Hans Oersted was born in 1777 in southern Denmark. He studied science at the university, but leaned far more toward philosophy. Oersted adopted the philosophy teachings of John Ritter, who advocated a natural science belief that there was unity in all natural forces.
Oersted believed that he could trace all natural forces back to the Urkraft, or primary force. When he was finally given a science teaching position (in 1813), he focused his re search efforts on finding a way to trace all chemical reactions back to Urkraft in order to create a natural unity in all of chemistry.
Research and interest in electricity mushroomed after Benjamin Frank lin's experiments with static electricity and sparks of energy created with Leyden jars. Then, in 1800, Volta invented the battery and the world's first continuous flow of electric current. Electricity became the scientific wonder of the world. Sixty-eight books on electric ity were published between 1800 and 1820.
Only a few scientists suspected that there might be a connection between electricity and magnetism. In 1776 and 1777 the Bavarian Academy of Sciences offered a prize to any one who could answer the question: Is there a physical analogy between electrical and magnetic force? They found no winner. In 1808, the London Scientific Society made the same
offer. Again there was no winner.
In the spring of 1820, Hans Oersted was giving a lecture to one of his classes when an amazing thing happened. He made a grand discovery-the only major scientific discovery made in front of a class of students. It was a simple demonstra tion for graduate-level stu-dents of how electric current heats a platinum wire. Oersted had not focused his re search on either electricity or magnetism. Neither was of particular interest to him. Still, he happened to have a needle magnet (a compass needle) nearby on the table when he conducted his demonstration.
As soon as Oers ted connected battery power to his wire, the compass needle twitched and twisted to point perpendicular to the platinum wire. When he disconnected the battery, the needle drifted back to its original position.
Each time he ran an electric current through that platinum wire, the nee dle snapped back to its perpendicular position. Oersted's students were fascinated. Oersted seemed flustered and shifted the talk to another topic.
Oersted did not return to this amazing occurrence for three months, until the summer of 1820. He then began a series of experiments to discover if his electric current created a force that attracted the compass needle, or repelled it. He also wanted to try to relate this strange force to Urkraft.
He moved the wire above, beside, and below the compass needle. He reversed the current through his platinum wire. He tried two wires instead of one.
With every change in the wire and current, he watched for the effect these changes would produce on the compass needle.
Oersted finally realized his electric current created both an attractive and a repulsive force at the same time. After months of study, he concluded that an electric current created a magnetic force and that this force was a whole new type of force radically different than any of the forces Newton had described. This force acted not along straight lines, but in a circle around the wire carrying an electric current. Clearly, he wrote, wires carrying an electric current showed magnetic proper ties. The concept of electromagnetism had been discovered.
