Technology in the world varies greatly from nation to nation, particularly in development. Prior to the Hundred Year War, the Fire Nation underwent an industrial revolution that rapidly advanced manufacturing and vehicular technology, allowing it to become more powerful than all the other nations. While the Earth Kingdom did not industrialize, its technology was still more developed than that of the nature-oriented and unambitious Air Nomad civilization as well as the Water Tribe. The latter two societies used sophisticated technology only in conjunction with their corresponding bending arts, airbending and waterbending, respectively, for purposes such as opening a passageway.
In addition, technologies in general advanced differently based on bending. Some examples include the earthbending-powered monorail of Ba Sing Se and the use of lightning generation as a source of energy for power plants, applied extensively in Republic City.
Following the Hundred Year War, the industrial revolution spread to the Earth Kingdom, Water Tribes, and the newly founded United Republic of Nations. Great technological advances were made, including the widespread use of electricity, the invention of radios as well as telephones, and the development of automobiles and mechas. These changes raised the standards of living in much of the world, but also inadvertently reduced spirituality.
During the time of Avatars Aang and Korra, a rapid advance in all fields of technology occurred. In just two hundred years, society underwent unprecedented change; significant improvements were made to communication, transportation, manufacturing, building infrastructure, and warfare technology. This process was a direct result of the Hundred Year War and the Anti-bending Revolution, each of which in turn necessitated participating parties to create new technologies in order to discourage their opponents as well as lower battle costs and casualties.
Prior to the Hundred Year War, the primary form of long-distance communication was by sending a messenger bird carrying notes to and from the point of interest. Many people had personal messenger birds that could send messages to faraway locations at a relatively fast pace. However, this form of communication was not foolproof, as the birds did not always reach their destination.
After the Hundred Year War, advances in technology led to the introduction of telegraphy, which revolutionized long-distance communication. People living miles away from the broadcaster could receive messages instantaneously and partake in a conversation. Radios began being used by news broadcasters, sports commentators, and Republic City's police forces. Since many people had a personal radio, this type of broadcasting made it easy for small groups of people to communicate a message to a larger number of people in a region.
Aside from telegraphy, other innovative inventions were made in communication, such as the microphone and megaphone. These new sound amplifiers were commonly used in public events and protests, where it was imperative that all members of the audience be able to hear the words of the announcers clearly. Another significant innovation was the phonograph, which made sound recording possible. Telephones have also been developed, which make long-distance communication possible.
Before the advent of steam-powered and electric machines, travel in the world was difficult and arduous. During the reign of Earth King Yi Ming, the primary form of long-distance travel in the Earth Kingdom was by riding on animals. The animals that were used for transportation changed with location. Nobility traveled long distances by riding on animal-drawn carriages. Boats during this era were primitive as well, being limited to cutters, catamarans, barges, canoes, skiffs, and ferries. The Air Nomads traveled on their flying bison and flew around with their gliders.
The most notable issue with pre-industrial travel technology was that it often became unreliable. Since animals were so crucial to transportation, travel would easily be interrupted if the animals became tired, diseased, or injured. Animals would be harshly affected by rough terrain and inclement weather, especially if they were not familiar to the species. Sea travel was better trusted, although it did not come without its flaws either. Not all boats could travel everywhere; for example, cutters were specifically made to be able to bypass the icebergs surrounding the Southern Water Tribe, but would have no chance of getting past a swamp, for which skiffs were made. Other problems with pre-industrial travel technology included slow speed and limits on passenger amount.
During the latter half of the Hundred Year War, steam-powered machines were introduced. This new invention had immediate effects on warfare, which soon spread into transportation. By 100 AG, steam-powered trains had been introduced to the Fire Nation as a new form of public transportation. Unlike earlier forms of transportation, these trains could travel at high speeds and carry a lot of passengers in one ride. Trains also made travel much more convenient, as the ride was relaxing and smooth compared to traveling on the back of an animal. Despite being able to move only on land rails, they could still function on many types of terrain and weather.
Although trains radically changed travel, they did have a few setbacks. The foremost problem was that because they ran on rails, they could not go where rails had not been set. This meant that not everybody had access to trains or did not ride them because they were of no use. The solution did not come until decades later, when the automobile was invented. Being mass-produced in Republic City by 170 AG, the automobile was arguably the most important invention of the time.
Shortly after its invention, the automobile became the primary mode of transportation in Republic City, ousting mass transit. It quickly became crucial to the infrastructure of the city, as it permitted a faster way to move from place to place, traffic goods or supplies, and combat crime. Due to these changes, Republic City began to undergo an economic and construction boom. Trade became faster and easier, bolstering the city's already massive economy. Since construction materials flowed into the city more quickly, buildings were able to be erected faster and more often, which led to a separate economic boom and rise in population. When the city embraced the new invention, automobile manufacturers grew very wealthy. This allowed them to take bold steps in further developing the automobile. Soon, automobiles were being specialized for the needs of the consumers, for example, Future Industries, a major car manufacturing company, began making police vehicles specifically for the use of Republic City's Metalbending Police Force. Other specialized vehicles included racing cars, buses, and trucks. Future Industries also began to give their cars some style, as to make every consumer feel as though their vehicle is unique. Shortly thereafter, more diverse and complex cars began being manufactured, with the manufacturers taking into account what the consumers wanted.
A vehicular mode of transportation, automobiles ran on gasoline, becoming one of the first machines to do so. They were decorated metal boxes that came in multiple colors and ran on top of wheels. Automobiles had windows that let in light and seats that made room for passengers. The driver's seat, equipped with a steering wheel, was usually on the front left of the car. The engine of the car was typically on the outside, in front of the driver's seat.
In 171 AG, however, Varrick pioneered the development of a new magnetic rail line which increased the traveling speed of trains exponentially. By 174 AG, rail lines had become prevalent throughout the lands of the Earth Kingdom and were installed within the United Republic of Nations as well, allowing for expedient cross-continental travel.
Other less important, though still notable advancements in transportation were made. Late in the Hundred Year War, a highly secure prison known as the Boiling Rock was built in the Fire Nation. It was located on a volcanic island in the middle of a boiling lake, and the only way to get in or out of the prison complex was by riding on an elevated gondola, which ran beneath a suspended wire held high above the ground. The gondola itself was a rectangular prism-shaped metal box. Looking back at Republic City, the metropolis appeared to have a complex elevated railway system and a secret underground tramway being used by the Equalists for their own illegal purposes. Both were used for quick transportation and the trafficking of materials or goods.
Manufacturing technology improved significantly during and after the Hundred Year War. The Fire Nation, which was the leading country in technological advancements during the Hundred Year War, was able to mass-produce large metal warships and airships by 100 AG, a feat that was not previously accomplished by any other nation. The Northern Air Temple was also known to have had a complex system of manufacturing at the time; there were two rooms specifically built for this purpose - the workshop and the sanctuary. The workshop was where the mechanist would conduct experiments and tests with new inventions and prototypes. He kept many blueprints here, ranging from gliders to hot air balloons. The sanctuary was the place where the mechanist would secretly manufacture warfare technology for the Fire Nation. The manufacturing technology there was on-par with that of the Fire Nation, being able to mass-produce large and deadly metal objects.
In 170 AG, manufacturing technology had advanced even further. By this time, Republic City had an entire sector in the south of the metropolis built solely for manufacturing companies. One of the most important businesses here was Future Industries, which was among the largest automobile manufacturers in the world. It was the first company known to have used the assembly line manufacturing technique, in which the parts-to-be-manufactured were placed on a conveyor belt that conveniently moves them through different stations in the factory. Each station had a different purpose and job. This technique allowed cars to be made faster and more often. Also, it lessened the need for human labor.
The Air Nomads were never industrialized. Their insistence on making the least amount of environmental impact on the world as possible, and their relatively peaceful way of life, meant that they were satisfied with conventional and classic technology. The Air Nomads did however have enough technical knowledge to produce their own gliders. By 170 AG, when technology had become widespread, they were not above using devices such as lamps, radios, and telephones on Air Temple Island.
Examples of technology
- Air temple sanctuary door - This door is opened only through the use airbending, by sending a gust of air through two trumpet-like objects, which eventually turn three locks that unlock the door. It seems that the structure itself can be entered without the need of airbending, as the mechanist was able to enter the sanctuary in the Northern Air Temple without having to open the door.
- Glider - A support tool that airbenders have frequently used for assistance in airbending.
The Northern Water Tribe had achieved moderate advances in technology, as made evident by many complex hydraulics-based structures present in the city. Though its southern counterpart lacked access to technology during the war years due to its small population limited resources, heavy modernization and the establishment of international trade following the Hundred Year War has resulted in rapid development in the Southern Water Tribe, resulting in the emergence of a shipping industry and several skyscrapers in the city.
Examples of technology
- Battlecruisers - Modern warships used by the Northern Water Tribe. They are similar in design to those used by the United Forces.
- Canal - Canal lock system in the Northern Water Tribe passable only through the use of waterbending.
- In addition to this, much of their architecture involved ice, a substance they could bend into formations. The Northern Water Tribe featured large walls and buildings, and it was seen in Hama's flashback of the Southern Tribe that it once had large walls and igloos as well. In its lack of benders, the southern tribe was reduced to animal-skin tents. In The Legend of Korra, it seems to have been restored, and the ice structures are again present.
- Ice torpedo - A weapon designed for the waterbending-powered submarines, used during the invasion of the Fire Nation.
- Motion picture projector - A device invented by Varrick in order to project films onto a screen.
- Snowmobile - A small motorized vehicle, designed for use in a snowy landscape.
- Tangle mines - Aquatic bomb invented by Hakoda, also called the "stink 'n sink".
- Waterbending-powered submarine - An underwater naval vessel used in the invasion of the Fire Nation, envisioned by Sokka and built by the mechanist.
The Earth Kingdom was in the eve of industrialization during the war era, with the limited manipulation of steam and metal machines toward the end of the war, most which were invented by the mechanist. The majority of their technologies have earthbending as their main sources of power.
Examples of technology
- Monorail - Enormous train network stretching across the whole city of Ba Sing Se, connecting all three rings. It serves as the city's mass transit system. The monorail is pushed from one end of the rail network to the other by a group of elite earthbenders.
- Earth Kingdom ferries - Vessels powered by a paddle wheel.
- Fireworks - Explosive pyrotechnic device used primarily for aesthetic and entertainment purposes.
- Omashu delivery system - The Omashu mail system is a linking slide that spreads for miles in the city of Omashu. Earthbenders use their bending to place carts filled with a variety of cargo in specific lanes. Gravity provides the carts with potential energy, which they use to maneuver through the mail system. The parcels arrive at specific stations, where they are reloaded and sent to another lane.
- Planetary calendar room - An enormous mechanical planetarium constructed by the spirit Wan Shi Tong and a prominent feature of his vast library.
- Sand-sailers - Gliders used by sandbenders to travel through the Si Wong Desert. They are equipped with compasses that allow the users to determine their position relative to the Si Wong Rock.
The mechanist is a prolific technological innovator from the Earth Kingdom. He has settled in the Northern Air Temple after the flooding of his village. The mechanist created schematics and sample weapons for the Fire Nation as payment for safe refuge in the temple. His invention of the hot air balloon allowed the Fire Nation to develop a powerful air force. His real name is never revealed.
- Cut-safe knife sharpener - A knife sharpener invented by the mechanist.
- Earth Kingdom supply truck - Motorized, metallic vehicles supposedly designed by Sokka in preparation for the invasion of the Fire Nation. They were used as a means of cargo transportation.
- Earthbending-powered tank - Armored vehicles owned and operated by the Earth Kingdom military. Used during the invasion of the Fire Nation.
- Eclipse glasses - Special glasses worn during an eclipse to prevent eye damage upon eye contact.
- Elevators - Machines invented by the mechanist to lift people to high elevations. War Minister Qin is seen riding one up to the mechanist's workshop for blueprints, and a man is seen briefly in the temple riding one up to a platform. These are steam driven.
- Gliders - Simple flying apparatus based on the airbenders' gliders.
- Hot air balloon - Experimental weapon developed for the Fire Nation.
- Ice torpedo - A weapon designed for the waterbending-powered submarines, used during the invasion of the Fire Nation.
- Peanut sauce bombs - Explosive weapons (failed).
- Time candles - Candles used to determine the time.
- Timing device - Apparatus used to keep track of time during an eclipse.
- Waterbending-powered submarines - Naval vehicles used in the invasion of the Fire Nation; they were envisioned by Sokka and built by the mechanist.
The Fire Nation was the most technologically advanced nation during the Hundred Year War. A majority of the Fire Nation technologies are made out of metal and fueled by burning coal. Being the orchestrators of the Hundred Year War, most of these technologies are war-oriented.
Examples of technology
- Ballista - Huge crossbow type weapon that uses torsional force to propel generally smaller and lighter projectiles, for example darts or arrows, much further and faster than a catapult or similar device.
- Cannon - Powerful artillery mounted to Fire Nation airships, used for launching high explosives.
- Fire Nation airship - A massive aerial vehicle built from the foundation of the war balloon.
- Fire Nation drill - A very large, hydraulic metal drill designed to penetrate the walls of Ba Sing Se, so that the Fire Nation could conquer the Earth Kingdom capital and ultimately win the War.
- Fire Nation trebuchet - Catapults used to conduct long-range warfare. They have appeared in different sizes from being huge fixed catapults on Fire Nation ships to small portable catapults to be used by infantry.
- Fireworks - Explosive pyrotechnic device used primarily for aesthetic and entertainment purposes. Used in the Fire Days Festival.
- Great Gates of Azulon - Built to prevent enemies from entering the Fire Nation Capital, the Great Gates of Azulon are a large set of gates that are capable of being set on fire.
- Gondola - This gondola was seen used at the Boiling Rock prison as a transport for prisoners and personnel. It was also used in Sokka's escape plan.
- Hot air balloon - War balloon that uses a small valve in the top of the vehicle that allows control of the balloon's motion.
- Jet ski - Steam-powered jet skis perfect for short-range water travel and warfare.
- Tank train - A Fire Nation engineering marvel. It is a cross between a tank and a train.
- Tundra tank - Large armored vehicles.
United Republic of Nations
Examples of technology
- Automobiles - Automobiles are used throughout Republic City, and come in a variety of different types, including cars, trucks, and motorcycles.
- Automated printing press - A device that enables papers like leaflets and newspapers to be mass-produced quickly. One was uncovered by the Metalbending Police Force during a search for Equalist propaganda at Cabbage Corp.
- Battleships - Large ships used by the United Forces during naval warfare. Each battleship bears the characteristic insignia of each of the three nations. Battleships have Earth Kingdom insignias located on their bows and hulls, Fire Nation insignias on their guns, and Water Tribe insignias also on the hulls. The hulls are also decorated with two large, golden dragons on the bow of the ship.
- Cameras - A camera is a device that captures and stores images. Mostly used by Republic City reporters and journalists alike.
- Clock - A clock is used to measure time.
- Electrified gloves - Small, hand-mounted electroshock devices used to immobilize people on contact.
- Highway system - A system of elevated roadways that allow for traffic to move through the city on many different paths.
- Flashlights - A flashlight is a device used to illuminate dark spots, usually looking for something. Flashlights are used by the Metalbending Police Force to do security sweeps.
- Intercom system - An electronic sound system that is manually turned on and off at will. The user simply speaks into a microphone and the message is sent to wherever speakers are placed. Systems such as this are used on battleships.
- Mecha tank - A large mechanized suit originally manufactured by Hiroshi Sato for use by the Equalists. Constructed out of solid platinum, it is impervious to metalbending.
- Microphones - A device that amplifies sound. It is used to announce the start of pro-bending matches, and can also be installed on police vehicles, allowing officers to address a large mob or crowd. A larger but related device, known as the megaphone, can also amplify sound, and is used by public speakers to attract a large audience.
- Naval mine - A floating explosive device that explodes when a ship makes contact with it. Several of these mines were used to disable General Iroh's fleet of battleships. It is different from a tangle mine as it only explodes.
- Phonographs - A small appliance that spins a record in order to play music on the record. It is popular enough that whole stores in Republic City are dedicated to selling them.
- Plasma saws - Future Industries employs industrial plasma saws to cut platinum. Hiroshi Sato aided in adapting the welding torches on Asami's hummingbird mecha suits into more portable plasma saws by adding an electrical element to it.
- Police airship - Large airships are used by the police force of Republic City to monitor various criminal activities from above.
- Police scanner - A device that allows someone to listen in on Metalbending Police Force radio conversations. One is installed in the black Satomobile sports car that Asami Sato utilized during an anti-Equalist patrol.
- Power grid - The method of powering a large city with electricity. It distributes power to certain parts of a metropolis. Councilman Tarrlok once shut down power to the Dragon Flats borough because of a supposed Equalist rally.
- Power plant - The main source of energy for power plants in Republic City. Firebenders use lightning generation to produce energy.
- Radios - Radios are devices used to transmit radio broadcasts to the citizens of Republic City. Events such as pro-bending matches or speeches are often broadcasted through the use of radios.
- Smoke grenades - Smoke grenades are devices that, when used, create a thick layer of smoke, greatly impeding visibility.
- Stoplights - A small electrical fixture at intersections and other various road sections in Republic City that controls the flow of traffic to make it safer.
- Telephones - Telephones serve as a system of communication in Republic City, allowing two people separated by large distances to talk to each other. Some calls are managed by a switchboard, such as the one located in the police headquarters.
- Trams and mine-cart systems - Used primarily by the Equalists to travel through the tunnels beneath Republic City, the trams and mine-carts are vital in transporting goods and people between various Equalist hideouts.