Hans Christian Ørsted (1777-1851) was a
distinguished Danish physicist and chemist who is credited with some of the
most important scientific contributions of his time, including the discovery of
electromagnetism.
Ørsted – whose name is commonly spelled Oersted by
English speakers – was born August 14, 1777, in Rudkøbing, a village on the
island of Langeland, Denmark. His father was a practicing pharmacist, and while
helping in the family business as a youngster Ørsted was first introduced to
chemistry and science. Ørsted studied French, German, and Latin as a youth, and
at age 17 entered the University of Copenhagen to major in philosophy and
science. He was particularly influenced by the ideas of the German philosophers
Immanuel Kant and Friedrich W. Schelling. Ørsted earned an undergraduate degree
in pharmacy, graduating with honors, and then in 1799 he was awarded a Doctor
of Philosophy.
Alessandro Volta discovered the galvanic battery in
1800, and this inspired Ørsted to ponder the nature of electricity and conduct
his first electrical research experiments. Between 1800 and 1803 Ørsted
traveled and lectured, visiting Germany, France, and Holland. Returning to the
University of Copenhagen he accepted a position teaching medicine. Professor
Ørsted would remain on the faculty of the University of Copenhagen for the
remainder of his life.
In 1812 he returned to Germany and France, and
while doing research in Berlin he wrote a paper describing the relationship
between chemical and electrical forces. The ideas expressed in the essay formed
a theoretical foundation for future experiments that eventually led to his most
famous scientific contribution.
In the spring of 1820, while conducting experiments
and performing classroom demonstrations for the benefit of his university
students, Ørsted placed an electrically charged wire near a compass, causing
the needle on the compass to swerve, deflected at a right angle. The
observation of this phenomenon clearly established a relationship between
magnetism and electricity, and through a series of subsequent experiments
Ørsted became the first to identify the force of electromagnetism.
Although he made no attempt to explain
electromagnetic presence through mathematical formulas, Ørsted was credited
with its discovery. Following this historic breakthrough, the pioneering field
of electromagnetic study rapidly evolved, accompanied by a surge of new
theories and fresh technological applications.
Five years after discovering electromagnetism Ørsted
made a monumental find in the field of chemistry, when he became the first
person to capture the element aluminum. Although aluminum is one of the most
plentiful elements on earth, it is always combined with other elements. Many
chemists who came before Ørsted thought it existed but failed in their attempts
to actually uncover it. He was the first to successfully distinguish it from
other chemical compounds and positively identify and extract it as a unique
element.
One of Ørsted’s goals was to make science more
popular with the general public, not just the academic and scientific
community. He often submitted articles to newspapers and magazines or gave
public lectures on scientific subjects to help teach people the relevance of
science. A distinguished scholar, Ørsted was Secretary of the Royal Society of
Sciences in Copenhagen, a Knight of the Prussian Order of Merit, and a member
of the French Legion of Honor.
In November of 1850 the government of Denmark
declared a national holiday in honor of Ørsted and his work at the University
of Copenhagen. Four months later, on March 9, 1851, Ørsted died in Copenhagen
and his funeral was attended by all of the leading public and private figures
of the Danish capital.
The term “oersted” was named after Hans Christian
Ørsted and is used to define a unit of magnetic field strength equal to 79.58
amperes per meter.