Georg Simon Ohm
- the man behind Ohm's Law
Ohm is a name synonymous with the very basis of electricity. Every school
child that studies physics will have heard of Ohm's Law. Yet behind the name for
the unit of resistance is a very real man. Someone who performed experiments
that were at the forefront of the technology of the time.
Early Life
Georg Simon Ohm was born on 18th March 1789 in Erlangen in Bavaria. He was the
eldest of three children born to Wofgang and Maria.
Georg entered school at the age of 11 and he proved to be a bright student,
and in 1805 he moved on to University at Erlangen. Unfortunately the social life
proved to be too much of an attraction and after just over a year he was forced
to leave.
Having learned some of the hard truths of life Ohm set to work again and this
time managed to gain his Ph.D. With this behind him he took up a career as a
teacher with the aim of becoming a professor. To gain recognition he published a
book on geometry, and this enabled him to move on to teach at the Jesuit's
College in Cologne.
Law Derived
In 1820 the phenomenon of electromagnetism had only just been discovered. Ohm
was fascinated by electricity and started to make some investigations. However
even basic measurements like measuring current were difficult. Measuring current
was accomplished by measuring the magnetic flux around the conductor. Whilst
doing this Ohm noticed that the type of conductor had an effect on the flux and
as a result he performed experiments to find out if there might be any
relationship between the voltage, current and the material of the wire.
Ohm derived a relationship between them, but his first attempt was incorrect,
involving logarithms. However Ohm continued to work on the problem. He refined
his results and used improved batteries that were a major source of error. Using
the improved system he was able to establish a new relationship that was very
much like the one we know today.
Ohm was now confident of his results and published them. However the
scientific community were very sceptical, and some people even ridiculed him.
Fortunately a few people recognised his work and this enabled him to move on to
Berlin to proceed with further research
Recognition
After his move to Berlin, much of Ohm's time was spent in research. He also
published the results of his work in a book entitled "Die Galvanische Kette
Mathematisch Bearbeitet" (The galvanic Circuit Investigated Mathematically).
Ohm's main aim was to become a professor. To be able to achieve this he
resigned from his post and became a part time teacher. In this way if a suitable
post arose then he would be able to take it up quickly and easily. Unfortunately
the plan did not work until 1833. At this time Ohm's work was beginning to be
recognised and he was offered the post of professor of physics in Nuremburg.
Further recognition came to Ohm. In 1841 the Royal Society in London awarded
him the Copley Medal and a year later he was made a foreign member. Finally in
1852 Ohm was appointed professor of physics at Berlin University. Unfortunately
he was unable to enjoy this success for long because he died shortly afterwards
in July 1854.
After his death Ohm's work was fully accepted. Many societies and
organisations saw the need for a unit of resistance. In fact it was in Britain
that the unit of resistance was first named after Ohm. Then in 1881 the unit was
adopted by international agreement and Ohm's name was made immortal.
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