20th century

== Engineering and technology ==
[[File:First flight2.jpg|thumb|right|First flight of the [[Wright brothers]]' ''[[Wright Flyer]]'' on December 17, 1903, in [[Kitty Hawk, North Carolina]]; Orville piloting with Wilbur running at wingtip.]]

One of the prominent traits of the 20th century was the dramatic growth of technology. Organized research and practice of science led to advancement in the fields of communication, electronics, engineering, travel, medicine, and war.
* Basic [[home appliance]]s including [[washing machine]]s, [[clothes dryer]]s, furnaces, [[exercise machine]]s, [[dishwashers]], [[refrigerator]]s, freezers, [[electric stove]]s and [[vacuum cleaner]]s became popular from the 1920s through the 1950s. Radios were popularized as a form of entertainment during the 1920s, followed by television during the 1950s.
* The first airplane, the ''[[Wright Flyer]]'', was flown in 1903. With the engineering of the faster [[jet engine]] in the 1940s, mass [[air travel]] became commercially viable.
* The [[assembly line]] made mass production of the automobile viable. By the end of the 20th century, billions of people had automobiles for personal transportation. The combination of the automobile, [[motor boat]]s and air travel allowed for unprecedented personal mobility. In western nations, motor vehicle accidents became the greatest cause of death for young people. However, expansion of [[divided highway]]s reduced the death rate.
* The [[triode|triode tube]] was invented.
*Air conditioning of buildings became common
* New materials, most notably [[stainless steel]], [[Velcro]], [[silicone]], [[polytetrafluoroethylene|teflon]], and plastics such as [[polystyrene]], [[polyvinyl chloride|PVC]], [[polyethylene]], and nylon came into widespread use for many various applications. These materials typically have tremendous performance gains in strength, temperature, chemical resistance, or mechanical properties over those known prior to the 20th century.
* Aluminum became an inexpensive metal and became second only to iron in use.
* Thousands of [[chemical]]s were developed for industrial processing and home use.
* Digital computers came into use

=== Space exploration ===
[[File:Buzz salutes the U.S. Flag.jpg|thumb|Photo of American astronaut [[Buzz Aldrin]] during the [[Apollo 11|first moonwalk]] in 1969, taken by [[Neil Armstrong]]. The relatively young [[aerospace engineering]] industries rapidly grew in the 66 years after the Wright brothers' first flight.]]
* The [[Space Race]] between the United States and the [[Soviet Union]] gave a peaceful outlet to the political and military tensions of the [[Cold War]], leading to the first [[human spaceflight]] with the Soviet Union's [[Vostok 1]] mission in 1961, and man's first landing on another world—the [[Moon]]—with America's [[Apollo 11]] mission in 1969. Later, the first [[space station]] was launched by the [[Soviet space program]]. The United States developed the first reusable spacecraft system with the [[Space Shuttle program]], first launched in 1981. As the century ended, a permanent crewed presence in space was being founded with the ongoing construction of the [[International Space Station]].
* In addition to human spaceflight, uncrewed space probes became a practical and relatively inexpensive form of exploration. The first orbiting space probe, [[Sputnik 1]], was launched by the [[Soviet Union]] in 1957. Over time, a massive system of artificial satellites was placed into orbit around Earth. These satellites greatly advanced navigation, communications, military intelligence, geology, climate, and numerous other fields. Also, by the end of the 20th century, uncrewed probes had visited or flown by the Moon, [[Mercury (planet)|Mercury]], [[Venus]], [[Mars]], [[Jupiter]], [[Saturn]], [[Uranus]], [[Neptune]], and various asteroids and comets, with ''[[Voyager 1]]'' being the farthest manufactured object from Earth at 23,5&nbsp;billion kilometers away from Earth as of 6 September 2022, and together with ''[[Voyager 2]]'' both carrying The [[Voyager Golden Record]] containing sounds, music and greetings in 55 languages as well as 116 images of nature, human advancement, space and society.
* The [[Hubble Space Telescope]], launched in 1990, greatly expanded our understanding of the Universe and brought brilliant images to TV and computer screens around the world.
* The [[Global Positioning System]], a series of satellites that allow land-based receivers to determine their exact location, was developed and deployed.<ref>{{cite web|url=https://www.nasa.gov/directorates/heo/scan/communications/policy/GPS_History.html|title= Global Positioning System History|date=2012-10-27|access-date=2018-02-07}}</ref>