Computer simulations are computer programs that are used to represent and study the behavior of objects or systems in situations that cannot be studied safely or easily in the real world. It is also cheaper to study these subjects with computer simulation. These programs may use a single computer or a network of computers and may run various lengths of time, from a few minutes to several days.
Simulations are similar in principle to children role-playing imaginary scenarios, but instead they use mathematical models to represent something using a computer program. Usually they model real-world systems, but they may also be used to represent imaginary or hypothetical ones.
Simulations are used in a variety of applications, including physics, chemistry, and biology as well as economics, psychology, social sciences, government, and industry. Simple examples of computer simulations include business models such as spreadsheets and graphs used in financial and statistical planning and analysis. Simulations help in the designing and engineering and evaluation of systems such as bridges, highways, and dams. In these cases, engineers may analyze simulations of river systems or traffic patterns before any construction begins.
Computer simulations have been used even since computers were built, and they have contributed to major developments in scientific research. Some computer simulations have made a particularly large impact: One example is the development of the hydrogen bomb. The first general-use digital supercomputer, called the Electronic Numerical Integrator and Computer (or ENIAC) was a massive machine consisting of more than 17,000 vacuum tubes and taking up 1,800 sq. ft. (167 sq m). First used by the U.S. government to calculate ballistic trajectories during World War II (1939–45), shortly after the end of the war it was used for a simulation to test the feasibility of the hydrogen bomb.
Computer simulations continued to be used in military applications in the mid-2010s. In the 1990s, the U.S. Department of Defense ran a massive computer simulation of a desert battle in Kuwait involving a simulation of more than 66,239 tanks, trucks, and other vehicles. It was the largest military simulation of its kind at that time. In the field of astronomy, computer models include simulated space flight for astronauts and mapping of stars and galaxies.
The study of worldwide diseases also makes use of computer simulations. For example, in 2006, researchers from the Fred Hutchinson Cancer Research Center and the Los Alamos National Laboratory with support from the National Institutes of Health conducted a simulation to study the impact of pandemic bird flu in the United States. Researchers used the computer models to measure the impact and results of different interventions (such as distributing antiviral treatments) on the spread of the virus. The results provided information about the effectiveness of different interventions in slowing such a bird flu pandemic long enough to develop an effective vaccine.
In cases of social simulations some critics say that computer-based simulations cannot possibly represent the complexity of human behavior or the human brain. However, simulation technologies continue to advance, enabling researchers to simulate and evaluate scenarios that otherwise could not be observed.
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