The theory of chemtrails originated from misinterpreting a US Air Force paper

Chemtrails are formed from condensing water vapor and soot from jet fuel

Conspiracy theories about the phenomenon—also known as contrails—began circulating in the 1990s, but have gained significant traction on social media platforms. Chemtrails are more common in high-humidity conditions, where they persist and form cirrus clouds.

The origin of atmospheric science while testing nuclear weapons during the Cold War

The arms race between the US and the Soviet Union saw both countries stockpiling and detonating hundreds of bombs underground, underwater, and in the atmosphere. To better predict where nuclear fallout would travel after these tests, scientists developed models that would serve as a foundation for those used to explain atmospheric circulation.

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.

'Birds Aren't Real' parodies the way memes traffic conspiracy theories

Peter McIndoe claims the US government killed 12 billion birds only to replace them with drones. These statements have powered protests—and McIndoe's fictional campaign that highlights how conspiracies and their theorists are treated.

The history of germ theory, which explains that illnesses are caused by microorganisms

For centuries, the miasma theory, which held that illnesses were caused by clouds of "bad air" produced by decaying organic matter, was the accepted explanation for the spread of disease. The development of microscopes and the subsequent technology to isolate bacteria and test disease spread in mice greatly contributed to contagionists overturning miasmatists.

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

Airborne microplastics may influence cloud formation and climate

Microplastics are increasingly found in the atmosphere and may affect the climate by reflecting or absorbing sunlight based on their pigmentation. Like mineral dust, they may become cloud seeders and alter regional precipitation patterns as they become more abundant.

Project STORMFURY explored modifying hurricanes with silver iodide

Between 1962 and 1983, researchers at the National Oceanic and Atmospheric Administration investigated whether weakening and controlling hurricanes was possible. The investigation showed very few hurricanes met the criteria for modification, despite successfully weakening two storms.

The 1978 prediction of the Kessler syndrome popularized the risks of space trash

A paper published by NASA scientists Don Kessler and Burton Cour-Palais described a scenario where the density of objects in orbit becomes so high that collisions between them create a cascading effect of runaway debris, preventing future space travel. The risks were confirmed from returned telescope parts showing debris impacts.

Stratospheric balloons: a visual guide

In late January 2023, a Chinese high-altitude balloon, believed to be for surveillance purposes, traversed the US and caused a diplomatic stir. The technology itself is established—though typically used for atmospheric measurements. This visual...

An LSD scientist's role in a US mind control project

Within a decade of LSD's discovery, the US government had launched a secret initiative involving hypnosis and hallucinogens. LSD researcher Louis Jolyon West conducted experiments for the CIA's MKUltra project, which focused on the potential of mind control. He later took part in a criminal trial that hinged on testimony whose sourcing was seemingly inspired by MKUltra experiments. This article explores light shed by West's personal archive.

Why helium helped preserve the US' founding documents, but was later replaced

In 1951, the Charters of Freedom were stored in glass and metal cases filled with helium, which would not chemically react with the documents. After microscopic cracks were identified in the glass through which helium could leak out of and—experts feared—pollutants could infiltrate, new encasements made of aluminum, titanium, and argon replaced the old system in 2003.

Scientists have diverted the path of lightning using lasers

A proof of concept for a laser protection system, which could be used to protect launchpads and airports in the future, was conducted on the Säntis mountain in northeastern Switzerland. Rapid laser pulses heated air molecules, creating a more conductive, 50-meter (164-foot) path for the electrical discharge to travel through.

How sunlight helps chlorofluorocarbons destroy the ozone molecules that block solar radiation

CFCs, which are used in old refrigerants, air conditioners, and aerosol sprays, do not react with atmospheric molecules. Once they reach the stratosphere, ultraviolet radiation breaks chlorine atoms off of them, which can each break apart more than 100,000 ozone molecules, thinning Earth's protective layer against ultraviolet radiation.

Is Agent Orange still causing birth defects?

Though the dangerous nature of the chemical is clear, its impact across generations is less so. How far down the bloodline does Agent Orange travel, and what does it leave in its wake, if anything? This Scientific American article examines why there’s debate about Agent Orange’s legacy.

People have long suspected that aliens and UFOs can be found at Area 51

Area 51 is a highly classified US military facility located in Nevada. Because of its remote location and secrecy, many Americans have speculated that the location hosts aliens. However, critics of this theory believe the UFO sightings are actually just military aircraft.

Particle detection has evolved from cloud and bubble chambers to digital 3D displays

As invisible particles passed through cloud and bubble chambers, they disrupted supersaturated vapor and superheated liquid, respectively, creating trails that served as proxies for cosmic rays. The transition from photographed events to digital sensors enhanced data collection and accuracy.

Tornado chasers include scientists conducting field projects

Research teams use drones, mobile weather stations, and radar systems to capture real-time meteorological data, better understand conditions that favor tornado formation, and improve forecasting models. As of 2022, model limitations result in roughly 70% of tornado warnings being false alarms.

Scientists still don't know why DEET is such an effective bug repellent

This chemical, used to keep ticks, fleas, mosquitoes, and other nuisance bugs away, is used by an estimated one-third of the US population and has been available to consumers since 1957. Researchers theorize that multiple mechanisms may be at work to deter bugs, including perhaps masking or confusing bugs' olfactory receptors.

Rachel Carson didn't argue for wholly organic farming

Her 1962 book, “Silent Spring,” inspired many people to consider the chemicals used to grow their food, but Carson didn’t think that manufactured fertilizers needed to be banned from farming, writing that “The ultimate answer is to use less toxic chemicals so that the public hazard from their misuse is greatly reduced.” When she testified to Congress in 1963, she said, “I think chemicals do have a place.”

The 'butterfly effect' is the informal name for chaos theory

In mathematics, chaos theory involves complex systems that are highly sensitive to their initial conditions. Originally discovered when analyzing weather data, slight variations in the data input into such systems create drastically different results, despite following known physical laws.

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.

The discovery of antimatter came from addressing a prediction of negative energy

Combining the mathematics of quantum mechanics and special relativity, Paul Dirac came up with an equation that suggested a matter particle, such as an electron, could exist in four quantum states—two of which possessed negative energy. The solution came from realizing that the states referred to positive-energy antiparticles, whose charge is the opposite of that of their normal-matter equivalent.

An investigation suggests a Scottish island became awash in forever chemicals via seafoam and seaspray—raising questions about what that means for the safety of other coastal areas.

'Last Week Tonight' explores the risks of forever chemicals (warning: language)

Per- and polyfluoroalkyl substances (PFAS) are a group of man-made chemicals used in a wide range of products due to their unique properties. However, because they can persist in the body and environment for thousands of years, they’ve earned the moniker “forever chemicals”—and have been linked with numerous health risks.

Experimental hantavirus vaccines and therapies, still under development, have long been funded by the US military.

According to Bill Nye, science is under threat from an erosion in critical thinking

He states that conducting research online cannot replace consulting with scientific experts who have spent their entire lives intimately studying a field. The former science education show host argues that deepening cynicism towards scientific institutions has been fueled by leaders embracing debunked and unsupported claims.

The Clean Air Act became the cornerstone of modern air pollution control

Passed in 1970 and strengthened through multiple amendments, the Clean Air Act authorizes the EPA to set national air quality standards, regulate industrial and vehicle emissions, and reduce pollutants such as ozone, sulfur dioxide, and lead.

Wilbur published key papers, gave speeches in the burgeoning aviation community

Much of the theoretical work is credited to Wilbur, whose scientific mind observed birds and early pioneers to discover the key problem to solve was control. This 1901 speech surveys the recent work in the field and showcases what the brothers worked on two years before their breakthrough flight.

All rainbows are 'raincircles' caused by water droplets separating white sunlight into a spectrum of colors, but Earth's surface blocks the bottom half of the circle from our line of sight.

US intelligence allegedly pursued more than 600 schemes to assassinate Cuban revolutionary Fidel Castro.

Shooting stars, or meteors, are fragments of asteroids and comets that burn up as they enter Earth's atmosphere, creating streaks in the sky called meteor showers.

A 2019 Facebook event called on attendees to "Storm Area 51, They Can't Stop All of Us," resulting in countless memes, the creation of a music festival, and eventually the arrests of those who did try to approach the area.

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 boiling temperature of water decreases with increasing elevation because the molecules need less energy to overcome the lower atmospheric pressure associated with thinner air.

See how fireworks are made and learn how metals like magnesium and copper are responsible for different colors.

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.

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.

View the ten deadliest tornadoes in US history.

During the French Revolution, a botanist's letter asking about "dear Rhus" (poison ivy) was intercepted, leading authorities to suspect he was conspiring with the Russians.

Astronauts have repaired genetic damage in space using CRISPR—a molecular tool that can make precise changes to DNA and is used in single-celled organisms to attack invasive viruses.

The original copy of the Declaration of Independence is not a pristine document, and even features a smudged anonymous handprint in the bottom left corner.

In 2009, the nation was gripped by the story of a missing young boy who was believed to be floating over Colorado in a homemade balloon, until it was revealed that he was at home the whole time.

While atoms are normally made of protons, neutrons, and electrons, exotic ones have been built with antimatter—alternate versions of normal matter that live for fractions of a second and are about a billion times as rare.

'Saturday Night Fever,' the 1977 film that introduced disco to the mainstream, was based on a fabricated magazine story.

Fear or disgust related to clusters of holes and cracks, called trypophobia, may stem from evolutionary processes to help us avoid pathogens.

The American cockroach is actually from Africa, an apparent hitchhiker aboard ships carrying enslaved people, with evidence suggesting the bug may have arrived in the New World as early as the 1600s.

The first horror movie is believed to be George Méliès' 1986 short 'The Haunted Castle,' which pioneered the use of special effects

The most expensive ad of all time was for Chanel No. 5 perfume and cost roughly $33M to produce in 2004—about $57M in today's dollars.