As scientists, we've made sacrifices some might consider a hardship. Our training took years, plus many, many lab hours and nights spent on the computer - all for modest pay. But honestly, those sacrifices pale in comparison to our predecessors, some of whom were persecuted, tortured, and killed for their beliefs.

One major figure was a highly educated scientist known as Rhazes. He lived in Iran between 860 and 932 AD and was regarded in Europe as one of the fifteen great sources of knowledge. Rhazes authored medical texts used by Western physicians until the rise of modern medicine. Yet, Rhazes was persecuted for his open-mindedness and belief that religious fanaticism breeds war and hatred. For that, he was exiled multiple times.

Scientific giant Galileo Galilei was born in 1564 in Pisa, Italy. The mathematician disproved Aristotle's dogma that heavier objects fall faster than lighter ones. Then, after hearing about the telescope, he made one without ever having seen it. Eventually, he used a telescope to identify Jupiter's moons and began thinking Earth was not the center of the universe. He wrote in support of Copernicus' theory that Earth was rotating around the sun. When denounced by the Catholic Church, Galileo stated the bible was irrelevant in scientific arguments, which got him a lifetime house arrest.

Another persecuted scientist was Michael Servetus, a Spanish physician in the 16th century who discovered pulmonary circulation but was burned alive by the Protestant Inquisition.

Even Albert Einstein was a victim. His theory of relativity and passivist stance brought him to Hitler's attention. Fortunately, Einstein was in California when the Nazis seized his property and burned his books.

Without the courage of these early scientists, some of the greatest discoveries would have had to wait. What they endured highlights the importance of an intellectually open society.