Hans Christian Ørsted

Danish physicist and chemist

• Born: August 14, 1777; Rudkøbing, Denmark
• Died: March 9, 1851; Copenhagen, Denmark

Hans Christian Ørsted, an early nineteenth-century physicist and chemist, is most famous for discovering electromagnetism—the phenomenon of electric currents producing magnetic fields. Nearly all modern electrical technologies are based on this discovery.

Also known as: Hans Christian Oersted

Primary fields: Physics; chemistry

Specialties: Electromagnetism; organic chemistry; metallurgy

Early Life

Hans Christian Ørsted was born in Rudkøbing, Denmark. His father was an apothecary, and his interest in chemistry developed early. With no schools in their hometown, he and his younger brother Anders Sandøe had a piecemeal education, learning the German language from a German wigmaker living nearby, literature from a visiting Norwegian student, and mathematics from a surveyor, among other tutors.

In 1793, Ørsted and his brother took the entrance exam for the University of Copenhagen. Their patchy education did not hinder either from passing, and Ørsted began his studies in medicine, as science was not taught separately then. During his studies, he became a fervent follower of the German philosopher Immanuel Kant, who believed among other things that all of nature consisted of the forces of attraction and repulsion.

Ørsted earned his pharmaceutical degree in 1797 and his doctorate in 1799. After a brief stint as the manager of a pharmacy, he spent a few years traveling Europe to meet with prominent philosophers of his time. Italian scientist Alessandro Volta had invented the first primitive battery in 1800, and Ørsted successfully copied Volta’s design and built one of his own, earning the respect of his peers.

During a trip abroad, Ørsted became overly enthusiastic about some new theories in chemistry introduced to him by his friend Johann Wilhelm Ritter. When he presented some papers on the subject in France, he was roundly criticized for his support of work that lacked evidence and solid empirical data. His first failure followed him back home to Copenhagen, and though he tried to obtain an appointment at the University of Copenhagen in 1804, it was not until 1806 that he was offered a professorship. Ørsted learned his lesson well, however, and his subsequent careful observation and experimentation allowed him to rebuild his scientific reputation. Ørsted introduced physical science instruction to the university and conducted research on electricity and acoustics. He was a romanticist, and the German romantic ideal influenced much of his work.

Life’s Work

During a lecture in 1820, Ørsted first observed the odd behavior of a compass needle when it was exposed to an electrically charged wire. The needle moved slightly when the current was turned on and back to north when the current was turned off. When the current was reversed, the needle moved in the opposite direction. This was proof of a connection between electricity and magnetism, an idea that had previously been hinted at but never taken seriously until Ørsted’s discovery. He had always believed in a connection between electricity and magnetism, and during a series of lectures at the university, he constructed several apparatuses to test his hypothesis.

Once his success became public, electromagnetism quickly became one of the most popular fields of research. Although the initial discovery is credited to Ørsted, it was the later work of scientists like André-Marie Ampère and James Prescott Joule that revealed the true potential of electromagnetism.

Ørsted’s other major contribution also occurred in 1820, in the field of chemistry. He was the first to isolate the chemical piperine, which gives pepper its smell. In the twenty-first century, piperine is sold as a dietary supplement to help promote nutrient absorption in the intestines. Its effects on drug metabolism and potential benefits in treating various diseases are the subjects of numerous medical studies.

In 1825, Ørsted continued his research in chemistry by creating the first metallic aluminum. Aluminum salts had been used as far back as the ancient Greeks for dyes and sealing wounds, but Ørsted is credited as the first to create aluminum in its metallic form. He combined aluminum salts with potassium and heated them, creating a lump of metallic aluminum.

After his discovery of electromagnetism, Ørsted’s presence was requested at scientific institutions throughout Europe. He toured Europe again in 1822–23 and noticed that England especially had many organizations dedicated to the dissemination of scientific knowledge to nonscientists. Ørsted recognized the benefits of ordinary business owners being kept abreast of the latest scientific and technological information, and he was determined to institute a similar organization in Denmark to keep his homeland competitive with other countries. To that end, in 1824, Ørsted founded the Selskabet for Naturlærens Udbredelse (Society for the Dissemination of Natural Science). Through hundreds of lectures in Copenhagen and in the more rural provinces of Denmark, Ørsted’s society strove to educate nonscientists and inspire passion and interest in science. Ørsted himself lectured five times a week, in addition to his professorial duties. From 1829 until his death in 1851, Ørsted served as director of the Polytechnic Institute in Copenhagen.

Ørsted’s Kantian philosophies and interest in the dissemination of science can be seen as evidence of his romanticism. A reaction against the harsh realities of the Industrial Revolution and the rationalism of the Enlightenment, the romantic movement sought truth through emotion and art and looked for unity in nature. While in Ørsted’s case, these ideals proved fruitful for his science, many other scientists took the idea too far. Ørsted’s romanticism was balanced by his rigorous experimentation, learned through his early humiliation in France. While he hoped to find a connection between electricity and magnetism because of his belief in the unity of nature, he expected to find the connection though experimentation, not through the romantic notion of self-reflection.

Ørsted was also interested in literature, befriending poet Adam Oehlenschläger and encouraging the career of writer Hans Christian Andersen, in addition to publishing some of his own work. When he died, he left an unfinished manuscript for his own philosophical treatise, The Soul in Nature.

Impact

Although Ørsted is credited with several important discoveries, later scientists were the ones who fully explored the implications of his research. In the case of electromagnetism, most of the subsequent research and advances were made by scientists such as André-Marie Ampère, who worked out the mathematics involved in the discovery, and Michael Faraday, who built the first primitive electric motor. Ørsted’s observations inspired the research and careers of many scientists who would become legends in their own right.

The sensation caused by Ørsted’s discovery of electromagnetism cannot be overstated. In the wake of his published findings, almost every scientist in the field began to study the connection between electricity and magnetism. This research in turn led to the discovery of the nature of light, the electromagnetic spectrum, and the beginnings of electric-powered technology.

The Selskabet for Naturlærens Udbredelse continues the education effort so dear to Ørsted and, since 1908, has awarded H. C. Oersted Medals to Danish scientists for excellence in science communication. In 1936, the American Association of Physics Teachers also established an Oersted Medal, given annually in recognition of outstanding physics teaching. Similarly, the unit of measurement for magnetic force has been named the oersted in recognition of Ørsted’s contributions to the field.

To honor Ørsted’s contributions to science and to the country, Denmark named one of its satellites after him. Launched in 1999, the satellite is still in operation, collecting data on the Earth’s magnetic field. Based on the satellite’s findings, Danish scientists discovered evidence that the magnetic poles of the Earth are moving rapidly and may someday reverse again, an occurrence that has not happened for nearly 800,000 years.

Bibliography

Brain, Robert Michael, R. S. Cohen, and Ole Knudsen. Hans Christian Ørsted and the Romantic Legacy in Science: Ideas, Disciplines, Practices. Dordrecht: Springer, 2007. Print. Describes Ørsted’s life and achievements in the context of the romantic movement in Europe.

Christensen, Dan C. Hans Christian Ørsted: A Biography. 2 vols. Copenhagen: Museum Tusculanum, 2010. Print. Provides historical background for the scientific work of Ørsted as well as its immediate impact.

H. C. Ørsted. Niels Bohr Institute, University of Copenhagen, n.d. Web. 6 July 2012. A series of English-language biographical articles discussing Ørsted’s youth, education, philosophical and scientific influences, and discovery of electromagnetism.