Maxwell was the most able theoretical physicist of the nineteenth
century. In fact he is even acclaimed as the father of modern physics.
He was a perfect complementary to Michael Faraday, the greatest
experimentalist of the nineteenth century. Maxwell developed a revolutionary
set of four equations called general equations of the electromagnetic
field that verified the existence of electromagnetic fields proposed
by Michael Faraday and showed that magnetism and electricity are
not two different fields but parts of the same unified field, the
electromagnetic field. These equations are now called Maxwell equations.
“The whole system of wireless telegraphy is a development
of the original and surprising theory of Clerk Maxwell, embodying
in mathematical form the experimental researches of Faraday.”
Maxwell postulated that light is a form of electromagnetic radiation
exerting pressure and carrying momentum. Maxwell expounded his theory
in his Treatise on Electricity and Magnetism published in 1873.
The special theory of relativity, as Einstein himself stated, owes
its origins to Maxwell’s equations of the electromagnetic
field. Maxwell is regarded as one of the founders of kinetic theory
Maxwell was the first Cavendish Professor of Experimental
Physics in the Cambridge University. In 1874 Maxwell established
the Cavendish Laboratory, a unique institution in physics, which
was subsequently to be headed by a succession of men of genius.
The Laboratory produced graduates who dominated physics for generations.
Maxwell was a shy and somewhat eccentric person.
Maxwell was a deeply religious man. He was a simple
man with a strong sense of humour. He was known for his devoutness
and modesty. Maxwell did not live long enough to see his theories
validated experimentally. He died at an early age of 48. Widespread
public recognition of his contribution to science and technology
came only in the last years of the nineteenth century. As days passed,
the relevance of Maxwell’s contribution became more and more
evident. Today, the design of tools and devices for a large number
of electrical technologies like radio, microwave, radar, optical
communications, lasers, power generation and transmission, electronic
components and so on are based on the correct understanding and
application of Maxwell’s equations. Even the most exiting
new promising technologies like lasers, fiber-optics, induction
motors and so on are heavily dependent on the application of Maxwell’s
Maxwell was born on June 13, 1831 in Edinburgh,
Scotland. It may be noted that it was in 1831 that Michael Faraday
made his most influential discovery, electromagnetic induction.
Maxwell’s father John Clerk had taken the name of Maxwell
as heir to the estate of Glenlair in the Galloway region of Scotland.
The Maxwells were comfortably well-off land owners. Maxwell’s
mother died when he was just eight years old. Maxwell’s father,
an educated man, well-versed in the law and interested in science
and invention had great influence on his son’s education.
Shortly after Maxwell’s birth, the family moved to their estate
at Glenlair, where he enjoyed a country upbringing. It is said that
his natural curiosity displayed at an early age. When Maxwell was
just three years old, he was described as follows: “He is
a very happy man, and has improved much since the weather got moderate;
he has great work with doors, locks, keys etc., and ‘Show
me how it doos’ is never out of his mouth. He also investigates
the hidden course of streams and bell-wires, the way the water gets
from the pond through the wall and a pend or small bridge and down
a drain…” His parents had planned that he would be educated
at home till the age of 13 and then he would join the Edinburgh
University. But the plan could not be carried out as his mother
died. He was sent to the Edinburgh Academy, Edinburgh in 1841. His
friend P. G. Tait described Maxwell’s school days in the following
way “At school he (Maxwell) was at first regarded as shy and
rather dull. He made no friendships and spent his occasional holidays
in reading old ballads, drawing curious diagrams and making rude
mechanical models. This absorption in such pursuits, totally unintelligible
to his schoolfellows, who were then totally ignorant of mathematics,
procured him a not very complimentary nickname. About the middle
of his school career however he surprised his companions by suddenly
becoming one of the most brilliant among them, gaining prizes and
sometimes the highest prizes for scholarship, mathematics, and English
verse.” His mathematical abilities were exceptional. At 15,
he submitted to the Royal Society of Edinburgh a paper on the drawing
of oval curves. His paper was so impressive that many members of
the society felt that it could not have written by someone so young.
The paper titled “On the description of oval curves, and those
having a plurality of foci”, was read to the Royal Society
of Edinburgh on April 06, 1846.
He joined the Edinburgh University at the age
of 16. At Edinburgh he first began to direct his attention to physics.
In 1850, Maxwell joined the Trinity College of the Cambridge University.
At Cambridge he came in contact with some of the finest mathematical
and scientific minds in Britain. His tutor at Cambridge was William
Hopkins. In 1855, he was elected a Fellow of the Trinity College.
P. G. Tait in an article in the Proceedings of the Royal Society
of Edinburgh wrote“…he brought to Cambridge in the autumn
of 1850, a mass of knowledge which was really immense for so young
a man, but in a state of disorder appalling to his methodical private
tutor. Though the tutor was William Hopkins, the pupil to a great
extent took his own way, and it may safely be said that no high
wrangler of recent years ever entered the Senate-house more imperfectly
trained to produce ‘paying’ work than did Clerk Maxwell.
But by sheer strength of intellect, though with the very minimum
knowledge how to use it to advantage under the conditions of the
Examination, he obtained the position of Second Wrangler, and was
bracketed equal with the Senior Wrangler, in the higher ordeal of
the Smith’s Prize.” In 1854 he graduated with a degree
in mathematics from Trinity College. He obtained the position of
the Second Wrangler. The First Wrangler in that year was Edward
John Routh (1831-1907), the British mathematical physicist who made
contribution to classical mechanics, including procedure for eliminating
cyclic co-ordinates from equations of motion.
Maxwell was short of stature and hesitant to speech
but nonetheless he made a deep impression on those around him. Describing
Maxwell’s undergraduate days, William Thomson (Lord Kelvin)
wrote: “…Scholars dined together at one table. This
brought Maxwell into daily contact with the most intellectual set
in the College, among whom were many who attained distinction in
later life. These in spite of his shyness and some eccentricities
recognized his exceptional powers….The impression of power
which Maxwell produced on all he met was remarkable; it was often
much more due to his personality than to what he said, for many
found it difficult to follow him in his quick changes from one subject
to another, his lively imagination started so many hares that before
he had run one down he was off on another.”
In 1856 Maxwell was appointed a Professor of Natural
Philosophy at Marischal College, Aberdeen, Scotland. In 1860 Maxwell
moved to London as professor of natural philosophy and astronomy
at King’s College, London, where he spent five years and then
moved back to Scotland to take care of his family estate where he
spent his time by researching and writing. He made periodic trips
to Cambridge. In 1871, Maxwell accepted an offer from Cambridge
to be the first Cavendish Professor of Experimental Physics at Cambridge.
This was the most substantial recognition Maxwell received in his
lifetime. He accepted the post rather reluctantly. However, he devoted
his time to establish the new Cavendish Laboratory. He designed
the laboratory and helped set it up. The Laboratory was formally
opened on June 16, 1874. Maxwell was the first Director of the Cavendish
Laboratory, which was to become one of the most famous physics laboratories
in the world.
Maxwell’s General Equations of the Electromagnetic
Field were first presented in his famous memoir entitled “A
Dynamical Theory of the Electromagnetic Field” published in
1865. This was one of the greatest papers in theoretical physics
of the nineteenth century. Maxwell after reading the works of William
Thomson and Michael Faraday, believed that the lines of force conceived
by Faraday to visualize the magnetic and electric phenomena represented
something real. Beginning in 1856, with his paper “Faraday’s
lines of Force”, Maxwell produced a long series of articles
which revolutionized ideas about electricity, magnetism and light.
Maxwell wrote: “As I proceeded with the study of Faraday,
I perceived that his method of conceiving the phenomena was also
a mathematical one, though not exhibited in the conventional form
of mathematical symbols. I also found that these methods were capable
of being expressed in the ordinary mathematical form, and thus compared
with those of the professed mathematicians.” After carefully
exploring the implications of Faraday’s ideas, Maxwell developed
analogies and models to show how these ideas can be related to familiar
concept and finally he formulated the mathematical expressions making
up famous equations of the electromagnetic field. Before Maxwell
came into the picture, it was widely believed that there was a fundamental
difference in the descriptions of nature used by mathematicians
and those by physicists, with a more purely physical outlook. This
was a reason why Faraday’s theoretical ideas were not closely
examined by mathematicians. However, Maxwell’s work changed
all of this. Maxwell was much influenced by William Thomson. Maxwell
wrote: “I was aware that there was supposed to be a difference
between Faraday’s way of conceiving phenomena and that of
the mathematicians, so that neither he nor they were satisfied with
each other’s language. I had also the conviction that this
discrepancy did not arise from either party being wrong. I was first
convinced of this by Sir William Thomson, to whose advice and assistance,
as well as to his published papers, I owe most of what I have learned
on the subject.”
While presenting his theory Maxwell wrote: “The
theory I propose may…be called a theory of Electromagnetic
Field, because it has to do with the space in the neighbourhood
of the electric or magnetic bodies…The electromagnetic field
is that part of space which contains and surrounds bodies in electric
or magnetic conditions…in order to bring these results within
the power of symbolical calculation, I then express them in the
form of the General Equations of the Electromagnetic Field.”
Maxwell’s equations of electromagnetic field
described the evolution in space and time of electric and magnetic
fields generated by charges, magnets and currents. These equations
also demonstrated that the two cannot be separated. An electric
field changing with time would invariably generate a magnetic field,
which would induce an electric field in adjacent regions of space
and which in turn would generate a magnetic field. And this process
goes on. Maxwell demonstrated that electric and magnetic fields
are not two different fields but part of a single unified field—the
Maxwell’s equations of electromagnetic field
predicted the existence of electromagnetic waves—changing
electric and magnetic fields propagating outward in all directions
result in a wave disturbance traveling in empty space. Maxwell calculated
the speed at which the electromagnetic waves propagate. By taking
into consideration of the values of purely electric and magnetic
measured quantities Maxwell calculated that electromagnetic waves
traveled approximately at the speed that of light. From this observation
Maxwell came to the conclusion that light itself must be an oscillating
electric charge. He concluded that light itself was electromagnetic
radiation. Maxwell did not stop there. He proposed that light (and
infrared and ultraviolet radiation) was probably just one of a large
family of radiations caused by charges oscillating at different
velocities. Maxwell wrote: “The velocity is so nearly that
of light, that it seems we have strong reasons to conclude that
light itself (including radiant heat and other radiations if any)
is an electromagnetic disturbance in the form of waves propagated
through the electromagnetic field according to electromagnetic laws.”
Maxwell predicted the existence of other forms of electromagnetic
radiations with frequencies and wavelength outside the infrared
and ultraviolet regions. The German physicist Heinrich Rudolf Hertz
(1857-1894) detected radio waves in 1887 and this led to the general
acceptance of Maxwell’s theory. Maxwell’s theory was
developed further by the Dutch physicist Hendrik Antoon Lorenz (1853-1928).
Maxwell proposed that light travelled through
an invisible medium, which he named ether. This medium filled all
space “unbroken from star to star.” In 1873, Maxwell
wrote: “There can be no doubt that the interplanetary and
interstellar spaces are not empty but occupied by a material substance
or body, which is certainly the largest, and probably the most uniform,
body of which we have any knowledge.” Maxwell was not the
first to propose that some invisible medium fill the vastness of
the space. The genesis of the idea can be traced back to the ancient
Greeks. For Maxwell there was an obvious need for proposing the
idea of the ether. If light was a wave then it seemed obvious that
it had to be wave traveling in some medium. Later it was proved
that Maxwell’s idea of the ether was erroneous. Albert Abraham
Michelson (1852-1931), an American physicist, while working with
Hermann Ludwig Ferdinand von Helmholtz (1821-1894) in Germany, tried
to verify the existence of ether experimentally. Michelson set out
to measure the speed with which the earth moved through the ether.
Michelson thought that in a universe filled with stationary ether,
the planet Earth would meet resistance as it moved through the ether.
And in the process the moving Earth would create a current, a sort
of “wind” in the ether. In such a situation a light
beam moving with the current would be carried along it but the light
beam moving against the current would be slowed down. To measure
such differences Michelson built an instrument called interferometer.
This device could split a beam of light into two halves running
perpendicular to each other and then it could rejoin the split beam.
In this way it was possible for the device to measure the difference
in the speeds of the two beams of light with great accuracy. Michelson
based on his own experiments concluded that “The result of
the hypothesis of a stationary ether is…shown to be incorrect,
and the necessary conclusion follows that the hypothesis is incorrect.”
Michelson carried out his experiments again and again to rule out
any experimental errors. He was joined by Edward Williams Morley
(1838-1923). Together they carried out a very precise experiment
but failed to detect the existence of ether. Some other experiments
designed to demonstrate the existence of ether also failed.
Maxwell made significant contributions to the
development of thermodynamics. He was one of the founders of the
kinetic theory of gases. His theory brought a new subject, the statistical
physics, into being. This linked thermodynamics and mechanics. Maxwell’s
theory is still widely used as a model for rarefied gases and plasmas.
Maxwell had written a paper, “On the Stability
of the Motion of Saturn’s Rings” for entering the competition
for the Adams Prize of 1857 of the St John’s College, Cambridge.
In this paper, Maxwell argued that the only structure of Saturn’s
rings that was consistent with the accepted laws of mechanics was
“one composed of an indefinite number of unconnected particles.”
He illustrated his argument, built on a skillful mathematical analysis,
with a model. The model constructed by Maxwell still can be seen
in the Cavendish Laboratory at Cambridge. The then Astronomer Royal
of England, Sir George Biddell Airy (1801-92), described the Maxwell’s
paper as “one of the most remarkable applications of Mathematics
to Physics that I have ever seen.” In 1610, when Galileo first
viewed the planet Saturn with a telescope, he saw what appeared
to him to be little stars attached to the planet. In 1655, that
is after 45 years of Galileo’s observation, the Dutch physicist
and astronomer Christiaan Huygens (1629-1695) discovered that these
were in fact rings circling Saturn. In the 1980s, the Voyager space
probes showed us that Saturn’s rings are made of millions
of particles, ranging in size from dust to many meters in diameter
and thus proved the prediction made by Maxwell based on his mathematical
In 1860, Maxwell was awarded the Rumford Medal
of the Royal Society for his work on colour perception. By using
devices called “colour wheel” and “colour box”
constructed by him, Maxwell demonstrated how mixtures of different
colours were perceived by different people. In this work he was
helped by his wife, Katharine Mary Dewar. Maxwell’s work on
colour perception is viewed as the beginning of the science of quantitative
colorimetry. Maxwell by using red, green and blue filters produced
the first true trichromatic colour photograph, of a Scottish tartan
ribbon. He displayed this photograph to Faraday and others at the
Royal Institution in 1861. Maxwell’s process of colour photography
was the forerunner of today’s modern colour photography. He
also invented the “fish-eye” lens.
Maxwell edited Henry Cavendish’s papers.
And this work occupied much of his time between 1874 and 1879. Cavendish
only published two papers and left twenty packages of manuscript
on mathematical experimental electricity. Commenting upon Maxwell’s
work in this period, R. L. Smith-Rose in his biography of Maxwell
titled James Clerk Maxwell: A physicist of the nineteenth century
(1948) wrote: “…Maxwell entered upon this work with
the utmost enthusiasm: he saturated his mind with the scientific
literature of Cavendish’s period; he repeated many of his
experiments, and copied out the manuscript with his own hand…The
volume entitled ‘The Electrical Researches of the Honourable
Henry Cavendish’ was published in 1879, and is unequalled
as a chapter in the history of electricity.”
James Clerk Maxwell died on November 05, 1879
in Cambridge. The year Maxwell died, Albert Einstein was born. “Like
Maxwell’s work in the 19th century, Einstein’s would
dominate much of the century to come.”
We conclude by quoting Max Plank on Maxwell: “His
name stands magnificently over the portal of classical physics,
and we can say this of him; by his birth James Clerk Maxwell belongs
to Edinburgh, by his personality he belongs to Cambridge, by his
work he belongs to the whole world.”
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Cambridge: Cambridge University Press, 2004.
- A Dictionary of Scientists. Oxford: Oxford University Press,
- The Cambridge Dictionary of Scientists (Second Edition). Cambridge:
Cambridge University Press, 2002.
- O’Connor, J. J. and E. F. Robertson. James Clerk Maxwell
(An article available on the internet).
- Heilbron, J. L. (Ed.). The Oxford Companion to the History
of Modern Science. Oxford: Oxford University Press, 2003.
- Domb, C. James Clerk Maxwell: 100Years Later. Nature, No. 282,
pp. 235-239, 1979.
- Campbell, L. and W. Garnett. The Life of James Clerk Maxwell.
London, 1882 (WWW version).
Material available on the internet was also referred to.