George Simon Ohm

Georg Simon Ohm (March 16, 1789, Erlangen, Bavaria - July 6, 1854, Munich) was a German physicist and mathematician who contributed Ohm's law to the theory of electricity.. Known mainly for his research on electric currents, he studied the relationship between the intensity of an electric current, its electromotive force and resistance, formulating in 1827 the law that bears his name which states that I = V / R. He was also interested in acoustics, battery polarization and light interference. The unit of electrical resistance, the ohm, is named in his honour.He ended up as Curator of the Physics Cabinet of the Bavarian Academy of Sciences. He was the son of a blacksmith, he alternated between work and studies in his teenage years, in which he showed a preference for those of a scientific nature. In 1803 he began to attend Earleng College, where he made rapid progress. In 1827 he published the book The Galvanic Circuit Treated Mathematically , in which he introduced the concept of electrical resistance.

Discoveries

Using the results of their experiments; Ohm was able to define the fundamental relationship between electrical voltage, current, and resistance. What is now known as Ohm's Law appeared in his most famous work, a book published in 1827 that gave his complete theory of electricity.

The equation I = V/R is known as Ohm's law. The amount of constant current through a material is stated to be directly proportional to the voltage across the material divided by the electrical resistance of the material. The ohm (Ω), a unit of electrical resistance, is equal to that of a conductor in which a current (I) of one ampere (1 A) is produced by a potential of one volt (1 V) across its conductors. terminals. These fundamental relationships represent the true beginning of electrical circuit analysis.

Current flows through an electrical circuit according to several defined laws. The basic law of current flow is Ohm's law. Ohm's law states that the amount of current that flows in a circuit made up of resistors is only related to the voltage in the circuit and the total resistance of the circuit. The law is usually expressed by the formula V = (I)(R) (described in the previous paragraph), where I is current in amps, V is voltage (in volts), and R is resistance in ohms.

The ohm, a unit of electrical resistance, is equal to that of a conductor in which a current of one ampere is produced by a potential of one volt across its terminals; thus, years before Ohm enunciated his law, other scientists had performed experiments with electric current and voltage. The case of the British Henry Cavendish stands out, who experimented with the Leyden jar in 1781 but did not publish his conclusions, nor were they known until they were published almost 100 years later, in 1879, by James Clerk Maxwell.

Biography

He was born in 1789 into a small Protestant family in Erlangen, Bavaria (at the time part of the Holy Roman Empire). His father, Johann Wolfgang Ohm, was a locksmith and his mother was Maria Elizabeth Beck. Despite not being educated people, his father was self-taught and gave his children an excellent education from his own teachings.

Ohm belonged to a large family, and as was normal in those times, many of his siblings died in infancy; Of the seven children that the Ohm couple brought into the world, only three survived: Georg Simon, his sister Elizabeth Barbara and his brother Martin, who became a well-known mathematician.

At the age of 16 he attended the University of Erlangen, where he apparently lost interest in his studies after three semesters, considering that he was wasting his time, and due to pressure from his father. Ohm was sent to Switzerland, where in September 1806 he obtained a post as teacher of mathematics at a school in Gottstadt, near Nidau.

Advised by his colleague Karl Christian von Langsdorf—whom he had met while at the university—to read the works of Euler, Laplace, and Lacroix, he continued his studies of mathematics until April 1811, when he decided to return to Erlangen.. There he received his doctorate on October 25 of that same year and immediately entered the university's payroll.

After three semesters he decided to leave his position as a mathematics professor at the university, coming to the conclusion that he could not improve his status in Erlangen, as he lived in poor conditions and saw no future there. His luck did not change, and the Bavarian government offered him a teaching position at a disreputable school in Bamberg, a job he accepted in January 1813. Three years later, after the school closed, he was sent to another school in Bamberg, who needed help in teaching mathematics and physics. During all this time, Ohm showed a visible discontent with his work, since it was not the brilliant career that he had hoped for himself: he considered himself more than just a teacher.

On September 11, 1817, he received a great opportunity as a teacher of mathematics and physics at the Jesuit Lyceum in Cologne, a school better than any other in which Ohm had been able to teach, since it even had its own well-equipped Physics Laboratory. Once installed there, Ohm continued his studies in mathematics, reading the works of leading French mathematicians of the time, such as Laplace, Lagrange, Legendre, Biot, and Poisson, as well as those of Fourier and Fresnel. He later carried on experimental work in the college's physics laboratory, after learning of Oersted's discovery of electromagnetism in 1820.

In 1825 he began to publish the results of his experiments on current and voltage measurements, in which he highlighted the decrease in the electromagnetic force that passes through a cable as it grew longer. He continued to publish his work, until —already convinced of his discovery— he published in 1827 Die galvanische Kette, mathematisch bearbeitet , a book in which he expounds all his theory on electricity. His most notable contribution was the statement of a fundamental relationship, now called Ohm's law . That same equation had been discovered 46 years earlier by the Englishman Henry Cavendish; but the semi-hermit character of this had prevented its dissemination. Regarding the book, it should be noted that he begins by teaching the basics of mathematics, with the purpose that the reader understands the rest of the book. It is that for the time even the best German physicists lacked an appropriate mathematical base for the understanding of the work, which is why it did not fully convince the most veteran German physicists, who did not believe that the mathematical approach to physics was the right one. more suitable, for which they criticized and ridiculed his work.

It was not until 1825 that he began to publish his work, while he was at the Jesuit Lyceum in Bavaria, where he was allowed to stay away from teaching for a year, so that he could continue with his discoveries. In August 1826, he received the not-very-generous sum of half his salary to spend the year in Berlin, working on his publishing house. Ohm thought that with the publication of his work he would be offered a better position at a university before returning to Cologne, but in September 1827 time was running out and he was getting no better offers. Feeling diminished, Ohm decided to stay in Berlin, and in March 1828 he resigned from his position in Cologne.

He worked temporarily in various schools in Berlin and in 1833 accepted a position at the University of Nuremberg, where he was awarded the title of professor; however, he had not yet achieved a position commensurate with what he believed to be his merits.

In 1841, his work was recognized by the Royal Society and he was awarded the Copley Medal; the following year he was incorporated as a foreign member of the Society. So did several academies, including those of Turin and Berlin, who made him an elected member. In 1845 he was already an active and formal member of the Bayerische Akademie.

Beyond his research on electricity, in 1843 he announced the fundamental principle of physiological acoustics, due to his concern with the way combinations of tones are heard:

Being exposed to a complex sound created by mixing several tones, individuals are able to listen separately to each tone.

Harvey Schiffman (2001)

But his hypotheses did not have a strong enough mathematical basis, and the brief life of his hypothesis ended in a dispute with the physicist August Seebeck, who discredited his theory. Finally, Ohm acknowledged his mistakes.

In 1849 Ohm accepted a position in Munich as Curator of the Physics Cabinet of the Bayerische Akademie and gave numerous lectures at the University of Munich. In 1852 he achieved his lifelong ambition: he was appointed full professor of physics at the University of Munich.

Georg Simon Ohm died on July 6, 1854 in Munich, Bavaria, present-day Germany. He is buried in the Alter Südfriedhof cemetery, in the same city.

Eponymy

• The Ohm Law and the electrical resistance unit, the ohm.
• The lunar crater Ohm, who carries this name in his memory.
• The asteroid (24750) Ohm also commemorates its name.