Daniel Isaachsen was a Norwegian physicist.

He was born in London

London

London is the capital city of :England and the :United Kingdom, the largest metropolitan area in the United Kingdom, and the largest urban zone in the European Union by most measures. Located on the River Thames, London has been a major settlement for two millennia, its history going back to its...

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

Isaach Isaachsen

Isaach Isaachsen was a Norwegian politician.He was born in 1774 as the son of wealthy businessman Daniel Isaachsen and his first wife Christiane Hedvig Christensen. He married a Hedevig Elisabeth Hansen. He was the brother of Peder and Daniel Otto Isaachsen.His son Daniel became a jurist...

, brother of scientist Haakon Isaachsen, nephew of painter Olaf Isaachsen

Olaf Isaachsen

Olaf Wilhelm Isaachsen was a Norwegian painter. Olaf Isaachsen is regarded as one of Norway’s more prominent artists and great colourist with motives from Setesdalen and the coast landscape of Southern Norway....

 and cousin of painter Herman Willoch

Herman Willoch

Herman Willoch was a Norwegian painter.He was born in Lindås as the son of vicar Christian Abel Isaachsen, a grandson of Isaach Isaachsen. He was the cousin of Odd Isaachsen Willoch....

 and naval officer Odd Isaachsen Willoch

Odd Isaachsen Willoch

Odd Isaachsen Willoch 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:...

. In 1861 he married Asta Lie, a daughter of Jonas Lie

Jonas Lie

Jonas Lauritz Idemil Lie was a Norwegian novelist, poet, and playwright who is considered to have been one of the Four Greats of 19th century Norwegian literature, together with Henrik Ibsen, Bjørnstjerne Bjørnson and Alexander Kielland.-Background:Jonas Lie was born at Hokksund in Øvre Eiker, in...

.

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

International Bureau of Weights and Measures

The International Bureau of Weights and Measures , is an international standards organisation, one of three such organisations established to maintain the International System of Units under the terms of the Metre Convention...

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

Berlin

Berlin is the capital city of Germany and is one of the 16 states of Germany. With a population of 3.45 million people, Berlin is Germany's largest city. It is the second most populous city proper and the seventh most populous urban area in the European Union...

 from 1886 to 1887. He was hired as a research fellow

Research fellow

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

 at the Royal Frederick University

University of Oslo

The University of Oslo , formerly The Royal Frederick University , is the oldest and largest university in Norway, situated in the Norwegian capital of Oslo. The university was founded in 1811 and was modelled after the recently established University of Berlin...

 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

Norwegian Naval Academy

- External links :*...

 from 1893. He directed the Norwegian Metrology Service

Norwegian Metrology Service

Norwegian Metrology Service 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 subordinate the Norwegian Ministry of Trade and Industry....

 from 1914 to 1929.

He was a member of the Norwegian Academy of Science and Letters

Norwegian Academy of Science and Letters

The Norwegian Academy of Science and Letters is a learned society based in Oslo, Norway.-History:The University of Oslo was established in 1811. The idea of a learned society in Christiania surfaced for the first time in 1841. The city of Throndhjem had no university, but had a learned...

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

Gabriel Gabrielsen Holtsmark

Gabriel Gabrielsen Holtsmark was a Norwegian educator, physicist and actuary.-Personal life:He was born in Asker as a son of farmer and mayor Bent Holtsmark and his wife Anne Elisabeth Gabrielsen. He was a brother of Bernt, Torger and Wilhelm Holtsmark...

), and popular science

Popular science

Popular science, sometimes called literature of science, is interpretation of science intended for a general audience. While science journalism focuses on recent scientific developments, popular science is broad-ranging, often written by scientists as well as journalists, and is presented in many...

books like Elektriciteten: en populær fremstilling from 1897.