Cooling each square foot of a room requires at least 20 BTUs of capacity

Data centers require interconnected server- and building-level cooling systems

Computer equipment can be cooled by circulating cold air or water through the equipment racks, siphoning the heated fluid into a heat exchanger. This exchanger transfers thermal energy to building cooling systems, which can dispose of the heat by evaporative cooling—the way humans cool off by sweating—or via air conditioning.

A basement of mechanical systems—collectively called the technosphere—supports B2

Twenty-six underground air handlers heat, cool, filter and manage the humidity of the air across the biomes of Biosphere 2. The above-ground Energy Center complex provides continuous power to these and other systems, including heating and cooling water for laboratory experiments and personal use.

13 unconventional ways to stay cool during heat waves

While air conditioning is the default solution for many in a heat wave, it can get expensive while requiring the consumption of fossil fuel energy. So, how else can you stay cool during a heat wave? This list compiles some practical, at times quirky, suggestions, including an ice-pack-filled aubergine hat.

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.

Broken or neglected air conditioners are risky for respiratory health

A well-maintained air conditioner can typically keep out unwanted pathogens, but units that are dusty or water-logged can foster germs and cause harm. AC units also remove moisture from the air, potentially causing mucus membranes to dry out and become vulnerable to infection.

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.

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.

Geothermal heat pumps have the greatest upfront cost of any home heating system

As of 2025, installations of these systems can range from $15,000 to over $40,000, significantly more than for furnace-air conditioner and air-source heat pump systems. However, they are up to 50% more efficient than these alternative systems, making them able to pay for themselves within 15 years.

Feels-like temperature indicates how our skin will feel

When the wind is moving faster, we tend to feel colder due to the so-called "wind chill," which cools our bodies by moving heat away from them and making water evaporate faster. On the other hand, high levels of humidity can make us feel 10 degrees warmer at times.

Bath bombs can produce endothermic reactions that cool water

In bath bombs containing citric acid and sodium bicarbonate, water facilitates the reaction between the bicarbonate and acid, providing energy as the salt dissolves. The loss of energy in the water reduces the average speed of the water molecules, reducing the temperature of the bath.

How 'vibes' factor into scientists' decisions about using certain units

Although there are absolute quantities from which units can be defined, such as the speed of light and the corresponding light year for distance, the usefulness of units comes from their ability to easily communicate values, rather than how fundamental their origins are. For example, while Kelvin measures absolute temperature, Celsius is scaled to the temperatures of boiling and freezing water, making them more practical for everyday usage.

Hubble's average used power is less than half the power generated by its solar arrays

The space telescope's components use about 2,100 watts, or about as much power as five refrigerators. When exposed to sunlight, the solar arrays can generate over 5,200 watts for the observatory, which was engineered by a team that included Judith Love Cohen, mother of actor Jack Black.

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.

Explaining why Earth's atmosphere doesn't crush us, despite weighing 11.24 quintillion pounds

Gravity pulling down on over 5.1 quintillion kilograms of gases surrounding Earth's surface produces an atmospheric pressure of 15 pounds per square inch (101,325 Newtons per square meter). However, since air surrounds objects, the forces from opposing air pressures normally cancel each other out, eliminating any detectable weight.

What is metabolic rate?

Read this article to better understand the concept of metabolic rate, which is defined as the amount of energy expended by an organism over the course of a day. Basic metabolic rate (or BMR) is this metabolic rate at rest, during which the body only...

RTGs convert heat generated by the decay of radioactive plutonium into electricity

Radioisotope thermoelectric generators use a thermocouple—two plates of different metals joined at two junctions to make a closed circuit. When heating one junction while keeping the other cool, a voltage and an electric current are created.

The sound of thunder can vary based on your distance from lightning

The rapid flow of electricity heats and pressurizes air, causing it to expand and produce a shockwave at each point along the bolt at multiple frequencies. As these shockwaves overlap, higher-frequency sounds, which produce a sudden crack, dissipate more quickly, while lower-frequency sounds—long booms and rumbles—travel farther.

The properties of helium, which has the lowest boiling point of any element

The colorless, odorless, mainly unreactive element condenses from a gas into a liquid at -268.928 degrees Celsius (-452.07 degrees Fahrenheit)—near the lowest theoretically possible temperature—allowing it to serve as a liquid coolant in machines without the risk of causing damage as a solid.

Bright light therapy involves basking in 10,000 lux of light for 30 minutes each morning

Nothing is better than going outside and soaking up real sunlight. However, this is harder in winter, especially in very cold and cloudy regions. SAD lamps are designed to project 10,000 lux—a unit of illuminance, or how much light actually hits a surface (rather than how much is produced, like watts). This video discusses product options and practical considerations.

As much as 10% of home energy use comes from unused, plugged in devices

Vampire or phantom energy includes smart features that keep devices connected to the internet and standby modes that allow quick wake-ups. Turning off these background features or unplugging devices from outlets can help reduce emissions by as much as 20%.

Cloud formation requires water vapor and condensation nuclei to build from

The nuclei—particles like dust, salt, and smoke—act like jumpstarts that water molecules can start to accumulate onto to form clouds. Condensation nuclei are about 1/100th the size of cloud droplets, which are mostly water.

Wind turbines are limited to capturing no more than 59.3% of incoming wind energy

In 1919, German physicist Albert Betz applied the laws of conservation of mass and momentum to airstreams to calculate the theoretical limit. However, real-world turbines only convert 35 to 45% of available wind energy into electricity.

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.

The incredibly advanced engineering of the B-2 Bomber

B-2 Bombers are the world's most expensive plane, coming in at a cost of $2B per aircraft. There are roughly 20 in the world, all in use by the United States Air Force. They are known for their single-wing profile, allowing for stealth and the ability to transport some of the world's largest bombs.

Burning Man hosts roughly 70k attendees each year

Since 1986, the Burning Man organization has shared a census tracking growth, fluctuations, demographics, and burners' attitudes each year. Part of the organization's motivation is to monitor and reduce carbon emissions at the event.

US homes have been shrinking in recent years

Specifically, the median square footage of new single-family homes in the US has decreased in each of the past several years. In 2015, the typical new-construction home was about 2,467 square feet—but by 2024, that number had shrunk to 2,146 square feet.

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.

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

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.

A pickleball's loud 'pop' sound can reach 120 decibels, which is equivalent to a hammer hitting a nail

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.

Scientists testing how climate change affects plants found, in a years-long simulation study, that poison ivy grew 70% faster with the resulting extra carbon dioxide.

Explore what it's like inside a patient isolation unit, used in situations such as treating a patient or suspected patient with Ebola.

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

Chaos theory—informally known as the butterfly effect—is the reason why weather forecasts are presented with probabilities rather than certainties.

Calculate how much of your tax dollars go to each federal program based on your income, filing status, and number of children

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

Legendary architect Frank Lloyd Wright designed the SC Johnson headquarters in Wisconsin, aiming to make a cathedral-like workplace

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

Most of the observable universe's volume consists of voids and supervoids—enormous regions of space with little to no galaxies, stars, or light.

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.

The Beatles' US label rejected the band's first two singles, 'Please Please Me' and 'From Me to You,' with one executive calling the band 'dead in the water.'

Studies suggest when you sleep is as important as how much you get, and syncing with your circadian rhythms may lead to less fatigue and improved long-term health outcomes

Lesser-known phobias include turophobia, or the fear of cheese, and nomophobia, the fear of being without your cell phone.

See a 3D reconstruction of Tenochtitlan, the Aztec capital that was home to an estimated population of 200,000 to 400,000.

Trace how the Bill of Rights, inspired by centuries of political theory, took shape between 1774 and 1789.

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

Browse a detailed visual analysis of over 200,000 similes—comparisons that often use 'like' or 'as'—from popular fiction to see how frequently writers the same idiomatic expressions.

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.

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