Penicillin was discovered by accident

Penicillin’s pioneers were awarded the Nobel Prize in 1945

Alexander Fleming, Howard Florey, and Ernst Chain received the 1945 Nobel Prize in Physiology or Medicine for discovering and developing penicillin.

Penicillin’s discoverer predicted antibiotic resistance

Alexander Fleming’s discovery of penicillin revolutionized modern medicine. But the same man who pioneered the development of antibiotics also recognized that bacteria could make sntibiotics obsolete if they were used irresponsibly. This story sheds light on Fleming’s discovery—and on his prophetic warning about antibiotic resistance.

Penicillin is considered one of history’s greatest medical breakthroughs

Experts widely rank penicillin’s discovery among the most important advances in medicine. It launched the antibiotic era, transformed once-deadly infections into treatable illnesses.

Penicillin was hailed as a 'wonder drug' upon its release

When penicillin became widely available in the 1940s, newspapers and doctors alike celebrated it as a “wonder drug” that could cure infections once considered fatal.

Oxford scientists turned Fleming’s mold discovery into medicine

In 1939, a team at Oxford—including Howard Florey, Ernst Chain, and Norman Heatley—revived Fleming’s forgotten discovery. Using makeshift equipment like bedpans and milk churns, they purified enough penicillin to prove it could treat deadly infections.

A moldy cantaloupe supercharged penicillin production

In 1943, a moldy cantaloupe found at a market in Peoria, Illinois, yielded a strain that produced six times more penicillin. Though often credited to lab worker “Moldy Mary” Hunt, accounts differ on who actually brought in the fruit.

It took 14 years to deploy penicillin after its discovery

Despite its promise, US production of penicillin remained minimal in 1942—enough to treat fewer than 100 patients nationwide. Within two years, output expanded into millions of doses to supply troops for D-Day.

The 'Penicillin Girls' made mass production possible

In Oxford during the early 1940s, six female technicians—later dubbed the “Penicillin Girls”—worked long hours tending mold cultures and extracting tiny amounts of penicillin.

The same mold behind penicillin also flavors blue cheese

There are over 300 species of Penicillium. The mold that produces the lifesaving antibiotic is a close relative to those used to make blue cheeses like Roquefort and Stilton and to flavor some types of ham.

Penicillin works by attacking the cell walls of bacteria

Penicillin targets bacteria at their weakest point—their cell walls. By blocking wall-building, it leaves microbes unable to survive, causing them to burst and die.

Most penicillin allergy diagnoses are wrong

A Freakonomics Radio episode investigates why so many people mistakenly believe they’re allergic to penicillin. This widespread misdiagnosis leads to costlier, less effective treatments and contributes to the growing problem of antibiotic resistance.

The pharmaceutical industry evolved, in part, from the discovery of synthetic dyes

In 1856, a chemist accidentally discovered mauveine, the world’s first synthetic dye, while trying to make quinine to treat malaria. The synthetic dyes that followed helped reveal germs under microscopes, paving the way for modern imaging techniques and breakthrough treatments, such as antibiotics.

Women's wartime suit features silk dyed with CRISPR-modified bacteria

Anna Dumitriu's bioart piece was created to commemorate the 75th anniversary of the first use of penicillin in a human patient and intends to raise awareness about the rapid development of antibiotic-resistant pathogens by using bacteria that have essentially been transformed into their pre-antibiotic era state.

LSD was discovered accidentally after its inventor touched his face and hallucinated

Unlike many drugs, the first time a human ever tripped on acid was recorded first-hand by a scientist. Swiss chemist Albert Hofmann, curious about the "not unpleasant intoxicated-like condition" that overcame him after an accidental exposure, set up a rigorous experiment to test the drug's effects on himself.

The cholera bacteria was first isolated in 1854—but the discovery was largely ignored

The pathogen was isolated by the Italian physician Filippo Pacini in Florence, Italy, though his discovery was largely ignored in favor of the popular miasma—bad air—theory of disease at the time. The pathogen was separately isolated about three decades later by German microbiologist Robert Koch.

Before discovering cells, life was believed to emerge suddenly from inorganic matter

Popularized by Aristotle in the 4th century BCE, spontaneous generation was used to explain phenomena like mice appearing in seemingly sealed grain storage. The invention of the compound microscope in the late 16th century led to the identification of cells as the basic unit of life, but it was not until 1855 that their origin from preexisting cells was established.

Research on bacterial cultures used in yogurt production led to CRISPR's discovery

Scientists learned it was a microbial immune system that could be repurposed to protect dairy cultures from viruses. Today, nearly all yogurt is made with CRISPRized bacteria, as are genetically modified crops like herbicide-resistant corn, wheat, and soy.

Peptide research dates back to the late 1800s

Peptide science dates back to the late 1800s with some early peptide synthesis work, but peptides took off in the medical sphere after surgeon Frederick Banting and his colleague's isolation of insulin from dog pancreases in 1921.

Lyme disease-causing bacteria predate any suspected biological weapons testing

Borrelia bacteria existed long before any US biological weapons program—or human presence in North America. One study comparing genomes of the bacteria behind Lyme disease collected samples of the bacteria over three decades and calculated that the bacterium has been in North America longer than humans, at least 60,000 years. Other work found related bacteria preserved in amber from millions of years ago.

Aspartame was a surprise discovery from a lab working on gastric ulcers

As with saccharin and cyclamate, the aspartame discovery arose from its discoverer tasting something sweet from his workplace. In 1965, American chemist James Schlatter licked a white powder off his finger as he picked up a piece of paper and was startled to discover it tasted sweet. He applied for a patent for the substance, and received it in 1970. It is now one of the most popular artificial sweeteners. (Some users may experience a paywall.)

The unexpected origin story of the snow globe

In 1900, a Vienna tradesman named Erwin Perzy I was attempting to invent an inexpensive way to improve light amplification in hospital operating rooms. After experimenting with a glass globe filled with water, the idea for the snow globe struck. Industrious as well as inventive, Perzy eventually turned his idea into a successful business. Read the full article to learn how the invention grew to become recognized globally.

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.

Pierre Curie found electricity could be generated by compressing certain crystals

Jacques and Pierre Curie discovered the piezoelectric effect in 1880. Pierre incorporated it into an apparatus used by Marie Curie to discover polonium and radium. This phenomenon is seen in barbecue lighter ignition mechanisms, where quartz is struck to create a spark that ignites fuel.

Pigeons were thought to be the cause of what would be evidence of the Big Bang

In 1964, Arno Penzias and Robert Wilson accidentally detected the CMB while trying to eliminate persistent static from their radio antenna. The pair initially blamed the signal on pigeon droppings inside their antenna—cleaning it didn’t help, but it did win them a Nobel Prize.

Leprosy bacteria are sometimes grown on mouse feet for research

The main leprosy-causing bacterium can't be grown in a petri dish, so the disease is challenging to study in the lab. For research purposes, it has been grown in the foot pads of mice.

Learn more about the history of fireworks, which dates back to an accidental invention during an alchemist's quest for information about immortality.

The terms 'bug' and 'debugging' were popularized by Grace Hopper's team

Engineers working on the Mark II computer at Harvard University identified a moth in one of its components in 1947, which caused it to malfunction. Describing the incident as the "first actual case of bug being found," the term first used by Thomas Edison in 1878 to describe faults in an apparatus caught on.

When a Paris department store hesitated to sell Estée Lauder's perfume, she 'accidentally' broke a bottle, causing the smell to spread throughout the store and shoppers to start asking to buy the scent.

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.

Elk Cloner, the first computer virus to spread in public, was written as a practical joke by Richard Skrenta, a Pittsburgh high school student.

Budweiser stores yeast derived from the original 1800s strain in a secret bunker, which only the Head of Yeast Management can access—not even the CEO

The first line of 'immortal' human cells, which can divide indefinitely and are used in scientific research, was nonconsensually taken from a Black woman.

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.

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.

The name 'Silicon Valley' arose from the founding of Shockley Semiconductor Laboratory in Fairchild Semiconductor in 1956-57, founded near Stanford University in Palo Alto

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.

Read a deep dive on the 'all-purpose healing' peptide BPC-157.

Volcanic activity may have triggered the Black Death by spewing gases that led to crop failures in Europe, thus forcing the import of grain ships with plague-infested fleas.

The concept of phantom limbs, the perception that amputated limbs are still present, dates back to a French military surgeon in the 16th century.

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.

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

See the evolution of Ebola vaccine and treatment development.

Clever Hans was a 1900s horse that was believed to be able to solve math equations, tell time, and read and comprehend German, until a psychology student discovered how he got his answers.

The Ramones' 'Pet Sematary,' the theme song for the Stephen King novel of the same name, was written while the band was admiring the writer's collection of horror memorabilia.

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.

Explore the archaeological treasures of Pompeii, the city buried under volcanic ash when Mount Vesuvius erupted in 79 CE.

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.

Some Pokémon have been named after real and fictional organisms, while some real-world species have been named after Pokémon, such as Chilicola charizard and Binburrum zapdos.

In 1939, baseball star Lou Gehrig delivered his inspirational 'Luckiest Man' speech after retiring due to the health condition that now bears his name.

For centuries, it was common to sleep in two shifts: a few hours at the beginning of the night, and a longer period beginning around midnight