André-Marie Ampère was a French physicist whose work helped establish the study of electrodynamics , which later became part of the broader field of electromagnetism. He was born in Lyon on January 20, 1775, and died in Marseille on June 10, 1836. His work connected electricity, magnetic fields and mechanical forces. In 1820, Ampère developed an astatic needle arrangement that reduced the effect of the Earth's magnetic field. This made it possible to build a more sensitive galvanometer for detecting electric currents. His work also included the solenoid, the study of forces between current-carrying wires, Ampère's circuit law and an early electrical telegraph design.
