Magnetism is the result of electrons moving in very par tic u lar ways within the atoms that make up a mag net ic substance. Since it is the movement of electrons that can cause a material to generate magnetic forces, a weak mag net ic fi eld can be generated when electrons fl ow through a wire. It is possible to use this idea to build a magnet. In this activity, you will use elec tric i ty to create mag net ic fi elds. In fact, by completing this investigation, you will be du pli cat ing the work of Hans Chris tian Oersted. He was not the fi rst scientist to notice a connection between elec tric i ty and mag ne tism, but Oer sted was the fi rst to be lieve it was more than just co in ci dence. Prov ing his theory, however, turned out to be more diffi cult than he thought. In 1820 Oersted brought his theory to his col leagues in a public lecture during which he showed the attending sci en tists the same dem on stra tion that you will recreate today.