The problems of rising prices of fuels such as oil and gas and the pollution they cause (air pollution) have led scientists to work on solar energy for future human use. About half of the sun’s energy is light, about half is infrared radiation (heat, energy, etc. in the rays), and very little ultraviolet radiation. In ancient China, Egypt, the Middle East, Greece, and Italy, solar energy was used to evaporate (turn into steam) salt water to obtain salt. Drying crops by the heat of the sun was also common. It was used to make wine in Chile (South America) in the 19th century. Into…