The Ancient Chinese harnessed solar power for heating and cooling 6,000 years ago

Home energy performance can be boosted through home orientation and shading

When designing a home, placing living areas to the north maximizes sun exposure during winter, while eaves and awnings can limit excessive summer heat. Breezeways and entry air locks can also reduce the dependence on heating and cooling costs.

Humans have used geothermal resources for thousands of years

In North America, Indigenous peoples viewed hot springs as sacred places and used them for medicinal purposes, cooking, and surviving cold weather. The ancient Greeks and Romans also viewed them as sacred, partaking in hot mineral baths to relieve ailments and using them for space heating.

The first rooftop solar panels were installed in 1883

In 1883, New York inventor Charles Fritts created the first solar cell by coating selenium with a thin layer of gold. The cell achieved energy conversion rates of 1 to 2% compared to the 15 to 20% of modern photovoltaics.

The ancient engineers inspiring modern building practices

Modern concrete structures need replacing every 50 to 100 years, so why are buildings by the Maya, ancient Rome, and ancient China still standing strong? This article details how scientists are looking into humanity's past for clues on how to craft long-lasting structures. Part of the problem is adopting old material recipes to hold up to modern demands.

Learn how the Egyptians, Romans, and other ancient civilizations worshipped the sun

In Egypt, the pharaoh was seen as the living embodiment of the son of Ra, the sun god. In Mesopotamia, the sun god Shamash was a divine judge whose light could reveal the truth. Huitzilopochtli, the Aztec god of sun and war, was thought to require sacrifices to prevent the universe's destruction.

East Asian records of auroras may date back to 10,000 BCE

Ancient texts from Japan, Babylon, and China contain accounts of auroras dating back millennia. Because auroral activity and intensity are driven by periodic ebbs and flows in solar activity, these records allow scientists to identify patterns that may help anticipate particularly dangerous future solar storms.

Ancient Chinese marriages began with an elaborate marriage proposal and acceptance between families

The chief objectives of early Chinese marriages involved joining and enhancing the two families and ensuring succession with numerous descendants. Chinese couples still compare astrological signs, although some of the more elaborate rituals of betrothal gifts and sleeping in the “cock loft” are far less common.

China has used several different calendars because of changes in government structure

For many centuries, during which China was an imperial nation, the lunar/lunisolar calendar (aka the “rural calendar”) was the basis for organizing the year. Several attempts were made over the decades to switch to the Gregorian calendar—which begins Jan. 1—but it wasn’t until the People’s Republic of China was founded in 1949 that it stuck.

Many early Chinese restaurants were aimed at travelers

As trade expanded throughout China's north and south in the 12th century, restaurants opened to offer traveling tradesmen their home region's cuisine while they were on the road: southern cooking for people visiting the north, and northern cooking for people visiting the south.

A history of China's ancient hidden tombs

Like many ancient cultures, the Chinese had a tradition of burying the dead in elaborate tombs, which would serve as both burial places and residences for the deceased. Archaeological evidence of these tombs, including those of former emperors, provides insights into the country's cultural evolution.

Medieval European winters were colder than ours, but peasants stayed warm

Medieval winters were colder than ours today while the continent was mired in the so-called Little Ice Age. Without modern technologies, peasants survived with simple, sometimes genius, solutions, including central, chimney-less fireplaces (vented by small, draftless vents) and decorative handwarmers.

City structures cause localized heat zones hotter than nearby rural areas

Urban materials like asphalt and concrete trap heat, while cities lack cooling features like trees and water. Due to hot runoff, urban streams can heat up by as much as 18°F more than forested streams.

Early timekeeping tools included sundials, water clocks, and astrolabes

Astrolabes also provided a person's latitude based on the height of the stars in the sky, thus aiding in navigation. Incense and candle clocks relied on the constant burning rate of fire to track the passage of time based on premarked locations with equal-interval spacing.

The architectural evolution of New York City's Chinatown

Cityscapes continuously evolve, and each stage in their transformation tells a unique story. In Manhattan's Chinatown from the 1940s to today, the architecture has bloomed from an ethnic conclave for often mistreated migrants to a vibrant cultural hub today. See varying elevations and facades over time.

Ice cream can be traced back to the 7th century

Documents from ancient China refer to a frozen milk dish, a predecessor of the treat we now know. That evolved into a blend of buffalo milk, flour, and fragrant camphor oil that more closely resembled our ice cream.

View a photo essay of renewable power landscapes in China

Using a drone, Chinese photographer Weimin Chu captured the deployment of solar and wind power installations across the country, which accounted for half of all global installations in 2025. The images show modern infrastructure juxtaposed with natural landscapes and was featured in an award-winning exhibition presented by Greenpeace in 2025.

A clean house is essential for celebrating the Lunar New Year

The earliest recorded instance of this cleaning ritual is from 241 B.C.E. By sweeping out dust and dirt and getting rid of clutter and unwanted items, it’s believed that you won’t carry extra burdens into the new year and will have space for the prosperity and fortune coming your way.

The greenhouse effect was discovered by analyzing Earth's temperature

Using mathematical techniques developed to analyze heat transfer, Jean-Baptiste Joseph Fourier showed that Earth should be significantly cooler if solar radiation were the only contributor to its surface temperature. By considering that the atmosphere could amplify the sun's warming effect, he formulated what became known as the greenhouse effect.

Concentrated solar power systems focus sunlight in order to boil water

These systems use thousands of mirrors to reflect sunlight onto a central tower storing molten salt or multiple receivers housing heat transfer fluid that absorbs the radiation. The material is pumped through water to boil it, creating steam that drives a generator.

Asia's agriculture-focused set of 24 'small seasons'

In contrast to the four broad seasons and their basis in astronomy and climate, ancient farmers in China and Japan had many more and varied seasons (or "sekki). Take Keichitsu (March 6 to 21), for example: this means "going-out of the worms" when bugs come out from hibernation.

Greek-Egyptian scientist Heron invented automatic doors for a temple

The doors opened when a fire was lit in front of the temple, causing heat and pressure to build in a nearby vessel that would force its contents into a higher secondary vessel. This secondary vessel would lower, pulling the doors open. When the fire extinguished, the pressure and liquid in the vessel would reverse course, closing the temple doors.

An engineer tracked his moods for decades and helped researchers identify SAD

Civil engineer Herb Kern had bipolar and would record his moods dating back to 1967. He noticed the seasons were a major factor in the increase and severity of his episodes. By reaching out to researchers at the National Institute of Mental Health, Kern became the first human to confirm increased melatonin levels during winter and to receive bright light therapy.

The Four Great Inventions are historically significant Chinese technological advancements

The inventions of paper, gunpowder, printing, and the compass advanced civilizations worldwide by spreading knowledge, enhancing warfare, and improving navigation.

Take a virtual tour inside Stonehenge

Prehistoric visitors approached Stonehenge along a processional route known as the Avenue, where the sunrise of the summer solstice aligns with the sarsen stones. This interactive 3D tour recreates that experience with explainer videos and detailed sidebars.

Climate determinism wrongly linked human traits and societal progress to geography

Historically rooted in Greek philosophy, its ideas used the latitudes where people were located to justify racial hierarchies, casting tropical peoples as lazy or inferior. These biases still influence how media and research portray people in climatically disadvantaged regions. (Some readers may experience a paywall.)

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.

Electrical grids worldwide must double their power delivery capacity by 2050 to meet surging demand from AI and electric vehicles.

Visualize the path of every solar eclipse from 1900 to 2099 and see what each looks like when observed from different locations on Earth.

For centuries, it was common to sleep in two shifts: a few hours at the beginning of the night, and a longer period beginning around midnight

In 1963, a basement renovation in Turkey revealed a passageway to a hidden, multilevel underground city that once housed as many as 20,000 people

Scientists can determine Earth's past climate conditions by analyzing air trapped in microscopic bubbles within ice cores—columns of compressed snow layers that build up over hundreds of thousands of years.

Graffiti dates back to at least ancient Pompeii, where citizens scrawled messages to one another on public walls

Stanford built a Google Maps for the Roman Empire, revealing how much it cost to travel in the ancient world

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

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

NBA superstar Victor Wembanyama spent the 2025 summer training with monks in central China to enhance his body and mind.

While the sun's gravity keeps the planets in orbit, their gravity also pulls on the sun, causing it and everything else in the solar system to orbit around a mutual balance point called the barycenter—the true center of the solar system.

Massive 3D printers have been used to build homes by stacking layers of 'concrete toothpaste,' a fire-resistant material that effectively insulates against outside noise.

In its famous catalog, Sears sold $600 DIY house kits from 1908 through the 1940s, resulting in an estimated 100,000 'Sears and Roebuck homes.'

The name 'Silicon Valley' arose from the founding of Shockley Semiconductor Laboratory in Fairchild Semiconductor in 1956-57, founded near Stanford University in Palo Alto

Before writing 'Walden,' transcendentalist Henry David Thoreau nearly burned down his hometown with a campfire that grew out of control.

US housing costs have risen by roughly 175% between 1991 and 2026—but a growing number of Gen Zers are becoming homeowners anyway. In 2025, 4% of homebuyers were Gen Z, up from 3% the year before.

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

El Niño, Spanish for 'the boy,' was named after Jesus Christ because the phenomenon resembled the weather changes observed around Christmastime.

Crows are believed to have intelligence on par with a seven-year-old child and demonstrate complex behaviors, from problem-solving with tools to recognizing human faces.

Poison ivy can cause rashes year-round since all parts of the plant contain urushiol, the oil that triggers our allergic response.

Mid-century modern graphic designers, known for their bright colors and bold lines in advertising, also found success with children's books.

The identity of the Tank Man in the iconic photo from the 1989 Tiananmen Square protests remains unknown and was possibly killed.

The hormonal disorder PCOS was renamed PMOS in 2026, a move designed to improve care and research by shifting the focus to the hormonal causes of this condition that affects 1 in 8 women.

The US Constitution is widely regarded as the longest-standing written national constitution still in force—see how it has influenced rights worldwide.