What Was the First Submarine Journey? 

  • Early French submarine
Early French submarine
Credit: Chris Hellier/ Alamy Stock Photo

Submarines have come a long way in the last century. During World War I, their effectiveness became truly apparent, with German U-boats sinking more than 5,000 Allied ships, forever changing the nature of war at sea. Since then, submarine technology has advanced greatly, and today they perform a wide variety of tasks in our seas and oceans. 

Civilian submarines engage in exploration, marine science, salvage operations, and the construction and maintenance of underwater infrastructure. In the military arena, meanwhile, submarines prowl the oceans undetected, capable in some cases of staying submerged for months at a time. Military submarines offer a range of capabilities, whether it’s reconnaissance, the covert insertion of special forces, silently attacking enemy surface ships, or — in the case of the most advanced nuclear submarines — strategic nuclear deterrence. 

The use of submarines, however, predates World War I by longer than we might imagine. For many centuries, inventors and visionaries have conceived of vessels capable of moving underwater. These early ideas, ranging from theoretical designs to actual working prototypes, represent crucial steps in maritime technology. Here, we look at three submarine journeys that represent firsts of their kind, from the ancient world to the first use of a submarine in combat. 

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Alexander the Great’s Legendary Submarine

It’s hard to say with certainty when the first submarine journey occurred, partly because of how, exactly, we define a submarine. If simply defined as a submersible craft used for warfare, it could be argued that the earliest documented case dates all the way back to Alexander the Great. According to Aristotle’s work Problemata, Alexander, or at least his divers, descended into the depths during the siege of Tyre in 332 BCE, possibly to destroy the city’s underwater defenses. Written works and paintings over the years have told legendary stories of Alexander exploring the sea in what could be described as a diving bell, bathysphere, or rudimentary submarine. But like many tales involving Alexander the Great, the story has been embellished over the centuries.

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Why Are Old Photos Sepia-Toned?

  • Family photograph, 1905
Family photograph, 1905
Credit: Fototeca Storica Nazionale/ Hulton Archive via Getty Images

Developed in the late 1820s, photography revolutionized the way history could be documented, blending art and science to create lasting visual records. Early photographs were exclusively black and white, featuring stark, contrast-heavy images that showcased the technical brilliance of the new medium. By the 1880s, however, photographs began taking on a warm, brownish tint. This distinctive aesthetic, known as sepia toning, became a hallmark of photography, particularly portraiture, around the turn of the 20th century.

Sepia-toned photography was not just an aesthetic preference, but a direct result of technological advancements aimed at improving the longevity and visual quality of photographs. As pioneers in the field experimented with ways to improve the durability of their images, sepia toning emerged as a practical and widely adopted solution. The process extended the lifespan of photographs, preventing fading and deterioration over time. As a result, sepia-toned prints dominated photography for several decades.  

Despite their brownish hues, these photographs are still considered a form of black-and-white photography. While the sepia toning process adds warmth to the monochromatic image, it doesn’t technically introduce additional colors.

Credit: Marie C Fields/ Shutterstock 

Sepia-Toning Was Used To Preserve Photos

In the early days of photography, creating an image was a complicated chemical process that required precise control over light-sensitive materials. Photographers used silver-based compounds, such as silver halides, to develop images on a variety of surfaces, including glass, metal, and paper. When exposed to light, these silver compounds would undergo a chemical reaction and form a visible image.

Despite their remarkable ability to capture detail, early photographs were highly susceptible to environmental damage. Over time, exposure to light, heat, and air caused the silver particles to oxidize, leading to fading and discoloration of the photographs.

To address this issue, photographers developed a technique known as “toning,” a process that involved treating photographic prints with chemical solutions both to enhance their color and to improve their longevity. Sepia toning, named after the ink from the cuttlefish species Sepia officinalis, became one of the most effective and widely adopted methods of toning. 

This process replaced some of the sensitive metallic silver in a print with silver sulfide, a more stable compound that was less prone to oxidation and fading. The chemical transformation not only gave the photographs their characteristic warm, brownish hue but also extended their lifespan, making it possible to preserve images for generations to come in an era when photography was an expensive and time-consuming process.

Sepia toning gained popularity in the 1880s as photographers experimented with ways to create prints that were visually appealing as well as long-lasting. In fact, sepia-toned photographs last up to 50% to 100% longer than black-and-white images. However, there was no universal formula for creating sepia-toned images, so each photographer had to develop their own chemical combination. This resulted in a variety of brown hues, ranging from light golden brown to dark reddish brown. The toning process remained in widespread use well into the 20th century, allowing countless photographs from that era to survive to the present day. 

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Where Did the QWERTY Keyboard Layout Come From?

  • 1950s typewriter keys
1950s typewriter keys
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The QWERTY keyboard layout is so common that most of us never stop to question its unusual arrangement of letters. But when we do look down at our keyboards, we might find ourselves struggling to understand the logic behind the layout: Why does the top row begin with the letters Q, W, E, R, T, Y? 

Found on nearly every computer, laptop, and smartphone worldwide (at least in countries that use a Latin-script alphabet), this seemingly random configuration of keys has an interesting history — though perhaps not the one most people have been led to believe.

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The Rise of the Typewriter

During the 19th century, inventors came up with various kinds of machines designed to type out letters. Most of these machines, however, were large and cumbersome, often resembling pianos in size and shape. In some cases, they proved highly valuable to people with visual impairments, but for general use they were inefficient, being much slower than simple handwriting.

Enter Christopher Latham Sholes, an American inventor who, in 1866, was working alongside Carlos Glidden on developing a machine for numbering book pages. Sholes was inspired to build a machine that could print words as well as numbers, and he and Glidden soon received a patent for their somewhat ungainly prototype. The contraption had a row of alphabetized keys that, when struck, swung little hammers with corresponding letters embossed in their heads. The keys, in turn, struck an inked ribbon to apply the printed letters to a sheet of paper. It was far from the perfect solution, however, so Sholes persevered. 

Five years later, in 1872, Sholes and his associates produced the first-ever practical typewriter. Rather than an alphabetized row of keys, this new typewriter featured a four-row layout with what was then a QWE.TY keyboard (with a period where the R is today). In 1873, Sholes sold the manufacturing rights to the Remington Arms Company, which further developed the machine. It was marketed as the Remington Typewriter — complete with the slightly altered QWERTY key layout. It became the first commercially successful typewriter, and in so doing made the QWERTY keyboard the industry standard. 

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How Were the Egyptian Pyramids Built?

  • Engraving of the Pyramids of Giza
Engraving of the Pyramids of Giza
Credit: World History Archive/ Alamy Stock Photo

Ancient Egypt was home to more than 100 pyramids, many of which still stand today. One of the oldest monumental pyramids in Egypt, the Step Pyramid of Djoser, was built sometime between 2667 BCE and 2648 BCE and began a period of pyramid construction lasting more than a thousand years. The most famous monuments are found at the Giza complex, home to the Great Pyramid, the Pyramid of Khafre, and the Pyramid of Menkaure, all built during the Fourth Dynasty around 2600 to 2500 BCE — the golden age of ancient Egypt.

The Egyptian pyramids stand as one of humanity’s most remarkable architectural achievements, and their incredible precision and massive scale have confounded researchers for centuries. Despite numerous theories and extensive archaeological research, the exact methods of their construction remain a subject of scholarly debate. How did ancient Egyptians erect pyramids using millions of massive blocks weighing as much as 2.5 tons each? And how, more specifically, did they move those blocks up the superstructure? 

To this day, there is no known historical or archaeological evidence that resolves the question definitively. While popular speculation often veers into fantastical explanations — yes, including aliens — serious historians and archaeologists have given much thought as to how these monumental structures might have been erected using the technological capabilities of the time. Here are three of the most likely construction theories. 

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The Herodotus Machine

The first historical account of the construction of the pyramids came from the ancient Greek historian Herodotus in the fifth century BCE. In his Histories, he wrote that the Great Pyramid took 20 years to build and demanded the labor of 100,000 people. Herodotus also wrote that after laying the stones for the base, workers “raised the remaining stones to their places by means of machines formed of short wooden planks. The first machine raised them from the ground to the top of the first step. On this there was another machine, which received the stone upon its arrival and conveyed it to the second step,” and so on. 

These “Herodotus Machines,” as they later became known, are speculated to have used a system of levers or ropes (or both) to lift blocks incrementally between levels of the pyramid. Egyptian priests told Herodotus about this system — but it’s important to note that this was a long time after the construction of the Great Pyramid, so neither the priests nor Herodotus were actual eyewitnesses to its construction. It is certainly feasible, however, that the machines he described may have been used, either by themselves or, more likely, in conjunction with other methods.

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What Did People Do Before Eyeglasses?

  • Old spectacles on a book
Old spectacles on a book
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Somewhere in the vicinity of Pisa, Italy, around 1286, an unknown craftsman fastened two glass lenses to a frame likely made of wood or bone to create the first eyeglasses.

With approximately two out of three adults in the United States today requiring some form of visual aid, it’s safe to say that invention has been well received. But even though 1286 is well before any of us first discovered the splendor of improved eyesight, it’s relatively recent in the larger picture of human existence. So how did people with subpar vision get by before there was a convenient LensCrafters to pop into?

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There’s not much historical evidence explaining how our prehistoric ancestors fared in the absence of visual aids, so we’re left to use some combination of deduction and common sense to determine how, say, a sight-impaired individual would keep up with the pack in a group of hunter-gatherers.

A person with imperfect vision could still be useful to a group simply because sharp eyesight to read signs, documents, and the like wasn’t necessary in prehistoric times. As civilization progressed, those with visual impairments could even find their condition produced certain advantages. A myopic (nearsighted) person, for example, could find themselves steered toward a craftsman role for their ability to focus on detail.

That said, humankind used visual aids for many centuries before the first eyeglasses appeared in the Middle Ages. Here are a few of the tools that helped those dealing with hyperopia (farsightedness) and other sight-related challenges.

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Early Lenses

Archaeological digs in the eastern Mediterranean area have uncovered the existence of plano-convex lenses (flat on one side and rounded on the other) made of glass and rock crystal that date back to the Bronze Age. The most well known example is the Nimrud lens, which was found in the remains of an Assyrian palace in modern-day Iraq. While it’s unknown what these lenses were used for, some of them magnify objects between seven and nine times, rendering them useful for work on items in close quarters. 

In his book Renaissance Vision From Spectacles to Telescopes, Vincent Ilardi suggests that the presence of holes or “resting points” on some of these lenses indicates they may have been propped up in a way that allowed artisans to use their hands. Additionally, he offers the discovery of a 5,300-year-old Egyptian ivory knife handle with carved microscopic figures as evidence that ancient Egyptians had a means for providing vision enhancements.

These weren’t the only civilizations to discover uses for lenses. A 2.3-gram convex crystal lens was found in the tomb of a son of Chinese Emperor Liu Xiu, who lived in the first century CE. Its creation was fostered by the optical studies published centuries earlier by Chinese scholars, including the philosopher Mozi and King Liú Ān.

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5 WWII Fighter Planes You Should Know

  • Supermarine Spitfires, 1943
Supermarine Spitfires, 1943
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World War II was an unprecedented time for advancements in aviation technology, and fighter aircraft played a crucial role in the conflict’s outcome. Fighter planes — the so-called “knights of the sky”— were agile, powerful aircraft designed primarily for air-to-air combat, whether in dramatic dogfights against enemy fighters or while intercepting enemy bombers. 

The demands of the war pushed fighter designs to new heights, resulting in planes that were faster, more maneuverable, and more lethal than ever before. And with air superiority often proving pivotal on any given front, from the Battle of Britain to the Battle of Kursk, these machines and their brave pilots helped shape the course of history. 

Here we look at five World War II fighter planes — from Britain, the U.S., Germany, Japan, and Russia — that left an indelible mark on aviation history. 

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Supermarine Spitfire

Both the Supermarine Spitfire and the Hawker Hurricane played crucial roles during the Battle of Britain, defending British airspace against wave after wave of German bombers and fighters. The sturdier Hurricane was often tasked with intercepting enemy bombers and engaging in ground attack missions, while the Spitfire, with its superior speed and agility, had the edge when engaging enemy fighters. 

Both planes were vital, but the elegant Spitfire is regarded by many as the most iconic fighter aircraft of all time. The Spitfire evolved as the war progressed, from the early Mk I to, finally, the Mk 24. More powerful engines, improved armaments, and enhanced aerodynamics allowed the plane to remain competitive against newer Axis designs. Not only was it an engineering marvel, but the Spitfire also became an enduring symbol of British resistance and ingenuity. 

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Why Do Older Movies Look Faster? 

  • Charlie Chaplin, 1914
Charlie Chaplin, 1914
Credit: Hulton Archive/ Archive Photos via Getty Images

When we think about old, silent films, we’re likely to picture the choppy, fast-paced movements of Charlie Chaplin or Buster Keaton, or perhaps the newsreel footage of Babe Ruth hitting a home run and seemingly zipping around the bases at 40 miles per hour. As talented as these individuals were, they weren’t capable of moving at speeds far beyond the range of normal people. So why do they appear that way on film?

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Film Only Provides the Illusion of Movement

To answer this question, we need to go back to some of the basics of filmmaking. Throughout the history of cinema, movie cameras have never been able to faithfully capture real-life movement. Rather, they record a series of still images in rapid succession, and replay them at speeds fast enough to trick the human mind into perceiving movement.

The number of individual images (or frames) displayed in one second of film is known as the frame rate, measured in frames per second (fps). Thomas Edison, who patented (but didn’t invent) the movie camera, noted that film needed to be shown at a speed of at least 46 fps to provide the illusion of movement. But in the early days of cinema, this proved too pricey to be practical, and some filmmakers found that the visual illusion could be sustained — and expensive celluloid film stock conserved — with frame rates closer to 16 fps, or even as low as 12 fps. While this speed was considered fast enough for a movie camera of that era, it is noticeably slower than the 24 fps rate that later became commonplace for both filming and projecting. And when old footage filmed at 16 fps or lower is accelerated for replaying at modern speeds, it will make the objects on screen move noticeably faster.

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5 Inventions You Didn’t Realize Came From Ancient Rome

  • Codex-style book
Codex-style book
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In 500 BCE, Rome was nothing more than a minor city-state on the Italian Peninsula. But with its eyes set on expansion, Rome began to conquer its neighbors until it controlled all of Italy. It didn’t stop there. It became an empire in 27 BCE, and at its height — around 100 CE — the vast and immensely powerful Roman Empire stretched from Britain to Egypt. 

Rome’s influence on the world was both widespread and long-lasting. The Romans were great innovators and inventors, sometimes appropriating and advancing aspects from other cultures, and other times inventing entirely new technologies and systems. These innovations covered a wide range of fields, including state institutions, cultural practices, and engineering techniques. 

The Roman Empire eventually fell in 476 CE, but its legacy and influence carried on — all the way to the present day. Some of Rome’s most famous innovations, such as sanitation systems and road networks, are well known and still very much in evidence; in the United Kingdom, for example, many modern roads still follow the routes laid down by the Romans. Other Roman innovations, however, are more obscure. Here are five inventions that continue to shape our modern world, but that many people don’t realize originated in ancient Rome. 

The First Bound Books

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In the ancient world, the first written documents were typically recorded on clay or wax tablets, or on sheets or scrolls of papyrus. The Romans also used scrolls, but during the first and second centuries CE, a new form of storing and accessing information emerged: the codex-style book. These notebooks, known as pugillares membranei (roughly translating to “parchment book”), were formed by stacking pages — typically made of vellum or papyrus — that were then joined along one set of edges, much like modern books. They were mainly used for personal writing, and represent the first true form of the bound book. The codices soon became popular throughout Western Europe and the Middle East, eventually superseding scrolls and tablets. 

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How Did People Wake Up on Time Before Alarm Clocks?

  • Man waking up to alarm
Man waking up to alarm
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Timekeeping technology has come a long way from ancient Egyptian sundials, and with it, so has the ability to wake up at whatever precise time might be needed for work, school, or appointments — even if we often ignore a ringing alarm in favor of snoozing for just 10 more minutes. While the demands of modern society are certainly more rigid than they once were, people have long had various reasons to keep a tight schedule, and at times they had to rely on more than just the crow of the rooster or the chirping of birds at dawn to make sure they were up to meet the day.

The most basic way people woke up before the invention of alarms was strictly biological in nature. Long before the advent of mechanical clocks or artificial light, people lived in harmony with the natural rhythms of day and night. Two biological processes dictate this natural sleep-wake cycle: homeostasis and circadian rhythms. Homeostasis governs our body’s drive for sleep, which increases the longer we’re awake and dissipates once we fall asleep, eventually signaling when it’s time to wake up. Circadian rhythms, meanwhile, control alertness and drowsiness throughout the day, influenced by light (more alert) and darkness (sleepy time). 

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This isn’t the only internal body process that served as a primal wake-up call before alarm clocks: Some people relied on their bladders. In biographer Stanley Vestal’s 1984 book about the life of 19th-century Lakota warrior White Bull, he noted, “Indian warriors could determine in advance their hour of rising by regulating the amount of water drunk before going to bed.” Of course, these bodily functions still exist as natural wake-up calls, but circadian rhythms often get disrupted by modern light sources such as screens, and given the strict nature of our 21st-century work schedules, one’s bladder might not be the most reliable alarm.

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5 Common Items From Colonial America You’ve Never Heard Of

  • Student with hornbook
Student with hornbook
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Life in colonial America was undeniably challenging, and early settlers had to be resilient and resourceful in order to survive. Many of the items that colonists used in day-to-day life were either brought from Europe or based on tools they had used in their old lives. While some remnants of the colonial era, such as spinning wheels and quill pens, remain a part of our collective memory, many lesser-known items have faded into obscurity or been replaced by modern innovations. Here are five once-common objects you may not have heard of before, each of which served an important role in sustaining family life and building communities in colonial America.

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Hornbook

A simple, durable tablet used as a primer for children’s studies, the hornbook originated in England around 1450 and was a staple of early childhood education in colonial America. Hornbooks were crafted by affixing a single page of parchment or paper onto a paddle-shaped wooden board and covering it with a translucent protective sheet made from an animal’s horn. This was created by soaking the horn in cold water to separate the parts, then heating and pressing the needed part into a thin, clear layer. A fundamental lesson was printed on the paper, such as the alphabet in lowercase and capital letters, simple vowel-consonant combinations, Roman numerals, and religious texts. Hornbooks remained popular well into the era of mass-printed books because they were both sturdy and functional.

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