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

The history of iconic pigments used in seven famous paintings

While art paints can be bought by the bucket at any craft store today, pigments throughout history have been difficult to come by. Art historian Kelly Grovier traces the fascinating history of pigments that make up hidden layers in masterpieces from Picasso and Hokusai’s Prussian Blue to Vermeer’s shade of red.

Watch Apple Watch cases be 3D printed from titanium powder

Apple Watch Ultra 3 cases are 3D printed entirely from recycled, aerospace-grade titanium powder using lasers to fuse particles. Over 400 metric tons of raw titanium were saved in 2025, with two watches fabricated from the same amount of raw material that would have previously been used to make one.

Yale returns Inca artifacts to Peru

From the time he came upon Machu Picchu in 1911, Hiram Bingham began removing artifacts and human remains from the site and bringing them back to Yale University. Yale's Peabody Museum held them for 100 years, despite demands by the Peruvian government and the public that they be repatriated. Finally, in 2011, Yale returned thousands of items, including ceramics, jewelry and human skeletons.

The Inca Empire: a timeline

When did the Inca Empire solidify into an empire? When was it invaded by the Spanish? What remains of it today? Click through this timeline to learn more.

The history of metallurgy: an interactive timeline

Humans have long been shaping metals into useful tools and aesthetic accessories. By 8,700 BCE, humans already had mastered four types of casting copper. Within a few thousand years, people were combining metals to make the alloy bronze and had...

'Tattoo' comes from a Polynesian word that means 'to strike'

“Tatatau” roughly translates to “strike,” a reference to the ancient process, which involved tapping ink into the skin with sharpened objects, like the bronze implements used circa 1450 BCE in Egypt, below.

Twain didn’t start wearing his iconic white suit until later in life

The writer first wore the white suit in 1906, at the Library of Congress. “I have reached the age where dark clothes have a depressing effect on me,” Twain told the Washington Post. “I prefer light clothing, colors, like those worn by the ladies at the opera.”

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.

How the great city of Cusco came to be, according to the Inca

The chronicler Inka Garcilaso de la Vega recorded the origin story of the Inka (also spelled Inca) and the founding of Cusco, the capital of the society's great empire. Listen to the Inca origin story in this 4-minute video narrated by a child.

The pharmaceutical industry evolved, in part, from the discovery of synthetic dyes

In 1856, a chemist accidentally discovered mauveine, the world's first synthetic dye, while trying to make quinine to treat malaria. The synthetic dyes that followed helped reveal germs under microscopes, paving the way for modern imaging techniques and breakthrough treatments, such as antibiotics.

The world's first artificial element, technetium, was discovered 68 years after its existence was predicted in order to fill a gap in the periodic table.

Rediscovering the Inca Empire

In 1991, anthropologist Johan Reinhard was trekking up the snowy face of a dormant volcano when he came face to face with the mummified remains of a teenager who had been sacrificed to the Incan gods centuries earlier. The story of “Juanita the Ice Maiden” is just one of the riveting tales featured in this four-part series from the popular podcast "History Hit".

The iconic Aztec 'crystal skulls' were 19th-century fakes

The crystal skulls long displayed as Aztec artifacts were actually fabricated in the late 1800s, all linked to French antiquities dealer Eugène Boban. Anthropologist Jane Walsh's investigation exposed their modern origins, overturning a century of mistaken museum lore.

Learn more about the history of fireworks, which date back to an accidental invention during an alchemist's quest for information about immortality.

The history of chemistry up to World War I, from alchemists seeking gold to probing atomic structure

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.

Pigments in paint can come from rocks, plants, insects or synthetic sources

Paint's composition is varied through the combination of pigments with binding agents. In the past, artists created their own paints by mixing pigments with water, oils or egg yolks to bind the colors together.

How billiard balls catalyzed the 'Plastics Century'

For centuries, billiard balls were made of ivory from elephant tusks. But when excessive hunting caused elephant populations to decline, they began to look for alternatives: celluloid, which would become known as the first plastic.

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.

The mysterious qualities of obsidian and magnetite

Obsidian is a dark volcanic glass created when lava cools quickly and frequently contains magnetite, a key early mineral used in compasses. Large deposits were discovered and used in central Mexico by the Toltecs roughly 1,000 years ago at the ancient site of Teotihuacan. This essay explores obsidian's cultural impact and the mysterious presence of magnetite in migratory birds.

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.

The chemistry of ancient tacos

This 16-minute podcast explores the chemistry of Mesoamerica's corn tortillas, which involve a 3,500-year-old chemical process called nixtamalization that releases vitamins, including niacin, one of the essential B vitamins. This process also makes the tortillas softer and more delicious. Corn tortillas were a staple in Mesoamerica, and the archaeologist interviewed in this podcast argues cultures like the Aztecs and Maya wouldn't have thrived without nixtamalization.

The ancient Romans invented the first known artificial sweetener—it involved lead.

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.

How nylon was created

Nylon, one of the most ubiquitous materials in the world, was invented in 1935. Chemist Wallace Carothers was hired by American conglomerate DuPont to perform research. After seven years of work he produced nylon, the first wholly synthetic fabric. Carothers’ life ended tragically, but his contributions revolutionized everything from military equipment to women’s fashion.

Machu Picchu is an ancient Incan citadel set high in the Andes Mountains in Peru, abandoned for centuries before its rediscovery in 1911.

One of the hottest known exoplanets seems to snow an active ingredient of sunscreen, titanium dioxide—but only on the dark side of the planet.

As of 2026, the rarest mineral on Earth may be kyawthuite, an orange gemstone whose only known specimen was found in Myanmar in 2010.

The US senator who found a city in the sky

Dr. Hiram Bingham, a Yale graduate and explorer, is credited with rediscovering Machu Picchu in 1911. Financially supported by his marriage to the Tiffany jewelry heiress, Bingham ventured into the Peruvian Andes in search of the lost Inca city of Vilcabamba. Instead, guided by local farmer Melchor Arteaga, he stumbled upon the awe-inspiring ruins of Machu Picchu.

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

The red light originates from a long-lasting excited electron state in the element's atomic structure. The brittle gray metal has historically been used in pigment production, the manufacturing of rust-resistant stainless steel, and the creation of durable coatings with long-lasting shine for metals, wood, and leather.

The original article revealing Machu Picchu to the world

After first coming upon the ruins of Machu Picchu in 1911, Hiram Bingham’s subsequent expeditions were funded by Yale University, the Peruvian government, and $10,000 from a then-young National Geographic Society—in fact, it was the first archaeological grant that NatGeo ever issued. The magazine devoted its entire April 1913 issue, all 192 pages, to Bingham and his findings. You can read that issue in its entirety here.

Layers of minerals revealed by erosion give Vinicunca its distinct colorations

Located in Peru's Andean mountains, Rainbow Mountain is known for its vibrant colors, which result from layers of minerals such as clay, sandstone, argillite, and limonite exposed over millions of years by rain, snowfall, and strong winds.

The world’s oldest tattoos belong to 'Iceman' Ötzi

Ötzi is the corpse of "the Iceman" found in the Alps along the Italian and Austrian border in 1991. His mummified body was covered with lines and crosses along the “hard-working” areas of his body, signifying their potential application for therapeutic pain management.

How the Inca used threads to communicate

One of the great mysteries of ancient Peru is that the Inca did not have a system of writing, but communicated with a system of strings tied with knots. This 4-minute video explores its possible uses.

Local limestone made waterproof cement for the Erie Canal

In 1818, engineer Canvass White discovered that limestone near Chittenango, New York, could be processed into hydraulic (or waterproof) cement. This breakthrough replaced costly European imports, enabling watertight locks and aqueducts and revolutionizing American construction.

Colored paint lines on new tires mark different types in the factory

Each stripe helps warehouse workers and distributors identify tire types at a quick glance. This innovation became important a century ago as manufacturers scaled operations and developed distinct product lines.

When did people start making and using glass?

This article details the search for the ancient origins of glass, a now-common item through which archaeologists can spot histories of trade and innovation. Bronze Age glass was made from crushed quartz instead of sand, and artisans could color glass with materials such as cobalt. These trace metallic add-ons have given scientists a vital clue into the origins of glass, which is currently debated as either Egypt or the Near East.

Oral history and artifacts suggest the Wampanoag inhabited the area for 12,000 years

By 1621, Native Americans had been interacting with European explorers along the coasts for hundreds of years. European adventurers, including Giovanni da Verrazzano, mapped the coastline as early as 1524, as this timeline from the National Museum of the American Indian explains.

How 'the Iceman' got his tattoos remains a mystery

Ötzi the Iceman, discovered in 1991, is one of the oldest human mummies ever found—and his 61 tattoos remain a mystery. This explainer looks at how researchers believe the tattoos were made, what their placement suggests about ancient medicine and culture, and why we’re still piecing together their true purpose today.

Diamond engagement rings didn’t become popular until the 1900s

However, the history of engagement rings stretches all the way back to the year 850, when the pope said that a ring symbolized a man’s intent to marry. At the time, gold was the most popular choice for engagement rings. See a full timeline of the engagement ring’s history.

The story of the Radium Girls, who exposed the dangers of radioactive paint

After radium was discovered in 1898, companies began using radium-based paints on watch and clock dials to create a glow-in-the-dark effect. Women who worked to apply the paint were encouraged to use their lips and tongues to help create the fine point needed to draw small numbers, unknowingly poisoning themselves.

Why did the Spanish steal the Inca's mummies?

From inside stone palaces and atop sacred mountaintops, the Inca dead continued to wield incredible power over the living. So much so that the Spanish confiscated them. Read more about the afterlife of these mummies here.

Plastic's history began with an inventor seeking a $10,000 prize offer

In 1869, the first synthetic polymer—celluloid—was created as a substitute for ivory in billiard balls. It became the historical catalyst for the eventual manufacturing of plastics everywhere as an alternative to the depletion of other natural resources, including tortoiseshell and horns.

View a timeline of 3D printing technology through 2019

The first working 3D printing device was invented in 1983 and utilized stereolithography, a process in which a laser triggers a chemical reaction that hardens liquid resin. Powder-based laser sintering technology was patented in 1987, with metal-based powders first being used for 3D printing in 1997.

The earliest mention of time travel

Time travel has fascinated humans for centuries. It appears in myths, literature, and science fiction. One of the earliest examples comes from the 400 BCE Hindu epic Mahabharata, describing time dilation long before Einstein’s Theory of Relativity. By the 19th century, stories introduced machines enabling time travel—setting the stage for modern sci-fi.

Tattoos suppressed during colonization are experiencing a revival

A few decades ago, the distinct facial tattoos worn by Maori people were on the brink of disappearing. Then, Maori artists brought the cultural practice back into the spotlight. This TVNZ story follows one reporter’s mother as, at 59 years old, she receives tā moko from a Maori artist.

America's oldest companies still operating today

Did you know that the Ticonderoga pencil company dates back to 1795? Or that Baker's Chocolate started in 1765? This visualization depicts the oldest American companies that are still in operation today in a timeline—see it here.

What llama beans can tell us about the Inca Empire

Fun fact: Llama bean is just another term for llama poop. Another fun fact: Scientists are using these beans and related microorganisms to learn more about the Inca Empire. Read this article to learn how.

Tennis balls are yellow, partly thanks to a suggestion by British naturalist and broadcaster Sir David Attenborough.

The decline of the Inca Empire

The Inca Empire was awash with gold, and the Spanish knew it. So what happened next? Read this BBC article to learn what happened during the last days of the Inca Empire.

Aspirin was the first synthesized anti-inflammatory drug

Once used by the ancient Sumarians—extracted from willow bark—but now synthesized in the lab, the active ingredient of this popular medication has been used to treat headaches and pain for thousands of years.