GEORG OHM - Ω Physicist and Mathematician

GEORG OHM - Ω Physicist and Mathematician

The start Georg Simon Ohm was born on 16th of March 1789 in Erlangen in Germany and died on 6th of July 1854 in Munich, Germany. He was born into a Protestant family and was the son of Johann Wolfgang Ohm and Maria Elizabeth Beck. The family had seven children, but only three survived: Georg, his younger brother Martin and his sister Elizabeth Barbara. His mother died when Georg was only 10 years old.

Education Georg and Martin were taught by their father who brought them to a high standard in mathematics, physics, chemistry and philosophy. Georg Simon attended Erlangen Gymnasium from age eleven to fifteen where he hardly received any scientific education. After the Gymnasium, he was sent to Switzerland as his father was concerned that his son was wasting his educational opportunity. In September 1806 Ohm accepted a position as a mathematics teacher in a school in Gottstadt. Ohm restarted his mathematical studies, left his teaching post in March 1809 and became a private tutor in Neuchâtel. For two years he carried out his duties as a tutor while he followed private studies of mathematics. Then in April 1811 he returned to the University of Erlangen.

Teaching Ohm received his doctorate from the University of Erlangen on October 25, 1811. He immediately joined the faculty there as a lecturer in mathematics but left after three semesters because of unpromising prospects. He could not survive on his salary as a lecturer. He had a few more teaching jobs after that and unhappy with his job, Georg began writing an elementary textbook on geometry as a way to prove his abilities.

Ohm sent his completed manuscript to King Wilhelm III of Prussia, who appreciated Ohm's book and offered him a position at the Jesuit Gymnasium of Cologne on 11 September 1817. This school had a reputation for good science education and Ohm was required to teach physics as well as mathematics. The school had a brilliantly equipped physics laboratory, which allowed Ohm to begin experimenting with physics. Being the son of a locksmith, Ohm had some practical experience with mechanical devices, which came in handy.

Publishings

“Die galvanische Kette, mathematisch bearbeitet” (The Galvanic Circuit Investigated Mathematically) was published in 1827. His employers did not appreciate his book and Ohm resigned from his position. He then made an application to, and was employed by, the Polytechnic School of Nuremberg and joined them in 1833. In 1852 he became a professor of experimental physics at the University of Munich.

In 1849, Ohm published “Beiträge zur Molecular-Physik“, (in English: Molecular Physics). He had hoped to write a second and third volume "and if God gives me length of days for it, a fourth". However, on finding that an original discovery recorded in it was being anticipated by a Swedish scientist he did not publish it, stating: "The episode has given a fresh and deep sense for my mind to the saying 'Man proposes, and God disposes'. The project that gave the first impetus to my inquiry has been dissipated into mist, and a new one, undesigned by me, has been accomplished in its place." Ohm’s Law Ohm's law first appeared in his famous book “Die galvanische Kette, mathematisch bearbeitet”, in which he gave his complete theory of electricity. In this work, he stated his law for electromotive force acting between the extremities of any part of a circuit is the product of the strength of the current, and the resistance of that part of the circuit.

A good mathematical background is needed to understand the rest of the work. While his work greatly influenced the theory and applications of current electricity, it was not warmly received at that time. Ohm presents his theory as one of contiguous action, a theory which opposed the concept of action at a distance. Ohm believed that the communication of electricity occurred between "contiguous particles" which is the term he himself used.

Using equipment of his own creation, Ohm found that there is a direct proportionality between the potential difference (voltage) applied across a conductor and the resultant electric current.

Look at the drawing and see if it makes sense to you that:

 If you increase the voltage in a circuit while the resistance is the same, you get more current.  If you increase the resistance in a circuit while the voltage stays the same, you get less current.

Ohm’s law is a way of describing the relationship between the voltage, resistance and current using math:

V = RI

 V is the symbol for voltage  I is the symbol for current.  R is the symbol for resistance. He related to the strength of a current in a wire. Ohm found that electricity acts like water in a pipe and discovered that the current in a circuit is directly proportional to the electric pressure and inversely to the resistance of the conductors. It was adopted as the SI unit of resistance, the ohm (symbol Ω).

Acoustic law Ohm's acoustic law, sometimes called the acoustic phase law or simply Ohm's law, states that a musical sound is perceived by the ear as a set of a numbers of constituent pure harmonic tones. It is well known to be not quite true.

Recognition Although Ohm's work strongly influenced theory, at first it was received with hardly any enthusiasm. However, in the end his work was recognized by the Royal Society with its award of the Copley Medal in 1841. He became a foreign member of the Royal Society in 1842, and in 1845 he became a full member of the Bavarian Academy of Sciences and Humanities.

Interesting facts

 Georg had no formal science training.  He created his own equipment.  Ohm’s theory on electricity was rejected at first.  His discovery was ignored for years.  He also wrote a textbook on Geometry.  He has his own symbol Ω (the Greek letter Omega).

Luke Moore / 10A