Harald Bohr

Infobox Person
name = Harald Bohr


imagesize = 164px
caption = Harald Bohr
birth_date = Birth date|1887|04|22
birth_place =
death_date = death date and age|1951|01|22|1887|04|22
death_place =
other_names =
known_for =
occupation = Mathematician
nationality = Danish

Harald August Bohr (22 April 1887 – 22 January 1951) was a Danish mathematician and football player. As a student, his footballing skill meant he was called up to the Danish national team for the 1908 Summer Olympics, where he won a silver medal. After receiving his doctorate in 1910, Bohr became an eminent mathematician, founding the field of almost periodic functions. His brother was the Nobel Prize-winning physicist Niels Bohr.

Biography

Bohr was born in 1887 to Christian Bohr, a professor of physiology, and Ellen Adler Bohr, a woman from a wealthy Jewish family of local renown.cite web
url=http://www-history.mcs.st-andrews.ac.uk/Biographies/Bohr_Harald.html
title=Harald August Bohr
accessdate=2008-08-17
author=J J O'Connor and E F Robertson] One of Harald's siblings was Niels Bohr, who later in life would win a Nobel Prize in physics. Harald had a close relationship with his elder brother, which "The Times" likened to that between Captain Cuttle and Captain Bunsby in Charles Dickens' "Dombey and Son". [cite news
title=Obituary: Prof. Harald Bohr |work=The Times |page=8 |date=1951-02-06 |format=Times Digital Archive 1785-1985 |accessdate=2008-08-17]

Mathematical career

Like his father and brother before him, in 1904 Bohr enrolled at the University of Copenhagen, where he studied mathematics, obtaining his masters in 1909 and his doctorate a year later. Among his tutors were Hieronymus Georg Zeuthen and Thorvald N. Thiele.Bull. Amer. Math. Soc. Volume 58, Number 1 (1952), 72-75.] Bohr worked in mathematical analysis; much of his early work was devoted to Dirichlet series including his doctorate, which was entitled "Bidrag til de Dirichletske Rekkers Theori" ("Contributions to the Theory of Dirichlet Series").cite web
url=http://arxiv.org/pdf/math.CV/9705204l
title=The Football Player and the Infinite Series
accessdate=2008-08-18
author=H P Boas] A collaboration with Göttingen-based Edmund Landau resulted in the Bohr-Landau theorem, regarding the distribution of zeroes in zeta functions.

Bohr worked in mathematical analysis, founding the field of almost periodic functions, and worked with the Cambridge mathematician G. H. Hardy.

In 1915 he became a professor at Copenhagen Polytechnic, working there until 1930, when he took a professorship at the University of Copenhagen. He remained in this post for 21 years until his death in 1951.

In the 1930s Bohr was a leading critic of the anti-Semitic policies taking root in the German mathematical establishment, publishing an article criticising Ludwig Bieberbach's ideas in Berlingske Aften in 1934. [cite book |last=Menzler-Trott |first=Eckart |title=Logic's Lost Genius: The Life of Gerhard Gentzen |publisher=AMS |date=2008 |id=ISBN 0821835505| pages=115]

Football

, making his debut as a 16 year old in 1903.cite web
url=http://www.ab-fodbold.dk/ab-as.aspx
title=AB's historie
accessdate=2008-08-18
author=Akademisk Boldklub] During the 1905 season he played alongside his brother Niels, who was a goalkeeper. Harald was selected to play for the Danish national football team in the 1908 Summer Olympics, where football was an official event for the first time. Though a Danish side had played at the 1906 Intercalated Games, the opening match of the 1908 Olympic tournament was Denmark's first official international football match. Bohr scored two goals as Denmark beat the French "B" team 9–0.cite web
url=http://www.sports-reference.com/olympics/athletes/bo/harald-bohr-1.html
title=Harald Bohr
accessdate=2008-08-18
publisher=Sports-Reference.com] In the next match, the semi-final, Bohr played in a 17–1 win against France, which remains an Olympic record to this day.cite web
url=http://results.beijing2008.cn/WRM/ENG/BCK/FB/36192.shtml
title=Facts and figures - Team achievements / records
accessdate=2008-08-18
publisher=Beijing Olympics 2008 official website] Denmark faced hosts Great Britain in the final, but lost 2–0, and Bohr won a silver medal. After the Olympics he made one further appearance for the national team, in a 2–1 victory against an England amateur team in 1910.cite web
url=http://www.rsssf.com/tablesd/den-intl0812.html
title=Denmark - Internationals 1908-1912
accessdate=2008-08-18
publisher=RSSSF] His popularity as a footballer was such that when he defended his doctoral thesis the audience was reported as having more football fans than mathematicians.cite web
url=http://plus.maths.org/blog/2007/01/mathematical-moments-harald-bohr.html
title= Mathematical Moments - Harald Bohr
accessdate=2008-08-20
publisher=Plus magazine]

Teacher

Bohr was known as an extremely capable academic teacher and the annual award for outstanding teaching at the University of Copenhagen is called the Harald, in honour of Harald Bohr. With Johannes Mollerup, Bohr wrote an influential four-volume textbook "Lærebog i matematisk Analyse" ("Textbook in mathematical analysis"). [cite web
url=http://www.math.ku.dk/ths/bohr_h/biblio.htm
title= Bibliography of Harald Bohr
accessdate=2008-08-20
publisher=University of Copenhagen]

ee also

*Bohr-Mollerup theorem
*Bohr compactification
*Bohr-Favard inequality

References

External links

*MacTutor Biography|id=Bohr_Harald
*MathGenealogy |id=44557
* [http://www.dbu.dk/lbase/playerInfo.aspx?playerid=960 Danish national team profile]
* [http://www-history.mcs.st-andrews.ac.uk/history/PictDisplay/Bohr_Harald.html Some photos of Harald Bohr]