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13 of the best conspiracy theories

Here, a real image of Buzz Aldrin saluting the U.S. flag on the surface of the moon.
(Image credit: NASA)

Conspiracy. Just saying the word in conversation can make people politely edge away, looking for someone who won't corner them with wild theories about how Elvis, John F. Kennedy and Bigfoot are cryogenically frozen in an underground bunker.

Yet conspiracies do exist. In the corporate world, major companies we buy products from everyday have been found guilty of conspiring to fix prices and reduce competition. Just about any planned criminal act committed by more than one person could be considered a conspiracy, from simple murder-for-hire to the Watergate break-in.

Many conspiracy theorists go much further, though, and they see a hidden hand behind the world's major events. The top conspiracy theories are often very difficult to dislodge: Some may contain grains of truth or feed an emotional need for believers. And hardcore believers are adept at rationalizing away evidence that contradicts their beliefs. Eyewitnesses who dispute the conclusions of even the biggest conspiracy theories are mistaken — or part of the conspiracy.

The truth, however, is out there … 

The 9/11 Conspiracies

An aerial view of the NYC Custom house and surrounding area after the 9/11 terrorist attacks. (Image credit: HUM Images/Universal Images Group via Getty Images)

The evidence is overwhelming that the terrorist attacks of Sept. 11, 2001, were indeed the result of a conspiracy: a conspiracy of Osama bin Laden and a crew of mostly Saudi hijackers. 

This is too simple for some, though. Conspiracy theorists have a variety of much more complex explanations for what happened at the World Trade Center and Pentagon that day, often involving insider knowledge by President George Bush, Vice President Dick Cheney and top Bush advisors. 

Some famous conspiracy theories rely on anti-Semetic tropes, such as the attacks being orchestrated by Israel. Many claim that because "jet fuel can't melt steel beams," the Twin Towers must have been brought down by controlled demolition from bombs planted before the planes hit. (A 2006 NOVA documentary debunked these claims. It is, in fact, quite possible for the columns holding up skyscrapers to fail catastrophically when exposed to fires burning on multiple floors.) 

Other claims are refuted by simple logic: If a hijacked airplane did not crash into the Pentagon, as is often claimed, then where is Flight 77 and its passengers? Are they with the Roswell aliens at Hangar 18? In many conspiracy theories, bureaucratic incompetence is often mistaken for conspiracy. Our government is so efficient, knowledgeable and capable — so the reasoning goes — that it could not possibly have botched the job so badly in detecting the plot ahead of time or responding to the attacks. 

Princess Diana's murder

(Image credit: Tim Graham Photo Library via Getty Images)

Within hours of Princess Diana's death on Aug. 31, 1997, in a Paris highway tunnel, conspiracy theories swirled. As was the case with the death of John F. Kennedy, the idea that such a beloved and high-profile figure could be killed so suddenly was a shock. This was especially true of Princess Diana: Royalty die of old age, political intrigue or eating too much rich food; they don't get killed by a common drunk driver.

Unlike many conspiracy theories, though, this one had a billionaire promoting it: Mohamed Al-Fayed, the father of Dodi Al-Fayed, who was killed along with Diana. Al-Fayed claims that the accident was in fact an assassination by British intelligence agencies, at the request of the Royal Family. Al-Fayed's claims were examined and dismissed as baseless by a 2006 inquiry; the following year, at Diana's inquest, the coroner stated that "The conspiracy theory advanced by Mohamed Al Fayed has been minutely examined and shown to be without any substance." On April 7, 2008, the coroner's jury concluded that Diana and Al-Fayed were unlawfully killed due to negligence by their drunken chauffeur and pursuing paparazzi, The New York Times reported.

Subliminal advertising

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Ever been watching a movie and suddenly get the munchies? Or sitting on your sofa watching TV and suddenly get the irresistible urge to buy a new car? If so, you may be the victim of a subliminal advertising conspiracy! Proponents of this conspiracy theory include Wilson Bryan Key (author of "Subliminal Seduction") and Vance Packard (author of "The Hidden Persuaders"), both of whom claimed that subliminal (subconscious) messages in advertising were rampant and damaging. Though the books caused a public outcry and led to FCC hearings, much of both books have since been discredited, and several key "studies" of the effects of subliminal advertising were revealed to have been faked.

In the 1980s, concern over subliminal messages spread to bands such as Styx and Judas Priest, with the latter band even being sued in 1990 for allegedly causing a teen's suicide with subliminal messages (the case was dismissed). Subliminal mental processing does exist, and can be tested. But just because a person perceives something (a message or advertisement, for example) subconsciously means very little by itself. There is no inherent benefit of subliminal advertising over regular advertising, any more than there would be in seeing a flash of a commercial instead of the full twenty seconds. Getting a person to see something for a split-second is easy; filmmakers do it all the time (watch the last few frames in Hitchcock's classic "Psycho"). Getting a person to buy or do something based on that split-second is another matter entirely. 

Moon landing hoax

Here, a real image of Buzz Aldrin saluting the U.S. flag on the surface of the moon. (Image credit: NASA)

NASA landed astronauts on the moon in 1969. By the 1970s, a bizarre conspiracy emerged — that the moon landing never happened. 

The conspiracy was described in a 1976 self-published book, "We Never Went to the Moon: America's Thirty Billion Dollar Swindle," and a 1978 movie, "Capricorn One." Even as late as 2001, there was a Fox documentary, "Conspiracy Theory: Did We Land on the Moon?" that gave air time to the claims that the whole Apollo moon-landing program was faked. 

There are plenty of debunkings of the various moon hoax claims, and then there's the issue of the hundreds of pounds of moon rocks that have been studied around the world and verified as being of extraterrestrial origin. How did NASA get the rocks if not during a moon landing? Why would scientists from around the globe willingly participate in the American space agency's hoax? 

Many astronauts have been offended by the implication that they faked their accomplishments. In 2002, when conspiracy theorist Bart Sibrel confronted Buzz Aldrin and called him a "coward and a liar" for faking the moon landings, the then 72-year-old punched Sibrel in the jaw.

Paul McCartney's death

Paul McCartney, who is very much alive, performs onstage during the 36th Annual Rock & Roll Hall Of Fame Induction Ceremony on Oct. 30, 2021 in Cleveland, Ohio. (Image credit: Kevin Mazur/Getty Images for The Rock and Roll Hall of Fame)

Paul McCartney is not dead. Until mid-2019, he was still touring, in fact, and he probably still would be if the coronavirus pandemic hadn't canceled his gigs. He gives interviews, he has a website, he occasionally appears in the tabloids. 

Pretty good for a guy that some conspiracy theorists think died in 1966. 

The "Paul is dead" conspiracy goes something like this: On Nov. 9, 1966, Paul McCartney got into an argument with the other Beatles, stormed out of the studio and was promptly decapitated in a car accident. To cover the whole thing up, the band hired a look-alike (and sound-alike). 

After going through all this trouble, though, the band then took great pains to drop clues in their album covers and lyrics to hint to the public that something was amiss. For example, on the cover of the Abbey Road album, all four Beatles are photographed striding across a zebra crossing, but only McCartney is barefoot and out of step with the other three. This must mean something, right? Despite public denials by the band (and many, many public appearances by McCartney), fans couldn't just let it be, and came together to look for more clues.

John F. Kennedy's assassination

President John Kennedy rides in a motorcade from the Dallas airport into the city with his wife Jacqueline and Texas Governor John Connally. (Image credit: Bettmann / Getty Images)

John F. Kennedy was shot in 1963 in a Dallas motorcade. But did Lee Harvey Oswald act alone? Or was there a second gunman on the grassy knoll? 

These questions are the gateway to a vast arena of conspiracy theories that have spawned endless speculation and hundreds of books, articles and films. It didn't help that Lee Harvey Oswald was murdered in the basement of Dallas Police Headquarters while surrounded by police officers only two days after the assassination — and by a guy with ties to the Mob. The whole thing stunk, people figured. 

Plenty of shadowy culprits have been suggested as the masterminds of the Kennedy assassination: Fidel Castro's government, or maybe anti-Castro activists, or organized crime, or the CIA, or Vice President Lyndon Johnson, or … Well, the thing about presidents is, it turns out, they have a lot of enemies. The Warren Commission report, produced by the official investigation into Kennedy's death, found no evidence of overarching conspiracies, though plenty of theories still flourish. 

Roswell crash & cover-up

The Roswell Daily Record from July 9, 1947, details the Roswell UFO incident. (Image credit: Roswell Daily Record)

There is one fact that almost all skeptics and believers agree on: Something crashed on a remote ranch outside of Roswell, New Mexico in 1947. The government at first claimed it was some sort of saucer, then retracted the statement and claimed it was really a weather balloon. Yet the best evidence suggests that it was neither a flying saucer nor a weather balloon, but instead a high-altitude, top-secret military balloon dubbed Project Mogul.

As it turns out, descriptions of the wreckage first reported by the original eyewitnesses very closely match photos of the Project Mogul balloons, down to the silvery finish and strange symbols on its side. The stories about crashed alien bodies did not surface until decades later and in fact no one considered the Roswell crash as anything extraterrestrial or unusual until thirty years later, when a book on the topic was published. There was indeed a cover-up, but it did not hide a crashed saucer. Instead, it hid a Cold War-era spying program.

Protocols of the Elders of Zion

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"The Protocols of the Learned Elders of Zion" is a hoaxed antisemitic book that purported to reveal a Jewish conspiracy to achieve world domination. It first appeared in Russia in 1905, and described how Christians' morality, finances, and health would be targeted by a small group of powerful Jews. The antisemitic idea that there is a Jewish conspiracy is nothing new, of course, and has been repeated by many prominent people including Henry Ford and Mel Gibson. In 1920, Henry Ford paid to have half a million copies of "The Protocols of the Elders of Zion" published, and in the 1930s, the book was used by the Nazis as justification for its genocide against Jews (in fact, Adolf Hitler referred to the "Protocols" in his book "Mein Kampf").

Though the book has been completely discredited as a hoax and forgery, it is still in print and remains widely circulated around the world.

The Satanic panic

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For years during the 1980s and 1990s, America became convinced that an underground network of Satanists was working together to kidnap, torture and abuse children. None of it was real, but the conspiracy theories destroyed lives and livelihoods. 

The pinnacle was Geraldo Rivera's infamous NBC special "Devil Worship: Exposing Satan's Underground," which aired on Oct. 28, 1988. Rivera relied on self-proclaimed "Satanism experts," misleading and inaccurate statistics, crimes with only tenuous links to Satanism, and sensationalized media reports. It was the most-viewed documentary in television history. "There are over one million Satanists in this country," Rivera said, adding that "The odds are, [they] are in your town." 

The panic grew out of the idea that memories of abuse were often repressed and could be recovered with the help of hypnosis and a therapist. This idea was popularized in the 1980 book "Michelle Remembers," co-written by a Canadian psychiatrist and the patient he eventually married (ethics red flag), in which the eponymous Michelle recovers memories of supposed ritual Satanic abuse conducted by her mother. 

In 1983, the panic exploded with the McMartin preschool trial, in which a California parent accused daycare owners of sexually abusing her son. Police then sent a letter to parents warning that their children may have been abused, urging the parents to ask what turned out to be leading questions to a bunch of suggestible preschoolers. Further questioning by authorities continued in this vein, yielding alleged eyewitness accounts by children of networks of secret tunnels and witches flying through the air. 

After seven years, the daycare owners were eventually acquitted or had the charges dismissed. One was jailed for five years while awaiting trials and retrials. In the meantime, similar accusations spread through daycares around the country. Most were spurred on by now-discredited methods of questioning small children, methods that often led to children making sensational accusations because they wanted to please the authority figures questioning them. 

In a 1992 report on ritual crime, FBI agent Kenneth Lanning concluded that the rampant rumors around ritual Satanism were unfounded. Phillips Stevens, Jr., associate professor of anthropology at the State University of New York at Buffalo, said that the widespread allegations of crimes by Satanists "constitute the greatest hoax perpetrated upon the American people in the twentieth century."

Chemtrails

(Image credit: Nicolas Economou/NurPhoto via Getty Images)

As airplanes travel, they leave behind them long water condensation trails called contrails. These cloud-like tracks dissipate quickly. 

But to some conspiracy theorists, these condensation trails are much more nefarious. The "Chemtrails" conspiracy theory holds that condensation trails are full of other chemicals that scientists and governments are seeding into the atmosphere. Why? Pick your reason. It might be biological warfare or population control or geoengineering or an attempt to manipulate the weather. 

Researchers who study things like clouds' impact on global temperatures are often harassed by Chemtrails believers, who think they're part of a large-scale conspiracy to secretly spray unknown chemicals into the atmosphere, according to Harvard University's David Keith. A 2016 study even debunked chemtrails scientifically, finding no evidence of unusual contrails or unexplained contamination in the environment. But true believers aren't swayed, as The Guardian reported in 2017.

Barack Obama birtherism

Phil Wolf, owner of a used car dealership, paid $2,500 to have this “birther” billboard painted, shown here on Nov. 21, 2009 in Wheat Ridge, Colorado. (Image credit: John Moore/Getty Images)

Some conspiracies, like chemtrails, percolate in the background of certain communities, never really penetrating the larger public. Others have big impacts. The Barack Obama birtherism conspiracy is one of the latter. 

Barack Obama, the 44th president of the United States, was born in 1961 in Honolulu, Hawaii. But as soon as Obama began his campaign for president in 2008, "birthers" began to circulate the conspiracy theory that Obama had actually been born in Kenya, the country of his father. They argued that this meant Obama was not "a natural-born citizen of the U.S." — even though his mother was an American citizen — and thus he could not be president.

Nevermind that there were announcements of Obama's birth in the Honolulu newspaper, or that friends of Obama's mother remembered the day she went into labor. To combat the conspiracies, Obama not only had to release a copy of his birth certificate in 2008, he had to follow up with a release of the original "long form" document in 2011, contrary to the hospital's usual policy of issuing computer copies of birth certificates as acceptable identification. 

The 2011 release reduced the number of Americans who believed in birtherism, according to Gallup polling. But many conservative political activists and pundits raised their profiles by advocating for birtherism. Among them? Donald Trump, who was at the time the soon-to-be-president. 

COVID and 5G

Anti-lockdown conspiracy theorists and coronavirus deniers protest in Trafalgar Square in London against the government and mainstream media who, they say, are behind disinformation and untruths about the COVID-19 pandemic, on Aug. 29, 2020. (Image credit: Richard Baker / In Pictures via Getty Images)

Probably no event since 9/11 has spawned more conspiratorial thinking than the COVID-19 pandemic. There are conspiracies about the origin of the virus as well as basically every government's reactions. Many people even believe doctors are lying about COVID-related deaths, blaming the virus for deaths with other causes. A distrust of "Big Pharma," fomented for years by "alternative medicine" advocates like Kevin Trudeau (bestselling author of "Natural Cures They Don't Want You To Know About" — a textbook conspiratorial title if there ever was one), have also fed into conspiracies about medical treatment and vaccination. 

One of the odder conspiracies mixes long-standing fears of 5G wireless technology with fears about the virus. According to the COVID 5G conspiracy, electromagnetic frequencies from cell phone towers undermine the immune system, making people sick with COVID, researchers reported in 2020 in the journal Media International Australia. Another conspiracy theory claims that the COVID-19 vaccines contain tracking chips that connect to 5G networks so that the government, or possibly billionaire and vaccine philanthropist Bill Gates, can surveille everyone's movements. 

As CNBC points out, 5G chips are too large to fit through a vaccine syringe, and even the smallest RFID chips that could fit require a power source that couldn't make the squeeze. 

Birds aren't real

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When is a conspiracy not a conspiracy? When it's an elaborate piece of performance art. 

Or… does that make it even more of a conspiracy theory? 

The Birds Aren't Real conspiracy is a movement developed by Peter McIndoe, 23, who started spreading the idea in 2017. Until a December 2021 interview in the New York Times, McIndoe stayed in-character as a true believer, insisting in media interviews and online that birds aren't real, but rather they are surveillance drones made by the U.S. government. Birds Aren't Real has a staff; it has organized real-life protests; it bought real-life billboards; and it emblazoned vans with their claim. The goal, says McIndoe, is to parody the misinformation that Gen Z finds itself stewing in.

"Birds Aren't Real is not a shallow satire of conspiracies from the outside. It is from the deep inside," he told The New York Times. "A lot of people in our generation feel the lunacy in all this, and Birds Aren't Real has been a way for people to process that."

The experiment revealed that conspiracies sometimes grow by credulity: Local media sometimes reported on Birds Aren't Real as if it was something young people really believed rather than an elaborate joke. Birds Aren't Real organizers hope the joke will become a force for good by exposing all the ways misinformation thrives. 

"Yes, we have been intentionally spreading misinformation for the past four years, but it's with a purpose," McIndoe said. "It's about holding up a mirror to America in the internet age."

Originally published on Live Science.

Benjamin Radford
Benjamin Radford
Benjamin Radford is the Bad Science columnist for Live Science. He covers pseudoscience, psychology, urban legends and the science behind "unexplained" or mysterious phenomenon. Ben has a master's degree in education and a bachelor's degree in psychology. He is deputy editor of Skeptical Inquirer science magazine and has written, edited or contributed to more than 20 books, including "Scientific Paranormal Investigation: How to Solve Unexplained Mysteries," "Tracking the Chupacabra: The Vampire Beast in Fact, Fiction, and Folklore" and “Investigating Ghosts: The Scientific Search for Spirits,” out in fall 2017. His website is www.BenjaminRadford.com.