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Science in a broad sense existed before the modern era and in many historical civilizations.Modern science is distinct in its approach and successful in its results, so it now defines what science is in the strictest sense of the term. Science in its original sense was a word for a type of knowledge, rather than a specialized word for the pursuit of such knowledge. In particular, it was the type of knowledge that people can communicate to each other and share. For example, knowledge about the working of natural things was gathered long before recorded history and led to the development of complex abstract thought. This is shown by the construction of complex calendars, techniques for making poisonous plants edible, public works at a national scale, such as those which harnessed the floodplain of the Yangtse with reservoirs,dams, and dikes, and buildings such as the Pyramids. However, no consistent conscious distinction was made between knowledge of such things, which are true in every community, and other types of communal knowledge, such as mythologies and legal systems. Metallurgy was known in prehistory, and the Vinča culture was the earliest known producer of bronze-like alloys. It is thought that early experimentation with heating and mixing of substances over time developed into alchemy.
Albert Einstein’s theory of relativity and the development of quantum mechanics led to the replacement of classical mechanics with a new physics which contains two parts that describe different types of events in nature.
In the first half of the century, the development of antibiotics and artificial fertilizers made global human population growth possible. At the same time, the structure of the atom and its nucleus was discovered, leading to the release of “atomic energy” (nuclear power). In addition, the extensive use of technological innovation stimulated by the wars of this century led to revolutions in transportation (automobiles and aircraft), the development of ICBMs, a space race, and a nuclear arms race.
Evolution became a unified theory in the early 20th-century when the modern synthesis reconciled Darwinian evolution with classical genetics. The molecular structure of DNA was discovered by James Watson and Francis Crick in 1953.
The discovery of the cosmic microwave background radiation in 1964 led to a rejection of the Steady State theory of the universe in favor of the Big Bang theory of Georges Lemaître.
The development of spaceflight in the second half of the century allowed the first astronomical measurements done on or near other objects in space, including six manned landings on the Moon. Space telescopes lead to numerous discoveries in astronomy and cosmology.
Widespread use of integrated circuits in the last quarter of the 20th century combined with communications satellites led to a revolution in information technology and the rise of the global internet and mobile computing, including smartphones. The need for mass systematization of long, intertwined causal chains and large amounts of data led to the rise of the fields of systems theory and computer-assisted scientific modelling, which are partly based on the Aristotelian paradigm.
Harmful environmental issues such as ozone depletion, acidification, eutrophication and climate change came to the public’s attention in the same period, and caused the onset of environmental science and environmental technology.
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