Let's look at experts. Sir Isaac Newton (1642-1727) was a mathematician and scientist. Newton has to be the greatest and most influential scientist who has ever lived. He laid the foundation for classical mechanics, and his genius transformed our understanding of science, particularly in the areas of physics, mathematics and astronomy. What's not widely known is that Newton spent most of his waking hours on alchemy; his experiments included trying to turn lead into gold. Though he wrote volumes on alchemy, after his death Britain's Royal Society deemed that they were "not fit to be printed."
Lord William Thomson Kelvin (1824-1907) was a Belfast-born British mathematical physicist and engineer. Kelvin's major contribution was in thermodynamics, and he is widely recognized for determining the correct value of absolute zero, approximately minus 273 degrees Celsius. In his honor, absolute temperatures are expressed in Kelvin units. Being an expert in one field doesn't spare one from being an arrogant amateur in others. Based on his knowledge of heat dissipation, Kelvin criticized geologists of his day and claimed that Earth was between 20 million and 100 million years old. Kelvin also said that "X-rays will prove to be a hoax," but he changed his mind after he experienced an X-ray of his own hand. Kelvin also predicted, "I can state flatly that heavier-than-air flying machines are impossible."
Linus Pauling (1901-94) was one of the most influential chemists in history. He was one of the founders of the field of quantum chemistry and is often called the father of molecular biology. Pauling won the Nobel Prize in chemistry in 1954 and the Nobel Peace Prize in 1962, making him the only person awarded two unshared Nobel Prizes. Later, he was awarded the International Lenin Prize for Strengthening Peace Among Peoples by the Soviet Union. Many of Pauling's colleagues who admired his scholarly work saw him as a naive spokesman for Soviet communism.