It's often said that there's a fine line between genius and madness, and history makes it clear how difficult it is for most people to tell the difference. It's easy to take certain ideas like handwashing, and the shape of the Solar System for granted after widespread understanding of them has taken hold for hundreds of years.
But both of these concepts were considered revolutionary and even ridiculous ideas at first. And it's only because the brilliant minds behind them and so many other ideas didn't give up in the face of intense scrutiny that they're common knowledge today.
Ignaz Semmelweis: Washing Hands
Although Ignaz Semmelweis's defining discovery seems so obvious now, it was revolutionary and alienating enough to the scientific community of the mid-19th century that it ruined his life.
According to NPR, he discovered that doctors could prevent the spread of fatal diseases by washing their hands with a chlorine solution between conducting autopsies and dealing with other patients. While his discovery showed promising results in his lifetime, it wasn't appreciated until after his death because doctors didn't like hearing that they were giving patients diseases.
Ernest Hemingway: The FBI Is Watching
Although Ernest Hemingway's prowess as a writer was undeniable even during his lifetime, The Guardian reported that friends like A.E. Hotchner became concerned about his mental health when he said the FBI was watching him in 1960. As Hemingway said at the time, "They've bugged everything. That's why we're using Duke's car. Mine's bugged. Everything's bugged. Can't use the phone. Mail intercepted."
However, those friends would discover he was right when a Freedom of Information request revealed the FBI's extensive file on him during the 1980s. The bureau was apparently suspicious of Hemingway's years of ties with Cuba.
Edwin Armstrong: A Static-Free Radio
As PBS reported, Edwin Armstrong's quest to eliminate radio static led him to develop a circuit that made FM radio possible. But since the radio industry didn't want to create new infrastructure to replace the existing AM band, RCA shelved his invention after he unveiled it in 1933.
Although patent lawsuits with RCA and battles with regulators the company had in its pocket destroyed Armstrong's life, his work would set a new standard for radio broadcasting after his 1954 death.
Edgar Allen Poe: His Dark Stories
Although Edgar Allen Poe has long been widely recognized as a Gothic pioneer of evocative horror stories, his reception during his life and shortly after his death was far more polarized.
Because while Benjamin Fisher's book Poe In His Own Time contains fawning accounts lauding Poe as a genius, others malign not only his work but his character. Artist John Frankenstein was particularly hostile and accused Poe of alcoholism, while Rufus Griswold vilified Poe twice after his death.
Subrahmanyan Chandrasekhar: The OG Black Hole
As The Guardian reported, scientists once believed that the only way a star could die was by becoming a white dwarf once it ran out of energy. But at the age of 19, Subrahmanyan Chandrasekhar challenged this theory and used Einstein's special theory of relativity to conclude that they could collapse into tiny points of infinite density if the star were large enough.
This concept is now recognized as a black hole, but it was ignored in the early 1930s and would inspire a bitter rivalry with Chandrasekhar's mentor Sir Arthur Stanley Eddington, that lasted over a decade. Finally, Chandrasekhar's discovery earned him a Nobel Prize in 1983.
Robert H. Goddard: A Rocket Can Go To The Moon
As the Smithsonian Magazine outlined, physicist Robert H. Goddard proved that rockets could work in a vacuum in 1916 and, by 1920, theorized a rocket capable of reaching the Moon. Some reports at the time claimed he had invented one, but he quickly pushed back against this sensationalism.
Still, some criticized his vision harshly, and one particularly smug response from the New York Times suggested Goddard "seems to lack the knowledge ladled out daily in high schools." Of course, Goddard would turn out to be right by 1969.
Galileo Galilei: The Earth Revolves Around The Sun
Although the idea of the Earth revolving around the Sun dates back to Ancient Greece, Galileo Galilei's work to confirm this concept is rooted in fact was considered revolutionary enough during the 17th century to cause a perilous clash with the Roman Catholic Church.
According to New Scientist, he was forced to recant his findings after facing violent threats from the Church in 1633. The Vatican wouldn't publicly admit Galileo was right until 1992.
Gregor Mendel: Inherited Traits And A New Genetic Model
Although Gregor Mendel wasn't the first to observe inherited traits from parent to child, he was the first to develop a genetic model for how those traits are inherited. It was also the first major case that saw someone incorporate statistical analysis into a biological study.
But while this was impressive in hindsight, this decision also earned him the wrath of other scientific figures when his work was discussed after his death in 1884. According to a 2003 article in Archives of Disease in Childhood: Fetal and Neonatal Edition, Mendel had been accused of falsifying data, and his work wasn't fully accepted until 1933.
Alfred Wegener: Believed Countries Once Fit Together
Although Alfred Wegener's work in meteorology was respected while he was alive, most scientists in 1912 could not get behind his assertion that the continents look like they fit together because they were once whole before drifting apart.
According to PBS, Wegener's biggest weakness in presenting the Continental Drift theory was that he didn't have a mechanism to explain how that drift happened. However, Harry Hess's seafloor spreading theory from 1960 would finally vindicate Wegener's ideas 30 years after his death.
John Yudkin: Sugar And The Heart Disease Epidemic
The Guardian reported that for a brief moment in 1957, John Yudkin's evolutionary study of why sugar was a more likely culprit for America's heart disease epidemic than saturated fats was taken seriously within the scientific community.
However, competing nutritionist Ancel Keys accused Yudkin of being factually incorrect "propaganda" for the dairy and meat industries. However, this turned out to be an ironic accusation as Keys' narrative had the weight of the sugar industry behind it. As such, it's only in fairly recent years that it's become widely understood that Yudkin was right about sugar all along.
Alice Catherine Evans: The Undulant Fever Bacteria
Undulant fever isn't a very well-known disease today, and that's largely because Alice Catherine Evans discovered the bacteria that causes it. Moreover, she revealed that the debilitating disease was so widespread because people made a habit of drinking raw, unpasteurized milk.
According to a 1999 article in The Yale Journal Of Biology And Medicine, Evans faced relentless opposition from the medical and dairy communities even after her research made her the first female president of the Society of American Bacteriologists.
Lynn Margulis: A New Way To Look At Evolution
In a 2021 article in the Biosystems journal, Antonio Lazcano and Juli Peretó outlined how seminal Lynn Margulis' studies into how interactions between life forms affect ecological systems were for the modern understanding of evolution.
Margulis was a relative newcomer by the time this work was done, and her work flew in the face of neo-Darwinists who assumed point mutations were the only source of biodiversity. But while these factors meant her peers would dismiss her work for decades, they didn't stop her from being right.
Marcello Malpighi: The Study Of How Lungs Work
According to a 2007 article in the journal of Medical History, Marcello Malpighi's work into frog lungs in the late 17th century led to the discovery of the tiny air sacs known as alveoli in the lungs of all creatures that have them.
But while Malpighi's discovery is now recognized as essential to understanding how lungs work, contemporaries such as Giovanni Girolamo Sbaraglia described his work as the "pointless excesses of anatomical investigations."
William Harvey: Identified How The Human Body Circulates Blood
After a series of experiments ending in 1628, William Harvey first correctly identified how the human body circulates blood. According to Nature, however, his published work was considered ridiculous by the medical community at the time.
And his critics didn't come to this conclusion by trying to recreate his experiments but rather because they noticed how much it contradicted what Galen had to say on the matter in the 2nd Century. The conventional thinking at the time was that anything that contradicted ancient teachings couldn't be true.
Heinrich Schliemann: The Lost City Of Troy
According to the Smithsonian Magazine, Heinrich Schliemann's amateur approach to archaeology and his destructive excavation methods made it hard to take him seriously when he claimed to discover the lost city of Troy. Nonetheless, the magazine confirmed that he had indeed come across the right location.
Still, this is a case where his contemporary critics in 1873 had a point because his rushed excavation nearly destroyed the lost city's ruins. As Kenneth Harl once joked, "Schliemann accomplished what the Greeks could not, finally leveling the walls of Troy."
William B. Coley: Immunotherapy
As a 2006 article in the Iowa Orthopaedic Journal explained, William B. Coley is regarded as the father of immunotherapy after he found that injecting a cancer patient with solutions derived from streptococcal bacteria shrank a person's tumors.
Although similar principles guided the creation of radiation therapy and chemotherapy, Coley's medical contemporaries widely criticized his methods for being risky and seemingly unsound. However, research since Coley's death has confirmed his theory that some cancers are vulnerable to enhanced immune systems.
Francis Peyton Rous: Viruses In Relation To Cancer
While working at New York City's Rockefeller Institute in 1911, Francis Peyton Rous discovered that a virus in a chicken was responsible for that chicken's cancerous tumor. Moreover, he found both those dramatic effects were as transmissible to others as the virus itself.
His findings were dismissed without attempts to replicate his experiments for years because cancers were understood not to work this way. However, the scientific community eventually came around to his discovery that certain cancers can be transmitted through viruses, and he was awarded a Nobel Prize in 1966.
Barry Marshall: The Discovery Of Helicobacter pylori
According to Discover Magazine, Australian doctor Barry Marshall discovered that a bacteria called Helicobacter pylori was not only responsible for stomach ulcers but stomach cancers. Unfortunately, the medical community dismissed his findings, as other doctors assumed ulcers were caused by stress.
Since he wasn't allowed to use human subjects to confirm his discovery, Marshall tested his theory on himself and drank a broth infected with Helicobacter pylori. Once he found the right conditions for an ulcer in his stomach, he proved his point and eventually became a Nobel Laureate in 2005.
Joseph Lister: Cleaning Surgical Tools
Before Joseph Lister's assertions in an 1867 Lancet article that surgical infections were caused by germs, doctors intended to assume bad air was the culprit. This made his antiseptic surgery techniques a world-changing concept, but not one that the world was initially ready to accept.
According to a 2012 article in The Canadian Journal Of Surgery, other doctors viciously opposed his findings because germs weren't visible in the day's microscopes. However, the results were self-evident once various European countries slowly started adopting his practices.
Jonas Salk: The Creation Of Vaccinations
Although he is now regarded as a national hero for developing the vaccine responsible for eradicating polio in the United States, Jonas Salk had to fight both his fellow scientists and the media for this recognition.
In the early '50s, more senior scientists rejected his idea of using "deactivated" viruses in vaccines and suggested only live ones would work. As USA Today reported, the hysteria around Salk was so great before he proved this assertion wrong that famed newscaster Walter Winchel warned the public away from his "killer" vaccine.
Aristarchus of Samos: Planets Revolve Around The Sun
Aristarchus of Samos was the first known person in the world to propose a heliocentric model of the Solar System that sees all its planets revolve around the Sun.
As this model is mostly lost to history, one of the only sources for its existence is his scientific contemporary Archimedes, who Forbes described as not believing it himself. If it's any consolation to Galileo, Archimedes's contemporaries found the truth just as hard to believe as his powerful critics did.
Clair Cameron Patterson: The Dangers Of Lead
After a string of mysterious deaths that were quickly preceded by erratic behavior, Clair Cameron Patterson went to extreme lengths to establish an ultra-clean lab to determine how likely lead contamination was to be a factor.
And as MentalFloss outlined, what he discovered was that the automotive and energy industry's widespread use of leaded gasoline was all but poisoning the world and causing these deaths. However, biologists dismissed him as he was normally a geologist, and the industries he was attacking used their academic connections to try and silence him. Nonetheless, his work would eventually influence the passage of the Clean Air Act of 1970.
Mary Anning: The Idea Of Extinction
As The Guardian reported, Mary Anning discovered an impressive collection of prehistoric fossils in the early 19th Century, including a monstrous sea creature belonging to the Ichthyosaurus genus. And her expertise on the dinosaur fossils she uncovered would make her an important person to consult for scientists at the time.
However, those who listened to her didn't credit her when they published papers, and those who didn't listen criticized her for gathering evidence supporting the idea of extinction. This was a controversial concept at the time because of the implication that God had imperfect creations. Even when her findings were discussed, she wasn't permitted to participate in those discussions because she was a woman.
Amedeo Avogadro: The Science Behind Gas
In a 1981 article in the History of Science Journal, John Hedley Brooke explained that Amedeo Avogadro described all gases of equal volume, temperature, and pressure as containing the same number of molecules. Although this practically goes without saying nowadays, it was a deeply controversial assertion during the early 19th Century.
That was partially because it was difficult to verify at the time but also because it clashed with John Dalton's atomic models, which were more widely accepted. As such, what is now an obvious fact went ignored for about 50 years.
Boris Belousov: Non-Linear Chemical Reactions
According to a 2009 article in the Journal of Biosciences, Boris Belousov changed chemistry forever by observing non-linear chemical reactions that changed over time without any further external stimulus.
Although the famous Belousov-Zhabotinsky reaction is considered one of the most important discoveries of the 20th century now, Soviet journals at the time rejected Belousov's papers on it. Moreover, the greater scientific community rejected the concept until well into the 1950s.
Giordano Bruno: The Earth Is Not the Center Of The Universe
It could take all day to discuss Giordano Bruno's iconoclastic philosophies during the Renaissance, but it's particularly worth noting that he went further than the heliocentric model of the Solar System.
Because while he noted that the Earth revolved around the Sun, he did not agree that it was the center of the universe nor that such a place necessarily exists. This is well in line with modern understandings of the universe, but the Stanford Encyclopedia of Philosophy explained that it was considered so heretical at the time that the Roman Catholic Church had Bruno executed in 1600.
John Snow: Cholera Spread Through Water
According to a 2014 article in the Journal of Epidemiology, cholera was largely understood to be an airborne disease by the time John Snow published an essay titled On the Mode of Communication of Cholera in 1855.
While Snow wasn't the first to argue that cholera could spread through water, Snow went further by positing that it was, first and foremost, a waterborne disease. A renowned expert named Edmund A. Parkes had famously argued against Snow's methodology, but Snow would turn out to be right.
Rick Rescorla: Vulnerable Infrastructure
Rick Rescorla was a British-American veteran who served as Morgan Stanley Dean Witter & Co.'s vice president for corporate security at the World Trade Center in New York City.
According to the Coronado Eagle and Journal, he expressed concerns that the basement of the World Trade Center was vulnerable to attacks before the 1993 explosion and believed further attackers would return with aircraft later. Sadly, he was right.
Harry Markopolos: Bernie Madoff's Ponzi Scheme
About a decade before Bernie Madoff pled guilty to running one of the worst Ponzi schemes in history, Harry Markopolos had already figured out what he was doing. According to NPR, it was obvious that Madoff's investment strategy couldn't be real after Markopolos's bosses asked him to replicate it because Madoff kept luring their clients away.
However, the SEC consistently ignored his reports due to rigid whistleblower guidelines, a lack of understanding regarding what Markopolos had found, Madoff's inflated reputation, and rivalries between the SEC's Boston and New York offices. As such, Madoff got away with his crimes for years longer than he otherwise could have.
Roger Boisjoly: Nature Vs. Shuttle
Prior to the Challenger disaster of 1986, late rocket engineer Roger Boisjoly warned NASA and their contractor Morton Thiokol that the weather on the day of the launch was too cold to launch the shuttle safely. The reason was that the materials used to seal the rocket's joints were known to stiffen and come undone when they became too cold.
Nonetheless, neither organization he talked to wanted to delay the launch, and as a result, everyone on board lost their lives. As Boisjoly said shortly before his passing, "I fought like Hell to stop that launch. I'm so torn up inside I can hardly talk about it, even now."