Technology Technology is the making, modification or improvement, applied activity or behavior, use and knowledge of tools, machines, techniques, crafts, systems, methods of organization, or environmental modifications or arrangement in order to solve a problem, improve a preexisting solution to a problem, achieve a goal or perform a specific function. It can also refer to the collection of such tools, machinery, modifications, environmental arrangement and procedures. Technologies significantly affect human as well as other animal species' ability to control and adapt to their natural environments. The word technology comes from Greek ?????????? (technologia); from ????? (techne), meaning "art, skill, craft", and -????? (-logia), meaning "study of-". The term can either be applied generally or to specific areas: examples include construction technology, medical technology, and information technology. Technologies significantly affect human as well as other animal species' ability to control and adapt to their natural environments. The human species' use of technology began with the conversion of natural resources into simple tools. The prehistorical discovery of the ability to control fire increased the available sources of food and the invention of the wheel helped humans in travelling in and controlling their environment. Recent technological developments, including the printing press, the telephone, and the Internet, have lessened physical barriers to communication and allowed humans to interact freely on a global scale. However, not all technology has been used for peaceful purposes; the development of weapons of ever-increasing destructive power has progressed throughout history, from clubs to nuclear weapons. Technology has affected society and its surroundings in a number of ways. In many societies, technology has helped develop more advanced economies (including today's global economy) and has allowed the rise of a leisure class. Many technological processes produce unwanted by-products, known as pollution, and deplete natural resources, to the detriment of the Earth and its environment. Various implementations of technology influence the values of a society and new technology often raises new ethical questions. Examples include the rise of the notion of efficiency in terms of human productivity, a term originally applied only to machines, and the challenge of traditional norms. Philosophical debates have arisen over the present and future use of technology in society, with disagreements over whether technology improves the human condition or worsens it. Neo-Luddism, anarcho-primitivism, and similar movements criticise the pervasiveness of technology in the modern world, opining that it harms the environment and alienates people; proponents of ideologies such as transhumanism and techno-progressivism view continued technological progress as beneficial to society and the human condition. Indeed, until recently, it was believed that the development of technology was restricted only to human beings, but recent scientific studies indicate that other primates and certain dolphin communities have developed simple tools and learned to pass their knowledge to other generations.

Nuclear weapon "A-bomb" redirects here. For other uses, see A-bomb (disambiguation). For the 1979 song, see Nuclear Device (The Wizard of Aus). The mushroom cloud of the atomic bombing of Nagasaki, Japan on August 9, 1945 rose some 18 kilometers (11 mi) above the bomb's hypocenter. Nuclear weapons Background History Warfare Arms race Design Testing Effects Delivery Espionage Proliferation Arsenals Terrorism Opposition Nuclear-armed states United States Russia United Kingdom France China Israel India Pakistan North Korea South Africa (former) v t e A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions, either fission or a combination of fission and fusion. Both reactions release vast quantities of energy from relatively small amounts of matter. The first fission ("atomic") bomb test released the same amount of energy as approximately 20,000 tons of TNT. The first thermonuclear ("hydrogen") bomb test released the same amount of energy as approximately 10,000,000 tons of TNT.[1] A modern thermonuclear weapon weighing little more than 2,400 pounds (1,100 kg) can produce an explosive force comparable to the detonation of more than 1.2 million tons (1.1 million tonnes) of TNT.[2] Thus, even a small nuclear device no larger than traditional bombs can devastate an entire city by blast, fire and radiation. Nuclear weapons are considered weapons of mass destruction, and their use and control have been a major focus of international relations policy since their debut. Only two nuclear weapons have been used in the course of warfare, both by the United States near the end of World War II. On 6 August 1945, a uranium gun-type fission bomb code-named "Little Boy" was detonated over the Japanese city of Hiroshima. Three days later, on 9 August, a plutonium implosion-type fission bomb code-named "Fat Man" was exploded over Nagasaki, Japan. These two bombings resulted in the deaths of approximately 200,000 Japanese peoplemostly civiliansfrom acute injuries sustained from the explosions.[3] The role of the bombings in Japan's surrender, and their ethical status, remain the subject of scholarly and popular debate. Since the bombings of Hiroshima and Nagasaki, nuclear weapons have been detonated on over two thousand occasions for testing purposes and demonstrations. Only a few nations possess such weapons or are suspected of seeking them. The only countries known to have detonated nuclear weaponsand that acknowledge possessing such weaponsare (chronologically by date of first test) the United States, the Soviet Union (succeeded as a nuclear power by Russia), the United Kingdom, France, the People's Republic of China, India, Pakistan, and North Korea. In addition, Israel is also widely believed to possess nuclear weapons, though it does not acknowledge having them.[4][5][6] One state, South Africa, fabricated nuclear weapons in the past, but as its apartheid regime was coming to an end it disassembled its arsenal, acceded to the NPT and accepted full-scope international safeguards.[7] The Federation of American Scientists estimates there are more than 19,000 nuclear warheads in the world as of 2012, with around 4,400 of them kept in "operational" status, ready for use.