If you could witness any significant scientific discovery in history, which one would you choose and why?

A: I would choose to witness the discovery of penicillin by Alexander Fleming in 1928. This discovery revolutionized medicine by introducing the first antibiotic, saving countless lives and changing the course of infectious disease treatment. Witnessing this breakthrough would provide insight into the process of scientific discovery and the impact it can have on society. Additionally, seeing the initial reaction and excitement of Fleming and his colleagues would be truly inspiring.