James
Clerk Maxwell
(1831-1879)
James
Clerk Maxwell was one of the greatest scientists of the 19th
century. He is best known for the formulation of the theory
of electromagnetism and in making the connection between light
and electromagnetic waves. He also made significant contributions
in the areas of physics, mathematics, astronomy and engineering.
He considered by many as the father of modern physics.
Maxwell
was born in Edinburgh, Scotland in 1831. Even though most of
his formal higher education took place in London, he was always
drawn back to his family home in the hills of Scotland. As a
young child, Maxwell was fascinated with geometry and mechanical
models. When he was only 14 years old, he published his first
scientific paper on the mathematics of oval curves and ellipses
that he traced with pins and thread. Maxwell continued to publish
papers on a variety of subjects. These included the mathematics
of human perception of colors, the kinetic theory of gasses,
the dynamics of a spinning top, theories of soap bubbles, and
many others.
Maxwell's
early education took place at Edinburgh Academy and the University
of Edinburgh. In 1850 he went on to study at the University
of Cambridge and, upon graduation from Cambridge, Maxwell became
a professor of natural philosophy at Marischal College in Aberdeen
until 1860. He then moved to London to become a professor of
natural philosophy and astronomy at King's College. In 1865,
Maxwell's father died and he returned to the family home in
Scotland to devote his time to research. In 1871 he accepted
a position as the first professor of experimental physics at
Cambridge where he set up the world famous Cavendish Laboratory
in 1874.
While
at Aberdeen, Maxwell was challenged by the subject of the Adams
Prize of 1857: the motion of Saturn's rings. He had previously
thought and theorized about the nature of the rings when he
was only 16 years old. He decided to compete for the prize,
and the next two years were taken up with developing a theory
to explain the physical composition of the rings. He was finally
able to demonstrate, by purely mathematical reasoning, that
the stability of rings could only be achieved if they consisted
of numerous small particles. His theory won him the prize and,
more significantly, nearly a hundred years later, the Voyager
1 space probe proved his theory right.
Much
of modern technology has been developed from the basic principles
of electromagnetism formulated by Maxwell. The field of electronics,
including the telephone, radio, television, and radar, stem
from his discoveries and formulations. While Maxwell relied
heavily on previous discoveries about electricity and magnetism,
he also made a significant leap in unifying the theories of
magnetism, electricity, and light. His revolutionary work lead
to the development of quantum physics in the early 1900's and
to Einstein's theory of relativity.
Maxwell
began his work in electromagnetism by extending Michael Faraday's
theories of electricity and magnetic lines of force. He then
began to see the connections between the approaches of Faraday,
Reimann and Gauss. As a result, he was able to derive one of
the most elegant theories yet formulated. Using four equations,
he described and quantified the relationships between electricity,
magnetism and the propagation of electromagnetic waves. The
equations are now known as Maxwell's Equations.
One
of the first things that Maxwell did with the equations was
to calculate the speed of an electromagnetic wave and found
that the speed of an electromagnetic wave was almost identical
to the speed of light. Based on this discovery, he was the first
to propose that light was an electromagnetic wave. In 1862 Maxwell
wrote:
"We
can scarcely avoid the conclusion that light consists in the
transverse undulations of the same medium which is the cause
of electric and magnetic phenomena."
This
was a remarkable achievement, for it not only unifies the theories
of electricity and magnetism, but of optics as well. Electricity,
magnetism and light can now be understood as aspects of a single
phenomenon: electromagnetic waves.
Maxwell
also described the thermodynamic properties of gas molecules
using statistical mechanics. His improvements to the kinetic
theory of gases included showing that temperature and heat are
caused only by molecular movement. Though Maxwell did not originate
the kinetic theory, he was the first to apply probability and
statistics to describe temperature changes at the molecular
level. His theory is still widely used by scientists as a model
for rarefied gases and plasmas.
Maxwell
also contributed to the development of color photography. His
analysis of color perception led to his invention of the trichromatic
process. By using red, green and blue filters he created the
first color photograph. The trichromatic process is the basis
modern color photography.
Maxwell's
particular gift was in applying mathematical reasoning in solving
complex theoretical problems. Maxwell's Electromagnetic Equations
are perfect examples of how mathematics can be used to provide
relatively simple and elegant explanations of the complex mysteries
of the universe. Richard Feynman wrote of Maxwell:
"From
a long view of the history of mankind, seen from, say, ten thousand
years from now, there can be little doubt that the most significant
event of the 19th century will be judged as Maxwell's discovery
of the laws of electrodynamics."
Maxwell
continued his work at the Cavendish Laboratory until illness
forced him to resign in 1879. He returned to Scotland and died
soon afterwards. He was buried with little ceremony in a small
churchyard in the village of Parton in Scotland.
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