Louis Victor Pierre Raymond, 7th Duc de Broglie (,
also ,
or ; 15 August 1892 – 19 March 1987)
was a French
physicist
A physicist is a scientist who specializes in the field of physics, which encompasses the interactions of matter and energy at all length and time scales in the physical universe.
Physicists generally are interested in the root or ultimate cau ...
and
aristocrat
The aristocracy is historically associated with "hereditary" or "ruling" social class. In many states, the aristocracy included the upper class of people (aristocrats) with hereditary rank and titles. In some, such as ancient Greece, ancient R ...
who made groundbreaking contributions to
quantum theory. In his 1924 PhD thesis, he postulated the wave nature of
electrons
The electron ( or ) is a subatomic particle with a negative one elementary electric charge. Electrons belong to the first generation of the lepton particle family,
and are generally thought to be elementary particles because they have n ...
and suggested that
all matter has wave properties. This concept is known as the de Broglie hypothesis, an example of
wave–particle duality
Wave–particle duality is the concept in quantum mechanics that every particle or quantum entity may be described as either a particle or a wave. It expresses the inability of the classical physics, classical concepts "particle" or "wave" to fu ...
, and forms a central part of the theory of
quantum mechanics
Quantum mechanics is a fundamental theory in physics that provides a description of the physical properties of nature at the scale of atoms and subatomic particles. It is the foundation of all quantum physics including quantum chemistry, ...
.
De Broglie won the
Nobel Prize for Physics
)
, image = Nobel Prize.png
, alt = A golden medallion with an embossed image of a bearded man facing left in profile. To the left of the man is the text "ALFR•" then "NOBEL", and on the right, the text (smaller) "NAT•" then " ...
in 1929, after the wave-like behaviour of matter was
first experimentally demonstrated in 1927.
The 1925
pilot-wave
In theoretical physics, the pilot wave theory, also known as Bohmian mechanics, was the first known example of a hidden-variable theory, presented by Louis de Broglie in 1927. Its more modern version, the de Broglie–Bohm theory, interprets quan ...
model, and the wave-like behaviour of particles discovered by de Broglie was used by
Erwin Schrödinger
Erwin Rudolf Josef Alexander Schrödinger (, ; ; 12 August 1887 – 4 January 1961), sometimes written as or , was a Nobel Prize-winning Austrian physicist with Irish citizenship who developed a number of fundamental results in quantum theo ...
in his formulation of
wave mechanics Wave mechanics may refer to:
* the mechanics of waves
* the ''wave equation'' in quantum physics, see Schrödinger equation
See also
* Quantum mechanics
* Wave equation
The (two-way) wave equation is a second-order linear partial different ...
.
[Antony Valentini: ''On the Pilot-Wave Theory of Classical, Quantum and Subquantum Physics'', Ph.D. Thesis, ISAS, Trieste 1992] The pilot-wave model and interpretation was then abandoned, in favor of the
quantum formalism, until 1952 when it was
rediscovered and enhanced by David Bohm.
Louis de Broglie was the sixteenth member elected to occupy
seat 1 of the
Académie française
An academy (Attic Greek: Ἀκαδήμεια; Koine Greek Ἀκαδημία) is an institution of secondary or tertiary higher learning (and generally also research or honorary membership). The name traces back to Plato's school of philosop ...
in 1944, and served as Perpetual Secretary of the
French Academy of Sciences
The French Academy of Sciences (French: ''Académie des sciences'') is a learned society, founded in 1666 by Louis XIV at the suggestion of Jean-Baptiste Colbert, to encourage and protect the spirit of French scientific research. It was at ...
. De Broglie became the first high-level scientist to call for establishment of a multi-national laboratory, a proposal that led to the establishment of the European Organization for Nuclear Research (
CERN
The European Organization for Nuclear Research, known as CERN (; ; ), is an intergovernmental organization that operates the largest particle physics laboratory in the world. Established in 1954, it is based in a northwestern suburb of Gen ...
).
Biography
Origin and education
Louis de Broglie belonged to the famous aristocratic family of
Broglie, whose representatives for several centuries occupied important military and political posts in France. The father of the future physicist,
Louis-Alphonse-Victor, 5th duc de Broglie, was married to Pauline d’Armaille, the granddaughter of the Napoleonic General
Philippe Paul, comte de Ségur Philippe is a masculine sometimes feminin given name, cognate to Philip. It may refer to:
* Philippe of Belgium (born 1960), King of the Belgians (2013–present)
* Philippe (footballer) (born 2000), Brazilian footballer
* Prince Philippe, Count ...
and his wife, the biographer,
Marie Célestine Amélie d'Armaillé. They had five children; in addition to Louis, these were: Albertina (1872–1946), subsequently the Marquise de Luppé;
Maurice Maurice may refer to:
People
* Saint Maurice (died 287), Roman legionary and Christian martyr
* Maurice (emperor) or Flavius Mauricius Tiberius Augustus (539–602), Byzantine emperor
*Maurice (bishop of London) (died 1107), Lord Chancellor and ...
(1875–1960), subsequently a famous experimental physicist; Philip (1881–1890), who died two years before the birth of Louis, and Pauline, Comtesse de Pange (1888–1972), subsequently a famous writer.
Louis was born in
Dieppe
Dieppe (; Norman: ''Dgieppe'') is a coastal commune in the Seine-Maritime department in the Normandy region of northern France.
Dieppe is a seaport on the English Channel at the mouth of the river Arques. A regular ferry service runs to N ...
, Seine-Maritime. As the youngest child in the family, Louis grew up in relative loneliness, read a lot, and was fond of history, especially political. From early childhood, he had a good memory and could accurately read an excerpt from a theatrical production or give a complete list of ministers of the
Third Republic of France
The French Third Republic (french: Troisième République, sometimes written as ) was the system of government adopted in France from 4 September 1870, when the Second French Empire collapsed during the Franco-Prussian War, until 10 July 194 ...
. For him it was predicted a great future as a statesman.
De Broglie had intended a career in
humanities
Humanities are academic disciplines that study aspects of human society and culture. In the Renaissance, the term contrasted with divinity and referred to what is now called classics, the main area of secular study in universities at t ...
, and received his first degree in history. Afterwards he turned his attention toward mathematics and physics and received a degree in physics. With the outbreak of the
First World War
World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was List of wars and anthropogenic disasters by death toll, one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, ...
in 1914, he offered his services to the army in the development of radio communications.
Military service
After graduation, Louis de Broglie as a simple sapper joined the engineering forces to undergo compulsory service. It began at
Fort Mont Valérien, but soon, on the initiative of his brother, he was seconded to the Wireless Communications Service and worked on the
Eiffel Tower
The Eiffel Tower ( ; french: links=yes, tour Eiffel ) is a wrought-iron lattice tower on the Champ de Mars in Paris, France. It is named after the engineer Gustave Eiffel, whose company designed and built the tower.
Locally nicknamed ...
, where the radio transmitter was located. Louis de Broglie remained in military service throughout the
First World War
World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was List of wars and anthropogenic disasters by death toll, one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, ...
, dealing with purely technical issues. In particular, together with
Léon Brillouin
Léon Nicolas Brillouin (; August 7, 1889 – October 4, 1969) was a French physicist. He made contributions to quantum mechanics, radio wave propagation in the atmosphere, solid state physics, and information theory.
Early life
Brillouin ...
and brother Maurice, he participated in establishing wireless communications with submarines. Prince Louis was demobilized in August 1919 with the rank of
adjudant. Later, the scientist regretted that he had to spend about six years away from the fundamental problems of science that interested him.
Scientific and pedagogical career
His 1924 thesis ''Recherches sur la théorie des quanta'' (Research on the Theory of the Quanta) introduced his theory of
electron
The electron ( or ) is a subatomic particle with a negative one elementary electric charge. Electrons belong to the first generation of the lepton particle family,
and are generally thought to be elementary particles because they have n ...
waves. This included the
wave–particle duality
Wave–particle duality is the concept in quantum mechanics that every particle or quantum entity may be described as either a particle or a wave. It expresses the inability of the classical physics, classical concepts "particle" or "wave" to fu ...
theory of matter, based on the work of
Max Planck
Max Karl Ernst Ludwig Planck (, ; 23 April 1858 – 4 October 1947) was a German theoretical physicist whose discovery of energy quanta won him the Nobel Prize in Physics in 1918.
Planck made many substantial contributions to theoretical p ...
and
Albert Einstein
Albert Einstein ( ; ; 14 March 1879 – 18 April 1955) was a German-born theoretical physicist, widely acknowledged to be one of the greatest and most influential physicists of all time. Einstein is best known for developing the theor ...
on light. This research culminated in the
de Broglie hypothesis
Matter waves are a central part of the theory of quantum mechanics, being an example of wave–particle duality. All matter exhibits wave-like behavior. For example, a beam of electrons can be diffracted just like a beam of light or a water w ...
stating that ''any moving particle or object had an associated wave''. De Broglie thus created a new field in physics, the ''mécanique ondulatoire,'' or wave mechanics, uniting the physics of energy (wave) and matter (particle). For this he won the
Nobel Prize in Physics
)
, image = Nobel Prize.png
, alt = A golden medallion with an embossed image of a bearded man facing left in profile. To the left of the man is the text "ALFR•" then "NOBEL", and on the right, the text (smaller) "NAT•" then " ...
in 1929.
In his later career, de Broglie worked to develop a
causal
Causality (also referred to as causation, or cause and effect) is influence by which one event, process, state, or object (''a'' ''cause'') contributes to the production of another event, process, state, or object (an ''effect'') where the ca ...
explanation of wave mechanics, in opposition to the wholly
probabilistic
Probability is the branch of mathematics concerning numerical descriptions of how likely an event is to occur, or how likely it is that a proposition is true. The probability of an event is a number between 0 and 1, where, roughly speaking, ...
models which dominate
quantum mechanical
Quantum mechanics is a fundamental theory in physics that provides a description of the physical properties of nature at the scale of atoms and subatomic particles. It is the foundation of all quantum physics including quantum chemistry, qua ...
theory; it was refined by
David Bohm
David Joseph Bohm (; 20 December 1917 – 27 October 1992) was an American-Brazilian-British scientist who has been described as one of the most significant theoretical physicists of the 20th centuryPeat 1997, pp. 316-317 and who contributed ...
in the 1950s. The theory has since been known as the
De Broglie–Bohm theory
The de Broglie–Bohm theory, also known as the ''pilot wave theory'', Bohmian mechanics, Bohm's interpretation, and the causal interpretation, is an Interpretations of quantum mechanics, interpretation of quantum mechanics. In addition to the wa ...
.
In addition to strictly scientific work, de Broglie thought and wrote about the
philosophy of science
Philosophy of science is a branch of philosophy concerned with the foundations, methods, and implications of science. The central questions of this study concern what qualifies as science, the reliability of scientific theories, and the ultim ...
, including the value of modern scientific discoveries. In 1930 he founded the book series Actualités scientifiques et industrielles published by
Éditions Hermann
Éditions Hermann () is a French publishing house founded in 1876, by the French professor of mathematics Arthur Hermann. It publishes books on science and the arts.
''Éléments de mathématique''
Hermann is noted for publishing several volu ...
.
De Broglie became a member of the
Académie des sciences
The French Academy of Sciences (French: ''Académie des sciences'') is a learned society, founded in 1666 by Louis XIV at the suggestion of Jean-Baptiste Colbert, to encourage and protect the spirit of French scientific research. It was at ...
in 1933, and was the academy's perpetual secretary from 1942. He was asked to join ''Le Conseil de l'Union Catholique des Scientifiques Francais'', but declined because he was non-religious.
On 12 October 1944, he was elected to the
Académie Française
An academy (Attic Greek: Ἀκαδήμεια; Koine Greek Ἀκαδημία) is an institution of secondary or tertiary higher learning (and generally also research or honorary membership). The name traces back to Plato's school of philosop ...
, replacing mathematician
Émile Picard
Charles Émile Picard (; 24 July 1856 – 11 December 1941) was a French mathematician. He was elected the fifteenth member to occupy seat 1 of the Académie française in 1924.
Life
He was born in Paris on 24 July 1856 and educated there at ...
. Because of the deaths and imprisonments of Académie members during the occupation and other effects of the war, the Académie was unable to meet the quorum of twenty members for his election; due to the exceptional circumstances, however, his unanimous election by the seventeen members present was accepted. In an event unique in the history of the Académie, he was received as a member by his own brother Maurice, who had been elected in 1934.
UNESCO
The United Nations Educational, Scientific and Cultural Organization is a List of specialized agencies of the United Nations, specialized agency of the United Nations (UN) aimed at promoting world peace and security through international coope ...
awarded him the first
Kalinga Prize
The Kalinga Prize for the Popularization of Science is an award given by UNESCO for exceptional skill in presenting scientific ideas to lay people. It was created in 1952, following a donation from Biju Patnaik, Founder President of the Kalinga ...
in 1952 for his work in popularizing scientific knowledge, and he was elected a Foreign Member of the
Royal Society
The Royal Society, formally The Royal Society of London for Improving Natural Knowledge, is a learned society and the United Kingdom's national academy of sciences. The society fulfils a number of roles: promoting science and its benefits, re ...
on 23 April 1953.
Louis became the 7th
duc de Broglie
The House of Broglie (, also ; french: Maison de Broglie, or ) is a French noble family, originally Piedmontese, who migrated to France in the year 1643.
History
() was the name of an old Piedmontese noble family, from which were descended ...
in 1960 upon the death without heir of his elder brother,
Maurice, 6th duc de Broglie
__NOTOC__
Louis-César-Victor-Maurice, 6th duc de Broglie (27 April 1875 – 14 July 1960) was a French physicist. Brother of the theoretical physicist, Louis de Broglie.
Biography
Early years
De Broglie was born in Paris, to Victor de Brogli ...
, also a physicist.
In 1961, he received the title of Knight of the Grand Cross in the
Légion d'honneur
The National Order of the Legion of Honour (french: Ordre national de la Légion d'honneur), formerly the Royal Order of the Legion of Honour ('), is the highest French order of merit, both military and civil. Established in 1802 by Napoleon ...
. De Broglie was awarded a post as counselor to the French High Commission of Atomic Energy in 1945 for his efforts to bring industry and science closer together. He established a center for applied mechanics at the
Henri Poincaré Institute
Henri is an Estonian, Finnish, French, German and Luxembourgish form of the masculine given name Henry.
People with this given name
; French noblemen
:'' See the ' List of rulers named Henry' for Kings of France named Henri.''
* Henri I de Mon ...
, where research into optics, cybernetics, and atomic energy were carried out. He inspired the formation of the
International Academy of Quantum Molecular Science
The International Academy of Quantum Molecular Science (IAQMS) is an international scientific learned society covering all applications of quantum theory to chemistry and chemical physics. It was created in Menton in 1967. The founding members we ...
and was an early member.
Louis never married. When he died on 19 March 1987 in
Louveciennes
Louveciennes () is a commune in the Yvelines department in the Île-de-France region in north-central France. It is located in the western suburbs of Paris, between Versailles and Saint-Germain-en-Laye, and adjacent to Marly-le-Roi.
Populat ...
at the age of 94,
[Extract of page 141]
/ref> he was succeeded as duke
Duke is a male title either of a monarch ruling over a duchy, or of a member of royalty, or nobility. As rulers, dukes are ranked below emperors, kings, grand princes, grand dukes, and sovereign princes. As royalty or nobility, they are r ...
by a distant cousin, Victor-François, 8th duc de Broglie
Prince Jean Marie François Ferdinand de Broglie (21 June 1921 – 24 December 1976) was a French politician and President of the National Assembly in 1959.
Family
Jean de Broglie was born in Paris on 21 June 1921. He was the first son of Prin ...
. His funeral was held 23 March 1987 at the Church of Saint-Pierre-de-Neuilly.
Scientific activity
Physics of X-ray and photoelectric effect
The first works of Louis de Broglie (early 1920s) were performed in the laboratory of his older brother Maurice and dealt with the features of the photoelectric effect
The photoelectric effect is the emission of electrons when electromagnetic radiation, such as light, hits a material. Electrons emitted in this manner are called photoelectrons. The phenomenon is studied in condensed matter physics, and solid sta ...
and the properties of x-rays
An X-ray, or, much less commonly, X-radiation, is a penetrating form of high-energy electromagnetic radiation. Most X-rays have a wavelength ranging from 10 picometers to 10 nanometers, corresponding to frequencies in the range 30&nbs ...
. These publications examined the absorption of X-rays and described this phenomenon using the Bohr theory, applied quantum principles to the interpretation of photoelectron spectra, and gave a systematic classification of X-ray spectra. The studies of X-ray spectra were important for elucidating the structure of the internal electron shells of atoms (optical spectra are determined by the outer shells). Thus, the results of experiments conducted together with Alexandre Dauvillier, revealed the shortcomings of the existing schemes for the distribution of electrons in atoms; these difficulties were eliminated by Edmund Stoner. Another result was the elucidation of the insufficiency of the Sommerfeld formula for determining the position of lines in X-ray spectra; this discrepancy was eliminated after the discovery of the electron spin. In 1925 and 1926, Leningrad physicist Orest Khvolson
Orest Danilovich Khvolson or Chwolson (russian: Орест Данилович Хвольсон) (November 22 (New Style, N.S. December 4), 1852 – May 11, 1934) was a Russian physicist and honorary member of the Soviet Academy of Sciences ( ...
nominated the de Broglie brothers for the Nobel Prize for their work in the field of X-rays.
Matter and wave–particle duality
Studying the nature of X-ray radiation and discussing its properties with his brother Maurice, who considered these rays to be some kind of combination of waves and particles, contributed to Louis de Broglie's awareness of the need to build a theory linking particle and wave representations. In addition, he was familiar with the works (1919–1922) of Marcel Brillouin
Louis Marcel Brillouin (; 19 December 1854 – 16 June 1948) was a French physicist and mathematician.
Born in Saint-Martin-lès-Melle, Deux-Sèvres, France, his father was a painter who moved to Paris when Marcel was a boy. There he attend ...
, which proposed a hydrodynamic model of an atom and attempted to relate it to the results of Bohr's theory. The starting point in the work of Louis de Broglie was the idea of A. Einstein about the quanta of light. In his first article on this subject, published in 1922, the French scientist considered blackbody radiation as a gas of light quanta and, using classical statistical mechanics, derived the Wien radiation law in the framework of such a representation. In his next publication, he tried to reconcile the concept of light quanta with the phenomena of interference and diffraction and came to the conclusion that it was necessary to associate a certain periodicity with quanta. In this case, light quanta were interpreted by him as relativistic particles of very small mass.
It remained to extend the wave considerations to any massive particles, and in the summer of 1923 a decisive breakthrough occurred. De Broglie outlined his ideas in a short note "Waves and quanta" (french: Ondes et quanta, presented at a meeting of the Paris Academy of Sciences on September 10, 1923), which marked the beginning of the creation of wave mechanics. In this paper, the scientist suggested that a moving particle with energy E and velocity v is characterized by some internal periodic process with a frequency (later known as Compton frequency), where is Planck's constant. To reconcile these considerations, based on the quantum principle, with the ideas of special relativity, de Broglie was forced to associate a "fictitious wave" with a moving body, which propagates with the phase velocity
The phase velocity of a wave is the rate at which the wave propagates in any medium. This is the velocity at which the phase of any one frequency component of the wave travels. For such a component, any given phase of the wave (for example, ...
. Such a wave, which later received the name phase wave, or de Broglie wave
Matter waves are a central part of the theory of quantum mechanics, being an example of wave–particle duality. All matter exhibits wave-like behavior. For example, a beam of electrons can be diffracted just like a beam of light or a water wave ...
, in the process of body movement remains in phase with the internal periodic process. Having then examined the motion of an electron in a closed orbit, the scientist showed that the requirement for phase matching directly leads to the quantum Bohr-Sommerfeld condition, that is, to quantize the angular momentum. In the next two notes (reported at the meetings on September 24 and October 8, respectively), de Broglie came to the conclusion that the particle velocity is equal to the group velocity
The group velocity of a wave is the velocity with which the overall envelope shape of the wave's amplitudes—known as the ''modulation'' or ''envelope'' of the wave—propagates through space.
For example, if a stone is thrown into the middl ...
of phase waves, and the particle moves along the normal to surfaces of equal phase. In the general case, the trajectory of a particle can be determined using Fermat's principle
Fermat's principle, also known as the principle of least time, is the link between ray optics and wave optics. In its original "strong" form, Fermat's principle states that the path taken by a ray between two given points is the pat ...
(for waves) or the principle of least action
The stationary-action principle – also known as the principle of least action – is a variational principle that, when applied to the '' action'' of a mechanical system, yields the equations of motion for that system. The principle states tha ...
(for particles), which indicates a connection between geometric optics and classical mechanics.
This theory set the basis of wave mechanics. It was supported by Einstein, confirmed by the electron diffraction experiments of G P Thomson and Davisson and Germer, and generalized by the work of Schrödinger.
However, this generalization was statistical and was not approved of by de Broglie, who said "that the particle must be the seat of an internal periodic movement and that it must move in a wave in order to remain in phase with it was ignored by the actual physicists
A physicist is a scientist who specializes in the field of physics, which encompasses the interactions of matter and energy at all length and time scales in the physical universe.
Physicists generally are interested in the root or ultimate caus ...
ho are
Ho (or the transliterations He or Heo) may refer to:
People Language and ethnicity
* Ho people, an ethnic group of India
** Ho language, a tribal language in India
* Hani people, or Ho people, an ethnic group in China, Laos and Vietnam
* Hiri ...
wrong to consider a wave propagation without localization of the particle, which was quite contrary to my original ideas."
From a philosophical viewpoint, this theory of matter-waves has contributed greatly to the ruin of the atomism of the past. Originally, de Broglie thought that real wave (i.e., having a direct physical interpretation) was associated with particles. In fact, the wave aspect of matter was formalized by a wavefunction
A wave function in quantum physics is a mathematical description of the quantum state of an isolated quantum system. The wave function is a complex-valued probability amplitude, and the probabilities for the possible results of measurements ...
defined by the Schrödinger equation
The Schrödinger equation is a linear partial differential equation that governs the wave function of a quantum-mechanical system. It is a key result in quantum mechanics, and its discovery was a significant landmark in the development of th ...
, which is a pure mathematical entity having a probabilistic interpretation, without the support of real physical elements. This wavefunction gives an appearance of wave behavior to matter, without making real physical waves appear. However, until the end of his life de Broglie returned to a direct and real physical interpretation of matter-waves, following the work of David Bohm
David Joseph Bohm (; 20 December 1917 – 27 October 1992) was an American-Brazilian-British scientist who has been described as one of the most significant theoretical physicists of the 20th centuryPeat 1997, pp. 316-317 and who contributed ...
. The de Broglie–Bohm theory
The de Broglie–Bohm theory, also known as the ''pilot wave theory'', Bohmian mechanics, Bohm's interpretation, and the causal interpretation, is an Interpretations of quantum mechanics, interpretation of quantum mechanics. In addition to the wa ...
is today the only interpretation giving real status to matter-waves and representing the predictions of quantum theory.
Conjecture of an internal clock of the electron
In his 1924 thesis, de Broglie conjectured that the electron has an internal clock that constitutes part of the mechanism by which a pilot wave
In theoretical physics, the pilot wave theory, also known as Bohmian mechanics, was the first known example of a hidden-variable theory, presented by Louis de Broglie in 1927. Its more modern version, the de Broglie–Bohm theory, interprets qua ...
guides a particle. Subsequently, David Hestenes
David Orlin Hestenes (born May 21, 1933) is a theoretical physicist and science educator. He is best known as chief architect of geometric algebra as a unified language for mathematics and physics, and as founder of Modelling Instructio ...
has proposed a link to the zitterbewegung
In physics, the zitterbewegung ("jittery motion" in German, ) is the predicted rapid oscillatory motion of elementary particles that obey relativistic wave equations. The existence of such motion was first discussed by Gregory Breit in 1928 and la ...
that was suggested by Erwin Schrödinger
Erwin Rudolf Josef Alexander Schrödinger (, ; ; 12 August 1887 – 4 January 1961), sometimes written as or , was a Nobel Prize-winning Austrian physicist with Irish citizenship who developed a number of fundamental results in quantum theo ...
.
While attempts at verifying the internal clock hypothesis and measuring clock frequency are so far not conclusive, recent experimental data is at least compatible with de Broglie's conjecture.
Non-nullity and variability of mass
According to de Broglie, the neutrino
A neutrino ( ; denoted by the Greek letter ) is a fermion (an elementary particle with spin of ) that interacts only via the weak interaction and gravity. The neutrino is so named because it is electrically neutral and because its rest mass ...
and the photon
A photon () is an elementary particle that is a quantum of the electromagnetic field, including electromagnetic radiation such as light and radio waves, and the force carrier for the electromagnetic force. Photons are massless, so they alwa ...
have rest masses that are non-zero, though very low. That a photon is not quite massless is imposed by the coherence of his theory. Incidentally, this rejection of the hypothesis of a massless photon enabled him to doubt the hypothesis of the expansion of the universe.
In addition, he believed that the true mass of particles is not constant, but variable, and that each particle can be represented as a thermodynamic
Thermodynamics is a branch of physics that deals with heat, work, and temperature, and their relation to energy, entropy, and the physical properties of matter and radiation. The behavior of these quantities is governed by the four laws of ...
machine equivalent to a cyclic integral of action.
Generalization of the principle of least action
In the second part of his 1924 thesis, de Broglie used the equivalence of the mechanical principle of least action with Fermat's optical principle: "Fermat's principle applied to phase waves is identical to Maupertuis' principle
In classical mechanics, Maupertuis's principle (named after Pierre Louis Maupertuis) states that the path followed by a physical system is the one of least length (with a suitable interpretation of ''path'' and ''length''). It is a special case of ...
applied to the moving body; the possible dynamic trajectories of the moving body are identical to the possible rays of the wave." This equivalence had been pointed out by Hamilton Hamilton may refer to:
People
* Hamilton (name), a common British surname and occasional given name, usually of Scottish origin, including a list of persons with the surname
** The Duke of Hamilton, the premier peer of Scotland
** Lord Hamilto ...
a century earlier, and published by him around 1830, in an era where no experience gave proof of the fundamental principles of physics being involved in the description of atomic phenomena.
Up to his final work, he appeared to be the physicist who most sought that dimension of action which Max Planck
Max Karl Ernst Ludwig Planck (, ; 23 April 1858 – 4 October 1947) was a German theoretical physicist whose discovery of energy quanta won him the Nobel Prize in Physics in 1918.
Planck made many substantial contributions to theoretical p ...
, at the beginning of the 20th century, had shown to be the only universal unity (with his dimension of entropy).
Duality of the laws of nature
Far from claiming to make "the contradiction disappear" which Max Born
Max Born (; 11 December 1882 – 5 January 1970) was a German physicist and mathematician who was instrumental in the development of quantum mechanics. He also made contributions to solid-state physics and optics and supervised the work of a ...
thought could be achieved with a statistical approach, de Broglie extended wave–particle duality to all particles (and to crystals which revealed the effects of diffraction) and extended the principle of duality to the laws of nature.
His last work made a single system of laws from the two large systems of thermodynamics and of mechanics:
That idea seems to match the continuous–discontinuous duality, since its dynamics could be the limit of its thermodynamics when transitions to continuous limits are postulated. It is also close to that of Leibniz
Gottfried Wilhelm (von) Leibniz . ( – 14 November 1716) was a German polymath active as a mathematician, philosopher, scientist and diplomat. He is one of the most prominent figures in both the history of philosophy and the history of ma ...
, who posited the necessity of "architectonic principles" to complete the system of mechanical laws.
However, according to him, there is less duality, in the sense of opposition, than synthesis (one is the limit of the other) and the effort of synthesis is constant according to him, like in his first formula, in which the first member pertains to mechanics and the second to optics:
:
Neutrino theory of light
This theory, which dates from 1934, introduces the idea that the photon is equivalent to the fusion of two Dirac neutrinos. It is not currently accepted by the majority of physicists.
Hidden thermodynamics
De Broglie's final idea was the hidden thermodynamics of isolated particles. It is an attempt to bring together the three furthest principles of physics: the principles of Fermat, Maupertuis, and Carnot.
In this work, action
Action may refer to:
* Action (narrative), a literary mode
* Action fiction, a type of genre fiction
* Action game, a genre of video game
Film
* Action film, a genre of film
* ''Action'' (1921 film), a film by John Ford
* ''Action'' (1980 fil ...
becomes a sort of opposite to entropy
Entropy is a scientific concept, as well as a measurable physical property, that is most commonly associated with a state of disorder, randomness, or uncertainty. The term and the concept are used in diverse fields, from classical thermodyna ...
, through an equation that relates the only two universal dimensions of the form:
:
As a consequence of its great impact, this theory brings back the uncertainty principle
In quantum mechanics, the uncertainty principle (also known as Heisenberg's uncertainty principle) is any of a variety of mathematical inequalities asserting a fundamental limit to the accuracy with which the values for certain pairs of physic ...
to distances around extrema of action, distances corresponding to ''reductions in entropy''.
Honors and awards
* 1929 Nobel Prize in Physics
)
, image = Nobel Prize.png
, alt = A golden medallion with an embossed image of a bearded man facing left in profile. To the left of the man is the text "ALFR•" then "NOBEL", and on the right, the text (smaller) "NAT•" then " ...
* 1929 Henri Poincaré Medal
* 1932 Albert I of Monaco
Albert I (Albert Honoré Charles Grimaldi; 13 November 1848 – 26 June 1922) was Prince of Monaco from 10 September 1889 until his death. He devoted much of his life to oceanography, exploration and science. Alongside his expeditions, Albert I ...
Prize
* 1938 Max Planck Medal
The Max Planck medal is the highest award of the German Physical Society , the world's largest organization of physicists, for extraordinary achievements in theoretical physics. The prize has been awarded annually since 1929, with few exceptions, ...
* 1938 Fellow, Royal Swedish Academy of Sciences
The Royal Swedish Academy of Sciences ( sv, Kungliga Vetenskapsakademien) is one of the royal academies of Sweden. Founded on 2 June 1739, it is an independent, non-governmental scientific organization that takes special responsibility for prom ...
* 1944 Fellow, Académie française
An academy (Attic Greek: Ἀκαδήμεια; Koine Greek Ἀκαδημία) is an institution of secondary or tertiary higher learning (and generally also research or honorary membership). The name traces back to Plato's school of philosop ...
* 1952 Kalinga Prize
The Kalinga Prize for the Popularization of Science is an award given by UNESCO for exceptional skill in presenting scientific ideas to lay people. It was created in 1952, following a donation from Biju Patnaik, Founder President of the Kalinga ...
* 1953 Fellow, Royal Society
The Royal Society, formally The Royal Society of London for Improving Natural Knowledge, is a learned society and the United Kingdom's national academy of sciences. The society fulfils a number of roles: promoting science and its benefits, re ...
Publications
* ''Recherches sur la théorie des quanta'' (''Researches on the quantum theory''), Thesis, Paris, 1924, Ann. de Physique (10) 3, 22 (1925).
* ''Introduction à la physique des rayons X et gamma'' (''Introduction to physics of X-rays and Gamma-rays''), with Maurice de Broglie
__NOTOC__
Louis-César-Victor-Maurice, 6th duc de Broglie (27 April 1875 – 14 July 1960) was a French physicist. Brother of the theoretical physicist, Louis de Broglie.
Biography
Early years
De Broglie was born in Paris, to Victor de Brogli ...
, Gauthier-Villars, 1928.
*
* ''Rapport au 5ème Conseil de Physique Solvay'' (''Report for the 5th Solvay Physics Congress''), Brussels, 1927.
*
*
* ''Matière et lumière'' (''Matter and Light''), Paris: Albin Michel, 1937.
* ''La Physique nouvelle et les quanta'' (''New Physics and Quanta''), Flammarion, 1937.
* ''Continu et discontinu en physique moderne'' (''Continuous and discontinuous in Modern Physics''), Paris: Albin Michel, 1941.
* ''Ondes, corpuscules, mécanique ondulatoire'' (''Waves, Corpuscles, Wave Mechanics''), Paris: Albin Michel, 1945.
* ''Physique et microphysique'' (''Physics and Microphysics''), Albin Michel, 1947.
* ''Vie et œuvre de Paul Langevin'' (''The life and works of Paul Langevin
Paul Langevin (; ; 23 January 1872 – 19 December 1946) was a French physicist who developed Langevin dynamics and the Langevin equation. He was one of the founders of the ''Comité de vigilance des intellectuels antifascistes'', an ant ...
''), French Academy of Sciences, 1947.
* ''Optique électronique et corpusculaire'' (''Electronic and Corpuscular Optics''), Herman, 1950.
* ''Savants et découvertes'' (''Scientists and discoveries''), Paris, Albin Michel, 1951.
* ''Une tentative d'interprétation causale et non linéaire de la mécanique ondulatoire: la théorie de la double solution.'' Paris: Gauthier-Villars, 1956.
** English translation: ''Non-linear Wave Mechanics: A Causal Interpretation.'' Amsterdam: Elsevier, 1960.
* ''Nouvelles perspectives en microphysique'' (''New prospects in Microphysics''), Albin Michel, 1956.
* ''Sur les sentiers de la science'' (''On the Paths of Science''), Paris: Albin Michel, 1960.
* ''Introduction à la nouvelle théorie des particules de M. Jean-Pierre Vigier et de ses collaborateurs'', Paris: Gauthier-Villars, 1961. Paris: Albin Michel, 1960.
** English translation: ''Introduction to the Vigier Theory of elementary particles'', Amsterdam: Elsevier, 1963.
* ''Étude critique des bases de l'interprétation actuelle de la mécanique ondulatoire'', Paris: Gauthier-Villars, 1963.
** English translation: ''The Current Interpretation of Wave Mechanics: A Critical Study'', Amsterdam, Elsevier, 1964.
* ''Certitudes et incertitudes de la science'' (''Certitudes and Incertitudes of Science''). Paris: Albin Michel, 1966.
* with Louis Armand, Pierre Henri Simon and others. ''Albert Einstein
Albert Einstein ( ; ; 14 March 1879 – 18 April 1955) was a German-born theoretical physicist, widely acknowledged to be one of the greatest and most influential physicists of all time. Einstein is best known for developing the theor ...
.'' Paris: Hachette, 1966.
** English translation: ''Einstein.'' Peebles Press, 1979.
* ''Recherches d'un demi-siècle'' (''Research of a half-century''), Albin Michel, 1976.
* ''Les incertitudes d'Heisenberg et l'interprétation probabiliste de la mécanique ondulatoire'' ('' Heisenberg uncertainty and wave mechanics probabilistic interpretation''), Gauthier-Villars, 1982.
References
External links
Les Immortels: Louis de BROGLIE
, Académie française
*
Fondation Louis de Broglie
*
English translation of his book on hidden thermodynamics by D. H. Delphenich
The Theory of measurement in wave mechanics
(English translation of his book on the subject)
"A new conception of light"
(English translation)
Louis de Broglie Interview
on Ina.fr
*
{{DEFAULTSORT:Broglie, Louis De
1892 births
1987 deaths
20th-century French physicists
People from Dieppe, Seine-Maritime
Louis
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University of Paris alumni
Foreign Members of the Royal Society
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