Ifyouhadtochoosethesinglemostimportantdiscoveryofthe20thcentury,youwouldhavearealdilemmaonyourhands.Injust100years,theworldchangedcompletely.Amazingdiscoveriesweremadeinm... If you had to choose the single most important discovery of the 20th century, you would have a real dilemma on your hands. In just 100 years, the world changed completely. Amazing discoveries were made in medicine, communications and transport, not to mention our knowledge of the world and space . Medical advances ranged from discovering the causes of diseased under microscopes to surgical procedures replacing diseased organs with donated ones.Communications changed with the introduction of mobile phones and the way we correspond went from writing letters to emailing. We started flying around the world and meanwhile, scientists figured out how to spilt the atom, previously thought to be the smallest particle of matter in the universe. Although it is impossible to choose the most important discovery, it is possible to single out a few pioneers of the 20th century.Here are five of them.