Electromagnetism is the combined power of electricity and magnetism. Almost everything we doâ€”from watching television to using a computerâ€”is affected by electromagnets. In the 1830s, scientist Michael Faraday proved that electricity and magnetism are different ways to observe a unified force that he called electromagnetism.
Albert Einstein is probably the most influential scientist and greatest physicist of the twentieth century. He revolutionized our ideas about time and space and is best known for his theory of relativity and his equation E=mc^2, which explains the relationship between energy and mass. By age 30, he was considered by many to be one of the world's greatest scientific thinkers.
Isaac Newton is considered one of the greatest scientists who ever lived. His work changed the way humans understand astronomy, physics, math, and more. He is probably most famous for three laws about the way things move, called Newton's Law of Motion.
Thomas Edison's inventions changed the world. His most famous invention is the light bulb, but he also invented generators and the power grid. Edison holds 1,000 patentsâ€”the record for the most new inventions. He even started his own electric company.
Hippocrates was a Greek doctor who is called The Father of Medicine. Before he was born around 460 B.C., there was little science in medicine. Doctors thought the gods were to blame for illness. Hippocrates studied the human body and tried to figure out what caused disease so he could develop cures. Hippocrates suggested rules for doctors to follow. The Hippocratic Oath, which doctors still follow, was based on his teachings.
Several major industrialists facilitated the growth of industry in America. These individuals, including Andrew Carnegie, John D. Rockefeller, J. P. Morgan, and Henry Ford, were responsible for building industries that employed many people and provided commodities necessary for life in the United States.
Bank tellers help people take care of their money. Long ago, bank tellers did most of their work by hand. Today, computers make their work faster and easier. There are even machines called Automatic Teller Machines, or ATMs. Although convenient, ATMs cannot replace bank tellers.