Editing 1991 in science

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{{Year nav topic5|1991|science}}
{{Science year nav|1991}}

The year '''1991 in science''' and technology involved many significant events, some listed below.

==Astronomy and space exploration==
* May 18 – [[Helen Sharman]] becomes the first [[British people|British person]] in space, flying with the [[Soyuz TM-12]] mission.<ref>{{cite news|url=http://news.bbc.co.uk/onthisday/hi/dates/stories/may/18/newsid_2380000/2380649.stm|title=1991: Sharman becomes first Briton in space|work=BBC News|accessdate=2008-02-01|date=1991-05-18|archiveurl= https://web.archive.org/web/20080307014408/http://news.bbc.co.uk/onthisday/hi/dates/stories/may/18/newsid_2380000/2380649.stm|archivedate=2008-03-07|url-status=live}}</ref>
* October 29 – The [[Galileo probe|''Galileo'' probe]] becomes the first spacecraft to visit an asteroid ([[951 Gaspra]]).
* [[Steven Balbus]] and [[John F. Hawley]] publish their insights on [[magnetorotational instability]].<ref>{{cite journal|last1=Balbus|first1=Steven A.|last2=Hawley|first2=John F.|year=1991|title=A powerful local shear instability in weakly magnetized disks|journal=[[The Astrophysical Journal]]|volume=376|pages=214–233|bibcode=1991ApJ...376..214B|doi=10.1086/170270}}</ref>
* Asteroid [[List of minor planets: 6001–7000#859|6859]] [[Meanings of minor planet names: 6001-7000#859|Datemasamune]] is discovered by [[Masahiro Koishikawa]].
* Asteroid [[List of minor planets: 11001–12000#514|11514]] [[Meanings of minor planet names: 11001–12000#514|Tsunenaga]] is discovered by [[Masahiro Koishikawa]].
* There are four [[lunar eclipse]]s: three penumbral on [[January 1991 lunar eclipse|January 30]], [[July 1991 lunar eclipse|July 26]], and [[June 1991 lunar eclipse|June 27]], and one minor partial lunar eclipse on [[December 1991 lunar eclipse|December 21]].
* There are two [[solar eclipse]]s: one annular eclipse on [[Solar eclipse of January 15, 1991|January 15]], and a very long total eclipse on [[solar eclipse of July 11, 1991|July 11]] (lasting 6 minutes and 53 seconds).

==Chemistry==
* [[Carbon nanotube]]s discovered in the insoluble material of arc-burned graphite rods by [[Sumio Iijima]] of [[NEC]].<ref>{{cite journal|first=Sumio|last=Iijima|title=Helical microtubules of graphitic carbon|journal=[[Nature (journal)|Nature]]|volume=354|pages=56–58|date=7 November 1991|doi=10.1038/354056a0|issue=6348|bibcode=1991Natur.354...56I|s2cid=4302490}}</ref><ref>{{cite journal|title=Who should be given the credit for the discovery of carbon nanotubes?|doi=10.1016/j.carbon.2006.03.019|first1=Marc|last1=Monthioux|journal=Carbon|volume=44|year=2006|url=http://www.cemes.fr/fichpdf/GuestEditorial.pdf|page=1621|last2=Kuznetsov|first2=Vladimir L.|issue=9|bibcode=2006Carbo..44.1621M |accessdate=2012-02-03}}</ref>

==Computer science==
* February 26 – [[Tim Berners-Lee]] introduces [[WorldWideWeb]] (the first [[web browser]]), and a [[WYSIWYG]] [[HTML editor]].
* May 14 – [[Nicola Pellow]], an intern working under the direction of Berners-Lee, introduces [[Line Mode Browser]], the first cross-platform web browser.
* June 5 – [[Phil Zimmermann]] posts the first [[Pretty Good Privacy]] (PGP) [[data encryption]] [[computer program|program]].<ref>{{cite web|url=http://www.philzimmermann.com/EN/news/PGP_10thAnniversary.html|title=PGP Marks 10th Anniversary|first=Philip|last=Zimmermann|date=2001-06-05|accessdate=2012-01-28|archive-date=2011-05-14|archive-url=https://web.archive.org/web/20110514200112/http://www.philzimmermann.com/EN/news/PGP_10thAnniversary.html|url-status=dead}}</ref>
* June 23 – The [[video game]] ''[[Sonic the Hedgehog (1991 video game)|Sonic the Hedgehog]]'' is first released, propelling the [[Sega Genesis]] [[History of video game consoles (fourth generation)|16-bit console]] into mass popularity.
* August 6 – The first [[website]] goes online at [[CERN]].<ref>{{cite web|title=Welcome to info.cern.ch, the website of the world's first-ever web server|publisher=CERN|url=http://info.cern.ch/|accessdate=25 May 2008|archiveurl=https://web.archive.org/web/20080527152659/http://info.cern.ch/|archivedate=27 May 2008|url-status=live}}</ref><ref>{{cite web|title=World Wide Web—Archive of world's first website|publisher=World Wide Web Consortium|url=http://www.w3.org/History/19921103-hypertext/hypertext/WWW/TheProject.html|accessdate=25 May 2008}}</ref><ref>{{cite web|title=World Wide Web—First mentioned on USENET|date=6 August 1991|url=http://groups.google.co.uk/group/alt.hypertext/msg/06dad279804cb3ba?dmode=source&hl=en|accessdate=25 May 2008|archiveurl=https://web.archive.org/web/20080512015304/http://groups.google.co.uk/group/alt.hypertext/msg/06dad279804cb3ba?dmode=source&hl=en|archivedate=12 May 2008|url-status=dead}}</ref><ref>{{cite web|title=The original post to alt.hypertalk describing the WorldWideWeb Project|work=[[Google Groups]]|date=9 August 1991|url =https://groups.google.com/group/comp.archives/browse_thread/thread/9fb079523583d42/37bb6783d03a3b0d?lnk=st&q=&rnum=2&hl=en#37bb6783d03a3b0d|accessdate=25 May 2008}}</ref>
* The [[Trojan Room coffee pot]] at the [[Computer Laboratory, University of Cambridge]], England, inspires the first [[webcam]].
* October - [[Apple Inc.|Apple]] releases the [[PowerBook]] [[laptop computer]].

==Conservation==
* October 1 – The [[New Zealand]] [[Resource Management Act 1991]] comes into effect.

==Geophysics==
* [[Alan Hildebrand]] and others provide support for the [[Alvarez hypothesis]] for the [[Cretaceous–Paleogene extinction event]] by proposing the [[Chicxulub crater]] in the [[Yucatán Peninsula]] of [[Mexico]] as the [[Impact crater|impact site]] for a large [[asteroid]] 66 million years ago.<ref>{{cite journal|author=Pope, Kevin O.|title=Mexican site for K/T impact crater?|journal=[[Nature (journal)|Nature]]|volume=351|date=9 May 1991|page=105|issue=6322|doi=10.1038/351105a0|bibcode = 1991Natur.351..105P |s2cid=36707836|display-authors=etal|doi-access=free}}</ref><ref>{{cite journal|author1=Hildebrand, Alan R. |author2=Penfield, Glen T. |author3=Kring, David A. |author4=Pilkington, Mark |author5=Zanoguera, Antonio Camargo |author6=Jacobsen, Stein B. |author7=Boynton, William V. |title=Chicxulub Crater: a possible Cretaceous/Tertiary Boundary impact crater on the Yucatán Peninsula, Mexico|date=September 1991|volume=19|issue=9|journal=[[Geology (journal)|Geology]]|pages=867–871|doi=10.1130/0091-7613(1991)019<0867:CCAPCT>2.3.CO;2|bibcode=1991Geo....19..867H}}</ref><ref>{{cite journal|author=Schulte, Peter|title=The Chicxulub Asteroid Impact and Mass Extinction at the Cretaceous- Paleogene Boundary|journal=[[Science (journal)|Science]]|volume=327|pages=1214–1218|year=2010|doi=10.1126/science.1177265|pmid=20203042|issue=5970|bibcode=2010Sci...327.1214S|s2cid=2659741|url=http://doc.rero.ch/record/210367/files/PAL_E4389.pdf|display-authors=etal}}</ref>
* The [[Ames crater]] [[impact structure]] is identified in [[Major County, Oklahoma]].

==Mathematics==
* July &ndash; English physicist [[Philip Candelas]] and colleagues show that [[Mirror symmetry (string theory)|mirror symmetry]] could be used to solve problems in [[enumerative geometry]].<ref>{{cite journal|last1=Candelas |first1=Philip|last2=de la Ossa|first2=Xenia|last3=Green|first3=Paul|last4=Parks|first4=Linda|year=1991|title=A pair of Calabi–Yau manifolds as an exactly soluble superconformal field theory|journal=[[Nuclear Physics B]]|volume=359|issue=1|pages=21–74|doi=10.1016/0550-3213(91)90292-6|bibcode = 1991NuPhB.359...21C }}</ref>
* [[Qiudong Wang]] produces a global solution to the [[n-body problem|''n''-body problem]].<ref>{{cite journal|last=Wang|first=Qiudong|title=The global solution of the n-body problem|journal=[[Celestial Mechanics and Dynamical Astronomy]]|issn=0923-2958|volume=50|issue=1|year=1991|pages=73–88|bibcode=1990CeMDA..50...73W|doi=10.1007/BF00048987|s2cid=118132097}}</ref>

==Physics==
* January 1 – [[Finland]] joins [[CERN]].
* July 1 – [[Poland]] joins [[CERN]].
* October 15 – the "[[Oh-My-God particle]]", the first [[ultra-high-energy cosmic ray]] measured at an energy of {{val|3|e=20|u=[[electronvolt|eV]]}} (40,000,000 times that of the highest energy protons that have been produced in a particle accelerator), is observed at the [[University of Utah]] [[High Resolution Fly's Eye Cosmic Ray Detector|HiRes]] observatory in [[Dugway Proving Ground]], [[Utah]].

==Physiology and medicine==
* [[Takotsubo cardiomyopathy]] first studied.

==Technology==
* July 1 – World's first [[GSM]] telephone call made in Finland.

==Publications==
* The first open-access scientific online archive, [[arXiv]], is begun as a preprint service for physicists, initiated by [[Paul Ginsparg]].

==Awards==
* [[Nobel Prize]]s
** [[Nobel Prize in Physics|Physics]] – [[Pierre-Gilles de Gennes]]
** [[Nobel Prize in Chemistry|Chemistry]] – [[Richard R. Ernst]]
** [[Nobel Prize in Physiology or Medicine|Medicine]] – [[Erwin Neher]], [[Bert Sakmann]]
* [[Turing Award]] – [[Robin Milner]]

==Births==
* February 28 – [[Sheree Atcheson]], Sri Lankan-Irish computer scientist

==Deaths==
* January 30 – [[John Bardeen]] (b. [[1908 in science|1908]]), [[Americans|American]] physicist, co-inventor of the [[transistor]] and twice winner of the [[Nobel Prize in Physics]].
* February 6 – [[Salvador Luria]] (b. [[1912 in science|1912]]), Italian-born [[biologist]], co-winner of the [[Nobel Prize in Physiology or Medicine]].
* February 23 – Sir [[Charles Illingworth]] (b. [[1899 in science|1899]]), [[British people|British]] [[surgeon]].
* March 1 – [[Edwin H. Land]] (b. [[1909 in science|1909]]), American inventor of the [[Land Camera]].
* June 2 – [[Mary Loveless]] (b. 1899), American [[immunologist]].
* June 5 – [[Min Chueh Chang]] (b. 1908), [[Chinese American]] [[embryologist]].
* July 4 – [[Victor Chang]] (b. [[1936 in science|1936]]), Australian [[cardiac surgeon]], murdered.
* August 23 – [[Florence B. Seibert]] (b. [[1897 in science|1897]]), American [[biochemist]].
* December 2 – [[Anne Beloff-Chain]] (b. [[1921 in science|1921]]), British biochemist.

==References==
{{Portal|1990s|Science}}
{{reflist}}

{{DEFAULTSORT:1991 In Science}}
[[Category:1991 in science| ]]
[[Category:20th century in science]]
[[Category:1990s in science]]