Danish physicist. 1August 777 14 was born in a pharmacist's family in Rude Jobin, Langlin Island. 1794 was admitted to the university of Copenhagen, and 1799 received his doctorate. 180 1 ~ 1803 visited Germany, France and other countries and met many physicists and chemists. 1806 Professor of Physics, University of Copenhagen, 18 15 Permanent Secretary, Royal Danish Society. 1820 won the Copley medal of the Royal Society for his outstanding discovery of the current magnetic effect. 1829 till now, President of Copenhagen Institute of Technology. 185 1 passed away in Copenhagen on March 9th.
He has done a lot of research in physics, chemistry and philosophy. Influenced by Kant's philosophy and Schelling's natural philosophy, I firmly believe that natural forces can be transformed into each other, and I have long explored the relationship between electricity and magnetism. 1820 in April, the effect of current on the magnetic needle was finally discovered, that is, the magnetic effect of current. On July 2 1 of the same year, he published his own findings on the topic of "Experiment of charged conflict effect of magnetic needle". This essay gave a great shock to the European physics field, which led to the appearance of a large number of experimental results, thus opening up a new physical field-electromagnetism.
He is a passionate teacher and attaches importance to scientific research and experiments. He said, "I don't like boring lectures without experiments. All scientific research begins with experiments. " Therefore, it is welcomed by students. He is also an excellent lecturer and natural science popularization worker. 1824, the Danish Association for the Advancement of Science proposed to establish the first physics laboratory in Denmark.
1908, the Danish Association for the Promotion of Natural Science established the "Oster Medal" to commend physicists who have made great contributions. 1934, the unit of magnetic field intensity in CGS unit system was named "Oster". 1937, the American Association of Physics Teachers established the "Oster Medal" to reward physics teachers who have contributed to physics teaching.
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 relationship 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, it swings through Oster's small magnetic needle near the platinum wire. 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".
anecdote
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.
Andre? Mary? Ampere (André-Marie Ampère, 1775—1836)
French physicist, who has made outstanding achievements in the study of electromagnetic action, has also made contributions in mathematics and chemistry. Ampere, the international unit of current, is named after its surname.
1775 65438+/kloc-0 was born in a wealthy family in Lyon on October 22nd, and died in Marseille on June 1836. From 65438 to 0802, he was a professor of physics and chemistry at Bourjean-Bryce Central School. 1808 was appointed as the Governor of Imperial University of France, and has been in this position ever since; 18 14 was elected as a member of the Department of Mathematics of Imperial College London; 18 19 presided over the philosophy lecture of the University of Paris; 1824 professor of experimental physics, French college.
The most important achievement of Ampere is the study of electromagnetic action from 1820 to 1827. 1820 In July, after H.C. Oster published a paper on the magnetic effect of current, Ampere reported his experimental results: the electrified coil is similar to a magnet; On September 25, he reported that two current-carrying wires interact with each other, and parallel currents in the same direction attract each other, while parallel currents in the opposite direction repel each other; The attraction and repulsion between the two coils are also discussed. Through a series of classic and simple experiments, he realized that magnetism is produced by moving electricity. He used this view to explain the causes of geomagnetism and material magnetism. He put forward the hypothesis of molecular current: the current flows from one end of the molecule and is injected from the other end through the space around the molecule; The current of non-magnetized molecules is evenly and symmetrically distributed and does not show magnetism to the outside; When influenced by an external magnet or current, the symmetry is destroyed, showing macroscopic magnetism, and then the molecules are magnetized. Today, with the high development of science, Ampere's molecular current hypothesis has real content and becomes an important basis for understanding the magnetism of matter. In order to further illustrate the interaction between currents, during the period of 182 1 ~ 1825, Ampere made four exquisite experiments on the interaction between currents, and based on these four experiments, the interaction force formula between two current elements was deduced. 1827, Ampere incorporated his research on electromagnetic phenomena into the book Mathematical Theory of Electrodynamics Phenomenon, which is an important classical treatise in the history of electromagnetism and has a far-reaching influence on the future development of electromagnetism. In order to commemorate the outstanding contribution of ampere in electricity, the unit ampere of current is named after his surname.
Ampere's life
When I was a child, Ampere had a strong memory and outstanding mathematical ability. His father was deeply influenced by Rousseau's (17 12- 1778) educational thought, and decided to let Ampere teach himself and often took him to the library to read books. Ampere taught himself the history of science, encyclopedias and other works. He was most fascinated by mathematics, and published his first mathematical paper at the age of 13, discussing the spiral line. 1799 ampere teaches mathematics in a middle school in Lyon. 1802 In February, Ampere left Lyon to teach physics and chemistry at Fort College. In April, he published an article about the mathematical theory of gambling, which revealed the excellent mathematical foundation and attracted the attention of the society. Later, he applied for a position in the French public school founded by Napoleon. 1808, Ampere was a governor of Imperial University of France, 1809, he was a professor of mathematics at the University of Paris. 18 14 was elected as an academician of the French Academy of Sciences. 1824 professor of experimental physics, French college. 1827 was elected as a member of the Royal Society of London. He is also an academician of the Academy of Sciences such as Berlin and Stockholm.
Ampere's main contribution to physics is that he has made important discoveries on the basic principles of electromagnetism, such as Ampere's law, Ampere's rule and molecular countercurrent. 1July 2, 8201day, Danish physicist Oster discovered the magnetic effect of current. French physicists have long believed in Coulomb's creed that electricity and magnetism have nothing to do with each other. This great discovery greatly shocked them, and French physicists represented by arago (1786- 1853) and Ampere responded quickly. At the end of August, arago heard the news of Oster's success in Switzerland and immediately rushed back to France. On September 1 1, he reported the details of Oster's experiment to the French Academy of Sciences. After listening to the report, Ann repeated Oster's experiment the next day, and reported the first paper to the French Academy of Sciences on September 18, proposing that the relationship between the direction of magnetic needle rotation and the direction of current should obey the right-hand rule. Later, this law was named Ampere's Law. On September 25th, Ampere reported the second paper to the Academy of Sciences, proposing that two parallel current-carrying wires with the same current direction attract each other and two parallel current-carrying wires with opposite current directions repel each other. 1On October 9th, the third paper was reported, and the interaction between various shapes of bent current-carrying wires was expounded. Later, Ampere did many experiments. In 1826, he summed up the law of force between current elements with high mathematical skills and described the relationship between the interaction between two current elements and the size, spacing and relative orientation of the two current elements. Later, people called this law ampere's law. 1February 4th, Ampere reported this achievement to the Academy of Sciences. Ampere is not satisfied with the results of these experimental studies. 182 1 year 1 month, he put forward the famous molecular current hypothesis that the circulation of each molecule forms ten small magnets, which is the reason why objects have macroscopic magnetism. Ampere also compared the names of statics and dynamics. He was the first to call the theory of electrodynamics "electrodynamics", and published "Observations on Electrodynamics" in' 1822 and "Electrodynamics Theory of Moths" in' 1827. In addition, Ampere found that the magnetism of the current flowing in the coil was similar to that of a magnet. He invented the first solenoid, and on this basis, he invented a galvanometer to detect and measure the current.
Ampere's research also involves philosophy, chemistry and other fields, and even studies complex problems in plant taxonomy.
1836, Ampere went out to inspect the work as a university inspector. Unfortunately, he contracted acute pneumonia on the way and died in Marseille on June 10 at the age of 6 1. In order to commemorate Ampere, later generations named the unit of current intensity after him, referred to as "An".