General

The 20th century witnessed radical changes in almost every area of human activity. Accelerating scientific understanding, better communications, and faster transportation greatly transformed the world in those hundred years more than nearly any time in the past. It was a century that started with steam-powered ships and ended with the space shuttle. Horses and other pack animals, Western society's basic form of personal transportation for thousands of years, were replaced by automobiles within the span of a few decades. The century also gave rise to humanity's first footsteps on the Moon and computer technology.

The period saw a remarkable shift in the way that vast numbers of people lived, as a result of technological, medical, social, ideological, and political innovation. Arguably more technological advances occurred in any ten-year period following World War I than the sum total of new technological development in any century before the industrial revolution. Terms like ideology, world war, genocide, and nuclear war entered common usage and became an influence on everyone's lives. War reached an unprecedented scale and sophistication; in the Second World War (1939-1945) alone, approximately 57-62 million people died, mainly due to massive advances in weaponry. The trends of mechanization of goods and services and networks of global communication, which began in the 19th century, continued at an ever-increasing pace.

Scientific discoveries such as the theory of relativity and quantum physics radically changed the worldview of scientists, causing them to realize that the universe was much more complex than previously believed, and dashing the hopes at the end of the nineteenth century that the last few details of scientific knowledge were about to be filled in.

The massive arms race of the Nineteenth Century finally culminated in a war which involved every powerful nation in the world - The Great War. After more than four years of horrifying trench warfare, and 10 million dead, Germany's imperial ambitions were finally thwarted, and her international status greatly reduced. The Russian Empire was plunged into revolution during the conflict, and the Austro-Hungarian, and Ottoman empires were dismantled at the war's conclusion. The conflict saw the beginning of international American involvement which would accelerate as that nation began to find itself in a position of extreme power. As the British Empire, its economy ruined by the war, began to shrink, a power vacuum began to develop. Fascism, a movement which grew out of post war angst, gained momentum in Italy, Germany and Spain in the 1920s and 1930s, finally culminating in the Second World War, sparked off by a revitalized Germany's aggressive expansion at the expense of her neighbours. The largest and most devastating war ever fought, World War II claimed the lives of 60 million people. The United States and the USSR emerged as the most powerful nations when the conflict ended in 1945, and subsequently began a new arms race, with new technologies such as nuclear weapons and space age technology, in the Cold War.

Wars and politics

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a British Mark I Tank crossing a trench,
the Royal Navy battleship HMS Irresistible sinking after striking a mine at the battle of the Dardanelles,
a Vickers machine gun crew with gas masks, and German Albatros D.III biplanes]]

After decades of struggle by the women's suffrage movement, all western countries gave women the right to vote.

Rising nationalism and increasing national awareness were among the causes of World War I (1914–1918), the first of two wars to involve all the major world powers including Germany, France, Italy, Japan, the United States and the British Empire. World War I led to the creation of many new countries, especially in Eastern Europe. Ironically, it was said by many to be the "war to end all wars".

A violent civil war broke out in Spain in 1936 when General Francisco Franco rebelled against the Second Spanish Republic. Many consider this war as a testing battleground for WWII as the fascist armies bombed some Spanish territories.

The economic and political aftermath of World War I and the Great Depression in the 1930s led to the rise of fascism and nazism in Europe, and subsequently to World War II (1939–1945). This war also involved Asia and the Pacific, in the form of Japanese aggression against China and the United States. Civilians also suffered greatly in World War II, due to the aerial bombing of cities on both sides, and the German genocide of the Jews and others, known as the Holocaust. In 1945, the atomic bombings of Hiroshima and Nagasaki took place.

During World War I, in Russia the Bolshevik putsch took over the Russian Revolution of 1917, precipitating the founding of the Soviet Union and rise of communism. After the Soviet Union's involvement in World War II, communism became a major force in global politics, notably in Eastern Europe, China, Indochina and Cuba, where communist parties gained near-absolute power. This led to the Cold War and proxy wars with the West, including wars in Korea (1950–1953) and Vietnam (1957–1975).

The civil rights movement in the USA and the movement against apartheid in South Africa successfully challenged racial segregation.

The two world wars led to efforts to increase international cooperation, notably through the founding of the League of Nations after World War I, and its successor, the United Nations, after World War II.

The creation of Israel by the British, a Jewish state in the Middle East fueled many regional conflicts. These were also influenced by the vast oil fields in many of the other countries of the mostly Arab region.

The end of colonialism led to the independence of many African and Asian countries. During the Cold War, many of these aligned with the USA, the USSR, or China for defense.

The revolutions of 1989 released Eastern and Central Europe from Soviet supremacy. Soon thereafter, the Soviet Union, Czechoslovakia, and Yugoslavia dissolved, the latter violently over several years, into successor states, many rife with ethnic nationalism. This left the United States as the world's only superpower.

After a long period of civil wars and conflicts with European powers, China's last imperial dynasty ended in 1912. The resulting republic was replaced, after yet another civil war, by a people's republic in 1949. At the end of the century, though still ruled by a communist party, China's economic system was well on its way to an almost complete transformation to capitalism.

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 century.

Culture and entertainment

As the century begins, Paris is the artistic capital of the world, where both French and foreign writers, composers and visual artists gather. By the end of the century, the focal point of culture had moved to the United States, especially New York City and Los Angeles.

Movies, music and the media had a major influence on fashion and trends in all aspects of life. As many movies and music originate from the United States, American culture spread rapidly over the world.

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.

In classical music, composition branched out into many completely new domains, including dodecaphony, aleatoric and chance music, and minimalism. Electronic musical instruments were developed as well, vastly broadening the scope of sounds available to composers and performers.

Rock and Roll and Jazz styles of music are developed in the United States, and quickly become the dominant forms of popular music in America, and later, the world. Many other styles of music develop and spread as well, also branching off and influencing each other, including Pop Music, Alternative, House or Dance, Soul, Rap and Hip-Hop.

The plastic arts developed new styles such as expressionism, cubism, and surrealism.

Modern architecture evolved within Europe with a radical departure from the excess decoration of the Victorian era — streamlined forms inspired by machines became more commonplace. Developments in building material technologies furthered this shift. European architects moved to the United States prior to World War II, where modern archiectural theory continued to blossom.

The automobile provided vastly increased transportation capabilities for the average member of Western societies in the early to mid-century, spreading even further later on. City design throughout most of the West became focused on transport via car. The car became a leading symbol of modern society, with styles of car suited to and symbolic of particular lifestyles.

Sports became an important part of society, becoming an activity not only for the privileged. Watching sports, later also on television, became a popular activity.

Medicine

Placebo controlled, ranzomized, blind clinical trials became a powerful tool for testing new medicines.

Antibiotics drastically reduced mortality from bacterial diseases and their prevalence.

A vaccine was developed for polio, ending a worldwide epidemic.

X-rays became powerful diagnostic tool for wide spectrum of diseases, from bone fractures to cancer. In the 1960s, computerized tomography was invented.

Another important diagnostics tool is sonography.

Development of vitamins virtually eliminated scurvy and other vitamin-deficiency diseases.

New psychiatric drugs were developed. This includes antipsychotics which are efficient in treating hallucinations and delusions, and antidepressants for treating depression.

Role of tobacco smoking in developing cancer and other diseases had been proved in 1950s (see British Doctors Study).

New methods for cancer treatment, namely chemotherapy, radiation therapy, and immunotherapy, were developed. As a result, in many cases cancer can be completely healed.

New methods for heart surgery were developed.

Cocaine and heroin were found to be dangerous addictive drugs, and their wide usage had been outlawed.

Contraceptive drugs were developed, which reduced population growth rates.

The development of medical insulin in the 1920s helped raise the life expectancy of diabetics three times of what it had been prior.

Natural resources and the environment

, 1938
The first modern oil well was drilled in 1848 by Russian engineer F.N. Semyonov, on the Apsheron Peninsula north-east of Baku.]]

The 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 vital 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).

A vast increase in fossil fuel consumption, according to some, leads to depletion of natural resources, global warming and both local and global climate change. The problem is increased by, believed by many, world-wide deforestation, also causing a loss of biodiversity.