis caused by deforestation—not enough trees to burn—led to the search for an alternative fuel source. Enter coal. The plentiful resource burned much hotter than wood, creating stronger glass that could stand up to the pressure of the carbon monoxide produced by the wine’s second fermentation and solving one of the fledgling industry’s most vexing problems.

Watch a crystal undergo X-ray diffraction to determine its internal geometry

In the early days of X-ray crystallography, getting photos of a single sample could take dozens of hours, followed by months of mathematical analysis. Today, automation and computer software can complete such tasks in a few hours.

Visualize the minerals used in a lithium-ion battery

The lithium cathode includes nickel to increase energy storage per unit volume, as well as cobalt and manganese as stabilizing agents. Anodes are composed entirely of graphite, with aluminum and copper composing the current collectors for the cathode and anode, respectively. The battery is enclosed in a steel casing.

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.

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.

The first line of 'immortal' human cells, which can divide indefinitely and are used in scientific research, was nonconsensually taken from a Black woman.

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.

As of 2025, the most cited papers in science include a review of graphene, methods to improve image recognition, streamlining electron density calculations, and optimizing protein studies.

When caught in the mouths of cardinal fish, seed shrimp release glowing, bioluminescent chemicals, which alert predators of the cardinal fish, prompting the shrimp's ejection.

In 2019, a laptop loaded with six of the worst malware in history and described as 'an exhibit of historical weaponry' sold for $1.3M.

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.

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

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.

The Dracula character, now seen as the vampire archetype, was inspired by a seafood-induced nightmare its creator experienced.

Objects can be 3D printed with light by projecting 2D computerized tomography (CT) scans onto rotating cylinders of resin, which solidify upon exposure.

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

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

Budweiser stores yeast derived from the original 1800s strain in a secret bunker, which only the Head of Yeast Management can access—not even the CEO

Poison ivy's characteristic rash is caused by an allergic response to an oily compound in the plant called urushiol.

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.

The Mona Lisa's celebrity status and repeated restorations have obscured what made the painting so revolutionary for its time

Louisiana's 'Cancer Alley' is infamous for having some of the highest industrial pollution, toxic air emissions, and cancer risks in the US.

Some coin denominations have ridges etched on their sides, partly to prevent counterfeiting, in a practice called 'reeding.'

Neutron stars, the remains of some massive stars after they explode in a supernova, are the densest directly observable objects in the universe.

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

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.