{{Short description|Subdivisions of science defined by their scope}}
{{Further|Outline of science}}
{{broader|Academic discipline}}
{{Science|expanded=Branches}}
The '''branches of science''', also referred to as '''sciences''', '''scientific''' '''fields''' or '''scientific disciplines''', are commonly divided into three major [[groups]]:
* [[Formal science]]s: the study of [[formal system]]s, such as those under the branches of [[logic]] and [[mathematics]], which use an ''[[a priori and a posteriori|a priori]]'', as opposed to [[Empirical evidence|empirical]], [[methodology]]. They study abstract structures described by [[formal system]]s.
* [[Natural science]]s: the study of natural phenomena (including [[cosmological]], [[geological]], [[Physics|physical]], [[Chemistry|chemical]], and [[biological]] factors of the [[universe]]). Natural science can be divided into two main branches: [[Outline of physical science|physical science]] and [[list of life sciences|life science]].
* [[Social science]]s: the study of [[human behavior]] in its social and cultural aspects.[{{Cite web|title=social science {{!}} History, Disciplines, & Facts|url=https://www.britannica.com/topic/social-science|access-date=2020-08-18|website=Encyclopedia Britannica|language=en}}]
Scientific knowledge must be grounded in observable phenomena and must be capable of being verified by other researchers working under the same conditions.{{sfn|Popper|2002|p=20}}
Natural, social, and formal science make up the [[Basic research|basic sciences]], which form the basis of [[interdisciplinarity]] - and [[applied science]]s such as [[engineering]] and [[medicine]]. Specialized scientific disciplines that exist in multiple categories may include parts of other scientific disciplines but often possess their own [[Terminology|terminologies]] and [[expert]]ises.[{{Cite web| author=Editorial Staff | date=March 7, 2008 | url=http://www.seedmagazine.com/news/2007/03/scientific_method_relationship.php | archive-url=https://web.archive.org/web/20070310222459/http://www.seedmagazine.com/news/2007/03/scientific_method_relationship.php | url-status=unfit | archive-date=March 10, 2007 | title=Scientific Method: Relationships among Scientific Paradigms | publisher=Seed magazine | access-date=2007-09-12 }}]
{{TOC limit|limit=4}}
== Formal sciences ==
{{Main|Formal sciences}}
{{For outline|Outline of formal science}}
The ''formal sciences'' are the branches of science that are concerned with [[formal system]]s, such as [[mathematics]], [[logic]], [[theoretical computer science]], [[information theory]], [[systems theory]], [[decision theory]], and [[statistics]].
Unlike other branches, the formal sciences are not concerned with the validity of [[Scientific theory|theories]] based on [[observation]]s in the [[Reality|real world]] ([[empirical knowledge]]), but rather with the properties of [[formal system]]s based on [[definition]]s and [[Rule of inference|rule]]s. Hence there is disagreement on whether the formal sciences actually constitute as a science. Methods of the formal sciences are, however, essential to the construction and testing of [[scientific model]]s dealing with observable reality,{{sfn|Popper|2002|pp=79–82}} and major advances in formal sciences have often enabled major advances in the [[empirical sciences]].
=== Logic ===
{{Main|Logic}}
{{For outline|Outline of logic}}
''Logic'' (from [[Ancient Greek|Greek]]: {{langx|grc|[[wikt:λογική|λογική]]|label=none|lit=possessed of [[reason]], [[intellectual]], [[dialectical]], [[argument]]ative|translit=logikḗ}})[[[Henry Liddell|Liddell, Henry George]], and [[Robert Scott (philologist)|Robert Scott]]. 1940. "[https://www.perseus.tufts.edu/hopper/text?doc=LSJ+logiko%2Fs&fromdoc=Perseus%3Atext%3A1999.04.0057 Logikos]." ''[[A Greek–English Lexicon]]'', edited by [[Henry Stuart Jones|H. S. Jones]] with R. McKenzie. Oxford: [[Oxford University Press|Clarendon Press]]. – via [[Perseus Project]]. Retrieved 9 May 2020.][Harper, Douglas. 2020 [2001]. "[https://www.etymonline.com/word/logic logic (n.)]." ''[[Online Etymology Dictionary]]''. Retrieved 9 May 2020.]{{NoteTag|Also related to {{Wikt-lang|en|λόγος}} (''logos''), "word, thought, idea, argument, account, reason, or principle." (Liddell and Scott, 1999).}} is the systematic study of valid [[rule of inference|rules of inference]], i.e. the relations that lead to the acceptance of one proposition (the [[consequent|conclusion]]) on the basis of a set of other propositions ([[premise]]s). More broadly, logic is the analysis and appraisal of [[argument]]s.[{{Cite book |last=Gensler |first=Harry J. |title=Introduction to logic |date=2017 |publisher=Routledge |isbn=978-1-138-91059-1 |edition=3rd |location=New York |page=1 |chapter=Chapter 1: Introduction |doi=10.4324/9781315693361 |oclc=957680480 |orig-date=2002}}]
It has traditionally included the classification of arguments; the systematic exposition of the [[logical form]]s; the [[Validity (logic)|validity]] and [[soundness]] of [[deductive reasoning]]; the [[Strong induction|strength]] of [[inductive reasoning]]; the study of [[formal proof]]s and [[inference]] (including [[paradox]]es and [[fallacies]]); and the study of [[syntax]] and [[semantics]].
Historically, logic has been studied in [[philosophy]] (since ancient times) and [[mathematics]] (since the mid-19th century). More recently, logic has been studied in [[cognitive science]], which draws on [[computer science]], [[linguistics]], philosophy and [[psychology]], among other disciplines.
=== Information science ===
{{Main articles|Information science}}Information science is an academic field which is primarily concerned with [[analysis]], collection, [[Categorization|classification]], manipulation, storage, [[Information retrieval|retrieval]], movement, [[dissemination]], and protection of [[information]]. Practitioners within and outside the field study the application and the usage of knowledge in [[organization]]s in addition to the interaction between people, organizations, and any existing [[information system]]s with the aim of creating, replacing, improving, or understanding the information systems.{{See also|Information visualization|DIKW pyramid}}
=== Mathematics ===
{{Main|Mathematics}}
{{For outline|Outline of mathematics}}
''Mathematics'', in the broadest sense, is just a synonym of formal science; but traditionally mathematics means more specifically the coalition of four areas: [[arithmetic]], [[geometry]], [[algebra]], [[analysis]].
=== Statistics ===
{{Main|Statistics}}
{{For outline|Outline of statistics}}
''Statistics'' is the study of the collection, organization, and interpretation of [[data]].[Dodge, Y. (2003) ''The Oxford Dictionary of Statistical Terms'', OUP. {{ISBN|0-19-920613-9}}][{{cite web |title=statistics |url=https://www.thefreedictionary.com/dict.asp?Word=statistics |website=TheFreeDictionary.com |access-date=25 August 2020}}] It deals with all aspects of this, including the planning of [[data collection]] in terms of the design of [[Statistical survey|surveys]] and [[experimental design|experiments]].[
A [[statistician]] is someone who is particularly well versed in the ways of thinking necessary for the successful application of statistical analysis. Such people have often gained this experience through working in any of a [[list of fields of application of statistics|wide number of fields]]. There is also a discipline called ''[[mathematical statistics]]'', which is concerned with the theoretical basis of the subject.
The word ''statistics'', when referring to the scientific discipline, is singular, as in "Statistics is an art."][{{cite web | url = http://www.merriam-webster.com/dictionary/statistics | title = Statistics | work = Merriam-Webster Online Dictionary}}] This should not be confused with the word ''statistic'', referring to a quantity (such as [[mean]] or [[median]]) calculated from a set of data,[{{cite web | url = http://www.merriam-webster.com/dictionary/statistic | title = Statistic | work = Merriam-Webster Online Dictionary| date = 29 March 2024 }}] whose plural is ''statistics'' ("this statistic seems wrong" or "these statistics are misleading").
=== Systems theory ===
{{Main|Systems theory}}
''Systems theory'' is the [[transdisciplinary]] study of [[system]]s in general, to elucidate principles that can be applied to all types of systems in all fields of research. The term does not yet have a well-established, precise meaning, but systems theory can reasonably be considered a specialization of [[systems thinking]] and a generalization of [[systems science]]. The term originates from [[Ludwig von Bertalanffy|Bertalanffy]]'s [[#General systems research and systems inquiry|General System Theory]] (GST) and is used in later efforts in other fields, such as the [[Action theory (sociology)|action theory]] of [[Talcott Parsons]] and the sociological [[autopoiesis]] of [[Niklas Luhmann]].
In this context the word ''systems'' is used to refer specifically to self-regulating systems, i.e. that are self-correcting through [[feedback]]. Self-regulating systems are found in nature, including the physiological systems of the human body, in local and global ecosystems, and climate.
=== Decision theory ===
{{Main|Decision theory}}
''Decision theory'' (or the ''theory of choice'' not to be confused with [[Rational choice theory|choice theory]]) is the study of an [[agent (economics)|agent's]] choices.[Steele, Katie and Stefánsson, H. Orri, "Decision Theory", The Stanford Encyclopedia of Philosophy (Winter 2015 Edition), Edward N. Zalta (ed.), URL = [http://plato.stanford.edu/archives/win2015/entries/decision-theory]] Decision theory can be broken into two branches: [[Norm (philosophy)|normative]] decision theory, which analyzes the outcomes of decisions or determines the [[optimal decision]]s given constraints and assumptions, and descriptive decision theory, which analyzes ''how'' agents actually make the decisions they do.
Decision theory is closely related to the field of [[game theory]][{{cite book|last1=Myerson|first1=Roger B.|title=Game theory analysis of conflict|date=1991|publisher=Harvard University Press|location=Cambridge, Massachusetts|isbn=978-0-674-72861-5|chapter=1.2: Basic concepts of Decision Theory}}] and is an interdisciplinary topic, studied by economists, statisticians, psychologists, biologists,[{{cite journal | vauthors = Habibi I, Cheong R, Lipniacki T, Levchenko A, Emamian ES, Abdi A | title = Computation and measurement of cell decision making errors using single cell data | journal = PLOS Computational Biology | volume = 13 | issue = 4 | article-number = e1005436 | date = April 2017 | pmid = 28379950 | pmc = 5397092 | doi = 10.1371/journal.pcbi.1005436 | bibcode = 2017PLSCB..13E5436H | doi-access = free }}] political and other social scientists, philosophers,[Hansson, Sven Ove. "Decision theory: A brief introduction." (2005) Section 1.2: A truly interdisciplinary subject.] and computer scientists.{{clarify|looks like something is missing here|date=November 2024}}
Empirical applications of this rich theory are usually done with the help of [[statistics|statistical]] and [[econometrics|econometric]] methods.
=== Theoretical computer science ===
{{Main|Theoretical computer science}}
''Theoretical computer science'' (''TCS'') is a subset of general [[computer science]] and [[mathematics]] that focuses on more mathematical topics of computing, and includes the [[theory of computation]].
It is difficult to circumscribe the theoretical areas precisely. The [[Association for Computing Machinery|ACM]]'s (Association for Computing Theory) [[ACM SIGACT|Special Interest Group on Algorithms and Computation Theory]] (SIGACT) provides the following description:[{{cite web | title = SIGACT | url = https://www.sigact.org/ | access-date = 2017-01-19}}]
{{Blockquote|TCS covers a wide variety of topics including [[algorithms]], [[data structure]]s, [[computational complexity theory|computational complexity]], [[parallel computation|parallel]] and [[distributed computation|distributed]] computation, [[probabilistic computation]], [[quantum computation]], [[automata theory]], [[information theory]], [[cryptography]], [[program semantics]] and [[Formal methods|verification]], [[machine learning]], [[computational biology]], [[computational economics]], [[computational geometry]], and [[computational number theory]] and [[Symbolic computation|algebra]]. Work in this field is often distinguished by its emphasis on mathematical technique and [[rigor#Mathematical rigour|rigor]].}}
== Natural sciences ==
{{Main|Natural science}}
{{For outline|Outline of natural science}}
''Natural science'' is a branch of science concerned with the description, prediction, and understanding of [[Phenomenon|natural phenomena]], based on [[empirical evidence]] from [[observation]] and [[experimentation]]. Mechanisms such as [[peer review]] and repeatability of findings are used to try to ensure the validity of scientific advances.
Natural science can be divided into two main branches: [[list of life sciences|life science]] and [[Outline of physical science|physical science]]. Life science is alternatively known as [[biology]], and physical science is subdivided into branches: [[physics]], [[chemistry]], [[astronomy]] and [[Earth science]]. These branches of natural science may be further divided into more specialized branches (also known as fields).
=== Physical science ===
{{For outline|Outline of physical science}}
''Physical science'' is an encompassing term for the branches of natural science that study non-living systems, in contrast to the life sciences. However, the term "physical" creates an unintended, somewhat arbitrary distinction, since many branches of physical science also study biological phenomena. There is a difference between physical science and physics.
==== Physics ====
{{Main|Physics|Branches of physics}}
{{For outline|Outline of physics}}
''Physics'' (from {{langx|grc|φύσις|[[physis]]|nature}}) is a [[natural science]] that involves the study of [[matter]]{{NoteTag|[[Richard Feynman]] begins [[The Feynman Lectures on Physics|his ''Lectures'']] with the [[atomic theory|atomic hypothesis]], as his most compact statement of all scientific knowledge: "If, in some cataclysm, all of scientific knowledge were to be destroyed, and only one sentence passed on to the next generations ..., what statement would contain the most information in the fewest words? I believe it is ... that ''all things are made up of atoms – little particles that move around in perpetual motion, attracting each other when they are a little distance apart, but repelling upon being squeezed into one another. ...''"[{{cite book
|author1=R.P. Feynman |author2-link=R.B. Leighton |author2=R.B. Leighton |author3-link=Matthew Sands |author3=Matthew Sands |year=1963
|title=The Feynman Lectures on Physics
|volume=1 |page=I-2
|isbn=0-201-02116-1
|title-link=The Feynman Lectures on Physics |publisher=Addison-Wesley }}]}} and its [[motion (physics)|motion]] through [[spacetime]], along with related concepts such as [[energy]] and [[force]].[
{{cite book
|author=J.C. Maxwell
|author-link=J.C. Maxwell
|year=1878
|title=Matter and Motion
|url=https://archive.org/details/matterandmotion03maxwgoog
|page=[https://archive.org/details/matterandmotion03maxwgoog/page/n3 9]
|publisher=[[D. Van Nostrand]]
|quote=Physical science is that department of knowledge which relates to the order of nature, or, in other words, to the regular succession of events.
|isbn=0-486-66895-9
}}] More broadly, it is the general analysis of [[nature]], conducted in order to understand how the [[universe]] behaves.[
{{cite book
|author1=H.D. Young |author2=R.A. Freedman |year=2004 |edition=11th
|title=University Physics with Modern Physics
|page=2
|publisher=[[Addison Wesley]]
|quote=Physics is an ''experimental'' science. Physicists observe the phenomena of nature and try to find patterns and principles that relate these phenomena. These patterns are called physical theories or, when they are very well established and of broad use, physical laws or principles.
}}][
{{cite book
|author=S. Holzner
|year=2006
|title=Physics for Dummies
|url=https://www.amazon.com/gp/reader/0764554336
|page=7
|publisher=[[John Wiley & Sons|Wiley]]
|quote=Physics is the study of your world and the world and universe around you.
|isbn=0-470-61841-8
}}]{{NoteTag|The term 'universe' is defined as everything that physically exists: the entirety of space and time, all forms of matter, energy and momentum, and the physical laws and constants that govern them. However, the term 'universe' may also be used in slightly different contextual senses, denoting concepts such as the [[cosmos]] or the [[world (philosophy)|philosophical world]]}}
Physics is one of the oldest [[academic discipline]]s, perhaps the oldest through its inclusion of [[astronomy]].{{NoteTag|Evidence exists that the earliest civilizations dating back to beyond 3000 BCE, such as the [[Sumer]]ians, [[Ancient Egyptians]], and the [[Indus Valley civilization]], all had a predictive knowledge and a very basic understanding of the motions of the Sun, Moon, and stars.}} Over the last two millennia, physics was a part of [[natural philosophy]] along with [[chemistry]], certain branches of [[mathematics]], and [[biology]], but during the [[Scientific Revolution]] in the 16th century, the [[natural science]]s emerged as unique research programs in their own right.{{NoteTag|[[Francis Bacon]]'s 1620 ''[[Novum Organum]]'' was critical in the [[History of scientific method|development of scientific method]].}} Certain research areas are [[interdisciplinary]], such as [[biophysics]] and [[quantum chemistry]], which means that the boundaries of physics are not [[demarcation problem|rigidly defined]]. In the nineteenth and twentieth centuries [[physicalism]] emerged as a major unifying feature of the [[philosophy of science]] as physics provides fundamental explanations for every [[observation|observed]] natural [[phenomenon]]. New ideas in physics often explain the fundamental mechanisms of other sciences, while opening to new research areas in mathematics and philosophy.
==== Chemistry ====
{{Main|Chemistry}}
{{For outline|Outline of chemistry}}
''Chemistry'' (the etymology of the word has been much disputed){{NoteTag|See [[Chemistry (etymology)]] for possible origins of this word.}} is the [[science]] of [[matter]] and the changes it undergoes. The science of matter is also addressed by [[physics]], but while physics takes a more general and fundamental approach, chemistry is more specialized, being concerned by the composition, behavior (or reaction), structure, and properties of matter, as well as the changes it undergoes during [[chemical reaction]]s.[{{cite web |title=Definition of CHEMISTRY |url=https://www.merriam-webster.com/dictionary/chemistry |website=www.merriam-webster.com |access-date=24 August 2020 |language=en}}][{{cite web |title=Definition of chemistry {{!}} Dictionary.com |url=http://dictionary.reference.com/browse/Chemistry |website=www.dictionary.com |access-date=24 August 2020 |language=en}}] It is a [[physical science]] which studies various [[chemical substance|substance]]s, [[atom]]s, [[molecule]]s, and matter (especially carbon based). Example sub-disciplines of chemistry include: [[biochemistry]], the study of substances found in [[biological organism]]s; [[physical chemistry]], the study of chemical processes using physical concepts such as [[thermodynamics]] and [[quantum mechanics]]; and [[analytical chemistry]], the analysis of material samples to gain an understanding of their [[chemical composition]] and [[Chemical structure|structure]]. Many more specialized disciplines have emerged in recent years, e.g. [[neurochemistry]] the chemical study of the [[nervous system]].
==== Earth science ====
{{Main|Earth science}}
{{For outline|Outline of Earth sciences}}
''Earth science'' (also known as ''geoscience'', ''the geosciences'' or ''the Earth sciences'') is an all-embracing term for the [[science]]s related to the [[planet]] [[Earth (planet)|Earth]].[{{cite web |title=WordNet Search: Earth science |url=http://wordnetweb.princeton.edu/perl/webwn?s=Earth+science&sub=Search+WordNet |website=wordnetweb.princeton.edu |access-date=23 August 2020}}] It is arguably a special case in [[planetary science]], the Earth being the only known [[life]]-bearing planet. There are both [[reductionist]] and [[holism|holistic]] approaches to Earth sciences. The formal discipline of Earth sciences may include the study of the [[Atmosphere of Earth|atmosphere]], [[hydrosphere]], [[lithosphere]], and [[biosphere]], as well as the [[solid earth]]. Typically Earth scientists will use tools from [[physics]], [[chemistry]], [[biology]], [[geography]], [[chronology]] and [[mathematics]] to build a quantitative understanding of how the Earth system works, and how it evolved to its current state.
===== Geology =====
{{Main|Geology}}
{{For outline|Outline of geology}}
''Geology'' (from the [[Ancient Greek]] γῆ, ''gē'' ("earth") and -λoγία, ''-logia'', ("study of", "discourse")[{{OEtymD|geology}}][{{LSJ|gh{{=}}|γῆ|ref}}]) is an [[Earth science]] concerned with the [[solid Earth]], the [[rock (geology)|rocks]] of which it is composed, and the processes by which they change over time. Geology can also include the study of the solid features of any [[terrestrial planet]] or [[natural satellite]] such as [[Geology of Mars|Mars]] or [[geology of the Moon|the Moon]]. Modern geology significantly overlaps all other Earth sciences, including [[hydrology]] and the [[atmospheric sciences]], and so is treated as one major aspect of integrated [[Earth system science]] and [[planetary science]].
===== Oceanography =====
{{Main|Oceanography}}
''Oceanography'', or ''marine science'', is the branch of [[Earth science]] that studies the ocean. It covers a wide range of topics, including [[marine organisms]] and [[ecosystem]] dynamics; [[ocean currents]], [[water waves|waves]], and geophysical fluid dynamics; [[plate tectonics]] and the geology of the seafloor; and [[flux]]es of various chemical substances and physical properties within the ocean and across its boundaries. These diverse topics reflect multiple disciplines that oceanographers blend to further knowledge of the world ocean and understanding of processes within it: [[biology]], [[chemistry]], [[geology]], [[meteorology]], and [[physics]] as well as [[geography]].
===== Meteorology =====
{{Main|Meteorology}}
{{For outline|Outline of meteorology}}
''Meteorology'' is the [[interdisciplinary]] scientific study of the [[atmosphere]]. Studies in the field stretch back millennia, though significant progress in meteorology did not occur until the 17th century. The 19th century saw breakthroughs occur after observing networks developed across several countries. After the development of the computer in the latter half of the 20th century, breakthroughs in [[weather forecasting]] were achieved.
==== Astronomy ====
{{Main|Astronomy}}
{{For outline|Outline of astronomy}}
''Space science'' is the study of everything in outer space.[{{cite web |title=space science |url=http://www.thefreedictionary.com/space+science |website=TheFreeDictionary.com |access-date=2020-08-23}}] This has sometimes been called astronomy, but recently astronomy has come to be regarded as a division of broader space science, which has grown to include other related fields,[[https://web.archive.org/web/20100531210227/http://science.nasa.gov/planetary-science/planetary-science-data/national-space-science-data-center-nssdc/ National Space Science Data Center (NSSDC) – NASA Science]] such as studying issues related to [[Spaceflight|space travel]] and [[space exploration]] (including [[space medicine]]), [[space archaeology]][{{Cite web|url=http://dictionary.reference.com/browse/space+science|title=Space science | Define Space science at Dictionary.com}}] and science performed in [[outer space]] (see ''[[space research]]'').
=== Biological science ===
{{Main|Biology}}
{{For outline|Outline of biology}}
{{See also|List of life sciences}}
''Life science'', also known as ''biology'', is the [[natural science]] that studies [[life]] such as [[microorganism]]s, [[plant]]s, and [[animal]]s including [[human being]]s, – including their [[anatomy|physical structure]], [[Biochemistry|chemical processes]], [[Molecular biology|molecular interactions]], [[Physiology|physiological mechanisms]], [[Developmental biology|development]], and [[evolution]].[Based on definition from: {{cite web |url=http://www.bio.txstate.edu/~wetlands/Glossary/glossary.html |archive-url=https://web.archive.org/web/20040608113114/http://www.bio.txstate.edu/~wetlands/Glossary/glossary.html |archive-date=2004-06-08 |title=Aquarena Wetlands Project glossary of terms |author= |publisher=Texas State University at San Marcos}}] Despite the complexity of the science, certain unifying concepts consolidate it into a single, coherent field. Biology recognizes the [[Cell (biology)|cell]] as the basic unit of life, [[genes]] as the basic unit of [[heredity]], and evolution as the engine that propels the [[Speciation|creation]] and [[extinction]] of [[species]]. [[Organism|Living organisms]] are [[Thermodynamic system|open systems]] that survive by transforming [[energy]] and decreasing their local [[entropy]][{{cite journal |author1=Davies, PC |author2=Rieper, E |author3=Tuszynski, JA | title=Self-organization and entropy reduction in a living cell | journal=Bio Systems | volume=111 | issue=1 | pages=1–10 | date=January 2013 | pmid=23159919 | pmc=3712629 | doi=10.1016/j.biosystems.2012.10.005 |bibcode=2013BiSys.111....1D }}] to maintain a stable and vital condition defined as [[homeostasis]].[{{Cite journal|last1=Modell|first1=Harold|last2=Cliff|first2=William|last3=Michael|first3=Joel|last4=McFarland|first4=Jenny|last5=Wenderoth|first5=Mary Pat|last6=Wright|first6=Ann|date=December 2015|title=A physiologist's view of homeostasis|journal=Advances in Physiology Education|volume=39|issue=4|pages=259–66|doi=10.1152/advan.00107.2015|issn=1043-4046|pmc=4669363|pmid=26628646}}]
==== Biochemistry ====
{{Main|Biochemistry}}
{{For outline|Outline of biochemistry}}
''Biochemistry'', or ''biological chemistry'', is the study of [[chemical process]]es within and relating to living [[organism]]s.[{{cite web|url=http://www.acs.org/content/acs/en/careers/college-to-career/areas-of-chemistry/biological-biochemistry.html.html |title=Biological/Biochemistry|work=acs.org}}] It is a sub-discipline of both biology and chemistry, and from a [[reductionist]] point of view it is fundamental in biology. Biochemistry is closely related to [[molecular biology]], [[cell biology]], [[genetics]], and [[physiology]].
==== Microbiology ====
{{Main|Microbiology}}
{{See also|Branches of microbiology}}
''Microbiology'' is the study of [[microorganism]]s, those being [[unicellular]] (single cell), [[multicellular]] (cell colony), or [[acellular]] (lacking cells). Microbiology encompasses numerous sub-disciplines including [[virology]], [[bacteriology]], [[protistology]], [[mycology]], [[immunology]] and [[parasitology]].
==== Botany ====
{{Main|Botany}}
{{For outline|Outline of botany}}
''Botany'', also called ''plant science(s)'', ''plant biology'' or ''phytology'', is the [[science]] of [[plant]] life and a branch of [[biology]]. Traditionally, botany has also included the study of [[fungi]] and [[algae]] by [[mycologists]] and [[phycologists]] respectively, with the study of these three groups of organisms remaining within the sphere of interest of the [[International Botanical Congress]]. Nowadays, botanists (in the strict sense) study approximately 410,000 [[species]] of [[Embryophyte|land plants]] of which some 391,000 species are [[vascular plant]]s (including approximately 369,000 species of [[flowering plant]]s),[RBG Kew (2016). The State of the World's Plants Report – 2016. Royal Botanic Gardens, Kew. https://stateoftheworldsplants.com/report/sotwp_2016.pdf {{Webarchive|url=https://web.archive.org/web/20160928190506/https://stateoftheworldsplants.com/report/sotwp_2016.pdf |date=2016-09-28 }}] and approximately 20,000 are [[bryophyte]]s.[{{Cite web|url=http://www.theplantlist.org/1.1/browse/B/|title=Bryophytes (Mosses and liverworts) — The Plant List|website=www.theplantlist.org}}]
==== Zoology ====
{{Main|Zoology}}
{{For outline|Outline of zoology}}
''Zoology'' ({{IPAc-en|z|oʊ|ˈ|ɒ|l|ə|dʒ|i|}}){{NoteTag|The pronunciation of zoology as {{IPAc-en|z|u|ˈ|ɒ|l|ə|dʒ|i}} is typically regarded as nonstandard, though is not uncommon.}} is the branch of [[biology]] that studies the animal kingdom, including the [[anatomy|structure]], [[embryology]], [[evolution]], [[Biological classification|classification]], [[Ethology|habits]], and distribution of all [[animal]]s, both living and [[extinction|extinct]], and how they interact with their ecosystems. The term is derived from [[Ancient Greek]] ζῷον, ''zōion'', i.e. "animal" and λόγος, ''logos'', i.e. "knowledge, study".[{{cite dictionary|title=zoology|url=http://www.etymonline.com/index.php?term=zoology&allowed_in_frame=0|dictionary=[[Online Etymology Dictionary]]}}] Some branches of zoology include: [[anthrozoology]], [[arachnology]], [[archaeozoology]], [[cetology]], [[embryology]], [[entomology]], [[helminthology]], [[herpetology]], [[histology]], [[ichthyology]], [[malacology]], [[mammalogy]], [[Morphology (biology)|morphology]], [[nematology]], [[ornithology]], [[palaeozoology]], [[pathology]], [[primatology]], [[protozoology]], [[Taxonomy (biology)|taxonomy]], and [[zoogeography]].
==== Ecology ====
{{Main|Ecology}}
{{For outline|Outline of ecology}}
''Ecology'' (from {{langx|el|οἶκος}}, "house", or "environment"; {{langx|el|-λογία|label=none}}, "study of"){{noteTag|In Ernst Haeckel's (1866) footnote where the term ecology originates, he also gives attribute to {{langx|grc|χώρας|khōrā |χωρα}}, meaning "dwelling place, distributional area" —quoted from Stauffer (1957).}} is a branch of [[biology]][{{Cite web|url=http://www.dictionary.com/browse/ecology|title=the definition of ecology|website=Dictionary.com|access-date=20 February 2018|url-status=live|archive-url=https://web.archive.org/web/20180221095929/http://www.dictionary.com/browse/ecology|archive-date=21 February 2018}}] concerning interactions among [[organism]]s and their [[biophysical environment]], which includes both [[Biotic component|biotic]] and [[Abiotic component|abiotic]] components. Topics of interest include the [[biodiversity]], distribution, [[Biomass (ecology)|biomass]], and [[Population (biology)|population]]s of organisms, as well as cooperation and competition within and between [[species]]. [[Ecosystems]] are dynamically interacting systems of [[organisms]], the [[Community (ecology)|communities]] they make up, and the non-living components of their environment. Ecosystem processes, such as [[primary production]], [[pedogenesis]], [[nutrient cycling]], and [[niche construction]], regulate the flux of energy and matter through an environment. Organisms with specific life history traits sustain these processes.
== Social sciences ==
{{Main|Social science}}
{{For outline|Outline of social science}}
''Social science'' is the branch of science devoted to the study of [[society|societies]] and the [[Social relation|relationships]] among [[individual]]s within those societies. The term was formerly used to refer to the field of [[sociology]], the original "science of society", established in the 19th century. In addition to sociology, it now encompasses a wide array of [[academic discipline]]s, including [[political science]], [[economics]], [[anthropology]], [[communication studies]], [[education]], [[geography]], [[history]], [[law]], [[linguistics]], and [[psychology]].
[[Positivism|Positivist]] social scientists use methods resembling those of the [[natural science]]s as tools for understanding society, and so define science in its stricter [[Modern science|modern sense]]. [[Antipositivism|Interpretivist]] social scientists, by contrast, may use social critique or symbolic interpretation rather than constructing empirically [[falsifiable]] theories. In modern academic practice, researchers are often [[Eclecticism|eclectic]], using multiple [[Methodology|methodologies]] (for instance, by combining both [[quantitative research|quantitative]] and [[qualitative research]]). The term "[[social research]]" has also acquired a degree of autonomy as practitioners from various disciplines share in its aims and methods.
== Applied sciences ==
{{Main|Applied science}}
{{For outline|Outline of applied science}}
''Applied science'' is the use of existing scientific knowledge to achieve practical goals, like [[technology]] or inventions.
Within [[natural science]], disciplines that are [[basic science]] develop basic ''[[information]]'' to explain and perhaps predict phenomena in the natural world. Applied science is the use of scientific processes and knowledge as the means to achieve a particularly practical or useful result. This includes a broad range of applied science-related fields, including [[agricultural science]], [[engineering]] & [[medicine]].
Applied science can also apply [[formal science]], such as [[statistics]] and [[probability theory]], as in [[epidemiology]]. [[Genetic epidemiology]] is an applied science applying both biological and statistical methods.
== Relationships between the branches ==
The relationships between the branches of science are summarized by the table.[{{cite book | last = Cohen | first = Eliel | year = 2021 | chapter = The boundary lens: theorising academic actitity | title = The University and its Boundaries: Thriving or Surviving in the 21st Century 1st Edition | url = https://www.routledge.com/The-University-and-its-Boundaries-Thriving-or-Surviving-in-the-21st-Century/Cohen/p/book/9780367562984 | pages = 14–41 | publisher = Routledge | location = New York, New York | isbn = 978-0-367-56298-4 }}]
{|class="wikitable" style="border: none;"
|rowspan=3 style="border: none;"|
!colspan=3|Science
|-
!rowspan=2|[[Formal science]]
!colspan=2|[[Empirical science]]s
|-
![[Natural science]]
![[Social science]]
|-
![[Fundamental science|Foundation]]
|
* [[Logic]]
* [[Pure Mathematics]]
|
* [[Physics]]
* [[Chemistry]]
* [[Biology]]
* [[Earth science]]
* [[Astronomy]]
|
* [[Political science]]
* [[Economics]]
* [[Sociology]]
* [[Psychology]]
* [[Anthropology]]
* [[Geography]]
* [[History]]
* [[Linguistics]]
|-
![[Applied science|Application]]
|
* [[Applied mathematics]]
* [[Statistics]]
* [[Computer science]]
|valign=top|
* [[Engineering]]
* [[Agricultural science]]
* [[Medicine]]
* [[Pharmacy]]
|
* [[Urban planning]]
* [[Jurisprudence]]
* [[Accounting]]
* [[Business administration]]
* [[Finance]]
* [[Pedagogy]]
|}
== Visualizations and metascience ==
[[Metascience]] refers to or includes a field of science that is about science itself. [[Our Research#OpenAlex|OpenAlex]] and [[Scholia]] can be used to visualize and explore [[scientific field]]s and research topics.
{{multiple image
| footer =
| direction = horizontal
| align = center
| image1 = Locations of papers in a map of science and locations of the key papers for Nobel prizes.tif
| alt1 = Locations of papers in a map of science and locations of the key papers for Nobel prizes
| caption1 = Cluster network of scientific publications in relation to Nobel prizes[{{cite journal |last1=Ioannidis |first1=John P. A. |last2=Cristea |first2=Ioana-Alina |last3=Boyack |first3=Kevin W. |title=Work honored by Nobel prizes clusters heavily in a few scientific fields |journal=PLOS ONE |date=29 July 2020 |volume=15 |issue=7 |article-number=e0234612 |doi=10.1371/journal.pone.0234612 |pmid=32726312 |pmc=7390258 |bibcode=2020PLoSO..1534612I |language=en |issn=1932-6203|doi-access=free }}]
| image2 = Academic papers by discipline over time (visualization of studies data in OpenAlex).png
| width2 = 300
| alt2 = Academic papers by discipline (visualization of 2012–2021 OpenAlex data; v2)
| caption2 = A visualization of scientific outputs by field in OpenAlex.[{{cite web |title=Open Alex Data Evolution |url=https://observablehq.com/@napsternxg/open-alex-data-evolution |website=observablehq.com |date=8 February 2022 |access-date=20 February 2022}}]
A study can be part of multiple fields and lower numbers of papers is not necessarily detrimental for fields.
| image3 = Change of number of scientific works by field (visualization of OpenAlex data).png
| alt3 = Change of number of scientific papers by field (visualization of 2012–2021 OpenAlex data)
| caption3 = Graph illustrating the recent development or history of scientific outputs based on data in OpenAlex.org