While not directly observing fusion, Rutherford's experiment, which involved bombarding nitrogen with alpha particles, resulted in the first transmutation of one element into another. This discovery was groundbreaking and provided evidence that nuclear reactions could occur, paving the way for later understanding of fusion processes.
It's important to note that actual fusion reactions were not directly observed until much later. In 1932, John Cockcroft and Ernest Walton were the first to successfully induce nuclear fusion in the laboratory, using a particle accelerator to bombard lithium with protons.
