Science

=== 20th century ===
{{Main|20th century in science}}
[[File:Carte trou ozone Antarctique.jpg|alt=Graph showing lower ozone concentration at the South Pole|thumb|A computer graph of the [[ozone hole]] made in 1987 using data from a space telescope]]
In the first half of the century, the development of [[antibiotics]] and [[artificial fertilizer]]s improved human [[standard of living|living standards]] globally.<ref>{{Cite journal |last=Goyotte |first=Dolores |year=2017 |title=The Surgical Legacy of World War II. Part II: The age of antibiotics |url=https://www.ast.org/ceonline/articles/402/files/assets/common/downloads/publication.pdf |url-status=live |journal=The Surgical Technologist |volume=109 |pages=257–264 |archive-url=https://web.archive.org/web/20210505180530/https://www.ast.org/ceonline/articles/402/files/assets/common/downloads/publication.pdf |archive-date=May 5, 2021 |access-date=January 8, 2021 }}</ref><ref>{{cite journal |last1=Erisman |first1=Jan Willem |author2=MA Sutton |author3=J Galloway |author4=Z Klimont |author5=W Winiwarter |date=October 2008 |title=How a century of ammonia synthesis changed the world |url=http://www.physics.ohio-state.edu/~wilkins/energy/Resources/Essays/ngeo325.pdf.xpdf |url-status=dead |journal=[[Nature Geoscience]] |volume=1 |issue=10 |pages=636–639 |bibcode=2008NatGe...1..636E |doi=10.1038/ngeo325 |s2cid=94880859 |archive-url=https://web.archive.org/web/20100723223052/http://www.physics.ohio-state.edu/~wilkins/energy/Resources/Essays/ngeo325.pdf.xpdf |archive-date=July 23, 2010 |access-date=October 22, 2010}}</ref> 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]].<ref>{{cite journal|editor-last1=Emmett|editor-first1=Rob|editor-last2=Zelko|editor-first2=Frank|url=http://www.environmentandsociety.org/perspectives/2014/2/minding-gap-working-across-disciplines-environmental-studies|title=Minding the Gap: Working Across Disciplines in Environmental Studies|archive-url=https://web.archive.org/web/20220121054306/https://www.environmentandsociety.org/perspectives/2014/2/minding-gap-working-across-disciplines-environmental-studies |archive-date=January 21, 2022|series=RCC Perspectives no. 2|year=2014|doi=10.5282/rcc/6313|last1=Emmett |first1=Robert |last2=Zelko |first2=Frank |journal=Environment & Society Portal }}</ref>

During this period, scientific experimentation became increasingly [[Big science|larger in scale and funding]].<ref>{{Cite journal |last=Furner |first=Jonathan |date=June 1, 2003 |title=Little Book, Big Book: Before and After Little Science, Big Science: A Review Article, Part I |journal=Journal of Librarianship and Information Science |volume=35 |issue=2 |pages=115–125 |doi=10.1177/0961000603352006 |s2cid=34844169}}</ref> The extensive technological innovation stimulated by [[World War I]], [[World War II]], and the [[Cold War]] led to competitions between [[Great power|global powers]], such as the [[Space Race]] and [[nuclear arms race]].<ref>{{cite book |last=Kraft |first=Chris |url=https://archive.org/details/flight00chri |title=Flight: My Life in Mission Control |author2=James Schefter |publisher=Dutton |year=2001 |isbn=0-525-94571-7 |location=New York |author-link=Christopher C. Kraft, Jr.|pages=3–5}}</ref><ref>{{cite book|last=Kahn|first=Herman|author-link=Herman Kahn|year=1962|title=Thinking about the Unthinkable|publisher=Horizon Press}}</ref> Substantial international collaborations were also made, despite armed conflicts.<ref>{{Cite book |last=Shrum |first=Wesley |url=https://www.worldcat.org/oclc/166143348 |title=Structures of scientific collaboration |date=2007 |publisher=MIT Press |others=Joel Genuth, Ivan Chompalov |isbn=978-0-262-28358-8 |location=Cambridge, Mass. |oclc=166143348 |access-date=May 31, 2022 |archive-date=July 30, 2022 |archive-url=https://web.archive.org/web/20220730034527/https://www.worldcat.org/title/structures-of-scientific-collaboration/oclc/166143348 |url-status=live }}</ref>

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.<ref>{{cite book |last=Rosser |first=Sue V. |title=Breaking into the Lab: Engineering Progress for Women in Science |date=March 12, 2012 |publisher=New York University Press |isbn=978-0-8147-7645-2 |location=New York |page=7}}</ref> The discovery of the [[cosmic microwave background]] in 1964<ref>{{cite journal |last=Penzias |first=A. A. |year=2006 |title=The origin of elements |url=http://nobelprize.org/nobel_prizes/physics/laureates/1978/penzias-lecture.pdf |journal=Science |publisher=[[Nobel Foundation]] |volume=205 |issue=4406 |pages=549–54 |doi=10.1126/science.205.4406.549 |pmid=17729659 |access-date=October 4, 2006 |archive-date=January 17, 2011 |archive-url=https://web.archive.org/web/20110117225210/http://nobelprize.org/nobel_prizes/physics/laureates/1978/penzias-lecture.pdf |url-status=live }}</ref> led to a rejection of the [[Steady-state model|steady-state model of the universe]] in favor of the [[Big Bang]] theory of [[Georges Lemaître]].<ref>{{cite book |last=Weinberg |first=S. |url=https://archive.org/details/gravitationcosmo00stev_0/page/495 |title=Gravitation and Cosmology |publisher=John Whitney & Sons |year=1972 |isbn=978-0-471-92567-5 |pages=[https://archive.org/details/gravitationcosmo00stev_0/page/495 495–464] |url-access=registration}}</ref>

The century saw fundamental changes within science disciplines. Evolution became a unified theory in the early 20th-century when the [[Modern synthesis (20th century)|modern synthesis]] reconciled Darwinian evolution with [[classical genetics]].<ref name="Futuyma2017a">{{Cite book |last1=Futuyma |first1=Douglas J. |url=https://global.oup.com/ushe/product/evolution-9781605356051 |title=Evolution |last2=Kirkpatrick |first2=Mark |date= 2017 |isbn=978-1605356051 |edition=4th |pages=3–26 |chapter=Chapter 1: Evolutionary Biology |publisher=Sinauer |access-date=May 30, 2022 |archive-url=https://web.archive.org/web/20220531025652/https://global.oup.com/ushe/product/evolution-9781605356051?cc=us&lang=en& |archive-date=May 31, 2022 |url-status=live}}</ref> [[Albert Einstein]]'s [[theory of relativity]] and the development of [[quantum mechanics]] complement classical mechanics to describe physics in extreme [[length]], time and [[gravity]].<ref>{{Cite book |last=Miller |first=Arthur I. |title=Albert Einstein's special theory of relativity. Emergence (1905) and early interpretation (1905–1911) |date=1981 |location=Reading |publisher=Addison–Wesley |isbn=978-0-201-04679-3}}</ref><ref>{{cite book |last=ter Haar |first=D. |url=https://archive.org/details/oldquantumtheory0000haar |title=The Old Quantum Theory |publisher=Pergamon Press |year=1967 |isbn=978-0-08-012101-7 |pages=[https://archive.org/details/oldquantumtheory0000haar/page/206 206] |url-access=registration}}</ref> Widespread use of [[integrated circuit]]s in the last quarter of the 20th century combined with [[communications satellite]]s led to a revolution in information technology and the rise of the global internet and [[mobile computing]], including [[smartphone]]s. The need for mass systematization of long, intertwined causal chains and large amounts of data led to the rise of the fields of [[systems theory]] and computer-assisted [[scientific modelling|scientific modeling]].<ref>{{cite journal |last1=von Bertalanffy |first1=Ludwig |year=1972 |title=The History and Status of General Systems Theory |journal=The Academy of Management Journal |volume=15 |issue=4 |pages=407–26 |jstor=255139}}</ref>