The Kardashev scale measures a civilization's advancement based on energy use

Universal limit to technological development may prevent finding alien civilizations

Given the vastness of the Universe, detecting alien life may require technological progress beyond the limits of what is sociologically viable and physically possible. Although interstellar civilizations are unlikely, messaging techniques and probes may improve the odds of successful communication with other intelligent life.

Visualizing the built world compared to the natural world

In the last century, humans have covered the Earth in 1,300 metric gigatons of built material, known as technomass. That amount is more than the Earth's entire biomass at 1,100 GT, which includes all living organisms. To get a sense of the scale of this comparison, click through this striking, simple visualization showcasing the various organisms comprising biomass as well as the materials making up the technomass.

The Köppen-Geiger system divides Earth’s climate into five main categories

This classification system, developed by a German-Russian botanist and a German climatologist, results from differences in the intensity of solar radiation and rainfall in different parts of the world. Each category is further divided into multiple coded zones.

Enough sunlight hits Earth in just 90 minutes to power the planet for an entire year

Despite this, in 2023, only 5.1% of electricity in the US came from solar energy. Solar panel technology has nonetheless made significant advancements since the 19th century, largely due to NASA's efforts in the space race.

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.

Scientists quantify how far from the poles auroras will be visible using the G-scale

The Geomagnetic Storm scale indicates the expected severity of the deformation of Earth's magnetic field based on the amount of energy injected by the solar wind. Solar activity is monitored using various satellites to forecast these storms, which can also be used to anticipate damage and disruption to power systems, radio communications, and satellite navigation.

Evaluating the world’s 'smartest' cities

A ranking of "smart cities" analyzes cities by economical and technological aspects as well as quality of life, inclusiveness, and care to the environment.

The Drake equation calculates the number of exoplanets that can harbor life

Developed in 1961 as part of the Search for Extra-Terrerestrial Intelligence initiative, the formula incorporates several estimated values, including the rate of star formation in the galaxy and the fraction of stars with planets.

The Kármán line is a suggested boundary between Earth and outer space

Beyond this line, approximately 100 kilometers above Earth's surface, aerodynamic lift is insufficient to keep aircraft aloft without special propulsion systems. The United Nations has historically accepted the line as delineating the boundary of space.

Explore how far you've traveled through space while living on Earth

Using the "Cosmic Odometer," users can enter their birthday and learn how far they have moved through space due to the combined effects of Earth's rotation around its axis, the planet's orbit around the sun, the solar system's trajectory through the Milky Way, and the galaxy's motion through the universe.

After NASA's Voyager 1 captured Earth as a single pixel as it left the solar system in 1990, astronomer Carl Sagan used the image to reflect on humanity's fragility and the responsibility to protect 'the only world we've ever known.'

Thermodynamics makes building data centers in space to cool equipment impractical

Rather than cooling via interactions with flowing cold air or water, data centers in space would dissipate energy primarily by radiation, in which an object at any temperature above absolute zero emits light. This method is much less efficient at cooling and would require hyperscale data centers to have radiator panels thousands of times larger than those on the International Space Station.

See South Korea's nighttime light usage, far surpassing North Korea's

You can tell a lot about a place by looking at satellite imagery of the earth at night. Economists use such images to study poverty and inequality, especially about secretive countries where it can be difficult to get information any other way. An image from NASA’s Earth Observatory shows the difference in electrification between North and South Korea (and the lights illuminating the DMZ are visible from space).

Dark energy dominance represents the final era of the universe

As the universe expanded after the Big Bang, matter and energy diluted at different rates, with light once the most dense substance in the cosmos, followed by a period when matter was the most dense component. About five billion years ago, the density of dark energy was higher than that of both light and matter, which will continue to dilute.

Is human evolution speeding up or slowing down?

In the past 3,000 years, many populations have evolved genetic adaptations to their local environments. People in Siberia and the high arctic are uniquely adapted to survive extreme cold. The Bajau people can dive 70 meters and stay underwater for almost 15 minutes. So what are other recent changes? And will our technological innovations impact our evolution?

The speed of electricity may refer to the movement of electrons or energy

In the 18th century, various experiments, including one in which monks holding an iron wire were shocked, suggested that electricity traveled at infinite speed. Advancements in technology, recognizing that electric currents were moving electrons, and the development of the theory of electromagnetism showed that electric signals can travel at near light speed, despite electrons moving much slower.

What is galactic archaeology?

In the same way that archaeologists excavate and analyze artifacts of human civilization, galactic archaeologists observe the light in the universe to glean lessons on its age, evolution, and more. Learn about this niche area of study with this 10-minute podcast.

Bill Nye believes a World War II-level mobilization is needed to end climate change

As part of his science advocacy efforts, Nye has argued that existing technologies, including electric vehicles and renewable energy, can already significantly reduce emissions. However, switching to these technologies requires a more expansive awareness of the problem and a greater sociopolitical willingness by policymakers and the general public.

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

Dragon seismometers, Baghdad batteries, and more ancient artifacts

The ancients were behind us in many ways, but some inventions from the time have not been surpassed in the modern era in effectiveness, beauty, or cleverness. This quick list of bizarre ancient inventions includes a battery from Baghdad, a Molotov cocktail-like explosive in Greece, and more.

A magnitude 25 earthquake would release enough energy to destroy the sun

Since Richter and moment magnitude scales rank earthquake energies logarithmically, theoretical magnitude values can cover an enormous range with no upper or lower mathematical limit. A particle of dust drifting onto a table would have a magnitude of about -15.

Hear Carl Sagan reflect on the smallness of humanity

Scientists keep track of time via light absorbed by cesium and strontium atoms

These absorptions happen in cycles, where one second is defined as 9,192,631,770 cycles of cesium atom radiation. Strontium atoms can be used to make clocks that do not gain or lose a second in 15 billion years.

Governments around the world are struggling to measure loneliness

Funding for policy resources often hinges on measuring the scale of a problem and then being able to measure the effectiveness of interventions, requiring data. Yet defining and measuring loneliness at a country-scale remains challenging. Typically, the University of California Los Angeles Loneliness Scale is sometimes used worldwide or adapted to measure loneliness.

The Society of Automotive Engineers sorts self-driving technology into six levels

At level 0, a vehicle cannot intervene on its own, and the driver controls all navigation. At level 3, the car operates autonomously under limited conditions, but a human can still take control. A future level 5 vehicle drives itself and lacks a steering wheel or pedals.

Energy Star certifies efficiency to help Americans save energy and cut emissions

Launched by the EPA in 1992, the Energy Star program identifies appliances, buildings, and electronics that meet high efficiency standards. It has helped consumers save over $500B in energy costs and prevent 4 billion metric tons of greenhouse gas emissions.

As of 2024, China is the largest overall contributor to global greenhouse gas emissions

Due to its large population, the nation's per capita emissions continue to lag behind those of the US, Canada, Russia, Australia, and Saudi Arabia. The Arab country has experienced the most significant increase in per capita greenhouse gas emissions since 1990, now leading the world at 22.8 metric tons of carbon dioxide equivalent per capita.

How fusion—which releases energy when two lighter atoms combine to form a heavier atom—differs from fission

Track the location of the Voyager probes, currently between 13 and 15 billion miles away from Earth.

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

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

According to the physics of black holes, our 4D reality may be a hologram—a projection of information coded on a 2D surface on the edge of the universe.

The American Society of Civil Engineers' infrastructure report card gave the US a C in 2025, its highest grade since the project launched in 1998.

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

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.

Before humans, the Soviet Union and the United States sent animals—including apes, dogs, and cats—to space during the Space Race.

Larger animals like giraffes, elephants, and blue whales have developed a unique defense against cancer, a phenomenon known as Peto's Paradox

Stars appear to twinkle because turbulence in the motion of molecules in Earth's atmosphere causes light to bend and wiggle rapidly on its way to the surface—a phenomenon called scintillation.

SpaceX's S-1 or 'prospectus' revealed many previously unknown details about the company, including its unprofitability despite doing $18.7B in revenue in 2025, exactly how many voting shares Elon Musk will have in the company (roughly 85%), and more.

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.

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.

The word 'jazz' evolved from 'jasm,' 19th-century American slang for 'energy'

In 2026, Finland was named the world's happiest country for the ninth consecutive year based on its wealth, social safety network, and high life expectancy, among other factors.

The power and influence of the American presidency have expanded significantly over time—far beyond what the founders envisioned.

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.

The first steps to rebuilding your credit score include getting to know exactly what's on your credit report and figuring out how far you are from the '700 club,' or 'good score' range.

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

The Russia-Ukraine conflict is the largest ground war in Europe since World War II in casualties, forces mobilized, and displacement of civilians.

Use this calculator to find the dollar value of your mental load, from meal planning to coordinating after-school care for your children.

The term 'algorithm' originated from the Latinized name of al-Khwārizmī, a 9th-century mathematician whose works introduced Arabic numerals and the decimal-based numeral system to Europe and whose treatise 'Al-Jabr' gave algebra its name.