Scottish bacteriologist Alexander Fleming accidentally discovered penicillin when he observed that a mold called Penicillium notatum killed bacteria.
Percy Spencer, an engineer working for Raytheon, noticed that a candy bar in his pocket had melted while he was working with a magnetron, a component of radar equipment.
Spencer Silver, a scientist at 3M, was trying to create a super-strong adhesive but instead developed a weak adhesive that could be easily removed.
Chemist Roy Plunkett discovered Teflon while working with refrigerants. It became a non-stick coating used in cookware and various industrial applications.
Charles Goodyear accidentally discovered the process of vulcanization when he dropped a mixture of rubber and sulfur onto a hot stove.
Pharmacist John Pemberton was attempting to create a headache remedy but ended up inventing the iconic soft drink Coca-Cola instead.
Alfred Nobel was trying to develop a safer alternative to nitroglycerin, a highly explosive substance.
Electrical engineer Wilson Greatbatch accidentally connected the wrong resistor to a heart rhythm recording device, creating the first implantable pacemaker.
Swiss engineer George de Mestral discovered Velcro when he noticed burrs sticking to his clothing and his dog's fur during a walk in the woods.
Russian chemist Constantin Fahlberg discovered saccharin when he forgot to wash his hands before dinner.