Chernobyl pushed the world to create rapid-alert systems for nuclear accidents

Watch an American news report of the Chernobyl disaster

Americans first heard about the Chernobyl nuclear disaster two days after the event, once abnormal radiation was detected in nearby countries. This forced Soviet officials to acknowledge the catastrophe publicly for the first time a few days after it occurred.

The Chernobyl disaster released more radioactive material than the Hiroshima bomb

A reactor explosion during a safety test resulted in a series of evacuations and resettlements that displaced over 300,000 people and left areas uninhabitable for up to 20,000 years. The Soviet government initially tried to hide the disaster, but rising radiation levels were identified by detectors in Sweden.

Limited transparency soon after Chernobyl made it a source of conspiracy theories

Some rumors about the event became perceived as more reliable than the Soviet mass media, which had omitted key information during the early days of uncertainty. The resulting theories included CIA involvement in the disaster, three-headed birds, aliens, and a weaponized earthquake.

View a timeline of the Chernobyl disaster

The 1986 Chernobyl meltdown, caused by a combination of poor safety design and human error, is the worst nuclear accident in history. At least three dozen people died in the direct aftermath, and experts believe thousands suffered premature cancer deaths from radiation exposure.

The Chernobyl disaster prompted a sharp decline in public confidence in nuclear power

A Gallup poll from two months after the disaster showed 73% of respondents opposed building a nuclear plant near their homes—up from 45% in 1976. Chernobyl and other nuclear accidents remain in the public consciousness today in debates about nuclear power.

An imbalance in nuclear reactivity factors caused Chernobyl's reactor to explode

The initial explosion resulted from excessive steam pressure that had built up in a runaway manner due to design flaws and violations of safety protocols. Once exposed to atmospheric oxygen, the hot graphite in the control rods underwent a combustion reaction, resulting in a secondary explosion.

Exposure to ionizing radiation from nuclear accidents can damage DNA

The damage can increase the risks of cancer, cataracts, heart disease, and other illnesses based on exposure times and intensities. Contaminated food, water, air, or soil from near nuclear accidents can further prolong one's exposure.

View a list of the worst nuclear meltdowns before 2013

Nuclear meltdowns occur when a reactor overheats and radioactive materials leach into the surrounding environment. While rare, the reasons for each occurrence—as detailed in this piece—can help establish new safety protocols for future reactors.

The threat of nuclear annihilation reshaped global diplomacy

The first use of atomic weapons introduced the possibility of a war with no survivors. This article examines how nuclear fear shaped Cold War diplomacy and continues to influence international relations today.

More than 500,000 people worked to contain Chernobyl's fallout

The group—collectively referred to as "liquidators"—included firefighters, military troops, miners, engineers and sanitation crews. Beyond clearing radioactive debris and performing decontamination work, they confined radioactive material to prevent its spread into groundwater.

Ukraine once had the third-largest nuclear arsenal—and gave them all up by 1996

After the rapid collapse of the Soviet Union, Ukraine was left with over 1,700 nuclear warheads positioned throughout its territory. A massive global effort ensued, led by the United States, to return these and other nuclear weapons in former Soviet allied states to Russia.

Discovering how the dinosaurs went extinct may have helped avert nuclear war

This NPR Throughline episode explains how the 1980 discovery that an asteroid-driven dust cloud killed the dinosaurs inspired Cold War scientists’ fears of “nuclear winter”—a sunlight-blocking aftermath of nuclear war that may have discouraged leaders from launching one.

The first nuclear reactor was built three years after nuclear fission was discovered

After learning that large atomic nuclei release energy upon being split apart, scientists quickly researched how to control the reaction to make electricity. Fusion—combining small atomic nuclei—generates massive energy in stars and hydrogen bombs.

A primer on the president's nuclear football

During the Cold War, the United States and the USSR were forced to prepare for a nuclear strike at a moment's notice, leading to a new innovation: the so-called "football" (known as the chemodanchik in Russia), a bag containing nuclear strike plans, authentication codes, and likely a communication device, which attended the country's leader wherever they went. This easy-to-read piece breaks down the history and lore around the high-stakes quirk in nuclear governance.

A history of raising the alarm, from rattles to 911

Because fires spread so quickly, communities around the world have deployed many tactics to raise the alarm to get help. This history from the Museum of Natural History dives into the use of rattles, bells, and brigades to gather help to fight fires, showing just how far we've come since 911 was introduced in 1968.

NUKEMAP lets you model the effects of a nuclear detonation anywhere on Earth

The tool was built by Alex Wellerstein, a historian of nuclear technology at the Stevens Institute of Technology in New Jersey. NUKEMAP uses declassified weapons data to calculate blast radius, thermal radiation, fallout patterns, and estimated casualties for any nuclear device dropped on any city. More than 50 million people have used it since its 2012 launch.

The alliance operates under a "flexible response" doctrine—that is, proportionality

NATO countries' main deterrent against aggression is their ability to respond with nuclear weapons. This video from "The Infographics Show" outlines the purpose of this nuclear arsenal, NATO’s strategy to prevent attacks, and its plans in the event of escalation toward nuclear war.

The failed Bay of Pigs invasion led to the Cuban Missile Crisis, which brought the world to the brink of nuclear annihilation

Moscow's decision to deploy nuclear missiles in Cuba—just 90 miles from the US—pushed the world to the brink of nuclear war. To prevent future crises, both sides later set up a direct hotline and boosted arms-control diplomacy

Some scientists propose AI-powered satellites to monitor nuclear weapons in place of arms control treaties

With the New START treaty expired, researchers at the Federation of American Scientists have proposed using satellites and AI to remotely verify nuclear arsenals—replacing the onsite inspections that once built trust between the US and Russia during the Cold War.

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.

How search and rescue teams remove survivors from rubble

At any time, large-scale seismic activity can devastate entire regions, often with little warning. Emergency responders, then, are perpetually on call. This is particularly critical in areas with poor infrastructure.

The environmental crises of the late 1960s led to the founding of the EPA

Disasters such as the Cuyahoga River fire and the Santa Barbara oil spill prompted Congress and President Nixon to establish the Environmental Protection Agency in December 1970, with the goal of unifying federal efforts to control pollution.

Earthquake early warning systems do not predict earthquakes

Systems like ShakeAlert® use a network of hundreds of ground sensors to detect earthquakes moments after they begin. Since seismic waves travel about 5 km/s, individuals may be notified of earthquakes before they feel the seismic activity has reached them.

The Challenger disaster led NASA to create an independent safety office

In response to the Challenger accident, NASA established the Office of Safety, Reliability, and Quality Assurance—now known as the Office of Safety and Mission Assurance—to strengthen oversight, elevate safety concerns, and mitigate managerial pressure on technical decisions.

In 1984, Operation Smash Hit intentionally crashed a 239-ton train into a nuclear waste canister at 100 miles per hour to prove the canister's safety, which remained completely intact and lost just 0.29 of its 100 pounds of pressure.

The failures of the interwar period made the case for a new international system

After World War I, countries devalued their currencies, raised tariffs to block imports, and seized territory unchecked, with the international community unable to organize effectively to stop them. The result was a global depression and, eventually, another world war.

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.

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

Discover the catastrophic consequences of a failure of the US electrical grid—something that is more likely than many Americans think.

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

The 2026 Ebola outbreak is hampered by a lack of vaccine against the species of the virus, heightening the need for rapid tests to aid in disease control.

Fireworks-related ER visits are on the rise—in 2024, they increased by 52% as compared to the prior year.

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

At the beginning of the 20th century, a group of young men ate standard American food—replete with food additives like borax and formaldehyde—as part of government research to better understand food safety.

Power lines are dotted with large, brightly colored balls to improve the visibility of these thin wires to helicopters and small planes and help prevent potential crashes.

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

The deadliest aspect of volcanic eruptions is often not lava, but pyroclastic flows—avalanches of ash, gas, and rock that can move more than half the speed of sound.

The US first hosted the World Cup in 1994, a tournament that lives in soccer infamy for its poor planning and the murder of Colombian player Andres Escobar, who'd accidentally scored on his own net.

Long before Major League Baseball began allowing instant replay for balls and strikes, an umpire reluctantly used the technology to determine whether a hit was a home run, a move that inadvertently ushered in a new era for the sport.

Abraham Lincoln was almost assassinated weeks before his inauguration as he traveled from Illinois to DC through Baltimore in 1861; it took two independent claims for Lincoln to be convinced the threat was real

The first image of a black hole was captured by creating an Earth-sized virtual observatory from a network of eight radio telescopes.

The United States has had a tumultuous relationship with Cuba since its 1959 revolution, highlighted by a nuclear crisis and a decades-long trade embargo.

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

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

Domino's Pizza's 30-minute delivery guarantee was responsible for the chain's 1980s surge, but it was discontinued after the company was found liable for delivery driver accidents.

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

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

The tragic Pulitzer Prize-winning image 'The Vulture and the Little Girl' (1993) generated controversy, raised concerns about ethics in photography, and eventually led to the photographer's death.

Watch contemporary footage covering the US-backed Shah of Iran fleeing the country in the face of the 1979 Iranian Revolution

American dance legend Martha Graham, sometimes called 'the Picasso of dance,' refused to perform at the 1936 Olympics in Berlin and conceived the piece 'Chronicle' in response to the experience.