Albert Einstein - famous as a theoretical physicist - was also known for a single significant experiment, one which has been found in France’s Ampère Museum.
Conducted in 1915, the Einstein-de Haas experiment was created to show that the magnetisation of ferromagnetic materials such as iron is related to the angular momentum of electrons. The experiment demonstrated molecular currents' existence and helped scientists better understand certain magnetic phenomena.
The museum near Lyon opened in 1931 and explores the history of electricity. Researchers at the museum explored its archives and discovered some of the apparatus used by Einstein alongside Dutch physicist Wander de Haas.
According to the museum, verified documents show that Geertruida de Haas-Lorentz - a physicist in her own right and the wife of Wander - donated the equipment to the museum during the 1950s.
“After several months of searching and several twists and turns, we finally found the object in the museum’s reserves on March 7, 2023,” said Alfonso San Miguel, a president of the Société des Amis d’André-Marie Ampère, which has managed the Ampère Museum since its foundation in 1931.
“The object had never been inventoried. It took a few more months to authenticate it and be certain that we had found the only complete copy of the only experiment that Einstein had experimented with and published.”
The discovered object, alongside a modern interactive version of the experiment, will go on display at the museum starting in mid-April.
The Einstein-de Haas experiment was recently discovered after being donated to the Ampère Museum in the 1950s
