In 1934, physicist Enrico Fermi made a discovery that was later revealed to be a mistake.
His announcement of new elements, ausenium and hesperium, garnered praise from the scientific community and the Italian Fascist regime.
However, in 1938, the discovery of nuclear fission by German scientists revealed that Fermi's 'elements' were actually the products of uranium fission.
Fermi's experiments, although flawed, laid the groundwork for understanding nuclear reactions and played a crucial role in the development of nuclear energy and medicine.