How can medicine that tastes like bubble gum make you feel better so quickly? It has penicillin in it-an antibiotic that helps treat bacterial infections. But we wouldn't have the drug without the work of Alexander Fleming. Learn about the lifesaving impact of penicillin on the practice of medicine. Events that Changed Your World When we get sick, our doctors give us medicine. When we want to visit our grandparents across the country, we hop on a plane. And when we want something in our community to change, we vote for people who share our ideas. A lot of the things we have and do now began as strange or challenging ideas-or even accidents! Discover the history behind events that changed your world-and the people who made them possible.