Science (from the Latin word scientia, meaning "knowledge")[1] is a systematic enterprise that builds and organizes knowledge in the form of testable explanations and predictions about the universe

The earliest roots of science can be traced to Ancient Egypt and Mesopotamia in around 3500 to 3000 BCE.[5][6] Their contributions to mathematics, astronomy, and medicine entered and shaped Greek natural philosophy of classical antiquity, whereby formal attempts were made to provide explanations of events in the physical world based on natural causes.[5][6] After the fall of the Western Roman Empire, knowledge of Greek conceptions of the world deteriorated in Western Europe during the early centuries (400 to 1000 CE) of the Middle Ages[7] but was preserved in the Muslim world during the Islamic Golden Age.[8] The recovery and assimilation of Greek works and Islamic inquiries into Western Europe from the 10th to 13th century revived "natural philosophy",[7][9] which was later transformed by the Scientific Revolution that began in the 16th century[10] as new ideas and discoveries departed from previous Greek conceptions and traditions.[11][12][13][14] The scientific method soon played a greater role in knowledge creation and it was not until the 19th century that many of the institutional and professional features of science began to take shape;[15][16][17] along with the changing of "natural philosophy" to "natural science."[18]

Modern science is typically divided into three major branches that consist of the natural sciences (e.g., biology, chemistry, and physics), which study nature in the broadest sense; the social sciences (e.g., economics, psychology, and sociology), which study individuals and societies; and the formal sciences (e.g., logic, mathematics, and theoretical computer science), which study abstract concepts. There is disagreement,[19][20][21] however, on whether the formal sciences actually constitute a science as they do not rely on empirical evidence.[22][20] Disciplines that use existing scientific knowledge for practical purposes, such as engineering and medicine, are described as applied sciences.[23][24][25][26]

Science is based on research, which is commonly conducted in academic and research institutions as well as in government agencies and companies. The practical impact of scientific research has led to the emergence of science policies that seek to influence the scientific enterprise by prioritizing the development of commercial products, armaments, health care, and environmental protection.

Technology ("science of craft", from Greek τέχνη, techne, "art, skill, cunning of hand"; and -λογία, -logia[2]) is the sum of techniques, skills, methods, and processes used in the production of goods or services or in the accomplishment of objectives, such as scientific investigation. Technology can be the knowledge of techniques, processes, and the like, or it can be embedded in machines to allow for operation without detailed knowledge of their workings. Systems (e.g. machines) applying technology by taking an input, changing it according to the system's use, and then producing an outcome are referred to as technology systems or technological systems.

The simplest form of technology is the development and use of basic tools. The prehistoric discovery of how to control fire and the later Neolithic Revolution increased the available sources of food, and the invention of the wheel helped humans to travel in and control their environment. Developments in historic times, 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.

Technology has many effects. It 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 Earth's environment. Innovations have always influenced the values of a society and raised new questions in the ethics of technology. Examples include the rise of the notion of efficiency in terms of human productivity, and the challenges of bioethics.

Philosophical debates have arisen over the use of technology, with disagreements over whether technology improves the human condition or worsens it. Neo-Luddism, anarcho-primitivism, and similar reactionary movements criticize the pervasiveness of technology, arguing 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.

Science in a broad sense existed before the modern era and in many historical civilizations.[27] 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.[3][5][28] 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,[29] 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

History of technology, timeline of electrical and electronic engineering, and timeline of historic inventions

Paleolithic (2.5 Ma – 10 ka)

A primitive chopper

Further information: Outline of prehistoric technology

The use of tools by early humans was partly a process of discovery and of evolution. Early humans evolved from a species of foraging hominids which were already bipedal,[22] with a brain mass approximately one third of modern humans.[23] Tool use remained relatively unchanged for most of early human history. Approximately 50,000 years ago, the use of tools and complex set of behaviors emerged, believed by many archaeologists to be connected to the emergence of fully modern language.[24]

Stone tools

Hand axes from the Acheulian period

A Clovis point, made via pressure flaking

Hominids started using primitive stone tools millions of years ago. The earliest stone tools were little more than a fractured rock, but approximately 75,000 years ago,[25] pressure flaking provided a way to make much finer work.

Fire

Main article: Control of fire by early humans

The discovery and use of fire, a simple energy source with many profound uses, was a turning point in the technological evolution of humankind.[26] The exact date of its discovery is not known; evidence of burnt animal bones at the Cradle of Humankind suggests that the domestication of fire occurred before 1 Ma;[27] scholarly consensus indicates that Homo erectus had controlled fire by between 500 and 400 ka.[28][29] Fire, fueled with wood and charcoal, allowed early humans to cook their food to increase its digestibility, improving its nutrient value and broadening the number of foods that could be eaten.[30]

Clothing and shelter

Other technological advances made during the Paleolithic era were clothing and shelter; the adoption of both technologies cannot be dated exactly, but they were a key to humanity's progress. As the Paleolithic era progressed, dwellings became more sophisticated and more elaborate; as early as 380 ka, humans were constructing temporary wood huts.[31][32] Clothing, adapted from the fur and hides of hunted animals, helped humanity expand into colder regions; humans began to migrate out of Africa by 200 ka and into other continents such as Eurasia.[33]

Neolithic through classical antiquity (10 ka – 300 CE)

An array of Neolithic artifacts, including bracelets, axe heads, chisels, and polishing tools

Human's technological ascent began in earnest in what is known as the Neolithic Period ("New Stone Age"). The invention of polished stone axes was a major advance that allowed forest clearance on a large scale to create farms. This use of polished stone axes increased greatly in the Neolithic, but were originally used in the preceding Mesolithic in some areas such as Ireland.[34] Agriculture fed larger populations, and the transition to sedentism allowed simultaneously raising more children, as infants no longer needed to be carried, as nomadic ones must. Additionally, children could contribute labor to the raising of crops more readily than they could to the hunter-gatherer economy.[35][36]

With this increase in population and availability of labor came an increase in labor specialization.[37] What triggered the progression from early Neolithic villages to the first cities, such as Uruk, and the first civilizations, such as Sumer, is not specifically known; however, the emergence of increasingly hierarchical social structures and specialized labor, of trade and war amongst adjacent cultures, and the need for collective action to overcome environmental challenges such as irrigation, are all thought to have played a role.[38]

Metal tools

Continuing improvements led to the furnace and bellows and provided, for the first time, the ability to smelt and forge gold, copper, silver, and lead – native metals found in relatively pure form in nature.[39] The advantages of copper tools over stone, bone, and wooden tools were quickly apparent to early humans, and native copper was probably used from near the beginning of Neolithic times (about 10 ka).[40] Native copper does not naturally occur in large amounts, but copper ores are quite common and some of them produce metal easily when burned in wood or charcoal fires. Eventually, the working of metals led to the discovery of alloys such as bronze and brass (about 4000 BCE). The first uses of iron alloys such as steel dates to around 1800 BCE.[41][42