Hagia Sophia

The awe-inspiring Hagia Sophia was built under Byzantine Emperor Justinian I between 532 and 537 CE — a remarkably quick construction considering the size of the project. With its vast central basilica, complex system of vaults and semi-domes, and high central dome spanning more than 101 feet in diameter, it was the world’s largest cathedral for nearly a thousand years (until the completion of Seville Cathedral in 1520). Considered one of the greatest examples of Byzantine architecture, Hagia Sophia represents the region’s shifting political and religious affiliations. Built as a Christian church, in later centuries it became a mosque, a museum, and a mosque once again. These changes are reflected in the building’s design, which features minarets and inscriptions from Islam as well as extravagant Christian mosaics. Hagia Sophia was the inspiration for many other Ottoman mosques, and has long been considered a unique architectural masterpiece. 

Machu Picchu

Perched high above the Urubamba River valley in a narrow saddle between two mountain peaks, with tropical cloud forests tumbling down below, Machu Picchu is simply mind-blowing. It’s hard not to look around and think, “How the heck did they build this here?” The site is situated at an elevation of 7,710 feet, and contains about 200 structures spread across zones dedicated to religious, ceremonial, astronomical, and agricultural activities, all surrounded by incredible farming terraces, connected by some 3,000 stone steps. Many mysteries still surround the construction and precise purpose of Machu Picchu. Historians estimate that it was built around 1450 CE and abandoned around 100 years later with the arrival of the Spanish conquistadors. The conquistadors never found Machu Picchu, and it stood for centuries known only to the peasant farmers who lived in the immediate area. It wasn’t until 1911, when American academic and explorer Hiram Bingham rediscovered the site, that the remarkable citadel was brought to the world’s attention. 

The Panama Canal

The idea of building a waterway across the isthmus of Panama to link the Atlantic and Pacific oceans dates back to at least the 1500s, when Spanish explorer Vasco Núñez de Balboa realized that the two oceans were separated by a 50-mile stretch of land. It wasn’t until 1880, however, that excavations for a canal first began, led by France. Unfortunately, the original nine-year project was devastated by malaria, yellow fever, and other tropical diseases, and ended with bankruptcy and the loss of some 20,000 lives. In 1904, the United States began the project anew. A major sanitation effort was put in place to help minimize disease, and the entire infrastructure was modernized. 

Perhaps most importantly, the project’s chief engineer, John Stevens, convinced President Theodore Roosevelt that the concept of the waterway must be changed from a sea level canal to a lock canal. The original locks (the system has since been expanded), each measuring 110 feet wide by 1,000 feet long, made it possible to lift ships 85 feet above sea level to the artificial Gatún Lake, and then back down to the sea. This incredible feat of engineering radically altered maritime travel and trade. By using the canal to cut across the isthmus, ships could avoid the lengthy trip around Cape Horn in South America, shortening sea voyages by about 8,000 nautical miles. 

The Channel Tunnel 

After six years of construction, the Channel Tunnel opened in May 1994, becoming the only fixed link between the island of Great Britain and the European mainland. The idea of building a tunnel between England and France was not new. French engineer Albert Mathieu had proposed such a project in 1802, his design featuring an artificial island halfway across for changing horses. Back then, the idea simply wasn’t technologically feasible, but by the 1980s, the tunnel project was given the green light. Digging began on both sides of the Channel, and the initial connection was completed in 1991. Three years later, the 31.5-mile tunnel was opened. It actually consists of three tunnels: two for rail traffic and a central tunnel for services and security. The tunnel descends to a depth of 246 feet below the sea bed. It is the third-longest railway tunnel in the world, and with 23.5 miles running under the English Channel, the world's longest undersea tunnel.

The International Space Station

Built between 1998 and 2011, the International Space Station (ISS) is the largest single structure humans ever put into space. It also represents arguably the greatest multinational collaborative construction project in history, involving Europe, the United States, Russia, Canada, and Japan. Elements of the station were built in multiple countries beginning in the late 1980s. In 1998, Russia’s Zarya control module and the U.S.-built Unity connecting node were launched into orbit, where they were connected by American space shuttle astronauts. In 2000, following the installation of the Russian-built habitat module Zvezda, the ISS received its first resident crew. Since then, it has been continuously occupied. Altogether, the space station is larger than a football field and weighs almost 450 tons. Maintaining an orbit with an average altitude of 250 miles, it circles the Earth in about 93 minutes, completing 15.5 orbits per day. The ISS is a truly unique engineering masterpiece, and its sophisticated science laboratory allows us to carry out research that is simply not possible on Earth — paving the way for future missions to Mars and beyond. 

The Lightbulb 

Thomas Edison is often — and incorrectly — given all the credit for inventing the lightbulb. But the lightbulb was actually the result of a process that began before Edison was even born. In 1802, English chemist Humphry Davy used a voltaic pile (invented by Alessandro Volta, after whom the volt is named) to create the first “electric arc lamp” between charcoal electrodes. His rudimentary lamp was too bright and burned out too quickly, but it was nonetheless an important breakthrough. Other scientists worked to refine the lightbulb, but problems with filaments and batteries made these early bulbs impractical for everyday use. In 1860, English physicist Joseph Swan developed a primitive electric light that utilized a filament of carbonized paper in an evacuated glass bulb. Lack of a good vacuum and an adequate electric source ultimately made it inefficient, but it did pave the way for later innovations, including those by Edison. Edison purchased some of his predecessor’s patents, improved upon them, and came up with his own lightbulb, which, while not the first overall, was the first to be commercially viable. 

The Automobile 

One commonly held misconception is that Henry Ford invented the automobile. In reality, the development of the automobile can be traced back to Nicolas-Joseph Cugnot, a French military engineer who, in 1769, built a steam-powered tricycle for hauling artillery. Due to its steam-powered nature, not everyone accepts Cugnot’s invention as the first true auto. Instead, that distinction often goes to vehicles made by two Germans, Karl Friedrich Benz and Gottlieb Daimler, who — working entirely separately — developed their own gasoline-powered automobiles in 1886, in two different German cities. Benz actually drove his three-wheeled vehicle in 1885, and it is regarded as the first practical modern automobile and the first commercially available car in history. As for Henry Ford, his name is forever remembered in auto history for the Model T, which he mass-produced using an innovative moving assembly line, making automobiles available to middle-class Americans.

Monopoly

Since the 1930s, it’s been common knowledge that Charles Darrow invented Monopoly, an idea that both he and the game’s manufacturer, Parker Brothers, freely propagated (it was printed in the instructions for decades). But it’s not quite true. Darrow got the idea for the game — which made him a millionaire — from a left-wing feminist named Elizabeth Magie. Magie created and patented an early version of Monopoly, called The Landlord’s Game, in 1903, about three decades before Darrow. Darrow learned about the game from a couple who had played it in Atlantic City (which is where many of the game’s street names come from) and made a few changes: The original game included a wealth tax, public utilities, and was designed as a protest against the big monopolists of her time. It had two sets of rules, one that allowed players to create monopolies and crush their opponents, and an anti-monopolist version that rewarded all players when wealth was created (the latter demonstrating what Magie believed to be a morally superior path). It’s only in recent years that Magie has started to receive the credit for inventing one of the world’s most popular and iconic board games.  

The iPod

Portable digital audio players have existed since the mid-1990s, but it was Apple’s iPod that revolutionized the industry upon its release in 2001. Yet it wasn’t the engineers at Apple who invented the iPod — not entirely, at least. British inventor Kane Kramer actually developed the technology behind the iPod as far back as 1979. His credit card-sized music player, which looked very similar to the iPod, could store only 3.5 minutes of music, but he was sure the storage capacity would increase over time. Unfortunately for Kramer, internal problems at his company ultimately led to his patent lapsing, at which point the technology became public. Apple later acknowledged Kramer’s involvement in inventing the technology behind the iPod.

Thomas Edison’s New X-Ray Machine Was Almost Used When President McKinley Was Shot

The 1901 Pan-American Exposition was held in Buffalo, New York, and showcased many cutting-edge advancements in science and technology. But it was also the site of tragedy. While greeting the public at the fair, U.S. President William McKinley was shot twice by an anarchist named Leon Czolgosz. The first bullet only grazed McKinley, but the second bullet hit him in the stomach, and the medical team could not locate it. As fate would have it, one of Thomas Edison’s new X-ray machines was on display at the fair. Edison had an assistant bring a machine to the house where McKinley was staying, but the medical team decided the President’s condition was too unstable to undergo the X-ray procedure, and the device was never used. McKinley passed away a week later, leading some to wonder whether Edison’s invention might have saved his life.

Chicago Almost Became Home to a Bigger Eiffel Tower, But Got a Ferris Wheel Instead

Four years after the Eiffel Tower was built for the Paris International Exposition of 1889, a Chicago committee started to plan its own world’s fair, soliciting ideas from U.S. architects that would “out-Eiffel, Eiffel.” Proposals included a 1,500-foot tower made of logs and what would have been the first bungee tower. The architect of the Eiffel Tower, Gustave Eiffel, even offered to build a larger version of his namesake landmark. Instead, the Chicago committee opted for something unique: the world’s first Ferris wheel, built by and named for George Washington Gale Ferris Jr. At 250 feet in diameter, and sitting atop 140-foot-tall towers, the Ferris wheel took riders higher than the crown of the Statue of Liberty. While the original Ferris wheel in Chicago has since been replaced by the Centennial Wheel, visitors from around the world continue to enjoy the architectural legacy of the world’s fair at Navy Pier.

A World’s Fair Helped a Woman Inventor Launch the Modern Dishwasher

In 1883, an American socialite named Josephine Cochrane grew frustrated with the tedious task of washing the fine china she used to entertain guests. She vowed, “If nobody else is going to invent a dishwashing machine, I’ll do it myself.” In 1886, Cochrane received a patent for her dishwashing machine, which could wash and dry up to 240 dishes in two minutes with its innovative use of water pressure. However, Cochrane struggled to sell her invention due to the high cost of manufacture, as well as the sexism of the time; potential investors wanted Cochrane to resign and turn over control of her company to men. The 1893 World's Columbian Exposition in Chicago gave her the platform she needed — after publicly demonstrating her machine, Cochrane was awarded the event’s highest prize, for “best mechanical construction, durability, and adaptation to its line of work.” Orders from restaurants and hotels throughout the region skyrocketed, paving the way for the modern dishwasher.

Video Chatting Was Initially a Flop

It’s easy to assume that video chatting is a recent invention that came along with the advent of the internet. But video chat technology has a history going back more than half a century. The public’s first contact with video chat was at the 1964 World’s Fair in New York, where Bell Labs debuted a “picturephone” that enabled fairgoers to make video calls with strangers across the country at California’s Disneyland. Long lines formed and Bell Labs (along with its parent company, AT&T) believed the technology would be a commercial hit, with executives projecting that a million picturephone sets would be sold by 1980. Alas, the device failed to take off, largely due to the high price tag. Bell Labs attempted to roll out various iterations of the picturephone in the following decades, but it wasn’t until the advent of the internet that video chat finally took off.

A Snake Oil Salesman Was a Showstopper

Today, the term “snake oil” signifies fraudulent goods and deceptive marketing, and it all started with a man named Clark Stanley, nicknamed “the Rattlesnake King.” Stanley introduced a “snake oil” product to the American public at the 1893 World's Columbian Exposition in Chicago, claiming to have learned about it from Hopi medicine men. As part of a dramatic live demonstration, he cut open a rattlesnake and submerged it in boiling water, skimming off the fat that rose to the surface to create “Stanley’s Snake Oil.” Spectators were wowed, and Stanley’s product became an immediate hit. But while the oil from certain snakes, such as Chinese water snakes, does have medicinal properties, oil from most snakes native to the U.S. does not. What’s more, Stanley’s product was later found by the FDA to not contain any snake oil at all, but rather beef fat, red pepper, and turpentine, forever making snake oil synonymous with fraud.

Air Conditioning Came From a New York Printing Press

Air conditioning has become a necessity for living and working comfortably in increasingly hot temperatures, but the AC unit actually originated as a way to fix a faltering printing press. In 1902, an engineer named Willis Carrier was working at Buffalo, New York’s Sackett-Wilhelms Lithographing and Publishing Company. He was tasked with finding a solution to control the humidity levels in the plant, which were wreaking havoc on paper and ink quality. His solution, known as the Apparatus for Treating Air, marked the birth of modern air conditioning.

Carrier's system consisted of steam coils and an industrial fan. The cold water in the coils produced excess condensation, which would be blown out of the room to lower humidity and cool the air. It not only solved the printing problem, but also inadvertently introduced a revolutionary technology with wide-ranging applications. While other people had experimented with cooling technology before Carrier, his pioneering work impacted architecture, engineering, and everyday life for generations to come.

Early Toothbrushes Were Made With Hog Hair

If there’s one item most people use every single day, it’s a toothbrush. While the humble oral hygiene tool dates back to ancient civilizations, when frayed twigs were used to scrub teeth, the model for bristle brushes as we know them today didn’t emerge until the late 15th century. According to the American Dental Association, a Chinese emperor patented a brush made of stiff, coarse hog hairs set into a handle made of bone or bamboo.

Hog or horse hair toothbrushes continued to be used for hundreds of years; by the late 1700s, they were even being mass-produced. It wasn’t until nylon was invented by a team at DuPont in 1935 that the material — the world’s first fully synthetic fiber — was put into toothbrushes. By 1938, the revolutionary product hit the market. Called Dr. West’s Miracle-Tuft Toothbrush, it wasn’t initially a hit, since early nylon was still far too stiff and abrasive, and brushing one’s teeth still wasn't considered a daily necessity. By the end of World War II, Americans were influenced by the hygiene habits of returning soldiers, and by the time DuPont introduced softer bristles in 1950, a booming industry was born.

The First Barcode Was Drawn in the Sand on Miami Beach

In 1948, Joseph Woodland, an inventor and grad student at the Drexel Institute in Philadelphia, was posed a challenge by a local grocer who wanted to speed up his checkouts. Given the limited technology at the time, how could they automate the process? Woodland was keen on the challenge, and pondered the problem while visiting family in Miami Beach. One day, inspiration struck on the beach. As Woodland drew in the sand with his fingertips, a vision of elongated bars, inspired by Morse code, came to him. Using a black-and-white bull's-eye design, he created a code that machines could decipher, pulling both the product information and its price. While early experiments were successful, it took several more decades of work from many thinkers before an IBM engineer designed the rectangle-shaped barcode we know and use regularly today.

While the barcode was originally created to answer supermarkets’ need for a faster checkout process, its true significance ended up being its ability to offer statistical insight into product sales. This innovation revolutionized market research, offering more detailed insights into consumer preferences, while also making manufacturing more efficient. In 1992, President George H.W. Bush presented Woodland with a National Medal of Technology and Innovation for his contributions to American retail and beyond.

The First Disposable Diapers Were Handmade by a Mom

Baby diapers may not be an everyday object for everyone, but anyone who has used them is keenly aware of their indispensability. While disposable diapers are now a multibillion-dollar global business, they began as a humble homemade project. In 1947, Valerie Hunter Gordon was just about to welcome her third child when she decided she’d had enough of washing soiled cloth diapers. She went on the hunt for single-use options; to her surprise, there were none available, so she sat down and made them herself.

Using her Singer sewing machine at her kitchen table, Gordon fashioned the “Paddi” out of gauze, for absorption, and with an outer nylon layer to hold the absorbent pad in place. (The nylon was actually a piece of parachute she got from her husband’s army base.) Snap closures were added for additional ease. As soon as her friends saw what she was making, they wanted some of their own; Gordon figures she handmade more than 600 of them at that time. The Gordons applied for a patent, and by 1949, they were producing the diapers in partnership with a U.K. company. By the 1960s, an American brand known as Pampers came along, and the Paddis business dwindled.

Kleenex Started as Wartime Gas Mask Filters

Kleenex tissues, like many other new products during the 1920s, were a wartime innovation. With an increased demand for cotton supplies on the battlefield, American paper company Kimberly-Clark developed a cotton substitute made from wood pulp. The company called it cellucotton, and sent it overseas to use as bandages and as filters in gas masks. Following the war, Kimberly-Clark sought civilian applications for its abundance of cellucotton. One employee, Walter Luecke, was inspired by Army nurses who used it as makeshift disposable sanitary napkins. The company initially pushed back, claiming sanitary napkins were “too personal” to produce and market, but it eventually relented, and in 1920, released its first consumer product, the revolutionary Kotex sanitary pads. Shortly after the success of Kotex, the surplus of cellucotton was further adapted into a thinner, softer product that was released in 1924 and marketed as a cold cream and makeup remover: Kleenex.