A piece of medieval wisdom

10 medieval inventions that changed the Western world

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The idea that the Middle Ages were a time of ignorance and technological stagnation is widespread, but nothing could be further from the truth, especially considering that the medieval period lasted nearly 10 centuries.

Although the first few centuries of the medieval period were marked by chaos due to the collapse of the Western Roman Empire and the birth of new nations, many technological advances during the Middle Ages contributed to shaping the modern world.

Mechanical Clock

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Humanity has been trying to measure time since the beginning of history. Ancient civilizations developed several types of clocks—some more accurate than others—such as sundials, hourglasses, and water clocks.

Fully mechanical clocks appeared in the 13th century, usually installed in church towers, and were equipped with bells to announce the passing of hours. More advanced versions also featured hands to display the time.

Three-Field Crop Rotation

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Growing the same crop repeatedly on the same plot of land leads to the soil losing nutrients and becoming unproductive. Farmers were aware of this and had been using crop rotation in a two-field system since antiquity: they would sow half of the land and leave the other half to rest. The following year, the roles would be reversed, ensuring the soil remained fertile.

In the 8th century, medieval farmers started dividing the land into three parts: one was planted with winter crops (sown in the fall), another with spring crops such as legumes, and the third was left to rest. This new method not only increased the harvest, but the greater diversity of crops improved overall nutrition due to the greater diversity of food.

Eyeglasses

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There are records of visual aids used in ancient Rome and Greece, often made from precious stones like emeralds, and Arabic sources describe the use of magnifying glasses. However, the first pair of eyeglasses was developed in Italy in the mid-13th century. These early glasses had convex lenses, meaning they were only useful for farsighted individuals. Glasses with concave lenses, suitable for nearsightedness, would not be developed until the 15th century.

Universities

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The existence of prestigious learning centers in antiquity is well documented, but universities as we know them are a medieval development. In the chaos of the early Middle Ages, Christian monasteries preserved and transmitted classical knowledge, becoming centers of education and research.

The University of Bologna, founded in 1088, is considered the first institution to be academically independent and to award higher education degrees to both clergy and laypeople.

Grindstone Machine

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While humans had already been using grindstones to sharpen knives and weapons for centuries, they used a static stone, which required a significant effort for the person doing the sharpening.

The earliest known record of a rotating grindstone machine operated by a lever dates to the 8th century. By the 14th century, a pedal-and-crank mechanism had been incorporated, allowing for better control of the speed and making the sharpening process much easier.

Magnetic Compass

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Ancient mariners and travelers used the stars and other natural landmarks to determine their geographic position, but this method depended on good weather and clear skies. By the 13th century, some records describe sailors using a magnetized needle floating in water to point north.

The modern, round compass is often attributed to the Italian sailor Flavio Gioia in the early 14th century. He is said to have combined the floating needle with a wind rose and encased it in a box, making it portable, reliable, and easy to use.

Movable Type Press

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Many people believe Gutenberg to be the inventor of the printing press, but woodblock printing dates back to ancient China, and the screw press had already been introduced by the Romans in the 1st century. By Gutenberg’s time, paper presses were widely used in Europe, but what was groundbreaking were the changes he introduced to the printing process.

Gutenberg modified the basic paper press to mechanize it and ensure even pressure across the paper surface. He also developed a system of movable type, which allowed the press to reproduce any text at a higher speed. He is also credited with the development of an oil-based ink, more suitable for paper printing than the traditional water-based ink.

Central Heating

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The ancient Greeks and Romans developed central heating systems that relied on hot air traveling through pipes, but these systems disappeared after the fall of the Roman Empire. During the medieval period, Christian monks living in the Alps developed a new system that used underfloor channels to carry heat from a furnace. By the 13th century, monasteries in Spain started using water to carry heat, in the same way that some of the modern heating systems do.

Chimneys

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Although the Romans had created industrial chimneys for their bakeries, true domestic chimneys and fireplaces were developed in the Middle Ages to allow people to cook indoors and heat their homes safely. These early chimneys were wider than modern chimneys to allow more heat to remain in the room, and had a cap to cover the chimney top in case of downdrafts. Though it’s worth noting that domestic chimneys became more common around the 12th–13th centuries in Europe.

Greek Fire

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Fire has long been used as a weapon during wars, especially to burn down fortresses and ships. However, fire can be easily countered with water or other fire-retardant materials.

In the 7th century, during the Muslim sieges of Constantinople, the Byzantines reportedly used an incendiary weapon developed by an architect named Callinicus. This formula produced a substance that could burn even on water, helping the Byzantines repel the enemy navy. Greek fire is considered a precursor to modern incendiary weapons, influencing the development of devices like the hand grenade.

12 times science messed up—and created something incredible

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Innovation often comes from the most unexpected places. Some of the world’s greatest discoveries and inventions were not the result of a planned experiment but rather accidents, mishaps, or just serendipity. From the creation of irreplaceable household items to revolutionary medical breakthroughs, these chance discoveries changed history. Here are 12 remarkable things invented or discovered purely by accident.

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In 1928, Alexander Fleming discovered penicillin when he accidentally left a petri dish of Staphylococcus bacteria uncovered. A spore of mold landed on it, killing the surrounding bacteria.

Intrigued, Fleming continued experimenting with the mold, leading to the development of antibiotics that have saved millions of lives and continue to combat infections today.

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In 1895, Wilhelm Röntgen discovered X-rays while experimenting with cathode rays in a dark lab. He noticed that a nearby fluorescent screen began to glow even though it wasn’t directly in the path of the rays.

This accidental finding led to the development of X-ray technology. Röntgen's discovery opened the door for modern diagnostic imaging and is still widely used in hospitals worldwide.

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In 1945, engineer Percy Spencer accidentally discovered microwaves' cooking potential when a chocolate bar in his pocket melted while he was working on radar technology.

He then experimented with popcorn kernels, further realizing the power of microwaves for cooking. This serendipitous discovery led to the microwave oven, which became a staple of modern kitchens.

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Charles Goodyear stumbled upon vulcanized rubber in 1839 when he accidentally dropped a mixture of rubber and sulfur onto a hot stove. The heat caused the rubber to harden and become more durable, which led to the invention of vulcanized rubber.

Vulcanization makes rubber stronger and more elastic, and the process is still used today in products ranging from tires to waterproof clothing.

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In 1826, chemist John Walker accidentally invented the first friction match when he scraped a chemical-coated stick on his hearth and saw it ignite. He had been experimenting with creating a new type of explosive but instead stumbled upon a practical way to create fire.

Walker’s matches were the first to be struck on any rough surface, paving the way for modern safety matches.

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In 1968, 3M scientist Spencer Silver was trying to create a super-strong adhesive but instead developed a weak one that could easily be removed.

Years later, his colleague Art Fry applied this adhesive to paper and created the now-iconic Post-it Note. Who could have guessed that a bad adhesive could become so popular?

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In 1938, chemist Roy Plunkett was researching refrigerants when he accidentally discovered Teflon. While he was trying to make a new refrigerant, the gas he was working with turned into a solid, creating a slippery substance that was non-reactive and heat-resistant.

Teflon’s unique properties made it perfect for non-stick cookware. It also found uses in industries ranging from aerospace to electronics, making it a critical material in modern technology.

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In 1903, French chemist Édouard Bénédictus discovered safety glass by accident. After dropping a glass flask coated with plastic, he noticed that it cracked but didn't shatter.

This led to the invention of laminated safety glass, which is now standard in car windows and other safety applications, and has saved countless lives by preventing dangerous shards from flying during an impact.

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In 1942, Dr. Harry Coover accidentally invented Super Glue while attempting to create a clear plastic for gun sights. He discovered that the substance he had created was incredibly sticky, but too sticky for its intended purpose. The compound, called cyanoacrylate, was shelved for being too impractical at the time.

However, when the remarkable adhesive properties of the substance were later re-examined, it was commercialized under the now-ubiquitous name "Super Glue" and quickly became a household staple for all kinds of quick fixes.

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In 1907, Leo Baekeland discovered the first synthetic plastic while trying to create a synthetic substitute for natural rubber. His accidental combination of phenol and formaldehyde led to a substance that was heat-resistant and very durable.

In fact, Bakelite marked the beginning of the plastic age. It revolutionized manufacturing worldwide, allowing the creation of everything from household items to electrical components.

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In 1956, engineer Wilson Greatbatch accidentally invented the pacemaker while attempting to build a heart rhythm recording device. By installing the wrong resistor, he unknowingly created a device capable of regulating heartbeats.

Who would have thought that a simple circuit mix-up would lead to such a revolutionary medical breakthrough?

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In 1879, chemist Constantin Fahlberg accidentally discovered saccharin while working with coal tar derivatives. He forgot to wash his hands and later noticed a sweet taste on his fingers.

Curious, he traced the unusual taste back to his experiment and recognized the potential of the new substance. Saccharin went on to become the first artificial sweetener, still widely used today in diet sodas and sugar substitutes.