Daniel Isaachsen (23 June 1859 – 29 March 1940) was a Norwegian physicist. He was born in

London London is the capital and List of urban areas in the United Kingdom, largest city of England and the United Kingdom, with a population of just under 9 million. It stands on the River Thames in south-east England at the head of a estuary dow ...

as the son of military officer Isak Tobias Isaachsen and Fredrikke Andrea Rude. He was a great-grandson of Isaach Isaachsen, brother of scientist

Haakon Isaachsen Haakon may refer to: Given names * Haakon (given name) * Håkon, modern Norwegian spelling of the name * Håkan, Swedish spelling of the name * Hakon, Danish spelling of the name People Norwegian royalty * Haakon I of Norway (c. 920–961), ...

and scientist Isak Isaachsen, nephew of painter

Olaf Isaachsen Olaf Wilhelm Isaachsen (May 16, 1835 – September 22, 1893) was a Norwegian landscape and genre painter. Biography He was born in Mandal in Vest-Agder county Norway. Isaachsen belonged to a branch of an affluent and educated merchant family fr ...

and cousin of painter Herman Willoch and naval officer

Odd Isaachsen Willoch Odd Isaachsen Willoch (26 February 1885 – 9 April 1940) was a Norwegian naval officer who commanded one of the two coastal defence ships defending Narvik during the German invasion of Norway on 9 April 1940. Personal life Odd Isaachsen Wi ...

. In 1861 he married Asta Lie, a daughter of Jonas Lie. He finished his education in 1877 and graduated from university with the cand.real. degree in 1883. He started his career as an assistant at the

International Bureau of Weights and Measures The International Bureau of Weights and Measures (french: Bureau international des poids et mesures, BIPM) is an intergovernmental organisation, through which its 59 member-states act together on measurement standards in four areas: chemistry ...

, where he stayed from 1889, interrupted by a period in

Berlin Berlin is Capital of Germany, the capital and largest city of Germany, both by area and List of cities in Germany by population, by population. Its more than 3.85 million inhabitants make it the European Union's List of cities in the European U ...

from 1886 to 1887. He was hired as a

research fellow A research fellow is an academic research position at a university or a similar research institution, usually for academic staff or faculty members. A research fellow may act either as an independent investigator or under the supervision of a p ...

at the

Royal Frederick University The University of Oslo ( no, Universitetet i Oslo; la, Universitas Osloensis) is a public research university located in Oslo, Norway. It is the highest ranked and oldest university in Norway. It is consistently ranked among the top universit ...

in 1889, and from 1891 he worked as a teacher and lecturer. He first worked at Trondhjem Technical School from 1891 to 1893, then at the

Norwegian Naval Academy The Royal Norwegian Naval Academy (RNoNA, ''Sjøkrigsskolen'' in Norwegian) is located at Laksevåg in Bergen. It was formally established 27 October 1817 in Frederiksvern. The institution educates officers for the Royal Norwegian Navy. History ...

from 1893. He directed the

Norwegian Metrology Service Norwegian Metrology Service ( no, Justervesenet) is a Norwegian government agency responsible for metrology. Its main responsibility is to ensure that all measuring equipment in Norway is trusted nationally and internationally. The agency is subo ...

from 1914 to 1929. He was a member of the

Norwegian Academy of Science and Letters The Norwegian Academy of Science and Letters ( no, Det Norske Videnskaps-Akademi, DNVA) is a learned society based in Oslo, Norway. Its purpose is to support the advancement of science and scholarship in Norway. History The Royal Frederick Unive ...

. He wrote textbooks like ''Lærebog i fysik for realgymnasiet og tekniske skoler'' (first time in 1903, from 1909 together with Gabriel Gabrielsen Holtsmark), and

popular science ''Popular Science'' (also known as ''PopSci'') is an American digital magazine carrying popular science content, which refers to articles for the general reader on science and technology subjects. ''Popular Science'' has won over 58 awards, incl ...

books like ''Elektriciteten: en populær fremstilling'' from 1897.List of publications
in BIBSYS

References

1859 births 1940 deaths Royal Norwegian Naval Academy alumni Norwegian physicists Norwegian expatriates in France Norwegian expatriates in Germany Directors of government agencies of Norway Members of the Norwegian Academy of Science and Letters {{Physicist-stub