Michael Faraday
Michael Faraday ( HYPERLINK
“http://en.wikipedia.org/wiki/September_22” \o “September 22” September
22 , HYPERLINK “http://en.wikipedia.org/wiki/1791” \o “1791” 1791 –
HYPERLINK “http://en.wikipedia.org/wiki/August_25” \o “August 25”
August 25 , HYPERLINK “http://en.wikipedia.org/wiki/1867” \o “1867”
1867 ) was a HYPERLINK “http://en.wikipedia.org/wiki/United_Kingdom”
\o “United Kingdom” British HYPERLINK
“http://en.wikipedia.org/wiki/Scientist” \o “Scientist” scientist (a
HYPERLINK “http://en.wikipedia.org/wiki/Physicist” \o “Physicist”
physicist and HYPERLINK “http://en.wikipedia.org/wiki/Chemist” \o
“Chemist” chemist ) who contributed significantly to the fields of
HYPERLINK “http://en.wikipedia.org/wiki/Electromagnetism” \o
“Electromagnetism” electromagnetism and HYPERLINK
“http://en.wikipedia.org/wiki/Electrochemistry” \o “Electrochemistry”
electrochemistry . He also invented the earliest form of the device that
was to become the HYPERLINK
“http://en.wikipedia.org/wiki/Bunsen_burner” \o “Bunsen burner” Bunsen
burner , which is used almost universally in science laboratories as a
convenient source of heat.
Michael Faraday was one of the great scientists in history. Some
historians of science refer to him as the greatest experimentalist in
the history of science. It was largely due to his efforts that
HYPERLINK “http://en.wikipedia.org/wiki/Electricity” \o “Electricity”
electricity became viable for use in technology. The HYPERLINK
“http://en.wikipedia.org/wiki/SI” \o “SI” SI unit of HYPERLINK
“http://en.wikipedia.org/wiki/Capacitance” \o “Capacitance” capacitance
, the HYPERLINK “http://en.wikipedia.org/wiki/Farad” \o “Farad” farad
(symbol F) is named after him.
Early career
Michael Faraday was born in HYPERLINK
“http://en.wikipedia.org/wiki/Newington%2C_London%2C_England” \o
“Newington, London, England” Newington Butts , near present-day
HYPERLINK “http://en.wikipedia.org/wiki/Elephant_and_Castle” \o
“Elephant and Castle” Elephant and Castle , HYPERLINK
“http://en.wikipedia.org/wiki/London” \o “London” London . His family
was poor (his father, James Faraday, was a blacksmith) and he had to
educate himself. At fourteen he became apprenticed to bookbinder and
seller HYPERLINK
“http://en.wikipedia.org/w/index.php?title=George_Riebau&action=edit” \o
“George Riebau” George Riebau and, during his seven year
apprenticeship, read many books, developing an interest in science and
specifically electricity.
At the age of twenty Faraday attended lectures by the eminent scientist
Sir HYPERLINK “http://en.wikipedia.org/wiki/Humphry_Davy” \o “Humphry
Davy” Humphry Davy , president of the HYPERLINK
“http://en.wikipedia.org/wiki/Royal_Society” \o “Royal Society” Royal
Society , and HYPERLINK “http://en.wikipedia.org/wiki/John_Tatum” \o
“John Tatum” John Tatum , founder of the HYPERLINK
“http://en.wikipedia.org/w/index.php?title=City_Philosophical_Society&ac
tion=edit” \o “City Philosophical Society” City Philosophical Society .
After Faraday sent Davy a sample of notes taken during the lectures,
Davy said he would keep Faraday in mind but should stick to his current
job of book-binding. After Davy damaged his eyesight in an accident with
HYPERLINK “http://en.wikipedia.org/wiki/Nitrogen_trichloride” \o
“Nitrogen trichloride” nitrogen trichloride , also known as
trichloramine, he employed Faraday as a secretary. When John Payne of
the HYPERLINK “http://en.wikipedia.org/wiki/Royal_Society” \o “Royal
Society” Royal Society was fired, Davy recommended Faraday for the job
of laboratory assistant. Faraday eagerly left his bookbinding job as his
new employer, HYPERLINK
“http://en.wikipedia.org/w/index.php?title=Henry_de_la_Roche&action=edit
” \o “Henry de la Roche” Henry de la Roche , was hot-tempered.
In a class-based society, Faraday was not considered a gentleman; it has
been said that Davy’s wife, HYPERLINK
“http://en.wikipedia.org/wiki/Jane_Apreece” \o “Jane Apreece” Jane
Apreece , refused to treat him as an equal and, when on a continental
tour, made Faraday sit with the servants. However, it was not long
before Faraday surpassed Davy.
He also was the first to link electricity to magnetism and then link
magnetism back to electricity – i.e. he induced an electric current
using magnets – thus inventing the dynamo, predecessor to today’s
HYPERLINK “http://en.wikipedia.org/wiki/Electric_generator” \o “Electric
generator” electric generator .
Scientific career
His greatest work was with electricity. In HYPERLINK
“http://en.wikipedia.org/wiki/1821” \o “1821” 1821 , soon after the
Danish chemist, HYPERLINK
“http://en.wikipedia.org/wiki/Hans_Christian_%C3%98rsted” \o “Hans
Christian Orsted” Hans Christian Orsted discovered the phenomenon of
HYPERLINK “http://en.wikipedia.org/wiki/Electromagnetism” \o
“Electromagnetism” electromagnetism , Davy and HYPERLINK
“http://en.wikipedia.org/wiki/William_Hyde_Wollaston” \o “William Hyde
Wollaston” William Hyde Wollaston tried but failed to design an
HYPERLINK “http://en.wikipedia.org/wiki/Electric_motor” \o “Electric
motor” electric motor . Faraday, having discussed the problem with the
two men, went on to build two devices to produce what he called
electromagnetic rotation: a continuous circular motion from the circular
magnetic force around a wire. A wire extending into a pool of
HYPERLINK “http://en.wikipedia.org/wiki/Mercury_%28element%29” \o
“Mercury (element)” mercury with a magnet placed inside would rotate
around the magnet if charged with electricity by a chemical battery.
This device is known as a HYPERLINK
“http://en.wikipedia.org/wiki/Homopolar_motor” \o “Homopolar motor”
homopolar motor . These experiments and inventions form the foundation
of modern electromagnetic technology. Unwisely, Faraday published his
results without acknowledging his debt to Wollaston and Davy, and the
resulting controversy caused Faraday to withdraw from electromagnetic
research for several years.
Ten years later, in HYPERLINK “http://en.wikipedia.org/wiki/1831” \o
“1831” 1831 , he began his great series of experiments in which he
discovered HYPERLINK
“http://en.wikipedia.org/wiki/Electromagnetic_induction” \o
“Electromagnetic induction” electromagnetic induction , though the
discovery may have been anticipated by the work of HYPERLINK
“http://en.wikipedia.org/wiki/Francesco_Zantedeschi” \o “Francesco
Zantedeschi” Francesco Zantedeschi . He found that if he moved a magnet
through a loop of wire, an electric current flowed in the wire. The
current also flowed if the loop was moved over a stationary magnet.
His demonstrations established that a changing magnetic field produces
an electric field. This relation was mathematically modelled by
HYPERLINK “http://en.wikipedia.org/wiki/Faraday%27s_law_of_induction” \o
“Faraday’s law of induction” Faraday’s law , which subsequently became
one of the four HYPERLINK
“http://en.wikipedia.org/wiki/Maxwell%27s_equations” \o “Maxwell’s
equations” Maxwell equations . These in turn evolved into the
generalization known as field theory.
Faraday then used the principle to construct the electric HYPERLINK
“http://en.wikipedia.org/wiki/Dynamo” \o “Dynamo” dynamo , the ancestor
of modern power generators.
Faraday proposed that electromagnetic forces extended into the empty
space around the conductor, but did not complete his work involving that
proposal. Faraday’s concept of lines of flux emanating from charged
bodies and magnets provided a way to visualize electric and magnetic
fields. That mental model was crucial to the successful development of
electromechanical devices which dominated engineering and industry for
the remainder of the 19th century.
Faraday also dabbled in HYPERLINK
“http://en.wikipedia.org/wiki/Chemistry” \o “Chemistry” chemistry ,
discovering chemical substances such as HYPERLINK
“http://en.wikipedia.org/wiki/Benzene” \o “Benzene” benzene , inventing
the system of HYPERLINK “http://en.wikipedia.org/wiki/Oxidation” \o
“Oxidation” oxidation numbers, and liquefying gases such as
HYPERLINK “http://en.wikipedia.org/wiki/Chlorine” \o “Chlorine”
chlorine . He also discovered the laws of HYPERLINK
“http://en.wikipedia.org/wiki/Electrolysis” \o “Electrolysis”
electrolysis and popularized terminology such as HYPERLINK
“http://en.wikipedia.org/wiki/Anode” \o “Anode” anode , HYPERLINK
“http://en.wikipedia.org/wiki/Cathode” \o “Cathode” cathode ,
HYPERLINK “http://en.wikipedia.org/wiki/Electrode” \o “Electrode”
electrode , and HYPERLINK “http://en.wikipedia.org/wiki/Ion” \o “Ion”
ion .
In HYPERLINK “http://en.wikipedia.org/wiki/1845” \o “1845” 1845 he
discovered what is now called the HYPERLINK
“http://en.wikipedia.org/wiki/Faraday_effect” \o “Faraday effect”
Faraday effect and the phenomenon that he named HYPERLINK
“http://en.wikipedia.org/wiki/Diamagnetism” \o “Diamagnetism”
diamagnetism . The plane of HYPERLINK
“http://en.wikipedia.org/wiki/Polarization” \o “Polarization”
polarization of linearly polarized light propagated through a material
medium can be rotated by the application of an external magnetic field
aligned in the propagation direction. He wrote in his notebook, “I have
at last succeeded in illuminating a magnetic curve or line of force and
in magnetising a ray of light”. This established that magnetic force and
light were related.
In his work on static electricity, Faraday demonstrated that the charge
only resided on the exterior of a charged conductor, and exterior charge
had no influence on anything enclosed within a conductor. This is
because the exterior charges redistribute such that the interior fields
due to them cancel. This shielding effect is used in what is now known
as a HYPERLINK “http://en.wikipedia.org/wiki/Faraday_cage” \o “Faraday
cage” Faraday cage .
Miscellaneous
He gave a successful series of lectures on the chemistry and physics of
flames at the HYPERLINK
“http://en.wikipedia.org/wiki/Royal_Institution” \o “Royal Institution”
Royal Institution , entitled HYPERLINK
“http://en.wikipedia.org/wiki/The_Chemical_History_of_a_Candle” \o “The
Chemical History of a Candle” The Chemical History of a Candle ; this
was the origin of the HYPERLINK
“http://en.wikipedia.org/wiki/Royal_Institution_Christmas_Lectures” \o
“Royal Institution Christmas Lectures” Christmas lectures for young
people that are still given there every year and bear his name.
Faraday was known for designing ingenious experiments, but lacked a good
HYPERLINK “http://en.wikipedia.org/wiki/Mathematics” \o “Mathematics”
mathematics education. (However, his affiliation with HYPERLINK
“http://en.wikipedia.org/wiki/James_Clerk_Maxwell” \o “James Clerk
Maxwell” James Clerk Maxwell helped in this regard, as Maxwell was
able to translate Faraday’s experiments into mathematical language.) He
was regarded as handsome and modest, declining a knighthood and
presidency of the Royal Society (Davy’s old position).
Michael Faraday on a British F20 banknote.
His picture has been printed on British F20 HYPERLINK
“http://en.wikipedia.org/wiki/British_banknotes” \o “British banknotes”
banknotes .
His sponsor and mentor was HYPERLINK
“http://en.wikipedia.org/wiki/John_%27Mad_Jack%27_Fuller” \o “John ‘Mad
Jack’ Fuller” John ‘Mad Jack’ Fuller , who created the Fullerian
Professorship of Chemistry at the Royal Institution. Faraday was the
first, and most famous, holder of this position to which he was
appointed for life.
Faraday was also devoutly religious and a member of the small
HYPERLINK “http://en.wikipedia.org/wiki/Sandemanian” \o “Sandemanian”
Sandemanian denomination, an offshoot of the HYPERLINK
“http://en.wikipedia.org/wiki/Church_of_Scotland” \o “Church of
Scotland” Church of Scotland . He served two terms as an elder in the
group’s church.
Faraday married Sarah Barnard in HYPERLINK
“http://en.wikipedia.org/wiki/1821” \o “1821” 1821 but they had no
children. They met through attending the Sandemanian church.
He died at his house at Hampton Court on HYPERLINK
“http://en.wikipedia.org/wiki/August_25” \o “August 25” August 25 ,
HYPERLINK “http://en.wikipedia.org/wiki/1867” \o “1867” 1867 .
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