Editing Rasmus Bartholin

{{short description|Danish scientist, physician and grammarian (1625–1698)}}
{{Use dmy dates|date=February 2025}}
{{Infobox scientist
|name              = Rasmus Bartholin
|image             =Rasmus Bartholin.jpg
|image_size       =150px
|caption           = Rasmus Bartholin
|birth_date        = 13 August 1625
|birth_place       = [[Roskilde]]
|death_date        = 4 November 1698 (aged 73)
|death_place       = [[Copenhagen]]
|residence         =
|citizenship       =
|nationality       = [[Denmark|Danish]]
|ethnicity         =
|field             = [[Physics]]
|work_institutions =
|alma_mater        =
|doctoral_advisor  =
|doctoral_students =
|known_for         = [[Birefringence|Double refraction]] of a light ray
}}
'''Rasmus Bartholin''' ({{IPAc-en|b|ɑr|ˈ|t|oʊ|l|ɪ|n|,_|ˈ|b|ɑr|t|əl|ɪ|n}}; Latinized: ''Erasmus Bartholinus''; 13 August 1625 &ndash; 4 November 1698) was a [[Denmark|Danish]] physician and grammarian.

==Biography==
Bartholin was born in [[Roskilde]]. He was the son of [[Caspar Bartholin the Elder]] (1585–1629) and Anna Fincke, daughter of the mathematician [[Thomas Fincke]].<ref>{{cite web|url=     https://runeberg.org/dbl/5/0152.html|title=   Fincke, Thomas, 1561-1656 |publisher =   	Dansk biografisk Lexikon|access-date=1 August 2019}}</ref>

As part of his studies, he travelled in Europe for ten years. He stayed in the Netherlands, England, France and Italy. In 1647, he took a [[Master's degree]] at the [[University of Copenhagen]]. In 1654, he received a Doctoral degree at the [[University of Padua]].

He was a professor at the [[University of Copenhagen]], first in [[Geometry]], later in Medicine. He was also dean of the faculty of medicine, librarian, and rector.<ref>[http://www-history.mcs.st-and.ac.uk/Biographies/Bartholin.html Erasmus Bartholin]
School of Mathematics and Statistics. University of St Andrews, Scotland</ref> He wrote, in Latin, the first grammar of the [[Danish language]], the 1657 ''De studio lingvæ danicæ''.

Rasmus Bartholin is remembered especially for his discovery (1669) of the [[birefringence|double refraction]] of a light ray by [[Iceland spar]] ([[calcite]]).<ref>Erasmus Bartholin, ''Experimenta crystalli islandici disdiaclastici quibus mira & insolita refractio detegitur'' ([[Copenhagen]] ("Hafniæ"), Denmark: Daniel Paulli, 1669). English translation: ''Experiments with the double refracting Iceland crystal which led to the discovery of a marvelous and strange refraction,'' tr. by Werner Brandt. Westtown, Pa., 1959.</ref> He published an accurate description of the phenomenon, but since the physical nature of light was poorly understood at the time, he was unable to explain it.<ref>{{Cite web|url=https://www.britannica.com/biography/Erasmus-Bartholin|title=Erasmus Bartholin &#124; Danish physician and physicist|website=Encyclopædia Britannica}}</ref> It was only after [[Thomas Young (scientist)|Thomas Young]] proposed the wave theory of light, c. 1801 that an explanation became possible.

==Personal==
He was a younger brother of [[Thomas Bartholin]] (1616–1680).<ref>{{cite web|url=   http://denstoredanske.dk/Dansk_Biografisk_Leksikon/Sundhed/L%C3%A6ge/Thomas_Bartholin  |title=   Thomas Bartholin|publisher =  Dansk Biografisk Leksikon Gyldendal|author=  V. Meisen |accessdate=1 August 2019}}</ref>

== References ==
{{reflist}}

== External links ==
* "De figura nivis". In Thomas Bartolin, {{google books|UYY8AAAAcAAJ|De nivis usu medico observationes variae. Accessit D. Erasmi Bartholini de figura nivis dissertatio|page=PA241}}. Copenhagen: P. Haubold, 1661
* {{MacTutor Biography|id=Bartholin|title=Erasmus Bartholin}}
* [http://www.worldcat.org/identities/lccn-n93-3891 Bartholin, Erasmus 1625-1698 ] worldcat.org

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{{DEFAULTSORT:Bartholin, Rasmus}}
[[Category:1625 births]]
[[Category:1698 deaths]]
[[Category:17th-century Danish physicians]]
[[Category:17th-century Danish scientists]]
[[Category:University of Copenhagen alumni]]
[[Category:University of Padua alumni]]
[[Category:Academic staff of the University of Copenhagen]]
[[Category:Medical educators]]
[[Category:Mathematics educators]]
[[Category:People from Roskilde]]
[[Category:Rectors of the University of Copenhagen]]
[[Category:Bartholin family]]