Science is a systematic discipline that builds and organises
knowledge
Knowledge is an awareness of facts ( descriptive knowledge), a familiarity with individuals and situations ( knowledge by acquaintance), or a practical skill ( procedural knowledge). Descriptive knowledge, also called ''propositional knowle ...
in the form of testable explanations about
nature
Nature, in the broadest sense, is the physical world or universe. In this general sense nature refers to the laws, elements and phenomena of the physical world, including life. Although humans are part of nature, human activity or humans ...
and
society
A society is a group of individuals involved in persistent social interaction or a large social group sharing the same spatial or social territory, typically subject to the same political authority and dominant cultural expectations. So ...
.
It is driven by the
scientific method: an empirical cycle that typically involves making observations, producing
hypotheses, testing them with
evidence, and drawing conclusions. Science encompasses this process and the body of knowledge it produces, which the
scientific community continuously challenges, validates, and organises.
Modern science is typically divided into twoor threemajor branches:
the
natural sciences, which study the physical world, and the
social sciences, which study individuals and societies.
While referred to as the
formal sciences, the study of
logic
Logic is the study of correct reasoning. It includes both formal and informal logic. Formal logic is the study of deductively valid inferences or logical truths. It examines how conclusions follow from premises based on the structure o ...
, mathematics, and
theoretical computer science are typically regarded as separate because they rely on
deductive reasoning instead of the
scientific method as their main methodology.
Meanwhile,
applied sciences are disciplines that use scientific knowledge for practical purposes, such as engineering and medicine.
The
history of science spans the majority of the historical record, with the earliest identifiable predecessors to modern science dating to the
Bronze Age in
Egypt
Egypt, officially the Arab Republic of Egypt, is a country spanning the northeast corner of Africa and southwest corner of Asia via the Sinai Peninsula. It is bordered by the Mediterranean Sea to the north, Palestine and Israel to the ...
and
Mesopotamia
Mesopotamia is a historical region of West Asia situated within the Tigris–Euphrates river system, in the northern part of the Fertile Crescent. It corresponds roughly to the territory of modern Iraq. Just beyond it lies southwestern ...
(). Their contributions to mathematics,
astronomy
Astronomy is a natural science that studies celestial objects and the phenomena that occur in the cosmos. It uses mathematics, physics, and chemistry to explain their origin and their overall evolution. Objects of interest include plan ...
, and medicine entered and shaped the Greek
natural philosophy of
classical antiquity and later
medieval scholarship, whereby formal attempts were made to provide explanations of events in the physical world based on natural causes; while further advances, including the introduction of the
Hindu–Arabic numeral system, were made during the
Golden Age of India and
Islamic Golden Age.
The recovery and assimilation of
Greek works and
Islamic inquiries into Western Europe during the
Renaissance
The Renaissance ( , ) was a European period of history and cultural movement taking place at the end of the Late Middle Ages and the beginning of the early modern era. It is variously defined as covering the 15th and 16th centuries revived natural philosophy,
which was later transformed by the
Scientific Revolution that began in the 16th century as new ideas and discoveries departed from previous Greek conceptions and traditions.
The scientific method soon played a greater role in the acquisition of knowledge, and in the
19th century, many of the
institutional and
professional
A professional is a member of a profession or any person who works in a specified professional activity. The term also describes the standards of education and training that prepare members of the profession with the particular knowledge and sk ...
features of science began to take shape, along with the changing of "natural philosophy" to "natural science".
New knowledge in science is advanced by research from scientists who are motivated by curiosity about the world and a desire to solve problems. Contemporary scientific research is often highly collaborative and is frequently carried out by teams in
academic
Academic or academics may refer to:
* Academic discipline, a subdivision of knowledge that is taught and researched at the college or university level
* Academic institution, an educational institution dedicated to education and research
* Acad ...
and
research institutions, government agencies,
and companies. At the same time, many major advances—particularly in
fundamental science—have come from individual researchers and are widely recognised through major international awards such as the
Nobel Prize. The practical results of scientific work have led to the emergence of
science policies that seek to prioritise the
responsible development of commercial products,
health care, public infrastructure,
environmental protection, and defense capabilities.
Etymology
The word ''science'' has been used in English since the 14th century (
Middle English) in the sense of "the state of knowing". The word was borrowed from the
Anglo-Norman language as the suffix , which was borrowed from the
Latin
Latin ( or ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally spoken by the Latins in Latium (now known as Lazio), the lower Tiber area around Rome, Italy. Through the expansi ...
word , meaning , a
noun derivative of meaning , itself the present active participle of .
There are many hypotheses for ''science''s ultimate word origin. According to
Michiel de Vaan, Dutch linguist and
Indo-Europeanist, may have its origin in the
Proto-Italic language as or meaning , which may originate from
Proto-Indo-European language as , meaning . The ''
Lexikon der indogermanischen Verben'' proposed is a
back-formation of , meaning , which may derive from Proto-Indo-European ' in Latin , or from meaning .
In the past, science was a synonym for "knowledge" or "study", in keeping with its Latin origin. A person who conducted scientific research was called a "natural philosopher" or "man of science". In 1834,
William Whewell introduced the term ''scientist'' in a review of
Mary Somerville's book ''
On the Connexion of the Physical Sciences'', crediting it to "some ingenious gentleman" (possibly himself).
History
Early history
Science has no single origin. Rather, scientific thinking emerged gradually over the course of tens of thousands of years, taking different forms around the world, and few details are known about the very earliest developments.
Women likely played a central role in prehistoric science, as did
religious rituals. Some scholars use the term "
protoscience" to label activities in the past that resemble modern science in some but not all features; however, this label has also been criticised as denigrating, or too suggestive of
presentism, thinking about those activities only in relation to modern categories.
Direct evidence for scientific processes becomes clearer with the advent of
writing systems in the
Bronze Age civilisations of
Ancient Egypt and
Mesopotamia
Mesopotamia is a historical region of West Asia situated within the Tigris–Euphrates river system, in the northern part of the Fertile Crescent. It corresponds roughly to the territory of modern Iraq. Just beyond it lies southwestern ...
(), creating the earliest written records in the
history of science.
Although the words and concepts of "science" and "nature" were not part of the conceptual landscape at the time, the ancient Egyptians and Mesopotamians made contributions that would later find a place in Greek and medieval science: mathematics, astronomy, and medicine.
From the 3rd millennium BCE, the ancient Egyptians developed a non-positional
decimal numbering system, solved practical problems using
geometry
Geometry is a branch of mathematics concerned with properties of space such as the distance, shape, size, and relative position of figures. Geometry is, along with arithmetic, one of the oldest branches of mathematics. A mathematician who wo ...
, and developed a
calendar
A calendar is a system of organizing days. This is done by giving names to periods of time, typically days, weeks, months and years. A date is the designation of a single and specific day within such a system. A calendar is also a p ...
. Their healing therapies involved drug treatments and the supernatural, such as prayers,
incantations, and rituals.
Ancient
Nubians pioneered early
antibiotics and established a system of geometrics which served as the basis for initial
sunclocks. Nubians also exercised a
trigonometric methodology comparable to their Egyptian counterparts.
The ancient
Mesopotamia
Mesopotamia is a historical region of West Asia situated within the Tigris–Euphrates river system, in the northern part of the Fertile Crescent. It corresponds roughly to the territory of modern Iraq. Just beyond it lies southwestern ...
ns used knowledge about the properties of various natural chemicals for manufacturing
pottery,
faience, glass, soap, metals,
lime plaster, and waterproofing.
They studied
animal physiology,
anatomy
Anatomy () is the branch of morphology concerned with the study of the internal and external structure of organisms and their parts. Anatomy is a branch of natural science that deals with the structural organization of living things. It i ...
,
behaviour, and
astrology for
divinatory purposes. The Mesopotamians had an
intense interest in medicine and the earliest
medical prescriptions appeared in
Sumerian
Sumerian or Sumerians may refer to:
*Sumer
Sumer ( ) is the earliest known civilization, located in the historical region of southern Mesopotamia (now south-central Iraq), emerging during the Chalcolithic and early Bronze Ages between the ...
during the
Third Dynasty of Ur.
They seem to have studied scientific subjects which had practical or religious applications and had little interest in satisfying curiosity.
Classical antiquity
In
classical antiquity, there is no real ancient analogue of a modern scientist. Instead, well-educated, usually upper-class, and almost universally male individuals performed various investigations into nature whenever they could afford the time. Before the invention or discovery of the
concept
A concept is a fundamental unit of cognition that classifies entities and encodes shared features. Concepts make it possible to form and combine ideas, draw inferences, and refer to external objects. They act as the meanings of words and pla ...
of ''
phusis'' or nature by the
pre-Socratic philosophers, the same words tend to be used to describe the natural "way" in which a plant grows, and the "way" in which, for example, one tribe worships a particular god. For this reason, it is claimed that these men were the first philosophers in the strict sense and the first to clearly distinguish "nature" and "convention".
The early
Greek philosophers of the Milesian school, which was founded by
Thales of Miletus and later continued by his successors
Anaximander and
Anaximenes, were the first to attempt to explain
natural phenomena without relying on the
supernatural
Supernatural phenomena or entities are those beyond the laws of nature. The term is derived from Medieval Latin , from Latin 'above, beyond, outside of' + 'nature'. Although the corollary term "nature" has had multiple meanings since the a ...
. The
Pythagoreans developed a
complex number philosophy
and contributed significantly to the development of mathematical science.
The
theory of atoms was developed by the Greek philosopher
Leucippus and his student
Democritus. Later,
Epicurus would develop a full natural cosmology based on atomism, and would adopt a "canon" (ruler, standard) which established physical criteria or standards of scientific truth. The Greek doctor
Hippocrates established the tradition of systematic medical science and is known as "
The Father of Medicine".
A turning point in the history of early philosophical science was
Socrates
Socrates (; ; – 399 BC) was an ancient Greek philosopher from Classical Athens, perhaps the first Western moral philosopher, and a major inspiration on his student Plato, who largely founded the tradition of Western philosophy. A ...
' example of applying philosophy to the study of human matters, including human nature, the nature of political communities, and human knowledge itself. The
Socratic method as documented by
Plato
Plato ( ; , ; ) was an ancient Greek philosopher of Classical Athens who is most commonly considered the foundational thinker of the Western philosophical tradition. An innovator of the literary dialogue and dialectic forms, Plato influe ...
's dialogues is a
dialectic method of hypothesis elimination: better hypotheses are found by steadily identifying and eliminating those that lead to contradictions. The Socratic method searches for general commonly held truths that shape beliefs and scrutinises them for consistency. Socrates criticised the older type of study of physics as too purely speculative and lacking in
self-criticism.
In the 4th century BCE,
Aristotle
Aristotle (; 384–322 BC) was an ancient Greek philosopher and polymath. His writings span the natural sciences, philosophy, linguistics, economics, politics, psychology, and the arts. As the founder of the Peripatetic schoo ...
created a systematic programme of
teleological philosophy. In the 3rd century BCE, Greek astronomer
Aristarchus of Samos was the first to propose a
heliocentric model of the universe, with the Sun at the centre and all the planets orbiting it.
Aristarchus's model was widely rejected because it was believed to violate the laws of physics,
while Ptolemy's ''
Almagest
The ''Almagest'' ( ) is a 2nd-century mathematical and astronomical treatise on the apparent motions of the stars and planetary paths, written by Claudius Ptolemy ( ) in Koine Greek. One of the most influential scientific texts in history, i ...
'', which contains a geocentric description of the
Solar System, was accepted through the early Renaissance instead. The inventor and mathematician
Archimedes of Syracuse made major contributions to the beginnings of
calculus.
Pliny the Elder was a Roman writer and
polymath
A polymath or polyhistor is an individual whose knowledge spans many different subjects, known to draw on complex bodies of knowledge to solve specific problems. Polymaths often prefer a specific context in which to explain their knowledge, ...
, who wrote the seminal encyclopaedia ''
Natural History''.
Positional notation for representing numbers likely emerged between the 3rd and 5th centuries CE along Indian trade routes. This numeral system made efficient
arithmetic operations more accessible and would eventually become standard for mathematics worldwide.
Middle Ages
Due to the
collapse of the Western Roman Empire, the 5th century saw an intellectual decline, with knowledge of classical Greek conceptions of the world deteriorating in Western Europe.
Latin encyclopaedists of the period such as
Isidore of Seville preserved the majority of general ancient knowledge. In contrast, because the
Byzantine Empire resisted attacks from invaders, they were able to preserve and improve prior learning.
John Philoponus, a Byzantine scholar in the 6th century, started to question Aristotle's teaching of physics, introducing the
theory of impetus.
His criticism served as an inspiration to medieval scholars and Galileo Galilei, who extensively cited his works ten centuries later.
During
late antiquity and the
Early Middle Ages, natural phenomena were mainly examined via the Aristotelian approach. The approach includes Aristotle's
four causes: material, formal, moving, and final cause. Many Greek classical texts were preserved by the
Byzantine Empire and
Arabic
Arabic is a Central Semitic language of the Afroasiatic language family spoken primarily in the Arab world. The International Organization for Standardization (ISO) assigns language codes to 32 varieties of Arabic, including its standard ...
translations were made by Christians, mainly
Nestorians and
Miaphysites. Under the Abbasids, these Arabic translations were later improved and developed by Arabic scientists.
By the 6th and 7th centuries, the neighbouring
Sasanian Empire established the medical
Academy of Gondishapur, which was considered by Greek, Syriac, and Persian physicians as the most important medical hub of the ancient world.
Islamic study of
Aristotelianism
Aristotelianism ( ) is a philosophical tradition inspired by the work of Aristotle, usually characterized by deductive logic and an analytic inductive method in the study of natural philosophy and metaphysics. It covers the treatment of the so ...
flourished in the
House of Wisdom established in the Abbasid capital of
Baghdad
Baghdad is the capital and largest city in Iraq. It is located on the banks of the Tigris in central Iraq. The city has an estimated population of 8 million. It ranks among the most populous and largest cities in the Middle East and the Ara ...
, Iraq and it flourished until the
Mongol invasions in the 13th century.
Ibn al-Haytham, better known as Alhazen, used controlled experiments in his optical study.
Avicenna
Ibn Sina ( – 22 June 1037), commonly known in the West as Avicenna ( ), was a preeminent philosopher and physician of the Muslim world. He was a seminal figure of the Islamic Golden Age, serving in the courts of various Iranian rule ...
's compilation of ''
The Canon of Medicine'', a medical encyclopaedia, is considered to be one of the most important publications in medicine and was used until the 18th century.
By the 11th century most of Europe had become Christian,
and in 1088, the
University of Bologna emerged as the first university in Europe. As such, demand for Latin translation of ancient and scientific texts grew,
a major contributor to the
Renaissance of the 12th century. Renaissance
scholasticism in western Europe flourished, with experiments done by observing, describing, and classifying subjects in nature. In the 13th century, medical teachers and students at Bologna began opening human bodies, leading to the first anatomy textbook based on human dissection by
Mondino de Luzzi.
Renaissance
From a single print shop in
Mainz, Germany around 1440, the
movable type printing-press had
spread to no less than around 270 cities in Central, Western and Eastern Europe and had already produced more than 20 million volumes by the end of the 15th century.
[Febvre, Lucien; Martin, Henri-Jean (1976). ''The Coming of the Book: The Impact of Printing 1450–1800''. London: New Left Books. Quoted in: Anderson, Benedict. ''Comunidades Imaginadas. Reflexiones sobre el origen y la difusión del nacionalismo''. Fondo de cultura económica, Mexico, 1993. . pp. 58f.] Printing made scholarly books more widely accessible, allowing researchers to consult ancient texts freely and to compare their own observations with those of fellow scholars. Printing ended the
manuscript culture of the Middle Ages, where
facts were few and far between, and replaced it with a
printing culture where reliable and documented facts rapidly proliferated and became the secure foundation for scientific knowledge.
In the 16th century,
Nicolaus Copernicus formulated a
heliocentric model of the Solar System, with the Sun positioned near the centre of the Universe, motionless, with Earth and the other planets orbiting around it in circular motions, modified by
epicycles, and at uniform speeds. The Copernican model challenged the dominant
geocentric model of
Ptolemy
Claudius Ptolemy (; , ; ; – 160s/170s AD), better known mononymously as Ptolemy, was a Greco-Roman mathematician, astronomer, astrologer, geographer, and music theorist who wrote about a dozen scientific treatises, three of which wer ...
, which had placed Earth at the centre of the Universe. 16th-century astronomers believed that Copernicus' elimination of the
equant was his chief achievement but his model never displaced Ptolemy's, which only fell out of favour 70 years later after
Galileo's telescopic observations of 1610.
Scientific Revolution
Tycho Brahe's unprecedentedly accurate
astronomical observations in the late 16th century and
Galileo Galilei’s
early 17th-century telescopic observations combined to turn astronomy into the first modern science. Galileo's observations ended a millennium of pre-modern astronomical orthodoxy while
Johannes Kepler used Brahe's data to discover that planets have
elliptical, not circular, orbits and develop the
laws of planetary motion. Because of Kepler, astronomical phenomena came to be seen as being governed by physical laws. The "New Science" that ultimately emerged by the end of the 17th century broke sharply with the natural philosophy that had preceded it,
departed from previous Greek conceptions and traditions,
was more mechanistic in its worldview and more integrated with mathematics,
and was obsessed with the acquisition and interpretation of new evidence.
Age of Enlightenment
At the start of the
Age of Enlightenment,
Isaac Newton formed the foundation of
classical mechanics by his greatly influencing future physicists.
Gottfried Wilhelm Leibniz incorporated terms from
Aristotelian physics, now used in a new non-
teleological way. This implied a shift in the view of objects: objects were now considered as having no innate goals. Leibniz assumed that different types of things all work according to the same general laws of nature, with no special formal or final causes.
During this time the declared purpose and value of science became producing wealth and inventions that would improve human lives, in the
materialistic sense of having more food, clothing, and other things. In
Bacon's words, "the real and legitimate goal of sciences ", and he discouraged scientists from pursuing intangible philosophical or spiritual ideas, which he believed contributed little to human happiness beyond "the fume of subtle, sublime or pleasing
peculation.
Science during the Enlightenment was dominated by
scientific societies and academies, which had largely replaced universities as centres of scientific research and development. Societies and academies were the backbones of the maturation of the scientific profession. Another important development was the
popularisation of science among an increasingly literate population. Enlightenment philosophers turned to a few of their scientific predecessors –
Galileo,
Kepler,
Boyle, and Newton principally – as the guides to every physical and social field of the day.
The 18th century saw significant advancements in the practice of medicine and physics; the development of biological
taxonomy
Taxonomy is a practice and science concerned with classification or categorization. Typically, there are two parts to it: the development of an underlying scheme of classes (a taxonomy) and the allocation of things to the classes ( classificati ...
by
Carl Linnaeus; a new understanding of
magnetism and electricity; and the maturation of
chemistry
Chemistry is the scientific study of the properties and behavior of matter. It is a physical science within the natural sciences that studies matter: composition, structure, properties, behavior and the changes they undergo during reactio ...
as a discipline. Ideas on human nature, society, and economics evolved during the Enlightenment.
Hume and other Scottish Enlightenment thinkers developed ''
A Treatise of Human Nature'', which was expressed historically in works by authors including
James Burnett,
Adam Ferguson,
John Millar and
William Robertson, all of whom merged a scientific study of how humans behaved in ancient and primitive cultures with a strong awareness of the determining forces of
modernity. Modern sociology largely originated from this movement. In 1776,
Adam Smith published ''
The Wealth of Nations'', which is often considered the first work on modern economics.
19th century
During the 19th century, many distinguishing characteristics of contemporary modern science began to take shape. These included the transformation of the life and physical sciences; the frequent use of precision instruments; the emergence of terms such as "biologist", "physicist", and "scientist"; an increased professionalisation of those studying nature; scientists gaining cultural authority over many dimensions of society; the industrialisation of numerous countries; the thriving of popular science writings; and the emergence of science journals. During the late 19th century, psychology emerged as a separate discipline from philosophy when
Wilhelm Wundt founded the first laboratory for psychological research in 1879.
During the mid-19th century
Charles Darwin and
Alfred Russel Wallace independently proposed the theory of evolution by
natural selection in 1858, which explained how different plants and animals originated and evolved. Their theory was set out in detail in Darwin's book ''
On the Origin of Species'', published in 1859. Separately,
Gregor Mendel presented his paper, "
Experiments on Plant Hybridisation" in 1865, which outlined the principles of biological inheritance, serving as the basis for modern genetics.
Early in the 19th century
John Dalton suggested the modern
atomic theory, based on Democritus's original idea of indivisible particles called ''atoms''. The laws of
conservation of energy,
conservation of momentum and
conservation of mass suggested a highly stable universe where there could be little loss of resources. However, with the advent of the
steam engine and the
Industrial Revolution there was an increased understanding that not all forms of energy have the same
energy qualities, the ease of conversion to useful
work
Work may refer to:
Common uses
* Work (human activity), intentional activity people perform to support themselves, others, or the community
** Manual labour, physical work done by humans
** House work, housework, or homemaking
** Working ...
or to another form of energy.
This realisation led to the development of the laws of
thermodynamics
Thermodynamics is a branch of physics that deals with heat, work, and temperature, and their relation to energy, entropy, and the physical properties of matter and radiation. The behavior of these quantities is governed by the four laws of the ...
, in which the free energy of the universe is seen as constantly declining: the
entropy of a closed universe increases over time.
The
electromagnetic theory was established in the 19th century by the works of
Hans Christian Ørsted,
André-Marie Ampère,
Michael Faraday,
James Clerk Maxwell,
Oliver Heaviside, and
Heinrich Hertz. The new theory raised questions that could not easily be answered using Newton's framework. The discovery of
X-ray
An X-ray is a form of high-energy electromagnetic radiation with a wavelength shorter than those of ultraviolet rays and longer than those of gamma rays. Roughly, X-rays have a wavelength ranging from 10 nanometers to 10 picom ...
s inspired the discovery of
radioactivity by
Henri Becquerel and
Marie Curie in 1896, Marie Curie then became the first person to win two Nobel Prizes.
In the next year came the discovery of the first subatomic particle, the
electron
The electron (, or in nuclear reactions) is a subatomic particle whose electric charge is negative one elementary charge. It is an elementary particle contained in the matter that makes up the universe.
All atoms are composed of electro ...
.
20th century
In the first half of the century the development of
antibiotics and
artificial fertilisers improved human living standards globally. Harmful
environmental issues such as
ozone depletion,
ocean acidification,
eutrophication, and
climate change came to the public's attention and caused the onset of
environmental studies.
During this period scientific experimentation became increasingly
larger in scale and funding. The extensive technological innovation stimulated by
World War I,
World War II
The world is the totality of entities, the whole of reality, or everything that exists. The nature of the world has been conceptualized differently in different fields. Some conceptions see the world as unique, while others talk of a "plur ...
, and the
Cold War led to competitions between
global powers, such as the
Space Race and
nuclear arms race. Substantial international collaborations were also made, despite armed conflicts.
In the late 20th century active recruitment of women and elimination of
sex discrimination greatly increased the number of women scientists, but large gender disparities remained in some fields. The discovery of the
cosmic microwave background in 1964 led to a rejection of the
steady-state model of the universe in favour of the
Big Bang theory of
Georges Lemaître.
The century saw fundamental changes within science disciplines. Evolution became a unified theory in the early 20th century when the
modern synthesis reconciled Darwinian evolution with
classical genetics.
Albert Einstein's
theory of relativity and the development of
quantum mechanics complement classical mechanics to describe physics in extreme
length
Length is a measure of distance. In the International System of Quantities, length is a quantity with dimension distance. In most systems of measurement a base unit for length is chosen, from which all other units are derived. In the In ...
, time and
gravity
In physics, gravity (), also known as gravitation or a gravitational interaction, is a fundamental interaction, which may be described as the force that draws material objects towards each other.
The gravitational attraction between cl ...
. 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
smartphone
A smartphone is a mobile device that combines the functionality of a traditional mobile phone ( feature phone) with advanced computing capabilities. It typically has a touchscreen interface, allowing users to access a wide range of applica ...
s. The need for mass systematisation 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.
21st century
The
Human Genome Project was completed in 2003 by identifying and mapping all of the genes of the
human genome. The first
induced pluripotent human stem cells were made in 2006, allowing adult cells to be transformed into
stem cells and turn into any cell type found in the body. With the affirmation of the
Higgs boson discovery in 2013, the last particle predicted by the
Standard Model of particle physics was found. In 2015,
gravitational waves, predicted by
general relativity a century before, were
first observed. In 2019, the international collaboration
Event Horizon Telescope presented the first direct image of a
black hole's
accretion disc.
Branches
Modern science is commonly divided into three major
branches:
natural science,
social science, and
formal science.
Each of these branches comprises various specialised yet overlapping scientific disciplines that often possess their own
nomenclature and expertise. Both natural and social sciences are
empirical sciences, as their knowledge is based on
empirical observations and is capable of being tested for its validity by other researchers working under the same conditions.
Natural
Natural science is the study of the physical world. It can be divided into two main branches:
life science and
physical science. These two branches may be further divided into more specialised disciplines. For example, physical science can be subdivided into physics,
chemistry
Chemistry is the scientific study of the properties and behavior of matter. It is a physical science within the natural sciences that studies matter: composition, structure, properties, behavior and the changes they undergo during reactio ...
,
astronomy
Astronomy is a natural science that studies celestial objects and the phenomena that occur in the cosmos. It uses mathematics, physics, and chemistry to explain their origin and their overall evolution. Objects of interest include plan ...
, and
earth science. Modern natural science is the successor to the
natural philosophy that began in
Ancient Greece.
Galileo,
Descartes,
Bacon, and
Newton
Newton most commonly refers to:
* Isaac Newton (1643–1727), English polymath
* Newton (unit), SI unit of force
Newton may also refer to:
Arts and entertainment
* ''Newton'' (film), a 2017 Indian film
* Newton (band), Spanish electronic musi ...
debated the benefits of using approaches that were more
mathematical and more experimental in a methodical way. Still, philosophical perspectives,
conjectures, and
presuppositions, often overlooked, remain necessary in natural science. Systematic data collection, including
discovery science, succeeded
natural history, which emerged in the 16th century by describing and classifying plants, animals, minerals, and other biotic beings. Today, "natural history" suggests observational descriptions aimed at popular audiences.
Social
Social science is the study of human behaviour and the functioning of societies.
It has many disciplines that include, but are not limited to
anthropology
Anthropology is the scientific study of humanity that crosses biology and sociology, concerned with human behavior, human biology, cultures, societies, and linguistics, in both the present and past, including archaic humans. Social anth ...
, economics, history,
human geography,
political science, psychology, and sociology.
In the social sciences, there are many competing theoretical perspectives, many of which are extended through competing
research programmes such as the
functionalists,
conflict theorists, and
interactionists in sociology.
Due to the limitations of conducting controlled experiments involving large groups of individuals or complex situations, social scientists may adopt other research methods such as the
historical method,
case studies, and
cross-cultural studies. Moreover, if quantitative information is available, social scientists may rely on statistical approaches to better understand social relationships and processes.
Formal
Formal science is an area of study that generates knowledge using
formal systems.
A formal system is an
abstract structure used for inferring
theorem
In mathematics and formal logic, a theorem is a statement that has been proven, or can be proven. The ''proof'' of a theorem is a logical argument that uses the inference rules of a deductive system to establish that the theorem is a logic ...
s from
axioms according to a set of rules. It includes mathematics,
systems theory, and
theoretical computer science. The formal sciences share similarities with the other two branches by relying on objective, careful, and systematic study of an area of knowledge. They are, however, different from the empirical sciences as they rely exclusively on deductive reasoning, without the need for empirical evidence, to verify their abstract concepts.
The formal sciences are therefore ''
a priori'' disciplines and because of this, there is disagreement on whether they constitute a science.
Nevertheless, the formal sciences play an important role in the empirical sciences.
Calculus, for example, was initially invented to understand
motion
In physics, motion is the change in position of an object or fluid with respect to a reference frame over a given time. Motion is mathematically described in terms of vector quantities such as displacement (with direction and distance), ...
in physics. Natural and social sciences that rely heavily on mathematical applications include
mathematical physics,
chemistry
Chemistry is the scientific study of the properties and behavior of matter. It is a physical science within the natural sciences that studies matter: composition, structure, properties, behavior and the changes they undergo during reactio ...
,
biology
Biology is the scientific study of life and living organisms. It is a broad natural science that encompasses a wide range of fields and unifying principles that explain the structure, function, growth, origin, evolution, and distributio ...
,
finance
Finance refers to monetary resources as well as the discipline that studies such resources, with related concepts such as money, currency, assets and liabilities. As a subject of study, it is related to the fields of economics (the study of ...
, and
economics
upright=1.5, Euro coins
Economics () is a social science that studies the production, distribution, and consumption of goods and services.
Economics focuses on the behaviour and interactions of economic agents and how economies wo ...
.
Applied
Applied science is the use of the
scientific method and knowledge to attain practical goals and includes a broad range of disciplines such as engineering and medicine.
Engineering is the use of scientific principles to invent, design and build machines, structures and technologies. Science may contribute to the development of new technologies. Medicine is the practice of caring for patients by maintaining and restoring health through the
prevention,
diagnosis, and
treatment
Treatment may refer to:
* "Treatment" (song), a 2012 song by featuring Etta Bond
* Film treatment, a prose telling of a story intended to be turned into a screenplay
* Therapy, or medical treatment
See also
*
*
* Special treatment (disam ...
of injury or disease.
Basic
The applied sciences are often contrasted with the
basic sciences, which are focused on advancing scientific theories and laws that explain and predict events in the natural world.
Blue skies
Computational
Computational science applies
computer simulations to science, enabling a better understanding of scientific problems than formal mathematics alone can achieve. The use of
machine learning and
artificial intelligence is becoming a central feature of computational contributions to science, for example in
agent-based computational economics,
random forests,
topic modelling and various forms of prediction. However, machines alone rarely advance knowledge as they require human guidance and capacity to reason; and they can introduce bias against certain social groups or sometimes underperform against humans.
Interdisciplinary
Interdisciplinary science involves the combination of two or more disciplines into one, such as
bioinformatics, a combination of biology and computer science or
cognitive sciences. The concept has existed since the ancient Greek period and it became popular again in the 20th century.
Research
Scientific research can be labelled as either basic or applied research.
Basic research is the search for knowledge and
applied research is the search for solutions to practical problems using this knowledge. Most understanding comes from basic research, though sometimes applied research targets specific practical problems. This leads to technological advances that were not previously imaginable.
Scientific method
Scientific research involves using the
scientific method, which seeks to
objectively explain the events of
nature
Nature, in the broadest sense, is the physical world or universe. In this general sense nature refers to the laws, elements and phenomena of the physical world, including life. Although humans are part of nature, human activity or humans ...
in a
reproducible way.
Scientists usually take for granted a set of basic assumptions that are needed to justify the scientific method: there is an
objective reality shared by all rational observers; this objective reality is governed by
natural laws; these laws were discovered by means of systematic
observation
Observation in the natural sciences refers to the active acquisition of information from a primary source. It involves the act of noticing or perceiving phenomena and gathering data based on direct engagement with the subject of study.
In liv ...
and experimentation.
Mathematics is essential in the formation of
hypotheses,
theories, and laws, because it is used extensively in quantitative modelling, observing, and collecting
measurements.
Statistics is used to summarise and analyse data, which allows scientists to assess the reliability of experimental results.
In the scientific method an explanatory
thought experiment or hypothesis is put forward as an explanation using
parsimony principles and is expected to seek
consilience – fitting with other accepted facts related to an observation or scientific question. This tentative explanation is used to make
falsifiable predictions, which are typically posted before being tested by experimentation. Disproof of a prediction is evidence of progress.
Experimentation is especially important in science to help establish
causal relationships to avoid the
correlation fallacy, though in some sciences such as astronomy or geology, a predicted observation might be more appropriate.
When a hypothesis proves unsatisfactory it is modified or discarded. If the hypothesis survives testing, it may become adopted into the framework of a
scientific theory, a
validly reasoned, self-consistent model or framework for describing the behaviour of certain natural events. A theory typically describes the behaviour of much broader sets of observations than a hypothesis; commonly, a large number of hypotheses can be logically bound together by a single theory. Thus, a theory is a hypothesis explaining various other hypotheses. In that vein, theories are formulated according to most of the same scientific principles as hypotheses. Scientists may generate a
model
A model is an informative representation of an object, person, or system. The term originally denoted the plans of a building in 16th-century English, and derived via French and Italian ultimately from Latin , .
Models can be divided into physi ...
, an attempt to describe or depict an observation in terms of a logical, physical or mathematical representation, and to generate new hypotheses that can be tested by experimentation.
While performing experiments to test hypotheses, scientists may have a preference for one outcome over another. Eliminating the bias can be achieved through transparency, careful
experimental design, and a thorough
peer review process of the experimental results and conclusions. After the results of an experiment are announced or published, it is normal practice for independent researchers to double-check how the research was performed, and to follow up by performing similar experiments to determine how dependable the results might be. Taken in its entirety, the scientific method allows for highly creative
problem solving while minimising the effects of subjective and
confirmation bias.
Intersubjective verifiability, the ability to reach a consensus and reproduce results, is fundamental to the creation of all scientific knowledge.
Literature
Scientific research is published in a range of literature.
Scientific journals communicate and document the results of research carried out in universities and various other research institutions, serving as an archival record of science. The first scientific journals, followed by ''
Philosophical Transactions'', began publication in 1665. Since that time the total number of active periodicals has steadily increased. In 1981, one estimate for the number of scientific and technical journals in publication was 11,500.
Most scientific journals cover a single scientific field and publish the research within that field; the research is normally expressed in the form of a
scientific article. Science has become so pervasive in modern societies that it is considered necessary to communicate the achievements, news, and ambitions of scientists to a wider population.
Philosophy
There are different schools of thought in the
philosophy of science. The most popular position is
empiricism, which holds that knowledge is created by a process involving observation; scientific theories generalise observations.
Empiricism generally encompasses
inductivism, a position that explains how general theories can be made from the finite amount of empirical evidence available. Many versions of empiricism exist, with the predominant ones being
Bayesianism and the
hypothetico-deductive method.
Empiricism has stood in contrast to
rationalism, the position originally associated with
Descartes, which holds that knowledge is created by the human intellect, not by observation.
Critical rationalism is a contrasting 20th-century approach to science, first defined by Austrian-British philosopher
Karl Popper. Popper rejected the way that empiricism describes the connection between theory and observation. He claimed that theories are not generated by observation, but that observation is made in the light of theories, and that the only way theory A can be affected by observation is ''after'' theory A were to conflict with observation, but theory B were to survive the observation.
[
Popper proposed replacing verifiability with falsifiability as the landmark of scientific theories, replacing induction with falsification as the empirical method.] Popper further claimed that there is actually only one universal method, not specific to science: the negative method of criticism, trial and error, covering all products of the human mind, including science, mathematics, philosophy, and art.
Another approach, instrumentalism, emphasises the utility of theories as instruments for explaining and predicting phenomena. It views scientific theories as black boxes, with only their input (initial conditions) and output (predictions) being relevant. Consequences, theoretical entities, and logical structure are claimed to be things that should be ignored. Close to instrumentalism is constructive empiricism, according to which the main criterion for the success of a scientific theory is whether what it says about observable entities is true.
Thomas Kuhn argued that the process of observation and evaluation takes place within a paradigm, a logically consistent "portrait" of the world that is consistent with observations made from its framing. He characterised ''normal science'' as the process of observation and "puzzle solving", which takes place within a paradigm, whereas ''revolutionary science'' occurs when one paradigm overtakes another in a paradigm shift. Each paradigm has its own distinct questions, aims, and interpretations. The choice between paradigms involves setting two or more "portraits" against the world and deciding which likeness is most promising. A paradigm shift occurs when a significant number of observational anomalies arise in the old paradigm and a new paradigm makes sense of them. That is, the choice of a new paradigm is based on observations, even though those observations are made against the background of the old paradigm. For Kuhn, acceptance or rejection of a paradigm is a social process as much as a logical process. Kuhn's position, however, is not one of relativism.
Another approach often cited in debates of scientific scepticism against controversial movements like " creation science" is methodological naturalism. Naturalists maintain that a difference should be made between natural and supernatural, and science should be restricted to natural explanations. Methodological naturalism maintains that science requires strict adherence to empirical study and independent verification.
One question for philosophy of science is how scientific evidence and theories can lead to decisions. As the is-ought problem highlights, facts alone cannot tell us what we should do. This connects to the key concept of ''value-ladenness'': how choices made on the basis of scientific findings depend on values.
Community
The scientific community is a network of interacting scientists who conduct scientific research. The community consists of smaller groups working in scientific fields. By having peer review, through discussion and debate within journals and conferences, scientists maintain the quality of research methodology and objectivity when interpreting results.
Scientists
Scientists are individuals who conduct scientific research to advance knowledge in an area of interest. Scientists may exhibit a strong curiosity about reality and a desire to apply scientific knowledge for the benefit of public health, nations, the environment, or industries; other motivations include recognition by peers and prestige.[ In modern times, many scientists study within specific areas of science in academic institutions, often obtaining advanced degrees in the process. Many scientists pursue careers in various fields such as academia, industry, ]government
A government is the system or group of people governing a country and its administrative divisions which is generally called as a state and as such the term is a metonym for it in governmental topics.
In the case of its broad associa ...
, and nonprofit organisations.
Science has historically been a male-dominated field, with notable exceptions. Women have faced considerable discrimination in science, much as they have in other areas of male-dominated societies. For example, women were frequently passed over for job opportunities and denied credit for their work. The achievements of women in science have been attributed to the defiance of their traditional role as labourers within the domestic sphere.
Learned societies
Learned societies for the communication and promotion of scientific thought and experimentation have existed since the Renaissance. Many scientists belong to a learned society that promotes their respective scientific discipline, profession, or group of related disciplines. Membership may either be open to all, require possession of scientific credentials, or conferred by election. Most scientific societies are nonprofit organisations, and many are professional associations. Their activities typically include holding regular conferences for the presentation and discussion of new research results and publishing or sponsoring academic journals in their discipline. Some societies act as professional bodies, regulating the activities of their members in the public interest, or the collective interest of the membership.
The professionalisation of science, begun in the 19th century, was partly enabled by the creation of national distinguished academies of sciences such as the Italian in 1603, the British Royal Society in 1660, the French Academy of Sciences in 1666, the American National Academy of Sciences in 1863, the German Kaiser Wilhelm Society in 1911, and the Chinese Academy of Sciences in 1949. International scientific organisations, such as the International Science Council, are devoted to international cooperation for science advancement.
Awards
Science awards are usually given to individuals or organisations that have made significant contributions to a discipline. They are often given by prestigious institutions; thus, it is considered a great honour for a scientist receiving them. Since the early Renaissance, scientists have often been awarded medals, money, and titles. The Nobel Prize, a widely regarded prestigious award, is awarded annually to those who have achieved scientific advances in the fields of medicine, physics, and chemistry
Chemistry is the scientific study of the properties and behavior of matter. It is a physical science within the natural sciences that studies matter: composition, structure, properties, behavior and the changes they undergo during reactio ...
.
Society
Funding and policies
Funding of science is often through a competitive process in which potential research projects are evaluated and only the most promising receive funding. Such processes, which are run by government, corporations, or foundations, allocate scarce funds. Total research funding in most developed countries is between 1.5% and 3% of GDP. In the OECD
The Organisation for Economic Co-operation and Development (OECD; , OCDE) is an intergovernmental organisation with 38 member countries. It was founded in 1961 to stimulate economic progress and world trade. The OECD is a forum whose memb ...
, around two-thirds of research and development in scientific and technical fields is carried out by industry, and 20% and 10%, respectively, by universities and government. The government funding proportion in certain fields is higher, and it dominates research in social science and the humanities
Humanities are academic disciplines that study aspects of human society and culture, including certain fundamental questions asked by humans. During the Renaissance, the term "humanities" referred to the study of classical literature and languag ...
. In less developed nations, the government provides the bulk of the funds for their basic scientific research.
Many governments have dedicated agencies to support scientific research, such as the National Science Foundation in the United States, the National Scientific and Technical Research Council in Argentina, Commonwealth Scientific and Industrial Research Organisation in Australia, National Centre for Scientific Research in France, the Max Planck Society in Germany, and National Research Council in Spain. In commercial research and development, all but the most research-orientated corporations focus more heavily on near-term commercialisation possibilities than research driven by curiosity.
Science policy is concerned with policies that affect the conduct of the scientific enterprise, including research funding, often in pursuance of other national policy goals such as technological innovation to promote commercial product development, weapons development, health care, and environmental monitoring. Science policy sometimes refers to the act of applying scientific knowledge and consensus to the development of public policies. In accordance with public policy being concerned about the well-being of its citizens, science policy's goal is to consider how science and technology can best serve the public. Public policy can directly affect the funding of capital equipment and intellectual infrastructure for industrial research by providing tax incentives to those organisations that fund research.
Education and awareness
Science education for the general public is embedded in the school curriculum, and is supplemented by online pedagogical content (for example, YouTube and Khan Academy), museums, and science magazines and blogs. Major organisations of scientists such as the American Association for the Advancement of Science (AAAS) consider the sciences to be a part of the liberal arts traditions of learning, along with philosophy and history. Scientific literacy is chiefly concerned with an understanding of the scientific method, units and methods of measurement
Measurement is the quantification of attributes of an object or event, which can be used to compare with other objects or events. In other words, measurement is a process of determining how large or small a physical quantity is as compared to ...
, empiricism, a basic understanding of statistics ( correlations, qualitative versus quantitative
Quantitative may refer to:
* Quantitative research, scientific investigation of quantitative properties
* Quantitative analysis (disambiguation)
* Quantitative verse, a metrical system in poetry
* Statistics, also known as quantitative analysis ...
observations, aggregate statistics), and a basic understanding of core scientific fields such as physics, chemistry
Chemistry is the scientific study of the properties and behavior of matter. It is a physical science within the natural sciences that studies matter: composition, structure, properties, behavior and the changes they undergo during reactio ...
, biology
Biology is the scientific study of life and living organisms. It is a broad natural science that encompasses a wide range of fields and unifying principles that explain the structure, function, growth, origin, evolution, and distributio ...
, ecology, geology, and computation. As a student advances into higher stages of formal education, the curriculum becomes more in depth. Traditional subjects usually included in the curriculum are natural and formal sciences, although recent movements include social and applied science as well.
The mass media face pressures that can prevent them from accurately depicting competing scientific claims in terms of their credibility within the scientific community as a whole. Determining how much weight to give different sides in a scientific debate may require considerable expertise regarding the matter. Few journalists have real scientific knowledge, and even beat reporters who are knowledgeable about certain scientific issues may be ignorant about other scientific issues that they are suddenly asked to cover.
Science magazines such as '' New Scientist'', '' Science & Vie'', and '' Scientific American'' cater to the needs of a much wider readership and provide a non-technical summary of popular areas of research, including notable discoveries and advances in certain fields of research. The science fiction genre, primarily speculative fiction, can transmit the ideas and methods of science to the general public. Recent efforts to intensify or develop links between science and non-scientific disciplines, such as literature or poetry, include the ''Creative Writing Science'' resource developed through the Royal Literary Fund.
Anti-science attitudes
While the scientific method is broadly accepted in the scientific community, some fractions of society reject certain scientific positions or are sceptical about science. Examples are the common notion that COVID-19
Coronavirus disease 2019 (COVID-19) is a contagious disease caused by the coronavirus SARS-CoV-2. Starting in January 2020, the disease spread worldwide, resulting in the COVID-19 pandemic. In March 2020, the World Health Organization ...
is not a major health threat to the US (held by 39% of Americans in August 2021) or the belief that climate change is not a major threat to the US (also held by 40% of Americans, in late 2019 and early 2020). Psychologists have pointed to several factors driving rejection of scientific results:
* Scientific authorities are sometimes seen as inexpert, untrustworthy, or biased.
* Some marginalised social groups hold anti-science attitudes, in part because these groups have often been exploited in unethical experiments.
* Messages from scientists may contradict deeply held existing beliefs or morals.
Anti-science attitudes often seem to be caused by fear of rejection in social groups. For instance, climate change is perceived as a threat by only 22% of Americans on the right side of the political spectrum, but by 85% on the left. That is, if someone on the left would not consider climate change as a threat, this person may face contempt and be rejected in that social group. In fact, people may rather deny a scientifically accepted fact than lose or jeopardise their social status.
Politics
Attitudes towards science are often determined by political opinions and goals. Government, business and advocacy groups have been known to use legal and economic pressure to influence scientific researchers. Many factors can act as facets of the politicisation of science such as anti-intellectualism
Anti-intellectualism refers to a range of attitudes, characterized by skepticism, mistrust or criticism of intellect, intellectuals, or intellectualism. It is commonly expressed as questioning the value or relevance of intellectual pursuits, ...
, perceived threats to religious beliefs, and fear for business interests. Politicisation of science is usually accomplished when scientific information is presented in a way that emphasises the uncertainty associated with the scientific evidence. Tactics such as shifting conversation, failing to acknowledge facts, and capitalising on doubt of scientific consensus have been used to gain more attention for views that have been undermined by scientific evidence. Examples of issues that have involved the politicisation of science include the global warming controversy, health effects of pesticides, and health effects of tobacco.
Challenges
The replication crisis is an ongoing systemic crisis that affects parts of science. The results of a fraction of scientific studies have been proven to be unreproducible. The crisis has long-standing roots; the phrase was coined in the early 2010s as part of a growing awareness of the problem. A 2026 replication study found low replication rates in social and behavioural sciences (business
Business is the practice of making one's living or making money by producing or buying and selling products (such as goods and services). It is also "any activity or enterprise entered into for profit."
A business entity is not necessaril ...
, economics
upright=1.5, Euro coins
Economics () is a social science that studies the production, distribution, and consumption of goods and services.
Economics focuses on the behaviour and interactions of economic agents and how economies wo ...
, education
Education is the transmission of knowledge and skills and the development of character traits. Formal education happens in a complex institutional framework, like public schools. Non-formal education is also structured but occurs outside ...
, political science, psychology
Psychology is the scientific study of the mind and behavior. Its subject matter includes the behavior of humans and nonhumans, both conscious and unconscious phenomena, and mental processes such as thoughts, feelings, and motives. Ps ...
and sociology
Sociology is the scientific study of human society that focuses on human social behavior, patterns of social relationships, social interaction, and aspects of culture associated with everyday life. The term sociology was coined in the late ...
). The replication crisis represents an important body of research in metascience, which aims to improve the quality of all scientific research, scientific integrity while reducing waste.
The term scientific misconduct refers to situations such as where researchers have intentionally misrepresented their published data or have purposely given credit for a discovery to the wrong person.
An area of study or speculation that masquerades as science in an attempt to claim legitimacy that it would not otherwise be able to achieve is sometimes referred to as pseudoscience, fringe science, or junk science. Physicist Richard Feynman coined the term " cargo cult science" for cases in which researchers believe, and at a glance, look like they are doing science but lack the honesty to allow their results to be rigorously evaluated. Various types of commercial advertising, ranging from hype to fraud, may fall into these categories. Science has been described as "the most important tool" for separating valid claims from invalid ones. Sometimes, research can be well-intended but is incorrect, obsolete, incomplete, or over-simplified expositions of scientific ideas.
Academic freedom can be reduced by scientific censorship caused by governments, institutions, other scientists or self-censorship. Some scientists were found to justify scientific censorship with harm avoidance. There can also be an element of political bias or ideological bias in science. Scientists in some countries were found to have a bias in political party preferences compared to the general population. The average political bias of a scientific field can change over time and can be explained with field-environment interaction and self-selection bias. Science activism which overlaps with political advocacy can decrease the credibility of science.
See also
* List of scientific occupations
* List of years in science
Notes
References
External links
*
{{Authority control
Observation
Main topic articles
Inquiry
Human activities