Hans christian oersted (1777 ~ 185 1 year) is a Danish physicist and chemist. 1777 August 14 was born in Luckbin, Denmark. 1794 entered the university of Copenhagen to study medicine and natural sciences, 1799 received his doctorate. 1801-1803 He traveled to Germany, France and other places and returned to China in 1804. 1806 was hired as a professor of physical chemistry at the University of Copenhagen, studying topics such as current and harmony. 1824, he initiated the establishment of the Danish Association for the Promotion of Natural Science. 1829 became the dean of Copenhagen Institute of Technology until his death in Copenhagen on March 9. At the age of 74.

Second, scientific achievements.

The magnetic effect of current is found in 1. 1820.

Since Coulomb put forward that electricity and magnetism are essentially different, few people have considered the connection between them. Physicists such as Ampere and Biot don't think there will be any connection between electricity and magnetism. However, Oster has always believed that electricity, magnetism, light and heat are interrelated in essence. Franklin, in particular, once found that Leiden bottle discharge can magnetize steel needles, which strengthened his view. At that time, someone tried to find the connection between electricity and magnetism, and the result failed. After analyzing these experiments, Oster thinks that there seems to be no effect in the direction of current, so will the magnetic effect be transverse?

1820 in April, there was a lecture in the evening, and Oster demonstrated the experiment of current magnetic effect. When the primary battery is connected to the platinum wire, the small magnetic needle near the platinum wire swings. This unremarkable phenomenon did not attract the attention of the audience, but Oster was very excited. He studied it deeply for three months in a row. On July 2 1820, he announced the experiment.

Oster connected one end of the wire to the positive electrode of galvani battery, and the wire was placed parallel to the small magnetic needle in the north-south direction. When the other end of the wire is connected to the negative electrode, the magnetic needle immediately points to the east-west direction. Non-magnetic objects such as glass plate, sawdust and stone are inserted between the wire and the magnetic needle, even if the small magnetic needle is immersed in a copper box filled with water, the magnetic needle will still deflect.

Oster believes that there is a "current surge" around the live wire. This impact can only act on magnetic particles, but it can pass through non-magnetic objects. When magnetic substances or particles are impacted, they are prevented from passing through, so they are driven to deflect.

When the wire is placed under the magnetic needle, the small magnetic needle deflects in the opposite direction; If the wire is placed horizontally in the east-west direction, the magnetic needle will always remain stationary regardless of whether the wire is placed above or below the magnetic needle.

He believes that the current shock propagates along the spiral line with the wire as the axis, and the thread direction is perpendicular to the axis. This is a description of the lateral effect of the image.

Although Oster's explanation of magnetic effect is not completely correct, it does not affect the great significance of this experiment. It is proved that electricity and magnetic energy are mutually transformed, which lays the foundation for the development of electromagnetism.

2. Other achievements

Oster once studied chemical affinity. 1822, he accurately measured the compressibility of water and demonstrated the compressibility of water. In 1823, he also made a successful research on thermoelectric. He also made some important improvements to the Coulomb torsion balance.

Oster first refined aluminum in 1825, but the purity was not high, so that this achievement was attributed to German chemist F. Willer (1827) in metallurgical history. His last research was the study of diamagnetism in the late 1940s, trying to explain the diamagnetism of matter by anti-parallel effect. During the same period, Faraday surpassed Oster and his French counterparts in this respect. Faraday proved that there is no so-called anti-magnetic pole. The concepts of magnetic permeability and magnetic field lines are used to explain magnetism and diamagnetism. However, Oster's method of studying antiferromagnets still has a profound influence.

3. Published Oster's scientific essays.

His important paper was edited and published on 1920, entitled "Oster's Scientific Papers".

Third, anecdotes

1. The beating of the magnetic needle made him fall down with excitement.

Influenced by Kant's philosophy, Oster has always believed that there must be some relationship between electricity and magnetism, and electricity can be transformed into magnetism. The urgent task is how to find the conditions to realize this transformation. Oster carefully examined Coulomb's papers and found that the objects of Coulomb's research were static electricity and magnetostatics, which really could not be transformed. He guessed that non-static electricity and non-static magnetism may be the conditions for transformation, and attention should be paid to the topic of whether there is interaction between current and magnet. He is determined to explore by experiment.

Oster continued to study the relationship between electricity and magnetism from the first half of 18 19 to the second half of 1820, while teaching electricity and magnetism. 1820 In April, at the end of a speech, Oster did another experiment with the feeling of giving it a try. He put a thin platinum wire on a small magnetic needle covered with a glass cover, turned on the power and found that the magnetic needle jumped. This jump made the thoughtful Oster overjoyed and fell down on the platform excitedly. However, due to the small and irregular deflection angle, this jump did not attract the attention of the audience. After that, Oster spent three months doing many experiments and found that the magnetic needle would deflect around the current. Above and below the wire, the deflection direction of the magnetic needle is opposite. Place non-magnetic substances, such as wood, glass, water, rosin, etc. The gap between the conductor and the magnetic needle will not affect the deflection of the magnetic needle. On July 2 1, 65438, 2 1, Oster wrote a paper on the current shock experiment of magnetic needle, and officially announced to the academic community that the current magnetic effect was discovered.

2. Establish the Oster Medal

Oster's achievements have been recognized by academic circles. In memory of him, the unit of magnetic field intensity in the world has been named Oster from 1934, abbreviated as "Austria". 1937 The American Association of Physics Teachers also established the Oster Medal to reward outstanding physics teachers with outstanding teaching achievements.