Luigi Galvani

The Italian scientist Luigi Galvani spent much of his life studying electricity. He found out that a dead frog's legs contract when they are attached to an iron board by brass hooks. He suspected that there was electricity in the frog's muscles, which he named animal electricity. Another Italian scientist, Alessandro Volta (1745–1827), challenged this idea. He believed that the two metals had reacted together to make the electricity. Neither theory was entirely correct. Galvani also carried out experiments with electric charges. An instrument for measuring electric current is called a galvanometer in his honor.

Alessandro Volta

The Italian physicist Alessandro Volta was a pioneer in the development of electricity. He created the first electric battery while working in Paris, France. His work impressed the French leader Napoleon Bonaparte (1769–1821), who made him a count. Volta was honored again after his death, when the volt (V), the unit for measuring electromotive force, was named for him. Volta also studied the properties of air. In 1783 he proposed the law that air expands at a constant rate with increasing temperature. This work was largely ignored, and the same idea was later advanced by others. Only in 1927 was he credited for this discovery.

Thomas Edison

The American inventor Thomas Edison lived and worked in the United States all his life. He was the most productive inventor ever. During his lifetime, he patented 1,093 different inventions, including the incandescent electric lamp (similar to the ordinary light bulb we know today), the motion-picture projector, and the phonograph. He also set up the first industrial research laboratory. Edison had a slow start in life. He was expelled from school because people did not realize that he was deaf, thinking instead that he was unable to learn. His mother taught him at home, where he had built his own laboratory by the time he was 10 years old.

Nicola Tesla

The Сroatian-born American inventor Nicola Tesla patented an electricity-generating and distribution system that transmitted alternating current (AC). He developed and applied many other important ideas in the fields of electricity and radio. The Tesla coil, an induction coil he invented, is used in radio technology and operates at every high frequencies. Tesla worked briefly for the American inventor Thomas Edison (1847–1931), but they fell out because they disagreed about the best form of electric current to use for large-scale supply. In the end, Tesla's alternating current system was favored over Edison's direct current (DC) system.