Scientific discoveries are typically made in laboratories with teams of scientists in specialized conditions. However, this was not always the case as scientists in the past would not only work alone, but also at home, often utilizing homemade tools. Hans Christian Ørsted is such a person, and this is the place where electromagnetism was discovered. 

The alleged “eureka moment” came when Ørsted was preparing a physics demonstration centered around electricity and circuits. He had a compass on the desk and noticed the needle moved whenever he closed the circuit. This led to more systematic experiments, where he used different conductors, swapped the direction of the electricity, and even experimented with what could shield the compass from the effect. Ørsted published his findings three months later.

This finding heavily perturbed the scientific community and other great thinkers of the time became interested in the problem. In fact, Ampere published a mathematical description of this effect only a few months after and Sturgeon designed the first dedicated electromagnet. This discovery brought much fame to Ørsted and Denmark as a physics country. 

The exact building where the discovery was made sadly no longer exists, but a sign can be found on the building that was put there in its stead. The sign translates to: “In a house on this site, the physicist Christian Ørsted, discovered electromagnetism in the year 1820.”