- Hans Christian Ørsted (August 14, 1777 – March 9, 1851) was a Danish physicist and chemist. He shaped post-Kantian philosophy and advances in science throughout the late nineteenth century.[1] He is best known for discovering the relationship between electricity and magnetism known as electromagnetism.
- Ørsted developed his interest in science while working as a young boy for his father, Søren Christian Ørsted, who owned a pharmacy. He and his brother, Anders Sandøe Ørsted, received most of their early education through self-study at home, leaving home for Copenhagen in 1793 to take entrance exams for the University of Copenhagen. The brothers passed and distinguished themselves academically at the University. By 1796, Ørsted received honours for his papers in both aesthetics and physics.
In 1801, Hans received a travel scholarship and public grant that enabled him to spend three years traveling in Europe. In Germany, he met Johann Wilhelm Ritter, a physicist who believed there was a connection between electricity and magnetism. The connection made sense to Ørsted since he believed in the unity of nature, and, therefore, that a relationship must exist between most natural phenomena.
Their conversations drew Ørsted into the study of physics. He became a professor at the University of Copenhagen in 1806 and continued his research with electric currents and acoustics. Under his guidance, the University developed a comprehensive physics and chemistry program and established new laboratories. - While preparing for an evening lecture on 21 April 1820, Ørsted developed an experiment which provided evidence that surprised him. As he was setting up his materials, he noticed a compass needle deflected from magnetic north when the electric current from the battery he was using was switched on and off. This deflection convinced him that magnetic fields radiate from all sides of a wire carrying an electric current, just as light and heat do, and that it confirmed a direct relationship between electricity and magnetism.
At the time of discovery, Ørsted did not suggest any satisfactory explanation of the phenomenon, nor did he try to represent the phenomenon in a mathematical framework. However, three months later he began more intensive investigations. Soon thereafter he published his findings, proving that an electric current produces a magnetic field as it flows through a wire. The CGS unit of magnetic induction (oersted) is named in honor of his contributions to the field of electromagnetism.
His findings resulted in intensive research throughout the scientific community in electrodynamics. The findings influenced French physicist André-Marie Ampère's developments of a single mathematical form to represent the magnetic forces between current-carrying conductors. Ørsted's discovery also represented a major step toward a unified concept of energy.
Michael Faraday:
- Michael Faraday, FRS (September 22, 1791 – August 25, 1867) was an English chemist and physicist (or natural philosopher, in the terminology of that time) who contributed to the fields of electromagnetism and electrochemistry.
Faraday studied the magnetic field around a conductor carrying a DC electric current, and established the basis for the magnetic field concept in physics. He discovered electromagnetic induction, diamagnetism and electrolysis. He established that magnetism could affect rays of light and that there was an underlying relationship between the two phenomena.[2][3] His inventions of electromagnetic rotary devices formed the foundation of electric motor technology, and it was largely due to his efforts that electricity became viable for use in technology.
As a chemist, Faraday discovered benzene, investigated the clathrate hydrate of chlorine, invented an early form of the bunsen burner and the system of oxidation numbers, and popularized terminology such as anode, cathode, electrode, and ion.
Although Faraday received little formal education and knew little of higher mathematics, such as calculus, he was one of the most influential scientists in history. Some historians[4] of science refer to him as the best experimentalist in the history of science.[5] The SI unit of capacitance, the farad, is named after him, as is the Faraday constant, the charge on a mole of electrons (about 96,485 coulombs). Faraday's law of induction states that a magnetic field changing in time creates a proportional electromotive force.
Faraday was the first and foremost Fullerian Professor of Chemistry at the Royal Institution of Great Britain, a position to which he was appointed for life.
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