When Google was looking for a scientist to honour on its main page, it wanted to present someone rarely acknowledged, whose discoveries had changed everyday life on Earth. On 14 August 2009, for his 200th birthday, Google the search engine chose the electromagnetic discoveries of HC Ørested to feature on its homepage. Google spokesperson Anne Espiritu explained that Ørsted reflected the company’s personality and love of innovation.
“We felt his work with electric current and electromagnetism would not only make for a fun doodle,” Espiritu told National Geographic News. “But we also wanted to celebrate the work of a scientist not too many people may have necessarily heard of but benefit from every day.”
Hans Christian Ørsted forever changed the way scientists think about electricity and magnetism. While preparing to perform an experiment during a lecture at the University of Copenhagen in 1820, he discovered that the magnetised needle of a compass was deflected according to the flow of an electric current through a voltaic pile (an early form of the battery). He noted that the compass needle moved away from magnetic north and pointed to the wire whenever current flowed from the battery. And he was also surprised to learn that the compass needle pointed in the opposite direction when the battery was flipped around.
This result provided solid evidence that electricity and magnetism are related phenomena. The announcement of Ørsted’s discovery incited a tremendous outbreak of research in the new but rising field of electromagnetics. Although this was the early 1820s, the experiments conducted eventually led to the development of electricity generators and transformers: the foundation of the modern power system.
HC Ørsted, who grew up in Rudkøbing on the island of Langeland, was more or less self-taught along with his brother, Anders Sandøe Ørsted, a future Danish prime minister (1853-54). The two brothers were able to instruct each other in various subjects, in addition to lessons in German and German religion from a local German wigmaker and his wife. Their father was a pharmacist, and as an 11-year-old, HC Ørsted became his pharmacy assistant and received practical training in chemistry. At the same time he developed a strong interest in poetry.
After finishing his doctorate in philosophy in Copenhagen, Ørsted travelled to Germany, France and the Netherlands in order to continue studying the natural sciences. At the renowned University in Jena in eastern Germany, Ørsted developed a close friendship with Johann Wilhelm Ritter, an imaginative scientist of around the same age. Ritter was already famous for his experiments on the chemical effects of electric currents. Ritter’s enthusiastic personality and original ideas about science were a great influence on Ørsted. In the German Romantic movement of the time, the notion of a unifying force underlying all nature was widely held. In the meantime, in 1800, Alessandro Voltas had created the first chemical battery, which allowed for closely controlled experimentation with electrical currents.
In April of 1820, Ørsted made the discovery of the connection between electrical and magnetic phenomena by observing the behaviour of a compass. That is, if a current is run through a wire – in this case, from the battery at the front – then the electricity creates a magnetic field, which will deflect a compass needle.
Ørsted’s initial interpretation of the experiment was that magnetic effects radiate from all sides of a wire carrying an electric current, as do light and heat. Three months later, he began more intensive investigations and published his findings, showing that an electric current produces a circular magnetic field as it flows through a wire.
Strangely enough, Ørsted did not continue his research in the field of electromagnetics after publishing the report on these initial investigations in 1820. Instead he threw himself into working out an earlier question about water compression that had obsessed him since 1798. He wrote a short treatise about electromagnetics, but others carried out most of the important subsequent work relating to the new field. Following Ørsted’s discovery, Andre-Marie Ampere worked on applying mathematics to the study of electromagnetism. The units of electrical current are still measured in his name as ‘amperes’ (or ‘amps’).
Another scientist, Italy’s Gian Domenico Romagnosi, had reportedly made the same discovery as Ørsted more than a decade and a half earlier. However, Romagnosi’s finding was described in only one Italian newspaper in 1802 and never received the recognition of his contemporaries. The details of the experiment and the claim of what Romagnosi proved are still in some dispute.
Ørsted himself moved on quickly to new experiments, in addition to literary and cultural pursuits of becoming of Denmark’s Golden Age. Ørsted was a close friend of other influential figures of the era including poet Adam Oehlenschläger, children’s writer Hans Christian Andersen and JL Heiberg. Being a follower of the Naturphilosophie school in Germany, HC Ørsted was concerned with the relationship between science and descriptive language. In 1836, he published his most famous work of poetry, ‘Luftskibet’ (Airship), a series of poems in different forms of verse that focus on the bridge between the worlds of science and poetry. He dedicated the series to the poet HC Andersen”.
Ørsted felt strongly about the popularisation of scientific knowledge. He wanted everyone to have access to an understanding of scientific discoveries. To this end, he founded the Society for the Dissemination of Natural Science (Selskabet for Naturlærens Udbredelse), which continues to present a prize in his honour (the Ørsted Medal) for remarkable Danish contributions to physics, chemistry or the popularisation of science in general. He was also the founder of the predecessor organisations that eventually became the Danish Meteorological Institute and the Danish Patent and Trademark Office.
In order for the new science to be explained, new language needed to be developed, and Ørsted became interested in creating technical expressions for art, science and daily life. He contributed over 2,000 new Danish words, many of which are still used today, among them: billedkunst (visual art), sommerfugl (butterfly), ilt (oxygen) and brint (hydrogen). The principles of Ørsted’s word creation had already been established in 1814: new words must not lead to false impressions, they must normally indicate, not describe; and materials that were not compounds must not have compound names (such as ‘sour-stuff’ for ‘oxygen’). Educational value carried more weight than national pride. Ørsted was regularly inspired by similar words in other languages.
For example, he took the word fordampe, which means ‘evaporate’, from German, while foretagsom, which means ‘enterprising’, was adapted from Swedish.
The unit of magnetic field strength was named in honour of Ørsted in the 1930s. One oersted is the centimetre-gram – second unit of magnetic intensity, equal to the magnetic pole of unit strength when undergoing a force of one dyne in a vacuum. Sadly for him, people no longer measure things in oersteds, because now the international metric system (SI) recognises Ampere, Georg Ohm, Heinrich Hertz, James Prescott Joule and James Watt instead.
Ørsted was made a knight of the Prussian Order of Merit, of the French Legion of Honour, and the Danish Order of the Dannebrog, in addition to having his own park in central Copenhagen. Ørstedsparken was inaugurated on 27 October 1879. It contained Copenhagen’s first public playground, a promenade, and a bronze statue of Ørsted mounted on a granite plinth, in which he is actively demonstrating the effect of an electric current on a magnetic needle. His bronze hands are connecting the wires from an electric battery, so that the magnet oscillates. The park still retains pieces from the old fortifications of the city in its topography: a section of the moat forms an elongated lake and former bastions, sloping hills. The park has become the perfect spot to commemorate the man looking for a union between art and science.