20 Experiments That Changed Everything

Penicillin – Alexander Fleming (1928)

It’s hard to believe that one of the world’s greatest medical breakthroughs was discovered because of a messy laboratory. In 1928, Alexander Fleming noticed a moldy Petri dish where colonies of bacteria had been wiped out by a stray fungus. That fungus turned out to be Penicillium notatum, and Fleming’s curious eye led to the birth of penicillin. This “accident” changed the course of medicine, making once-lethal infections treatable. During World War II, penicillin saved countless lives on the battlefield and in hospitals. According to the World Health Organization, antibiotics like penicillin have slashed mortality rates from bacterial diseases by more than half. What began as a simple oversight became a revolution in healthcare, touching billions of lives.

Post-it Notes – 3M (1974)

The iconic yellow sticky note almost never existed. In 1974, 3M scientist Spencer Silver was actually trying to invent a super-strong glue but ended up with a weak adhesive that could be peeled off easily. At first, it seemed useless—a failed experiment. But when colleague Arthur Fry used the adhesive to anchor his bookmarks in a church hymnal, the magic of Post-it Notes was born. Today, more than 50 billion Post-it Notes are sold each year, proving how a “mistake” can turn into a worldwide office staple. Their convenience and simplicity have changed the way people organize, brainstorm, and communicate at work and at home.

The Microwave Oven – Percy Spencer (1945)

Imagine discovering a kitchen revolution thanks to a melted chocolate bar. In 1945, while experimenting with radar technology, Percy Spencer noticed the chocolate in his pocket was melting unexpectedly. This led him to investigate the power of microwaves to heat food. The result was the world’s first microwave oven, sold commercially starting in 1947. Today, over 90% of homes in the United States have a microwave. The device has transformed cooking—making it faster, easier, and more accessible for millions. What started as a curious lab mishap is now a cornerstone of modern convenience.

The Big Bang Theory – Arno Penzias & Robert Wilson (1964)

Sometimes, the universe talks to you through static. In 1964, Arno Penzias and Robert Wilson were simply trying to clear up “noise” from their radio antenna at Bell Labs. What they found instead was the afterglow of the Big Bang—cosmic background radiation, a faint whisper from the universe’s birth. Their unplanned discovery provided the missing evidence for the Big Bang Theory. This evidence fundamentally changed how humanity understands the universe’s origins. Years later, their work earned them the Nobel Prize in Physics, and their “noise” became one of cosmology’s greatest discoveries.

CRISPR Gene Editing – Jennifer Doudna & Emmanuelle Charpentier

What started as research into a bacterial defense system snowballed into a revolution in genetic engineering. Jennifer Doudna and Emmanuelle Charpentier’s work on CRISPR-Cas9 allowed scientists to make precise edits to DNA, opening doors once thought sealed. Now, CRISPR is being used to study diseases, improve crops, and even explore potential cures for genetic disorders. The technology has led to heated debates about ethics and the limits of science, but its impact is undeniable. Since its debut, thousands of research papers have explored CRISPR’s potential, and it’s already reshaping medicine, agriculture, and biology.

The Internet – ARPANET (1969)

Linking a few computers together for military research didn’t seem world-changing at the time. Yet, ARPANET’s first successful message in 1969 marked the birth of the Internet. What began as a modest experiment soon exploded into a global communication network. Today, more than 4.9 billion people—over half the world’s population—are online. The Internet has transformed everything from business to education, entertainment to activism. It’s hard to imagine modern life without it, and all because of a small-scale experiment with humble beginnings.

Velcro – George de Mestral (1941)

One day in 1941, Swiss engineer George de Mestral came home from a walk with his dog and noticed how burrs stuck stubbornly to its fur. Driven by curiosity, he examined them under a microscope and realized their hook-like structure. Inspired, he invented Velcro, the now-ubiquitous hook-and-loop fastener. Velcro is used everywhere—from shoes and clothing to NASA space suits. The global market for Velcro is now valued at over $500 million. What started as an everyday annoyance became a simple invention that quietly holds the world together.

Coca-Cola – John Pemberton (1886)

John Pemberton wasn’t trying to launch the world’s most famous soft drink—he was concocting a medicinal tonic to soothe headaches. But when he mixed up his syrup with carbonated water in 1886, the result was an instant hit. Coca-Cola quickly spread across America and then around the globe. Today, Coca-Cola is enjoyed in over 200 countries, with more than 1.9 billion servings consumed every day. Its secret formula and clever marketing have turned it into a symbol recognized everywhere, all from a failed attempt at patent medicine.

The Pacemaker – Wilson Greatbatch (1956)

Sometimes, the wrong part makes everything right. In 1956, Wilson Greatbatch accidentally inserted the wrong resistor into a heart rhythm recording device, creating electrical pulses similar to a human heartbeat. This mistake led to the invention of the implantable pacemaker, a device that has since saved millions of lives. Modern pacemakers are highly sophisticated, offering remote monitoring and personalized adjustments. According to the American Heart Association, roughly 1 million pacemakers are implanted each year, making it one of the most important accidental inventions in medical history.

Teflon – Roy Plunkett (1938)

Roy Plunkett was trying to create a new refrigerant in 1938 when he discovered a slippery white powder with remarkable properties. That substance was polytetrafluoroethylene, better known as Teflon. Teflon’s non-stick qualities revolutionized cookware and countless other industries. Today, the non-stick cookware market alone is worth more than $2 billion. Teflon’s uses go far beyond the kitchen—appearing in everything from electronics to aerospace, all thanks to a failed experiment.

X-rays – Wilhelm Röntgen (1895)

Wilhelm Röntgen’s curiosity about cathode rays led him to a stunning discovery in 1895: X-rays. He noticed that invisible rays could pass through flesh but not bone, revealing the inner workings of the human body without surgery. X-rays have since become a cornerstone of modern medicine, making it possible to diagnose everything from broken bones to lung infections. Today, millions of X-ray exams are performed each year, and Röntgen’s accidental finding continues to save lives.

LSD – Albert Hofmann (1943)

In 1943, chemist Albert Hofmann was searching for a circulatory stimulant when he first synthesized lysergic acid diethylamide, or LSD. After accidentally absorbing a small amount through his skin, Hofmann experienced vivid hallucinations. LSD quickly became a subject of scientific intrigue and cultural fascination, influencing psychology, neuroscience, and the counterculture of the 1960s. Current research is once again exploring its therapeutic potential for mental health conditions like depression and PTSD, showing how a lab accident can ripple through science and society for generations.

Super Glue – Harry Coover (1942)

Harry Coover stumbled upon cyanoacrylate, the main ingredient in Super Glue, while searching for materials to make clear plastic gun sights during World War II. Initially, the adhesive was deemed too sticky for practical use. Years later, its incredible bonding power found a place in homes, hospitals, and factories. Super Glue is now a staple for quick fixes and even medical emergencies, helping to close wounds in some surgeries. Its story proves that being “too sticky” can sometimes be the perfect solution.

Popsicles – Frank Epperson (1905)

Frank Epperson was just 11 years old when he left a glass of sugary soda and a stirring stick outside on a cold night in 1905. By morning, he had invented the first Popsicle. The frozen treat quickly became a summertime favorite, and Popsicles are now enjoyed worldwide in countless flavors. The frozen dessert industry continues to grow, with the global market expected to reach $10 billion by 2025. Sometimes, childhood curiosity leads to sweet success.

Synthetic Dye (Mauveine) – William Perkin (1856)

William Perkin’s search for a malaria cure in 1856 didn’t go as planned, but his “failure” led to the invention of the world’s first synthetic dye—mauveine. This vibrant purple hue changed the textile industry forever, making colored fabrics affordable and accessible. Today, the synthetic dye market is worth more than $20 billion, and the ripple effects of Perkin’s discovery are still felt in fashion, food, and beyond.

Graphene – Andre Geim & Konstantin Novoselov (2004)

Andre Geim and Konstantin Novoselov weren’t planning to change materials science forever when they used scotch tape to peel off layers of graphite. Yet, in 2004, they isolated graphene—a single layer of carbon atoms with astonishing strength and conductivity. Graphene is now considered a “wonder material,” with potential applications in electronics, energy, and even medicine. The global graphene market is projected to reach $1 billion by 2025, with research accelerating every year.

Play-Doh – Joe McVicker

Joe McVicker’s family business was struggling to sell wallpaper cleaner when teachers discovered that kids loved molding it. In the 1950s, Play-Doh was reborn as a modeling compound for children. With its bright colors and soft texture, Play-Doh became an instant hit in classrooms and homes. Today, Play-Doh is a multi-million dollar brand, sparking creativity and play for generations. Its humble beginnings show how a product’s purpose can change with a little imagination.

Viagra – Pfizer (1998)

Pfizer scientists were testing a new drug for angina when they noticed an unusual side effect—patients reported improved erectile function. Realizing the potential, the company shifted focus, and Viagra was born in 1998. The little blue pill became a cultural phenomenon and changed the conversation about sexual health. By 2025, the erectile dysfunction treatment market is expected to reach $4 billion. Viagra’s unexpected journey shows that even failed experiments can lead to life-changing results.

YouTube – Jawed Karim, Steve Chen, Chad Hurley (2005)

When YouTube’s founders launched their site in 2005, they imagined it as a dating platform where people would upload video profiles. That idea didn’t take off, but users quickly started sharing all kinds of videos instead. YouTube evolved into the world’s largest video-sharing platform, with over 2 billion monthly users today. It has transformed media, entertainment, and even politics, giving anyone with a camera and a story a global stage.

The Slinky – Richard James (1943)

Richard James was working on springs for naval equipment in 1943 when he accidentally knocked one off a shelf. To his amazement, the spring “walked” down instead of falling. This simple moment inspired the creation of the Slinky, a toy that has fascinated children and adults for generations. More than 300 million Slinkys have been sold worldwide, proving that sometimes, all it takes is a little curiosity—and a bit of luck—to make something magical.