Michael Faraday's scientific work laid the foundations
of all subsequent electro-technology. From his experiments came devices
which led directly to the modern electric motor, generator and transformer.
Faraday was also the greatest scientific lecturer of his day, who did much
to publicise the great advances of nineteenth-century science and technology
through his articles, correspondence and the Friday evening discourses which
he established at the Royal Institution. The Royal Institution Christmas
lectures for children, begun by Faraday, continue to this day.
Michael Faraday was born on 22nd September 1791. At
the age of fourteen he was apprenticed to a London bookbinder. Reading many of the books in the shop, Faraday
became fascinated by science, and wrote to Sir Humphry Davy at the Royal
Institution asking for a job. On 1st March 1813, he
was appointed laboratory assistant at the Royal Institution. There Faraday
immersed himself in the study of chemistry, becoming a skilled analytical
chemist.
In 1823 he discovered that chlorine could be liquefied and in 1825
he discovered a new substance known today as benzene. (today an indegredent
in petrol)
when Michael Faraday performed the initial experiments
which resulted in the discovery of the first dynamo, he also described a
phenomenon which has yet to be understood in terms of conventional electrical
theory. In paragraphs 255, 256, and 257 of his diary , dated December 26,
1831, is described the experiment of cementing a copper disc on top of a
cylinder magnet, paper intervening, and supporting the magnet by means of
a string so as to rotate axially, with the wires of a galvanometer connected
to the edge and axis of the copper plate. When this combination was caused
to rotate an electrical potential was found to be created. The polarity
and the magnitude of the potential was found to be the same as would occur
if the copper plate had moved and the magnet remained still. Faraday spent
his latter years pondering the relationship between the situation of magnet
and disc rotating together vis-a-vis the situation of fixed magnet and disc
rotating independently. He explained the situation by positing the assumption
that the magnetic field of a magnet remained stationary in space whilst
the metal of the magnet revolved axially. Thus a relative motion would exist
between the moving metal of the magnet and the posited stationary flux lines
giving rise to the expected potential which results from the motion of a
wire through a magnetic field [emphasis added].
Now also known as a "homopolar generator"
the profound mystery of the 173 year old "co-rotating Faraday disc-magnet"
-- how an electrical current can be created in a conductor which is apparently
not moving relative to the source of a magnetic field ! -- is still to this
day being hotly debated by physicists and electrical engineers. Or, as Dr.
Bruce DePalma elegantly phrased it, " a phenomenon which has yet to
be understood in terms of conventional electrical theory." DePalma,
an innovative experimental physicist, would go on to invent and build several
of his own versions of this remarkable generator.
Hans Christian Orsted
1777 - 1851
In
1821, the Danish chemist, Orsted, discovered
the phenomenon of Magnetism and Electricity being related. His picture is below.
He had observed
that a compass needle had moved after it was nearby a battery that had
been turned on to power up a light. He then immediatly thought that
there was (correctly) a relationship between magnetism and electricity.
Orsted did conclude there was an
actual relationship but was unable to take it further. Orsted would be
the very first person to correctly conclude a definite relationship
between Electricity and Magnetism.
Orsted was not the first person to examine the
relationship of Electricity and Magnetism.
in 1802 Gian Domenico
Romagnosi ( his picture is below )
an Italian legal Scholar, Deflected a Magnetic Needle by Electrostatic
Charge. An Account of this was published in 1802 in an Italian
Newspaper, with no interest, and was overlooked.
No Galvanic Current existed in the set-up and therefore no Electro-Magnetism was present.
There was no
relationship placed between Magnetism and Electricity back then - and
never understood.
Picture engraving below is Michael Faraday's lab at the Royal Institution
However, Michael Faradays' greatest work was with electricity.
In the autumn of 1831
Ten years after Orsted had discovered some relationship between a Compass and a Battery
On 29th August 1831, using
his "induction ring", Faraday made one of his greatest discoveries
- electromagnetic induction: the "induction" or generation of
electricity in a wire by means of the electromagnetic effect of a current
in another wire.
The induction ring was the first electric transformer.
In a second series of experiments in September he discovered magneto-electric
induction: the production of a steady electric current. To do this, Faraday
attached two wires through a sliding contact to a copper disc. By rotating
the disc between the poles of a horseshoe magnet he obtained a continuous
direct current.
This was the first generator.
Hippolyte Pixii
Although neither of Faraday's devices is of practical
use today they enhanced immeasurably the theoretical
understanding of electricity and magnetism.
He described these experiments
in two papers presented to the Royal Society on 24th November 1831, and
12th January 1832. These were the first and second parts of his "Experimental
researches into electricity" in which he gave his "law which
governs the evolution of electricity by magneto-electric induction".
After reading this, a young Frenchman, Hippolyte Pixii constructed an electric
generator that utilised the rotary motion between magnet and coil rather
than Faraday's to and fro motion in a straight line.
All the D.C. generators
today are direct descendants of the machine developed by Pixii from Faraday's
first principles.
He is another major trailblazer.
A.C. Alternators were invented by Nikola Tesla in the
later 1800's
A.C. Power generation and distribution is the electricity
we use in our houses and workplaces today.
Faraday continued his electrical experiments. In 1832
he proved that the electricity induced from a magnet, voltaic electricity
produced by a battery, and static electricity were all the same. He also
did significant work in electrochemistry, stating the First and Second Laws
of Electrolysis. This laid the basis for electrochemistry, another great
modern industry.
Faraday's "descriptive theory of lines of force moving
between bodies with electrical and magnetic properties" enabled
James Clerk
Maxwell ( picture below )
to formulate an exact mathematical theory of the propagation of
electromagnetic waves.
In 1865, Maxwell proved mathematically that electromagnetic
phenomena are propagated as waves through space with the velocity of light,
thereby laying the foundation of radio communication,
confirmed experimentally
in 1888 by Hertz,
And developed for practical use by Tesla and Marconi at
the turn of the century.
In 1865, Faraday ended
his connection with the Royal Institution after over 50 years of service.
He died at his house at Hampton Court on 25th August 1867.
His discoveries
have had an incalculable effect on subsequent scientific and technical development.
