Louis de Broglie

SummaryLouise-Victor de Broglie was born on August 15, 1892 at Dieppe, France. His parents were Louis Alphonse Victor de Broglie (born October 30, 1846), diplomat and 5th Duke de Broglie, and Pauline dArmaill (born December 22, 1851). He is the youngest in the family. His siblings are Albertine de Broglie de Lupp, Phillipe de Broglie, Laure Marie Pauline de Broglie de Pange and Maurice de Broglie, physicist and 6th Duke de Broglie.He studied high school in Lyce Janson de Sailly and graduated in 1909. He took up literary studies and took his degree in history in Sorbonne in 1910. Because of his love for science, he gained a science degree in 1913. He served the country through military during the World War 1. He remained for the whole war, 1914-1918. During this period, he was stationed at the Eiffel Tower where he studied technical problems. After the war, he resumed his study of general physics. He specialized in theoretical physics particularly, in the study of problems involving quanta. This was influenced by his brother, Maurice de Broglie, and his co-workers. In 1924, at the Faculty of Sciences at Paris University, he passed his thesis entitled Recherches sur la Thorie des Quantaor Researches on the Quantum Theory; this gained him a doctors degree. This thesis contained ideas which were confirmed by the discovery of electron diffraction by crystals by Davisson and Germer; the ideas now serve as the basis for developing the general theory known as wave mechanics. After teaching for free for two years in Sorbonne, he taught at the Institut Henri Poincar; this institute is built to teach and develop mathematical and theoretical physics.Between the years 1930 and 1950, de Broglie devoted most of his time to the study of various extensions of wave mechanics: Diracs electron theory, new theory of light, general theory of spin particles, application of wave mechanics, etc. He is the author of more than 25 books.

Together with his colleagues, de Broglie has resumed the study on the theory of the double solution to give a casual interpretation of wave mechanics in classical terms of time and space. He obtained a lot of results and he published them in Comptes Rendus de l'Acadmie des Sciences.Because of de Broglies so much work in pursuit of the knowledge for science, the Academie des Sciences awarded him in 1929 the Henri Poincar medal, then in 1932, the Albert I, Monaco Prize. He won the Nobel Prize for Physics for the discovery of the wave nature of electrons. In 1952, the KALINGA award was awarded to him by UNESCO. In 1956, he received a gold medal of the French National Scientific Centre. He has been elected as the permanent secretary of the Academy of Sciences of the French Institute in 1933.Louis de Broglie died due to old age on March 19, 1987 at Paris, France. His remains were buried at Cimetire de Neuilly-sur-Seine, Neuilly-sur-Seine, France.

Youth and EducationLouis de Broglie was born on August 15, 1892, in Dieppe, France. He was the second of the two sons of Victor, 5th duc de Broglie and Pauline dArmaille. His family is one of the most respected in France. The de Broglie family had many well-respected members who became politicians, diplomats, and soldiers.Louis de Broglies elder sister, Pauline wrote: This little brother had become a charming child, slender, svelte, with small laughing face, eyes full of mischief, curled like a poodle. Admitted to the great table, he wore in the evenings a costume of blue velvet, with breeches, black stockings and shoes with buckles, which made him look like a little prince in a fairy tale. His gaiety filled the house. He talked all the time even at the dinner table where the most severe injunctions of silence could not make him hold his tongue, so irresistible were his remarks. Raised in relative loneliness he had read much and lived in the unreal.he had a prodigious memory and knew by heart entire scenes from the classical theatre that he recited with inexhaustible verve.he seemed to have a particular taste for history, in particular political history.hearing our parents discuss politics he improvised speeches inspired by the accounts in the newspapers and could recite unerringly complete lists of ministers of the Third Republic, which changed so oftena great future as a statesman was predicted for Louis.When his father died in 1906, his elder brother, Maurice, 31, sent him to Lycee Janson de Sailly, where he completed secondary education in 1909 after previously being homeschooled. Maurice wrote: Having experienced myself the inconvenience of a pressure exercised on the studies of a young man I refrained from imparting a rigid direction to the studies of my brother, although at times his vacillation gave me some concern. He was good at French, history, physics, philosophy, indifferent in mathematics, chemistry and geography, poor in drawing and foreign language.After his stay at Lycee Janson de Sailly, Louis entered the University of Sorbonne. He had no initial career in mind. He studied history at first, but he did not appreciate the uncritical methods of teaching history in those days. So he shifted to law with a career in civil service in mind. He graduated with an arts degree when he was 18 years old. But instead of completing his post-graduate research in history, he decided to study theoretical physics. De Broglie had a few influences in studying theoretical physics, a couple of which include Maurice, who was also a physicist and had his own lab at their mansion, and Poincares books: La valeur de la science and La science et lhypothese.However, Sorbonne University wasnt exactly the best place to study theoretical physics. There, the teaching of physics didnt include the then recent developments in the subject such as Maxwells electromagnetic theory or statistical thermodynamics. Instead, the course focused on mechanics and wave optics, and the French translations of these topics werent very good. So Louis decided to attend Poincares lectures on electrodynamics, thermodynamics, celestial mechanics, and other such topics.When his elder sister, Princess Pauline, who was 20 years older than him, and to whom he was deeply attached to, got married, de Broglie had some emotional and psychological problems. He lost an exam in general physics. When his self-confidence could go no lower, he read a report about the first Solvay Conference on quantum theory, and he regained his confidence in himself and in the field he chose. He received his bachelor of science in theoretical physics in 1913.Scientific LifeLouis de Broglie was a French physicist well known for his work on the wave-particle duality. Louis de Broglie first studied history, before studying Math and Physics. In 1924, he came up with the de Broglie hypothesis, stating that all moving matter produced waves. This was a relatively new concept since at the time, scientists considered light as either a particle or a wave but not both. But by combining the two concepts, he paved the way for wave mechanics in Physics. He studied and came up with theories, winning the Nobel Prize for his findings.Matter and Wave-Particle DualityIn the year 1924, Louis de Broglie introduced the theory of particle-wave duality. That time, scientists had been debating whether light is a wave or a particle. Interpretations of light and matter were vague because light has several characteristics that can be used to define it as a wave yet there are also characteristics present that define it as matter. It was until de Broglie suggested that these different characteristics can be actually combined to propose the same behavior when it is observed from different perspectives. He proposed and wrote in his doctoral thesis that particles can behave like waves and at the same time waves can behave like particles. His professors and advisors that time were not confident in his proposal and they suggested to forward it to Albert Einstein for evaluation. Einstein was surprised at his theory and stated that de Broglie had just unraveled one of the greatest mysteries of the universe. This theory helped explain how atoms, molecules and subatomic particles (electrons and protons) behave. This study also inspired Erwin Schrdinger in his formulation of wave mechanics. For this theory, de Broglie won the Nobel Prize for Physics in 1929.Generalization of the Principle of Least ActionIn 1924, Louis de Broglie discovered something he thought was the most important realization in his life. He brought together Einsteins Theory of Relativity, Plancks Theory of Quanta, and Fermats Least Action Principle to explain the wave-particle paradox. In his doctoral dissertation, Recherches sur la Theorie des Quanta, he applied Fermats Least Action Principle to waves, theorizing that the possible trajectories of a moving body are analogous to a waves rays. Fermat himself defined his least action principle to explain that nature takes the path of least resistance, and this is the basis of all the operations in the universe. His new theorem, the harmony of the phases, explained that a particle within the wave must be consistent with the phase of a clock in its position, relative to an observer at rest. This resulted in the equation p=h/, in which the momentum of a particle is equal to Plancks constant divided by the wavelength.Conjecture of an Internal Clock of the ElectronIn 1927, de Broglie further expanded his thesis and made the theory that the electron has an internal clock which contributes to the mechanism by which it is guided by its pilot wave. The Pilot Wave theory was the first known example of a hidden variable theory and one of the several interpretations of quantum mechanics. This principle of this theory states that the positions and momentums of the particles are considered to be hidden variables and that the observer doesnt know the exact value of these variables. From Max Borns 1926 paper which suggested that the wave function of Schrodingers wave equation determines the probability density of finding a particle, de Broglie developed this theory. He derived a function for the guiding wave and used a double solution approach. This theory consists of a physical wave in real space and at the same time in which it has a spherical region that gives rise to particle-like behavior. In this initial form of his theory, it was not necessary to prove the existence of a quantum particle. Later on he simplified this theory into which a particle is accompanied by a pilot wave. At the Solvay Conference in 1927, he presented the Pilot Wave theory but Wolfgang Pauli was against it and stated that it did not consider the case of inelastic scattering. De Broglie was not able to counteract that objection and later on he abandoned the pilot-wave approach.Non-nullity and Variability of MassThe neutrino (small neutral particle that travels near the speed of light and is involved in nuclear reactions) and photon (electrons energy transfer particle and base particle of light) have rest masses, under normal circumstances, that are non-zero but still very low. Because of rejecting the hypothesis of a massless photon, he was then able to doubt the hypothesis of the expansion of the universe. According to de Broglie, particles real masses are not constant at all. They are variable and can be represented as a thermodynamic machine equivalent to a cyclic integral of action.Hidden ThermodynamicsIn 1960, de Broglie presented the main idea of the hidden thermodynamics of particles. This theory is an important part of the formulation of wave mechanics. The theory hypothesizes the existence of a chaotic deep medium (subquantum medium), which was introduced to explain the probability distribution, that led de Broglie to take into consideration the interaction of particles with a hidden thermostat. This concept takes the particle as a mathematical entity with a great number of degrees of freedom and a temperature and entropy of its own.

Sources: http://www.nndb.com/people/313/000072097/ http://www.nobelprize.org/nobel_prizes/physics/laureates/1929/broglie-bio.html http://www.spaceandmotion.com/quantum-theory-de-broglie-quotes.htm http://www.nobelprize.org/nobel_prizes/physics/laureates/1929/broglie-bio.html http://www.encyclopedia.com/topic/Louis_Victor_de_Broglie.aspx http://www.bookrags.com/biography/louis-victor-de-broglie-wsd/ http://www.nndb.com/people/313/000072097/ http://www.vigyanprasar.gov.in/scientists/ldbroglie.htm http://www.nobelprize.org/nobel_prizes/physics/laureates/1929/broglie.html http://bado-shanai.net/map%20of%20physics/mopLeastAction.htm