Scientists who have studied light and sound over the last few centuries invented many things that we still use today. Thomas Young, for example, proved that light moves in waves and invented prescription eyeglasses. The study of sound has led to inventions like the telephone and hearing aids. Thomas Edison studied both light and sound and invented such things as a long-lasting light bulb, the phonograph, and the first recording machine.
George Washington Carver was born a slave, but he became an important scientist and teacher. He experimented with soil and became famous for his work as a botanist. He used peanuts and other plants to make new products. Before Carver's research, plants were only used for food and clothing. His creative approach to agriculture taught people that plants could be used to make many products, like rubber, ink, fuel, and paper, to name a few.
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.