Hans Christian Ørsted in the context of Galvanometer

The ampere (/ˈæmpɛər/ AM-pair, US: /ˈæmpɪər/ AM-peer; symbol: A), often shortened to amp, is the unit of electric current in the International System of Units (SI). One ampere is equal to 1 coulomb (C) moving past a point per second. It is named after French mathematician and physicist André-Marie Ampère (1775–1836), considered the father of electromagnetism along with Danish physicist Hans Christian Ørsted.

As of the 2019 revision of the SI, the ampere is defined by fixing the elementary charge e to be exactly 1.602176634×10 C, which means an ampere is an electric current equivalent to 10 elementary charges moving every 1.602176634 seconds, or approximately 6.241509074×10 elementary charges moving in a second. Prior to the redefinition, the ampere was defined as the current passing through two parallel wires 1 metre apart that produces a magnetic force of 2×10 newtons per metre.

A needle telegraph is an electrical telegraph that uses indicating needles moved electromagnetically as its means of displaying messages. It is one of the two main types of electromagnetic telegraph, the other being the armature system, as exemplified by the telegraph of Samuel Morse in the United States. Needle telegraphs were widely used in Europe and the British Empire during the nineteenth century.

Needle telegraphs were suggested shortly after Hans Christian Ørsted discovered that electric currents could deflect compass needles in 1820. Pavel Schilling developed a telegraph using needles suspended by threads. This was intended for installation in Russia for government use, but Schilling died in 1837 before it could be implemented. In 1833 Carl Friedrich Gauss and Wilhelm Eduard Weber in Göttingen built a telegraph line that was used for scientific study and communication between university sites. In 1837 Carl August von Steinheil adapted Gauss and Weber's rather cumbersome apparatus for use on various German railways.

The Edinburgh Encyclopædia is an encyclopaedia in 18 volumes, printed and published by William Blackwood and edited by David Brewster between 1808 and 1830. In competition with the Edinburgh-published Encyclopædia Britannica, the Edinburgh Encyclopædia is generally considered to be strongest on scientific topics, where many of the articles were written by the editor.

The Edinburgh Encyclopædia was originally planned to encompassed 12 volumes, but by the time the final volume was published, in 1830, it counted 18 volumes. Some subjects, such as the polarization of light and electromagnetism, had not even been heard of when the project began, and yet the Encyclopedia had articles on them. The electromagnetism article was even contributed by Hans Christian Ørsted, the founder of modern electromagnetic studies. It also included information on contemporary events such as Christopher Hansteen's 1829 expedition to Siberia.

Christian Albrecht Jensen (26 June 1792 – 13 July 1870) was a Danish portrait painter who was active during the Golden Age of Danish Painting in the first half of the 19th century. Painting more than 400 portraits over the course of his career, he depicted most of the leading figures of the Danish Golden Age, including the writer Hans Christian Andersen, the painter Christoffer Wilhelm Eckersberg, the sculptor Bertel Thorvaldsen, the physicist Hans Christian Ørsted and the theologian N. F. S. Grundtvig.

Although Jensen experienced considerable commercial success, he received little official appreciation from the artistic establishment of his day. In particular, the art historian and critic Niels Lauritz Høyen criticized his style, finding his paintings 'unfinished'.

In classical electromagnetism, Ampère's circuital law, often simply called Ampère's law, and sometimes Oersted's law, relates the circulation of a magnetic field around a closed loop to the electric current passing through that loop.

The law was inspired by Hans Christian Ørsted's 1820 discovery that an electric current generates a magnetic field. This finding prompted theoretical and experimental work by André-Marie Ampère and others, eventually leading to the formulation of the law in its modern form.

The Technical University of Denmark (Danish: Danmarks Tekniske Universitet), often simply referred to as DTU, is a polytechnic university and school of engineering. It was founded in 1829 at the initiative of Hans Christian Ørsted as Denmark's first polytechnic, and it is today ranked among Europe's leading engineering institutions. It is located in the town Kongens Lyngby, 12 km (7.5 mi) north of central Copenhagen, Denmark.

Along with École Polytechnique in Paris, École Polytechnique Fédérale de Lausanne, Eindhoven University of Technology, Technical University of Munich and Technion – Israel Institute of Technology, DTU is a member of EuroTech Universities Alliance.