what are some significant discovery has been made by errors?

Many significant discoveries have resulted from errors, often referred to as "serendipity." For instance, Alexander Fleming discovered penicillin when he noticed that mold contaminated his petri dishes and inhibited bacterial growth. Similarly, Percy Spencer accidentally invented the microwave oven when he observed that a chocolate bar melted in his pocket while working on radar technology. These examples illustrate how unintended outcomes can lead to groundbreaking advancements in science and technology.