Galileo is considered the father of modern science. His discoveries included the laws of pendulums which led to the development of the first accurate clocks. But tragically, he was tried by the Inquisition of Rome for heresy. The science deniers of the Church threatened to burn him at the stake unless he recanted his claims that he could prove that Copernicus was right: that the Earth is not the center of the universe, that we live in a heliocentric system where the earth and the other planets revolve around the sun.

A lot of elements contributed into winning World War II: Britain refusing to make peace with Nazi Germany after the fall of France along with the Chinese and Soviets willingness to suffer millions of deaths. But World War II was a war between the factories; whichever side could produce the most military equipment would win. The deciding factor in World War II was the fantastic industrial output of the U.S.

Polio was one of the scourges of the 20th century. And it mainly struck children. All of a sudden a person contracted polio and suffered terribly for several days; sometimes they recovered, sometimes they died, and sometimes they were left permanently disabled. The most famous polio victim of all time, Franklin Roosevelt, hid his disability from the public. But this story has a true hero: Jonas Salk, who developed a vaccine which led to the almost complete eradication of this dreaded disease. And Dr. Salk never patented the vaccine or earned any money from his discovery.