Hendrik Antoon Lorentz was one of the greatest scientists of his
time. His work covered many fields of physics. However, his most
outstanding contributions were to the theory of electromagnetism.
Based on the Maxwellian framework, Lorentz proposed a universal
theory of physics based purely on the concepts of electromagnetism.
His fundamental postulates, which were independent of mechanical
principles, were presented in “Inquiry into a Theory of Electrical
and Optical Phenomena in Moving Bodies” published in 1895
in Dutch. Lorentz described the electromagnetic field in five equations
for the first time in compact vector notation. The first four equations
embodied the content of Maxwell’s theory, while the fifth
equation described, what was called Lorentz force, connected continuous
field with electricity. His discoveries prepared the ground for
many of the developments in modern physics. Lorentz was one of the
first to predict the existence of electrons. He explained the Zeeman
effect, a change in spectral lines in a magnetic field. Lorentz
further advanced the hypothesis of George Francis FitzGerald (18511901)
that the length of a body contracts in the direction of its motion
when it is moving. This phenomenon is now called Lorentz contraction.
Lorentz is also wellknown for Lorentz transformations which he
introduced in 1904. Lorentz transformations are a set of mathematical
equations that correlate space and time coordinates of one moving
system to known space and time of another system. Lorentz transformations
explained the experiment of Michelson and Morley and described the
shortening of length the increase in mass and dilation of time of
a moving body moving at a speed close to the velocity of light.
This work influenced, and was confirmed by Einstein’s special
theory of relativity. Lorentz did a great deal to found theoretical
physics as an academic discipline in Europe. Lorentz was much influenced
by Augustin Jean Fresnel’s (17881827) work. He admitted that
it was through Fresnel’s work that he acquired clarity in
thought and insight.
After the First World War, Lorentz strived hard
towards reorganisation of international cooperations especially
among scientists. He largely succeeded in his endeavours because
of the undisputed prestige and respect that he enjoyed among scientists
all over the world. Towards the end of his life he served as Chairman
of the League of Nations’ Committee of Intellectual Cooperation.
Lorentz was the President of the first Solvay Conference for Physics
held in Brussels and he continued to be president of Solvay Conferences
until his death.
Owen Williams Richardson (18791959) described
Lorentz as “[A] man of remarkable intellectual powers…Although
steeped in his own investigation of the moment, he always seemed
to have in his immediate grasp its ramifications into every corner
of the universe…The singular clearness of his writings provides
a striking reflection of his wonderful powers in this respect…He
possessed and successfully employed the mental vivacity which is
necessary to follow the interplay of discussion, the insight which
is required to extract these statements which illuminate the real
difficulties and the wisdom to lead discussion among fruitful channels,
and he did this so skilfully that the process was hardly perceptible.”
Lorentz was born on July 18, 1853 at Arnhem, the
Netherlands. His parents were Gerrit Frederik Lorentz and Geeruide.
Till the age of 13 he attended the Mr. Timmer’s Primary School
in Arnhem. He then entered the first High School to be opened at
Arnhem in 1866. In 1870, Lorentz entered the University of Leiden.
He obtained his BSc degree in mathematics and physics in 1872 and
then he returned to his native place Arnhem where he started teaching
evening classes. Though he left the university but he continued
to work for his doctorate degree.
In 1875, Lorentz obtained his PhD degree from
the Leiden University. At the time of his getting PhD, he was just
22 years old. In his research work for his PhD dissertation, Lorentz
refined the electromagnetic theory of Clerk Maxwell. Lorentz could
provide better explanation for reflection and refraction of light.
His doctoral dissertation was titled “The theory of the reflection
and refraction of light.”
Lorentz remained at his home without taking any
permanent profession even after receiving his doctoral degree. This
was due to the fact that he was in dilemma over the choice of a
career in physics or mathematics. In those days theoretical physics
was an isolated academic pursuit. It was yet to emerge as a distinct
scientific discipline of its own. In 1878, at the early age of 25,
Lorentz was appointed Professor of Mathematical Physics at the Leiden
University. The post, the first chair of theoretical physics in
Holland, was newly created for him. He remained at the Leiden University
till his retirement in 1912. This was in spite of the fact that
he received offers of many academic appointments abroad. Lorentz
engaged himself in developing a single theory to explain the relationship
of electricity, magnetism and light. His main objective in developing
such a unified theory was to refine the electromagnetic theory of
Clerk Maxwell so that the relationship between electromagnetism
and light can be explained. He proposed that the atoms might consist
of charged particles (later termed as electrons) and the oscillations
of these charged particles were the source of light. A consequence
of Lorentz’s electron theory was that a magnetic field would
affect the electron oscillations, and thereby the frequencies of
the light emitted. Lorentz adopted the term ‘electron’
in 1899 and identified electrons with cathode rays. He showed how
vibrations of electron give rise to Maxwell’s electromagnetic
waves. In 1896, Lorentz jointly with Pieter Zeeman (18651943) explained
the Zeeman effect whereby atomic spectral lines are split in the
presence of magnetic fields. For this work they were jointly awarded
the 1902 Nobel Prize in Physics. Lorentz’s ‘electron
theory’ proved to be so successful that its failure to explain
the photoelectric effect was a major clue to the need for quantum
theory.
Lorentz is wellknown for his suggested method
of resolving the problems raised by the results of the experiments
conducted by Albert Abraham Michelson (18521931) and Edward Williams
Morley (18381923) in the 1880s to demonstrate the existence of
hypothetical ether. MichelsonMorley experiment gave no indication
that the Earth was moving through the hypothetical ether. He showed
that if it was assumed that moving bodies contracted very slightly
in direction of their motion then the observed results of MichelsonMorley
experiment could be accounted for. FitzGerald also derived it independent
of Lorentz. This phenomenon is now known as LorentzFitzGerald contraction.
In 1904, Lorentz developed a firm mathematical description of this,
the Lorentz transformation. Einstein later showed that this emerges
naturally out of his special theory of relativity.
Lorentz presided over the first Solvay Conference
in Brussels in 1911. The main objective of this conference was to
look at the problems of having two different approaches in physics—classical
physics and quantum physics. In his Presidential address at the
opening ceremony of the conference, Lorentz observed: “In
this stage of affairs there appeared to us like a wonderful ray
of light the beautiful hypothesis of energy elements which was first
expounded by Planck and then extended by Einstein and Nernst and
others to many phenomena. It has opened for us unexpected vistas,
even those, who consider it with a certain suspicion, must admit
its importance and fruitfulness.” Lorentz himself never fully
accepted the quantum theory. He believed that eventually the new
theory would be fitted into the classical approach.
In 1912, Lorentz became the Director of research
at the Teyler Institute at Haarlem. However, he remained honorary
professor at Leiden and gave weekly lectures there.
Lorentz was elected a Fellow of the Royal Society
in 1905. He was also the recipient of the Rumford Medal (1908) and
Copley Medal (1918) of the Royal Society. In 1923, he was elected
to the membership of the “International Committee of Intellectual
Cooperations” of the League of Nations. Lorentz became its
President in 1925.
Lorentz died on February 04, 1928. He was the
most revered scientist of his time in the Netherlands. The Nobel
Laureate Owen W Richardson, while describing Lorentz’s funeral,
wrote: “The funeral took place at Haarlem at noon on Friday,
February 10. At the stroke of twelve the state telegraph and telephone
services of Holland were suspended for three minutes as the revered
tribute to the greatest man Holland has produced in our time. It
was attended by many colleagues and distinguished physicists from
foreign countries. The President, Sir Ernest Rutherford, represented
the Royal Society and made an appreciative oration by the graveside.”
This description gives an indication the respect that Lorentz held
in the Netherlands.
Lorentz’s contributions to the growth of
physics and his greatness as a human being were beautifully summarised
by Albert Einstein in his message delivered at Leiden in 1953 on
the occasion of commemorating of the one hundredth anniversary of
the birth of Lorentz. We quote here from this Einstein’s message:
“At the turn of the century the theoretical physicists of
all nations considered H. A. Lorentz as the leading mind among them,
and rightly so. The physicists of our time are mostly not fully
aware of the decisive part which H. A. Lorentz played in shaping
the fundamental ideas in theoretical physics. The reason for this
strange fact is that Lorentz’s basic ideas have become so
much a part of them that they are hardly able to realise quite how
daring these ideas have been and to what extent they have simplified
the foundations of physics…Thanks to the generosity of the
Leiden University, I frequently spent some time there staying with
my dear and unforgettable friend, Paul Ehrenfest. Thus I had often
the opportunity to attend Lorentz’s lectures which he gave
regularly to a small circle of young colleagues after he had already
retired from his professorship. Whatever came from this supreme
mind was as lucid and beautiful as a good work of art and was presented
with such facility and easy as I have never experienced in anybody
else. If we younger people had known H. A. Lorentz only as a sublime
mind, our admiration and respect for him would have been unique.
But what I feel when I think of H. A. Lorentz is far more than that.
He meant more to me personally than anybody else I have met in my
lifetime.”
References
 Einstein, Albert. Ideas and Opinions. New Delhi: Rupa &
Co, 1984.
 Dardo, Mauro. Nobel Laureates and Twentieth Century Physics.
Cambridge: Cambridge University Press, 2004.
 Heilbron, J. L. (Ed.) The Oxford Companion to the History of
Modern Science. Oxford: Oxford University Press, 2003.
 The Cambridge Dictionary of Scientists (Second Edition). Cambridge:
Cambridge University Press, 2003.
 The Nobel Foundation, Nobel Lectures: Physics 19011921, Amsterdam:
Elsevier, 1967.
 Dictionary of Scientists. Oxford: Oxford University Press,
1999.
 Parthasarathy, R, Paths of Innovators in Science, Engineering
and Technology (Vol. Two), Chennai: EastWest Books (Madras) Pvt.
Ltd, 2003.
