World
Penicillin was accidentally discovered by Alexander Fleming when he noticed that a mold in a petri dish killed all the nearby bacteria.
X-ray was discovered by Wilhelm Rongten during his experiment with cathode rays. He noticed a screen glowing that later became modern X-ray technology.
Charles Goodyear was the inventor of vulcanized rubber which is used in tires and other items. He invented it by accidentally dropping rubber onto a hot stove.
Started as a remedy for stomach ache, John Pemberton's drink later became the popular Coca-Cola we know today.
The microwave oven was accidentally discovered by Percy Spencer when he realized that a chocolate bar melted in his pocket while working with radar technology.