193 Years Ago: Hans Christian Ersted Discovered the Magnetic Effect of Electricity2 photos

On February 15, 1820, 43-year-old Danish physics professor Hans Christian Ersted demonstrated a simple experiment in class that revealed the magnetic effect of electricity. During the demonstration, he observed that an electric current flowing through a wire affected the magnetic needle of a compass placed beneath it.

This discovery was no accident. Ersted’s scientific research was based on his belief in the connection between electricity and magnetism. In fact, some sources even claim that Ersted always carried a magnet with him to constantly ponder this relationship. By showing how the magnetic needle was influenced by an electric current near the compass, Ersted also uncovered a new concept: the torque of force, which was previously unknown to science.

The news of Ersted’s discovery quickly spread among physicists around the world, sparking the development of new theories and unifying the separate fields of electricity and magnetism. As early as June 1820, Ersted published a short paper in Latin titled "Experiments Concerning the Effect of Electric Current on the Magnetic Needle." After this breakthrough, he became a globally recognized scientist. He was elected member of many prestigious scientific organizations, including the London Royal Society and the Paris Academy of Sciences. In 1830, he was honored to become an honorary member of the Petersburg Academy of Sciences. He continued his scientific research and, independently of Jean-François Fourier, discovered the thermoelectric effect and created the first thermoelectric element.

Ersted also studied the properties of liquids and gases, invented the piezometer, and attempted to detect electrical effects caused by sound. He contributed significantly to molecular physics as well. He passed away in Copenhagen on March 9, 1851, and was honored as a national hero upon his death.