The 20th (twentieth) century was a century that began on January 1, 1901[1] and ended on December 31, 2000.[2] It was the tenth and final century of the 2nd millennium. It is distinct from the century known as the 1900s which began on January 1, 1900 and ended on December 31, 1999.
A century is a period of 100 years. Centuries are numbered ordinally in English and many other languages. The word century comes from the Latin centum, meaning one hundred. Century is sometimes abbreviated as c.
The second millennium of the anno Domini or Common Era was a millennium spanning the years 1001 to 2000. It encompassed the High and Late Middle Ages of the Old World, followed by the Early Modern period, characterized by the Wars of Religion in Europe, the Age of Enlightenment, the Age of Discovery and the colonial period. Its final two centuries coincide with Modern history, characterized by industrialization, the rise of nation states, the rapid development of science, widespread education, and universal health care and vaccinations in the Western world. The 20th century saw increasing globalization, most notably the two World Wars and the subsequent formation of the United Nations. 20th-century technology includes powered flight, television and semiconductor technology, including integrated circuits. The term "Great Divergence" was coined to refer the unprecedented cultural and political ascent of the Western world in the second half of the millennium, emerging by the 18th century as the most powerful and wealthy world civilization, having eclipsed Qing China and the Islamic World. It differs from the millennium of the 1000s, which spans the years 1000 to 1999.
The 1918 influenza pandemic was an unusually deadly influenza pandemic, the first of the two pandemics involving H1N1 influenza virus. It infected 500 million people around the world, including people on remote Pacific islands and in the Arctic. Probably 50 million, and possibly as high as 100 million died, making it one of the deadliest epidemics in human history. Historical and epidemiological data are inadequate to identify with certainty the pandemic's geographic origin.
World War I, also known as the First World War, the Great War, the Seminal Catastrophe, and initially in North America as the European War, was a global war originating in Europe that lasted from 28 July 1914 to 11 November 1918. Contemporaneously described as "the war to end all wars", it led to the mobilisation of more than 70 million military personnel, including 60 million Europeans, making it one of the largest wars in history. It is also one of the deadliest conflicts in history, with an estimated nine million combatants and seven million civilian deaths as a direct result of the war, while resulting genocides and the resulting 1918 influenza pandemic caused another 50 to 100 million deaths worldwide.
World War II, also known as the Second World War, was a global war that lasted from 1939 to 1945. The vast majority of the world's countries—including all the great powers—eventually formed two opposing military alliances: the Allies and the Axis. A state of total war emerged, directly involving more than 100 million people from more than 30 countries. The major participants threw their entire economic, industrial, and scientific capabilities behind the war effort, blurring the distinction between civilian and military resources. World WarII was the deadliest conflict in human history, marked by 70 to 85 million fatalities, most of whom were civilians in the Soviet Union and China. It included massacres, the genocide of the Holocaust, strategic bombing, premeditated death from starvation and disease, and the only use of nuclear weapons in war.
The 20th century saw the largest transformation of the world order since the Fall of Rome: global total fertility rates, sea level rise and ecological collapses increased; the resulting competition for land and dwindling resources accelerated deforestation, water depletion, and the mass extinction of many of the world's species and decline in the population of others; consequences which are now being dealt with. The average global temperature on Earth has increased by about 0.8° Celsius (1.4° Fahrenheit) since 1880; Two-thirds of the warming has occurred since 1975, at a rate of roughly 0.15-0.20°C per decade.[5]
The total fertility rate (TFR), sometimes also called the fertility rate, absolute/potential natality, period total fertility rate (PTFR), or total period fertility rate (TPFR) of a population is the average number of children that would be born to a woman over her lifetime if:
She was to experience the exact current age-specific fertility rates (ASFRs) through her lifetime, and
She was to survive from birth to the end of her reproductive life.
Since at least the start of the 20th century, the average global sea level has been rising. Between 1900 and 2016, the sea level rose by 16–21 cm (6.3–8.3 in). More precise data gathered from satellite radar measurements reveal an accelerating rise of 7.5 cm (3.0 in) from 1993 to 2017, which is a trend of roughly 30 cm (12 in) per century. This acceleration is due mostly to human-caused global warming, which is driving thermal expansion of seawater and the melting of land-based ice sheets and glaciers. Between 1993 and 2018, thermal expansion of the oceans contributed 42% to sea level rise; the melting of temperate glaciers, 21%; Greenland, 15%; and Antarctica, 8%. Climate scientists expect the rate to further accelerate during the 21st century.
Ecological collapse refers to a situation where an ecosystem suffers a drastic, possibly permanent, reduction in carrying capacity for all organisms, often resulting in mass extinction. Usually, an ecological collapse is precipitated by a disastrous event occurring on a short time scale. Ecological collapse can be considered as a consequence of ecosystem collapse on the biotic elements that depended on the original ecosystem.
The repercussions of the World Wars, Cold War and Globalization crafted a world where people are more united than any previous time in human history, as exemplified by the establishment of the United Nations. The Marshall Plan—which spent $13 billion $100billion in 2018 US dollars)[6] to rebuild the economies of post-war nations—launched "Pax Americana". For decades, the United States shouldered the burden of protecting other nations so as to limit threat of nuclear proliferation, and this global stabilizing hegemony influence impeded the expansion of communism while allowing for democratic proliferation to more than half of the existing countries. Open warfare amongst large armies disappeared; an unprecedented historical period, dubbed the "Long Peace", occurred after the World Wars, in which the world transitioned from active wars between nation states to internal civil wars or local insurgency conflicts.
The United Nations (UN) is an intergovernmental organization responsible for maintaining international peace and security, developing friendly relations among nations, achieving international cooperation, and being a centre for harmonizing the actions of nations. It is the largest, most familiar, most internationally represented and most powerful intergovernmental organization in the world. The UN is headquartered on international territory in New York City; other main offices are in Geneva, Nairobi, Vienna and The Hague.
The Marshall Plan was an American initiative passed in 1948 to aid Western Europe, in which the United States gave over $12 billion in economic assistance to help rebuild Western European economies after the end of World War II. Replacing an earlier proposal for a Morgenthau Plan, it operated for four years beginning on April 3, 1948. The goals of the United States were to rebuild war-torn regions, remove trade barriers, modernize industry, improve European prosperity, and prevent the spread of Communism. The Marshall Plan required a reduction of interstate barriers, a dropping of many regulations, and encouraged an increase in productivity, as well as the adoption of modern business procedures.
Pax Americana is a term applied to the concept of relative peace in the Western Hemisphere and later the world beginning around the middle of the 20th century, thought to be caused by the preponderance of power enjoyed by the United States. Although the term finds its primary utility in the latter half of the 20th century, it has been used with different meanings and eras, such as the post-Civil War era in North America, and regionally in the Americas at the start of the 20th century.
It took over two-hundred thousand years of human history up to 1804 for the world's population to reach 1 billion;[7]world population reached an estimated 2 billion in 1927; by late 1999, the global population reached 6 billion.[8] Global literacy averaged 80%. Up until a couple hundred years ago, life expectancy was about thirty in most populations; global lifespan-averages exceeded 40+ years for the first time in history, with over half achieving 70+ years (three decades longer than it was a century ago).[9]
World population milestones were unnoticed until the 20th century, since there were no reliable data on global population dynamics.
Literacy is traditionally defined by dictionaries as the ability to read and write, although broader interpretations insist that any particular instance of reading and writing is always taking place in a specific context, as the proliferation of concepts like "conventional or basic literacy, functional literacy, digital literacy, media literacy, legal literacy, computer literacy, medical literacy and information literacy" suggest. The general consensus among researchers that literacy always includes social and cultural elements is reflected by UNESCO's inclusion of numbers, images, digital media, cultural consciousness, and other means of understanding, communicating, gaining useful knowledge, problem-solving, and using the dominant symbol systems of a culture in its definition of literacy. The concept of literacy is expanding across OECD countries to include skills to access knowledge through technology and ability to assess complex contexts.
A world war is a large-scale war which affects the whole world directly or indirectly. World wars span multiple countries on multiple continents, or just two countries fighting a war with battles in many theaters. While a variety of global conflicts have been subjectively deemed "world wars", such as the Cold War and the War on Terror, the term is widely and usually accepted only as it is retrospectively applied to two major international conflicts that occurred during the 20th century: World WarI (1914–18) and World WarII (1939–45).
Total war is warfare that includes any and all civilian-associated resources and infrastructure as legitimate military targets, mobilizes all of the resources of society to fight the war, and gives priority to warfare over non-combatant needs. The Oxford Living Dictionaries defines "total war" as "A war that is unrestricted in terms of the weapons used, the territory or combatants involved, or the objectives pursued, especially one in which the laws of war are disregarded."
Nationalism is an ideology and movement that promotes the interests of a particular nation, especially with the aim of gaining and maintaining the nation's sovereignty (self-governance) over its homeland. Nationalism holds that each nation should govern itself, free from outside interference (self-determination), that a nation is a natural and ideal basis for a polity, and that the nation is the only rightful source of political power. It further aims to build and maintain a single national identity—based on shared social characteristics such as culture, language, religion, politics, and belief in a shared singular history—and to promote national unity or solidarity. Nationalism, therefore, seeks to preserve and foster a nation's traditional culture, and cultural revivals have been associated with nationalist movements. It also encourages pride in national achievements, and is closely linked to patriotism. Nationalism is often combined with other ideologies, such as conservatism or socialism for example.
The century saw a major shift in the way that many people lived, with changes in politics, ideology, economics, society, culture, science, technology, and medicine. The 20th century may have seen more technological and scientific progress than all the other centuries combined since the dawn of civilization. Terms like ideology, world war, genocide, and nuclear war entered common usage. Scientific discoveries, such as the theory of relativity and quantum physics, profoundly changed the foundational models of physical science, forcing scientists to realize that the universe was more complex than previously believed, and dashing the hopes (or fears) at the end of the 19th century that the last few details of scientific knowledge were about to be filled in. It was a century that started with horses, simple automobiles, and freighters but ended with high-speed rail, cruise ships, global commercial air travel and the Space Shuttle. Horses, Western society's basic form of personal transportation for thousands of years, were replaced by automobiles and buses within a few decades. These developments were made possible by the exploitation of fossil fuel resources, which offered energy in an easily portable form, but also caused concern about pollution and long-term impact on the environment. Humans explored space for the first time, taking their first footsteps on the Moon.
(The map shows the flag of the Austrian Empire but in 1914 that did not exist, only the Austro-Hungarian Empire.)
World powers and empires in 1914, just before the First World War
Mass media, telecommunications, and information technology (especially computers, paperback books, public education, and the Internet) made the world's knowledge more widely available. Advancements in medical technology also improved the health of many people: the global life expectancy increased from 35 years to 65 years. Rapid technological advancements, however, also allowed warfare to reach unprecedented levels of destruction. World War II alone killed over 60 million people, while nuclear weapons gave humankind the means to annihilate itself in a short time. However, these same wars resulted in the destruction of the imperial system. For the first time in human history, empires and their wars of expansion and colonization ceased to be a factor in international affairs, resulting in a far more globalized and cooperative world. The last time major powers clashed openly was in 1945, and since then, violence has seen an unprecedented decline.[10]
At the beginning of the period, the British Empire was the world's most powerful nation,[12] having acted as the world's policeman for the past century. Fascism, a movement which grew out of post-war angst and which accelerated during the Great Depression of the 1930s, gained momentum in Italy, Germany, and Spain in the 1920s and 1930s, culminating in World War II, sparked by Nazi Germany's aggressive expansion at the expense of its neighbors. Meanwhile, Japan had rapidly transformed itself into a technologically advanced industrial power and, along with Germany and Italy, formed the Axis powers. Japan's military expansionism in East Asia and the Pacific Ocean brought it into conflict with the United States, culminating in a surprise attack which drew the US into World War II. After some years of dramatic military success, Germany was defeated in 1945, having been invaded by the Soviet Union and Polandfrom the East and by the United States, the United Kingdom, Canada, and Francefrom the West. After the victory of the Allies in Europe, the war in Asia ended with the dropping of two atomic bombs on Japan by the US, the first nation to develop and use nuclear weapons. In total, World War II left some 60 million people dead. After the war, Germany was occupied and divided between the Western powers and the Soviet Union. East Germany and the rest of Eastern Europe became Soviet puppet states under communist rule. Western Europe was rebuilt with the aid of the American Marshall Plan, resulting in a major post-war economic boom, and many of the affected nations became close allies of the United States.
With the Axis defeated and Britain and France rebuilding, the United States and the Soviet Union were left standing as the world's only superpowers. Allies during the war, they soon became hostile to one another as their competing ideologies of communism and democratic capitalism proliferated in Europe, which became divided by the Iron Curtain and the Berlin Wall. They formed competing military alliances (NATO and the Warsaw Pact) which engaged in a decades-long standoff known as the Cold War. The period was marked by a new arms race as the USSR became the second nation to develop nuclear weapons, which were produced by both sides in sufficient numbers to end most human life on the planet had a large-scale nuclear exchange ever occurred. Mutually assured destruction is credited by many historians as having prevented such an exchange, each side being unable to strike first at the other without ensuring an equally devastating retaliatory strike. Unable to engage one another directly, the conflict played out in a series of proxy wars around the world–particularly in China, Korea, Cuba, Vietnam, and Afghanistan–as the USSR sought to export communism while the US attempted to contain it. The technological competition between the two sides led to substantial investment in research and development which produced innovations that reached far beyond the battlefield, such as space exploration and the Internet.
Following World War II, the United Nations, successor to the League of Nations, was established as an international forum in which the world's nations could discuss issues diplomatically. It enacted resolutions on such topics as the conduct of warfare, environmental protection, international sovereignty, and human rights. Peacekeeping forces consisting of troops provided by various countries, with various United Nations and other aid agencies, helped to relieve famine, disease, and poverty, and to suppress some local armed conflicts. Europe slowly united, economically and, in some ways, politically, to form the European Union, which consisted of 15 European countries by the end of the 20th century.
In the last third of the century, concern about humankind's impact on the Earth's environment made environmentalism popular. In many countries, especially in Europe, the movement was channeled into politics through Green parties. Increasing awareness of global warming began in the 1980s, commencing decades of social and political debate.
The computer is a major technological advancement in this century.
At the beginning of the century, strong discrimination based on race and sex was significant in general society. Although the Atlantic slave trade had ended in the 19th century, the fight for equality for non-white people in the white-dominated societies of North America, Europe, and South Africa continued. During the century, the social taboo of sexism fell. By the end of the 20th century, women had the same legal rights as men in many parts of the world, and racism had come to be seen as abhorrent.[13] Attitudes towards homosexuality also began to change in the later part of the century.
The world at the end of the 20th century
Communications and information technology, transportation technology, and medical advances had radically altered daily lives. Europe appeared to be at a sustainable peace for the first time in recorded history. The people of the Indian subcontinent, a sixth of the world population at the end of the 20th century, had attained an indigenous independence for the first time in centuries. China, an ancient nation comprising a fifth of the world population, was finally open to the world, creating a new state after the near-complete destruction of the old cultural order. With the end of colonialism and the Cold War, nearly a billion people in Africa were left in new nation states after centuries of foreign domination.
The world was undergoing its second major period of globalization; the first, which started in the 18th century, having been terminated by World War I. Since the US was in a dominant position, a major part of the process was Americanization. The influence of China and India was also rising, as the world's largest populations were rapidly integrating with the world economy.
Terrorism, dictatorship, and the spread of nuclear weapons were pressing global issues. The world was still blighted by small-scale wars and other violent conflicts, fueled by competition over resources and by ethnic conflicts. Despots such as Kim Jong-il of North Korea continued to lead their nations toward the development of nuclear weapons.
Disease threatened to destabilize many regions of the world. New viruses such as SARS and West Nile continued to spread. Malaria and other diseases affected large populations. Millions were infected with HIV, the virus which causes AIDS. The virus was becoming an epidemic in southern Africa.
Based on research done by climate scientists, the majority of the scientific community consider that in the long term environmental problems may threaten the planet's habitability.[14] One argument is that of global warming occurring due to human-caused emission of greenhouse gases, particularly carbon dioxide produced by the burning of fossil fuels.[15] This prompted many nations to negotiate and sign the Kyoto treaty, which set mandatory limits on carbon dioxide emissions.
World population increased from about 1.6billion people in 1901 to 6.1billion at the century's end.[16][17]
Map of territorial changes in Europe after World War I (as of 1923).
The number of people killed during the century by government actions was in the hundreds of millions. This includes deaths caused by wars, genocide, politicide and mass murders. The deaths from acts of war during the two world wars alone have been estimated at between 50 and 80 million[citation needed]. Political scientist Rudolph Rummel estimated 262,000,000 deaths caused by democide, which excludes those killed in war battles, civilians unintentionally killed in war and killings of rioting mobs.[18] According to Charles Tilly, "Altogether, about 100 million people died as a direct result of action by organized military units backed by one government or another over the course of the century. Most likely a comparable number of civilians died of war-induced disease and other indirect effects."[19] It is estimated that approximately 70 million Europeans died through war, violence and famine between 1914 and 1945.[20]
After gaining political rights in the United States and much of Europe in the first part of the century, and with the advent of new birth control techniques, women became more independent throughout the century.
Rising nationalism and increasing national awareness were among the many causes of World War I (1914–1918), the first of two wars to involve many major world powers including Germany, France, Italy, Japan, Russia/USSR, the British Empire and the United States. World War I led to the creation of many new countries, especially in Eastern Europe. At the time, it was said by many to be the "war to end all wars".
Civil wars occurred in many nations. A violent civil war broke out in Spain in 1936 when General Francisco Franco rebelled against the Second Spanish Republic. Many[21] consider this war as a testing battleground for World War II, as the fascist armies bombed some Spanish territories.
The Cold War had caused an arms race and increasing competition between the two major players in the world: the Soviet Union and the United States. This competition included the development and improvement of nuclear weapons and the Space Race.
The Soviet authorities caused the deaths of millions of their own citizens in order to eliminate domestic opposition.[22] More than 18 million people passed through the Gulag, with a further 6 million being exiled to remote areas of the Soviet Union.[23]
The civil rights movement in the United States and the movement against apartheid in South Africa challenged racial segregation in those countries.
The end of colonialism led to the independence of many African and Asian countries. During the Cold War, many of these aligned with the United States, the USSR, or China for defense.
The Great Chinese Famine was a direct cause of the death of tens of millions of Chinese peasants between 1959 and 1962. It is thought to be the largest famine in human history.[24]
Hong Kong, under British administration from 1842 to 1997, is one of the original four Asian tigers.
The Tiananmen Square protests of 1989, culminating in the deaths of hundreds of civilian protesters, were a series of demonstrations in and near Tiananmen Square in Beijing, China. Led mainly by students and intellectuals, the protests occurred in a year that saw the collapse of a number of communist governments around the world.
European integration began in earnest in the 1950s, and eventually led to the European Union, a political and economic union that comprised 15 countries at the end of the 20th century.
As the century began, Paris was the artistic capital of the world, where both French and foreign writers, composers and visual artists gathered. By the end of the century New York City had become the artistic capital of the world.
Theater, films, music and the media had a major influence on fashion and trends in all aspects of life. As many films and much music originate from the United States, American culture spread rapidly over the world.
Visual culture became more dominant not only in films but in comics and television as well. During the century a new skilled understanding of narrativist imagery was developed.
Computer games and internet surfing became new and popular form of entertainment during the last 25 years of the century.
In Literature, science fiction, fantasy (with well-developed fictional worlds, rich in detail), and alternative history fiction gained unprecedented popularity. Detective fiction gained unprecedented popularity in the interwar period. In the United States in 1961 Grove Press published Tropic of Cancer a novel by Henry Miller redefining pornography and censorship in publishing in America.
Music
Led Zeppelin are widely considered one of the most successful, innovative, and influential rock groups in history.
The invention of music recording technologies such as the phonograph record, and dissemination technologies such as radio broadcasting, massively expanded the audience for music. Prior to the 20th century, music was generally only experienced in live performances. Many new genres of music were established during the 20th century.
Tango was created in Argentina and became extremely popular in the rest of the Americas and Europe.
Blues and jazz music became popularized during the 1910s and 1920s in the United States.
Blues went on to influence rock and roll in the 1950s, which along with Folk Music, increased in popularity with the British Invasion of the mid-to-late 1960s.
This was challenged with the rise of hip hop in the 1980s and 1990s.
Other genres such as house, techno, reggae, and soul all developed during the latter half of the century and went through various periods of popularity.
Synthesizers began to be employed widely in music and crossed over into the mainstream with new wave music in the 1980s. Electronic instruments have been widely deployed in all manners of popular music and has led to the development of such genres as house, synthpop, electronic dance music, and industrial.
Film as an artistic medium was created in the 20th century. The first modern movie theatre was established in Pittsburgh in 1905.[26]Hollywood developed as the center of American film production. While the first films were in black and white, technicolor was developed in the 1920s to allow for color films. Sound films were developed, with the first full-length feature film, The Jazz Singer, released in 1927. The Academy Awards were established in 1929.
Modern Dance is born in America as both a 'rebellion' against centuries-old European ballet, as well as born from the oppression in America. Dancers and choreographers Alvin Ailey, Isadora Duncan, Vaslav Nijinsky, Ruth St. Denis, Martha Graham, Jose Limon, Doris Humphrey, Merce Cunningham, and Paul Taylor re-defined movement, struggling to bring it back to its 'natural' roots and along with Jazz, created a solely American art form. Alvin Ailey is credited with popularizing modern dance and revolutionizing African-American participation in 20th-century concert dance. His company gained the nickname "Cultural Ambassador to the World" because of its extensive international touring. Ailey's choreographic masterpiece Revelations is believed to be the best known and most often seen modern dance performance.
Video games—due to the great technological steps forward in computing since the second post-war period—are the new form of entertainment emerged in the 20th century alongside films.
Art Nouveau began as advanced architecture and design but fell out of fashion after World War I. The style was dynamic and inventive but unsuited to the depression of the Great War.
In Europe, modern architecture departed from the decorated styles of the Victorian era. Streamlined forms inspired by machines became commonplace, enabled by developments in building materials and technologies. Before World War II, many European architects moved to the United States, where modern architecture continued to develop.
The automobile increased the mobility of people in the Western countries in the early-to-mid-century, and in many other places by the end of the 20th century. City design throughout most of the West became focused on transport via car.
Sport
The popularity of sport increased considerably—both as an activity for all, and as entertainment, particularly on television.
The modern Olympic Games, first held in 1896, grew to include tens of thousands of athletes in dozens of sports.
The FIFA World Cup was first held in 1930, and was held every 4 years after World War II.
A much better understanding of the evolution of the universe was achieved, its age (about 13.8 billion years) was determined, and the Big Bang theory on its origin was proposed and generally accepted.
The age of the Solar System, including Earth, was determined, and it turned out to be much older than believed earlier: more than 4billion years, rather than the 20 million years suggested by Lord Kelvin in 1862.[33]
The planets of the Solar System and their moons were closely observed via numerous space probes. Pluto was discovered in 1930 on the edge of the solar system, although in the early 21st century, it was reclassified as a plutoid instead of a planet proper, leaving eight planets.
No trace of life was discovered on any of the other planets in the Solar System (or elsewhere in the universe), although it remained undetermined whether some forms of primitive life might exist, or might have existed, somewhere. Extrasolar planets were observed for the first time.
Biology
Norman Borlaug, father of the Green Revolution, is often credited with saving over a billion people worldwide from starvation.
The convergence of various sciences for the formulation of the modern evolutionary synthesis (produced between 1936 and 1947), providing a widely accepted account of evolution.
Medicine
A stamp commemorating Alexander Fleming. His discovery of penicillin had changed the world of modern medicine by introducing the age of antibiotics.
Cocaine/crack and heroin were found to be dangerous addictive drugs, and their wide usage had been outlawed; mind-altering drugs such as LSD and MDMA were discovered and later outlawed. In many countries, a war on drugs caused prices to soar 10–20 times higher, leading to profitable black marketdrugdealing, and to prison inmate sentences being 80% related to drug use by the 1990s.[citation needed]
Contraceptive drugs were developed, which reduced population growth rates in industrialized countries, as well as decreased the taboo of premarital sex throughout many western countries.
The development of medical insulin during the 1920s helped raise the life expectancy of diabetics to three times of what it had been earlier.
Vaccines, hygiene and clean water improved health and decreased mortality rates, especially among infants and the young.
Notable diseases
An influenza pandemic, Spanish Flu, killed anywhere from 20 to 100 million people between 1918 and 1919.
A new viral disease, called the Human Immunodeficiency Virus, or HIV, arose in Africa and subsequently killed millions of people throughout the world. HIV leads to a syndrome called Acquired Immunodeficiency Syndrome, or AIDS. Treatments for HIV remained inaccessible to many people living with AIDS and HIV in developing countries, and a cure has yet to be discovered.
Sedentary lifestyles, due to labor-saving devices and technology, along with the increase in home entertainment and technology such as television, video games, and the internet contributed to an "epidemic" of obesity, at first in the rich countries, but by the end of the 20th century spreading to the developing world.
Energy and the environment
Oil field in California, 1938. The first modern oil well was drilled in 1848 by Russian engineer F.N. Semyonov, on the Apsheron Peninsula north-east of Baku.
Widespread use of petroleum in industry—both as a chemical precursor to plastics and as a fuel for the automobile and airplane—led to the geopolitical importance of petroleum resources. The Middle East, home to many of the world's oil deposits, became a center of geopolitical and military tension throughout the latter half of the century. (For example, oil was a factor in Japan's decision to go to war against the United States in 1941, and the oil cartel, OPEC, used an oil embargo of sorts in the wake of the Yom Kippur War in the 1970s).
The increase in fossil fuel consumption also fueled a major scientific controversy over its effect on air pollution, global warming, and global climate change.
First flight of the Wright Flyer I, December 17, 1903, Orville piloting, 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.
The first airplane 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 boats 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 highways reduced the death rate.
New materials, most notably stainless steel, Velcro, silicone, teflon, and plastics such as polystyrene, 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 chemicals were developed for industrial processing and home use.
Space exploration
American Buzz Aldrin during the first moonwalk in 1969. 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 manned presence in space was being founded with the ongoing construction of the International Space Station.
In addition to human spaceflight, unmanned 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, unmanned probes had visited the Moon, Mercury, Venus, Mars, Jupiter, Saturn, Uranus, Neptune, and various asteroids and comets. 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.[36]
The MOSFET (metal-oxide-silicon field-effect transistor), also known as the MOS transistor, was invented by Mohamed Atalla and Dawon Kahng at Bell Labs,[48][49][50][37] in November 1959.[51] It was the first truly compact transistor that could be miniaturised and mass-produced for a wide range of uses.[47] The widespread adoption of MOSFETs revolutionized the electronics industry,[52] and it is the fundamental building block of the Digital Revolution.[53][37] The MOSFET went on to become the most widely manufactured device in history.[54][55]
Semiconductor materials were discovered, and methods of production and purification developed for use in electronic devices. Silicon became one of the purest substances ever produced. The wide adoption of the MOSFET led to silicon becoming the dominant manufacturing material during the late 20th century to early 21st century,[44][45] a period that has been called the Silicon Age,[44][45][46] similar to how the Stone Age, Bronze Age and Iron Age were defined by the dominant materials during their respective ages of civilization.[44]
The number and types of home appliances increased dramatically due to advancements in technology, the wide adoption of MOSFETs, electricity availability, and increases in wealth and leisure time. The microwave oven became popular during the 1980s and have become a standard in all homes by the 1990s. Cable and satellite television spread rapidly during the 1980s and 1990s. Personal computers began to enter the home during the 1970s–1980s as well. The age of the portable music player was enabled by the development of the transistor radio, 8-track and cassette tapes in the 1960s, which slowly began to replace record players, culminating in the Sony Walkman in the late 1970s. These were in turn replaced by the CD during the late 1980s to 1990s. The proliferation of the Internet in the mid-to-late 1990s made digital distribution of music (MP3s) possible. VCRs were popularized in the 1970s, but by the end of the 20th century, DVD players were beginning to replace them, making the VHS obsolete by the end of the first decade of the 21st century.
Electrical engineering is a technical discipline concerned with the study, design and application of equipment, devices and systems which use electricity, electronics, and electromagnetism. It emerged as an identified activity in the latter half of the 19th century after commercialization of the electric telegraph, the telephone, and electrical power generation, distribution and use.
Electronics comprises the physics, engineering, technology and applications that deal with the emission, flow and control of electrons in vacuum and matter.
An integrated circuit or monolithic integrated circuit is a set of electronic circuits on one small flat piece of semiconductor material that is normally silicon. The integration of large numbers of tiny MOS transistors into a small chip results in circuits that are orders of magnitude smaller, faster, and less expensive than those constructed of discrete electronic components. The IC's mass production capability, reliability, and building-block approach to circuit design has ensured the rapid adoption of standardized IC's in place of designs using discrete transistors. ICs are now used in virtually all electronic equipment and have revolutionized the world of electronics. Computers, mobile phones, and other digital home appliances are now inextricable parts of the structure of modern societies, made possible by the small size and low cost of ICs.
A semiconductor material has an electrical conductivity value falling between that of a conductor, such as metallic copper, and an insulator, such as glass. Its resistance falls as its temperature rises; metals are the opposite. Its conducting properties may be altered in useful ways by introducing impurities ("doping") into the crystal structure. Where two differently-doped regions exist in the same crystal, a semiconductor junction is created. The behavior of charge carriers which include electrons, ions and electron holes at these junctions is the basis of diodes, transistors and all modern electronics. Some examples of semiconductors are silicon, germanium, gallium arsenide, and elements near the so-called "metalloid staircase" on the periodic table. After silicon, gallium arsenide is the second most common semiconductor and is used in laser diodes, solar cells, microwave-frequency integrated circuits and others. Silicon is a critical element for fabricating most electronic circuits.
A transistor is a semiconductor device used to amplify or switch electronic signals and electrical power. It is composed of semiconductor material usually with at least three terminals for connection to an external circuit. A voltage or current applied to one pair of the transistor's terminals controls the current through another pair of terminals. Because the controlled (output) power can be higher than the controlling (input) power, a transistor can amplify a signal. Today, some transistors are packaged individually, but many more are found embedded in integrated circuits.
The metal–oxide–semiconductor field-effect transistor (MOSFET, MOS-FET, or MOS FET), also known as the metal–oxide–silicon transistor (MOS transistor, or MOS), is a type of field-effect transistor that is fabricated by the controlled oxidation of a semiconductor, typically silicon. It has a covered gate, whose voltage determines the conductivity of the device. This ability to change conductivity with the amount of applied voltage can be used for amplifying or switching electronic signals. The MOSFET was invented by Egyptian engineer Mohamed M. Atalla and Korean engineer Dawon Kahng at Bell Labs in November 1959. It is the basic building block of modern electronics, and the most widely manufactured device in history, with an estimated total of 13sextillion (1.3 × 1022) MOSFETs manufactured between 1960 and 2018.
Complementary metal–oxide–semiconductor (CMOS), also known as complementary-symmetry metal–oxide–semiconductor (COS-MOS), is a type of MOSFET fabrication process that uses complementary and symmetrical pairs of p-type and n-type MOSFETs for logic functions. CMOS technology is used for constructing integrated circuits (ICs), including microprocessors, microcontrollers, memory chips, and other digital logic circuits. CMOS technology is also used for analog circuits such as image sensors, data converters, RF circuits, and highly integrated transceivers for many types of communication.
The Information Age is a historic period in the 20th century characterized by the rapid shift from traditional industry that the Industrial Revolution brought through industrialization, to an economy further based upon information technology. The onset of the Information Age can be associated with the development of transistor technology, particularly the MOSFET, which revolutionized modern technology and became the fundamental building block of digital electronics in the information age.
The semiconductor industry is the aggregate collection of companies engaged in the design and fabrication of semiconductors. It formed around 1960, once the fabrication of semiconductor devices became a viable business. The industry's annual semiconductor sales revenue has since grown to over $481 billion, as of 2018. The semiconductor industry is in turn the driving force behind the wider electronics industry, with annual power electronics sales of £135billion as of 2011, annual consumer electronics sales expected to reach $2.9 trillion by 2020, tech industry sales expected to reach $5 trillion in 2019, and e-commerce with over $29 trillion in 2017.
A television set or television receiver, more commonly called a television, TV, TV set, or telly, is a device that combines a tuner, display, and loudspeakers, for the purpose of viewing and hearing television shows broadcast through satellites or cables, or viewing and hearing a computer. Introduced in the late 1920s in mechanical form, television sets became a popular consumer product after World War II in electronic form, using cathode ray tube (CRT) technology. The addition of color to broadcast television after 1953 further increased the popularity of television sets in the 1960s, and an outdoor antenna became a common feature of suburban homes. The ubiquitous television set became the display device for the first recorded media in the 1970s, such as Betamax, VHS and later DVD. It has been used as a display device since the first generation of home computers and dedicated video game consoles in the 1980s. By the early 2010s, flat-panel television incorporating liquid-crystal display (LCD) technology, especially LED-backlit LCD technology, largely replaced CRT and other display technologies. Modern flat panel TVs are typically capable of high-definition display and can also play content from a USB device.
The history of telecommunication began with the use of smoke signals and drums in Africa, the Americas and parts of Asia. In the 1790s, the first fixed semaphore systems emerged in Europe. However, it was not until the 1830s that electrical telecommunication systems started to appear. This article details the history of telecommunication and the individuals who helped make telecommunication systems what they are today. The history of telecommunication is an important part of the larger history of communication.
This article details the history of electrical engineering.
The Digital Revolution is the shift from mechanical and analogue electronic technology to digital electronics which began anywhere from the late 1950s to the late 1970s with the adoption and proliferation of digital computers and digital record keeping that continues to the present day. Implicitly, the term also refers to the sweeping changes brought about by digital computing and communication technology during the latter half of the 20th century. Analogous to the Agricultural Revolution and Industrial Revolution, the Digital Revolution marked the beginning of the Information Age.
Nanocircuits are electrical circuits operating on the nanometer scale. This is well into the quantum realm, where quantum mechanical effects become very important. One nanometer is equal to 10−9 meters or a row of 10 hydrogen atoms. With such progressively smaller circuits, more can be fitted on a computer chip. This allows faster and more complex functions using less power. Nanocircuits are composed of three different fundamental components. These are transistors, interconnections, and architecture, all fabricated on the nanometer scale.
A transistor is a semiconductor device with at least three terminals for connection to an electric circuit. The vacuum-tube triode, also called a (thermionic) valve, was the transistor's precursor, introduced in 1907. The principle of a field-effect transistor was proposed by Julius Edgar Lilienfeld in 1925.
Digital Transformation is the use of new, fast and frequently changing digital technology to solve problems often utilising cloud computing, reducing reliance on user owned hardware but increasing reliance on subscription based cloud services. Some of these digital solutions enhance capabilities of traditional software products whilst others are entirely cloud based.
In engineering, electromechanics combines processes and procedures drawn from electrical engineering and mechanical engineering. Electromechanics focuses on the interaction of electrical and mechanical systems as a whole and how the two systems interact with each other. This process is especially prominent in systems such as those of DC or AC rotating electrical machines which can be designed and operated to generate power from a mechanical process (generator) or used to power a mechanical effect (motor). Electrical engineering in this context also encompasses electronics engineering.
This article details the history of electronic engineering. Chambers Twentieth Century Dictionary (1972) defines electronics as "The science and technology of the conduction of electricity in a vacuum, a gas, or a semiconductor, and devices based thereon".
Dawon Kahng was a Korean-American electrical engineer and inventor, known for his work in solid-state electronics. He is best known for inventing the MOSFET, also known as the MOS transistor, with Mohamed Atalla in 1959. Atalla and Kahng developed both the PMOS and NMOS processes for MOSFET semiconductor device fabrication. The MOSFET is the most widely used type of transistor, and the basic element in most modern electronic equipment.
Mohamed Mohamed Atalla was an Egyptian-American engineer, physical chemist, cryptographer, inventor and entrepreneur. His pioneering work in semiconductor technology laid the foundations for modern electronics. Most importantly, his invention of the MOSFET in 1959, along with his earlier surface passivation and thermal oxidation processes, revolutionized the electronics industry. He is also known as the founder of the data security company Atalla Corporation, founded in 1972, which introduced the first hardware security module and was a pioneer in online security. He received the Stuart Ballantine Medal and was inducted into the National Inventors Hall of Fame for his important contributions to semiconductor technology as well as data security.
↑ Ferguson, Niall (2004). Empire: The rise and demise of the British world order and the lessons for global power. New York: Basic Books. ISBN978-0-465-02328-8.
↑ "Total radiative forcing is positive, and has led to an uptake of energy by the climate system. The largest contribution to total radiative forcing is caused by the increase in the atmospheric concentration of CO2 since 1750." (p 11) "From 1750 to 2011, CO2 emissions from fossil fuel combustion and cement production have released 375 [345 to 405] GtC to the atmosphere, while deforestation and other land use change are estimated to have released 180 [100 to 260] GtC." (p. 10), IPCC, Climate Change 2013: The Physical Science Basis – Summary for Policymakers, Observed Changes in the Climate System, pp. 10–11, in IPCC AR5 WG1 2013.
↑ Devaney, Robert L. (1998). A first course in chaotic dynamical systems: theory and experiment (6. printing. ed.). Reading, Mass. [u.a.]: Addison-Wesley. ISBN978-0-201-55406-9.
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