Author: Bertrand Duplantier
Publisher: Springer
ISBN: 3034808348
Category : Mathematics
Languages : en
Pages : 246
Book Description
This thirteenth volume of the Poincaré Seminar Series, Henri Poincaré, 1912-2012, is published on the occasion of the centennial of the death of Henri Poincaré in 1912. It presents a scholarly approach to Poincaré’s genius and creativity in mathematical physics and mathematics. Its five articles are also highly pedagogical, as befits their origin in lectures to a broad scientific audience. Highlights include “Poincaré’s Light” by Olivier Darrigol, a leading historian of science, who uses light as a guiding thread through much of Poincaré ’s physics and philosophy, from the application of his superior mathematical skills and the theory of diffraction to his subsequent reflections on the foundations of electromagnetism and the electrodynamics of moving bodies; the authoritative “Poincaré and the Three-Body Problem” by Alain Chenciner, who offers an exquisitely detailed, hundred-page perspective, peppered with vivid excerpts from citations, on the monumental work of Poincaré on this subject, from the famous (King Oscar’s) 1889 memoir to the foundations of the modern theory of chaos in “Les méthodes nouvelles de la mécanique céleste.” A profoundly original and scholarly presentation of the work by Poincaré on probability theory is given by Laurent Mazliak in “Poincaré’s Odds,” from the incidental first appearance of the word “probability” in Poincaré’s famous 1890 theorem of recurrence for dynamical systems, to his later acceptance of the unavoidability of probability calculus in Science, as developed to a great extent by Emile Borel, Poincaré’s main direct disciple; the article by Francois Béguin, “Henri Poincaré and the Uniformization of Riemann Surfaces,” takes us on a fascinating journey through the six successive versions in twenty-six years of the celebrated uniformization theorem, which exemplifies the Master’s distinctive signature in the foundational fusion of mathematics and physics, on which conformal field theory, string theory and quantum gravity so much depend nowadays; the final chapter, “Harmony and Chaos, On the Figure of Henri Poincaré” by the filmmaker Philippe Worms, describes the homonymous poetical film in which eminent scientists, through mathematical scenes and physical experiments, display their emotional relationship to the often elusive scientific truth and universal “harmony and chaos” in Poincaré’s legacy. This book will be of broad general interest to physicists, mathematicians, philosophers of science and historians.
Henri Poincaré, 1912–2012
Author: Bertrand Duplantier
Publisher: Springer
ISBN: 3034808348
Category : Mathematics
Languages : en
Pages : 246
Book Description
This thirteenth volume of the Poincaré Seminar Series, Henri Poincaré, 1912-2012, is published on the occasion of the centennial of the death of Henri Poincaré in 1912. It presents a scholarly approach to Poincaré’s genius and creativity in mathematical physics and mathematics. Its five articles are also highly pedagogical, as befits their origin in lectures to a broad scientific audience. Highlights include “Poincaré’s Light” by Olivier Darrigol, a leading historian of science, who uses light as a guiding thread through much of Poincaré ’s physics and philosophy, from the application of his superior mathematical skills and the theory of diffraction to his subsequent reflections on the foundations of electromagnetism and the electrodynamics of moving bodies; the authoritative “Poincaré and the Three-Body Problem” by Alain Chenciner, who offers an exquisitely detailed, hundred-page perspective, peppered with vivid excerpts from citations, on the monumental work of Poincaré on this subject, from the famous (King Oscar’s) 1889 memoir to the foundations of the modern theory of chaos in “Les méthodes nouvelles de la mécanique céleste.” A profoundly original and scholarly presentation of the work by Poincaré on probability theory is given by Laurent Mazliak in “Poincaré’s Odds,” from the incidental first appearance of the word “probability” in Poincaré’s famous 1890 theorem of recurrence for dynamical systems, to his later acceptance of the unavoidability of probability calculus in Science, as developed to a great extent by Emile Borel, Poincaré’s main direct disciple; the article by Francois Béguin, “Henri Poincaré and the Uniformization of Riemann Surfaces,” takes us on a fascinating journey through the six successive versions in twenty-six years of the celebrated uniformization theorem, which exemplifies the Master’s distinctive signature in the foundational fusion of mathematics and physics, on which conformal field theory, string theory and quantum gravity so much depend nowadays; the final chapter, “Harmony and Chaos, On the Figure of Henri Poincaré” by the filmmaker Philippe Worms, describes the homonymous poetical film in which eminent scientists, through mathematical scenes and physical experiments, display their emotional relationship to the often elusive scientific truth and universal “harmony and chaos” in Poincaré’s legacy. This book will be of broad general interest to physicists, mathematicians, philosophers of science and historians.
Publisher: Springer
ISBN: 3034808348
Category : Mathematics
Languages : en
Pages : 246
Book Description
This thirteenth volume of the Poincaré Seminar Series, Henri Poincaré, 1912-2012, is published on the occasion of the centennial of the death of Henri Poincaré in 1912. It presents a scholarly approach to Poincaré’s genius and creativity in mathematical physics and mathematics. Its five articles are also highly pedagogical, as befits their origin in lectures to a broad scientific audience. Highlights include “Poincaré’s Light” by Olivier Darrigol, a leading historian of science, who uses light as a guiding thread through much of Poincaré ’s physics and philosophy, from the application of his superior mathematical skills and the theory of diffraction to his subsequent reflections on the foundations of electromagnetism and the electrodynamics of moving bodies; the authoritative “Poincaré and the Three-Body Problem” by Alain Chenciner, who offers an exquisitely detailed, hundred-page perspective, peppered with vivid excerpts from citations, on the monumental work of Poincaré on this subject, from the famous (King Oscar’s) 1889 memoir to the foundations of the modern theory of chaos in “Les méthodes nouvelles de la mécanique céleste.” A profoundly original and scholarly presentation of the work by Poincaré on probability theory is given by Laurent Mazliak in “Poincaré’s Odds,” from the incidental first appearance of the word “probability” in Poincaré’s famous 1890 theorem of recurrence for dynamical systems, to his later acceptance of the unavoidability of probability calculus in Science, as developed to a great extent by Emile Borel, Poincaré’s main direct disciple; the article by Francois Béguin, “Henri Poincaré and the Uniformization of Riemann Surfaces,” takes us on a fascinating journey through the six successive versions in twenty-six years of the celebrated uniformization theorem, which exemplifies the Master’s distinctive signature in the foundational fusion of mathematics and physics, on which conformal field theory, string theory and quantum gravity so much depend nowadays; the final chapter, “Harmony and Chaos, On the Figure of Henri Poincaré” by the filmmaker Philippe Worms, describes the homonymous poetical film in which eminent scientists, through mathematical scenes and physical experiments, display their emotional relationship to the often elusive scientific truth and universal “harmony and chaos” in Poincaré’s legacy. This book will be of broad general interest to physicists, mathematicians, philosophers of science and historians.
Henri Poincaré
Author: Ferdinand Verhulst
Publisher: Springer Science & Business Media
ISBN: 1461424070
Category : Mathematics
Languages : en
Pages : 266
Book Description
The book describes the life of Henri Poincaré, his work style and in detail most of his unique achievements in mathematics and physics. Apart from biographical details, attention is given to Poincaré's contributions to automorphic functions, differential equations and dynamical systems, celestial mechanics, mathematical physics in particular the theory of the electron and relativity, topology (analysis situs). A chapter on philosophy explains Poincaré's conventionalism in mathematics and his view of conventionalism in physics; the latter has a very different character. In the foundations of mathematics his position is between intuitionism and axiomatics. One of the purposes of the book is to show how Poincaré reached his fundamentally new results in many different fields, how he thought and how one should read him. One of the new aspects is the description of two large fields of his attention: dynamical systems as presented in his book on `new methods for celestial mechanics' and his theoretical physics papers. At the same time it will be made clear how analysis and geometry are intertwined in Poincaré's thinking and work.In dynamical systems this becomes clear in his description of invariant manifolds, his association of differential equation flow with mappings and his fixed points theory. There is no comparable book on Poincaré, presenting such a relatively complete vision of his life and achievements. There exist some older biographies in the French language, but they pay only restricted attention to his actual work. The reader can obtain from this book many insights in the working of a very original mind while at the same time learning about fundamental results for modern science
Publisher: Springer Science & Business Media
ISBN: 1461424070
Category : Mathematics
Languages : en
Pages : 266
Book Description
The book describes the life of Henri Poincaré, his work style and in detail most of his unique achievements in mathematics and physics. Apart from biographical details, attention is given to Poincaré's contributions to automorphic functions, differential equations and dynamical systems, celestial mechanics, mathematical physics in particular the theory of the electron and relativity, topology (analysis situs). A chapter on philosophy explains Poincaré's conventionalism in mathematics and his view of conventionalism in physics; the latter has a very different character. In the foundations of mathematics his position is between intuitionism and axiomatics. One of the purposes of the book is to show how Poincaré reached his fundamentally new results in many different fields, how he thought and how one should read him. One of the new aspects is the description of two large fields of his attention: dynamical systems as presented in his book on `new methods for celestial mechanics' and his theoretical physics papers. At the same time it will be made clear how analysis and geometry are intertwined in Poincaré's thinking and work.In dynamical systems this becomes clear in his description of invariant manifolds, his association of differential equation flow with mappings and his fixed points theory. There is no comparable book on Poincaré, presenting such a relatively complete vision of his life and achievements. There exist some older biographies in the French language, but they pay only restricted attention to his actual work. The reader can obtain from this book many insights in the working of a very original mind while at the same time learning about fundamental results for modern science
Henri Poincaré
Author: Jeremy Gray
Publisher: Princeton University Press
ISBN: 0691152713
Category : Biography & Autobiography
Languages : en
Pages : 608
Book Description
A comprehensive look at the mathematics, physics, and philosophy of Henri Poincaré Henri Poincaré (1854–1912) was not just one of the most inventive, versatile, and productive mathematicians of all time—he was also a leading physicist who almost won a Nobel Prize for physics and a prominent philosopher of science whose fresh and surprising essays are still in print a century later. The first in-depth and comprehensive look at his many accomplishments, Henri Poincaré explores all the fields that Poincaré touched, the debates sparked by his original investigations, and how his discoveries still contribute to society today. Math historian Jeremy Gray shows that Poincaré's influence was wide-ranging and permanent. His novel interpretation of non-Euclidean geometry challenged contemporary ideas about space, stirred heated discussion, and led to flourishing research. His work in topology began the modern study of the subject, recently highlighted by the successful resolution of the famous Poincaré conjecture. And Poincaré's reformulation of celestial mechanics and discovery of chaotic motion started the modern theory of dynamical systems. In physics, his insights on the Lorentz group preceded Einstein's, and he was the first to indicate that space and time might be fundamentally atomic. Poincaré the public intellectual did not shy away from scientific controversy, and he defended mathematics against the attacks of logicians such as Bertrand Russell, opposed the views of Catholic apologists, and served as an expert witness in probability for the notorious Dreyfus case that polarized France. Richly informed by letters and documents, Henri Poincaré demonstrates how one man's work revolutionized math, science, and the greater world.
Publisher: Princeton University Press
ISBN: 0691152713
Category : Biography & Autobiography
Languages : en
Pages : 608
Book Description
A comprehensive look at the mathematics, physics, and philosophy of Henri Poincaré Henri Poincaré (1854–1912) was not just one of the most inventive, versatile, and productive mathematicians of all time—he was also a leading physicist who almost won a Nobel Prize for physics and a prominent philosopher of science whose fresh and surprising essays are still in print a century later. The first in-depth and comprehensive look at his many accomplishments, Henri Poincaré explores all the fields that Poincaré touched, the debates sparked by his original investigations, and how his discoveries still contribute to society today. Math historian Jeremy Gray shows that Poincaré's influence was wide-ranging and permanent. His novel interpretation of non-Euclidean geometry challenged contemporary ideas about space, stirred heated discussion, and led to flourishing research. His work in topology began the modern study of the subject, recently highlighted by the successful resolution of the famous Poincaré conjecture. And Poincaré's reformulation of celestial mechanics and discovery of chaotic motion started the modern theory of dynamical systems. In physics, his insights on the Lorentz group preceded Einstein's, and he was the first to indicate that space and time might be fundamentally atomic. Poincaré the public intellectual did not shy away from scientific controversy, and he defended mathematics against the attacks of logicians such as Bertrand Russell, opposed the views of Catholic apologists, and served as an expert witness in probability for the notorious Dreyfus case that polarized France. Richly informed by letters and documents, Henri Poincaré demonstrates how one man's work revolutionized math, science, and the greater world.
The Scientific Legacy of Poincare
Author: Éric Charpentier
Publisher: American Mathematical Soc.
ISBN: 082184718X
Category : Biography & Autobiography
Languages : en
Pages : 410
Book Description
Henri Poincare (1854-1912) was one of the greatest scientists of his time, perhaps the last one to have mastered and expanded almost all areas in mathematics and theoretical physics. In this book, twenty world experts present one part of Poincare's extraordinary work. Each chapter treats one theme, presenting Poincare's approach, and achievements.
Publisher: American Mathematical Soc.
ISBN: 082184718X
Category : Biography & Autobiography
Languages : en
Pages : 410
Book Description
Henri Poincare (1854-1912) was one of the greatest scientists of his time, perhaps the last one to have mastered and expanded almost all areas in mathematics and theoretical physics. In this book, twenty world experts present one part of Poincare's extraordinary work. Each chapter treats one theme, presenting Poincare's approach, and achievements.
Gustav Robert Kirchhoff's Treatise "On The Theory Of Light Rays" (1882): English Translation, Analysis And Commentary
Author: Klaus Hentschel
Publisher: World Scientific
ISBN: 9813147164
Category : Science
Languages : en
Pages : 166
Book Description
'Although the editors admit that they cannot present an unequivocal explanation for the strange resilience of Kirchhoff’s flawed theory, their book is an admirable effort to meet this challenge … It is a concerted effort to resolve a persistent riddle in the history of physics — and an example of how expert knowledge from different specialties may be focused on a target of common interest.'ISIS JournalThe 1882 paper by the mathematical physicist Gustav Robert Kirchhoff on diffraction theory is still being discussed to this day, but has never been translated into English. This volume contains the first English translation of the Kirchhoff treatise, as well as background and commentary on it. Included are a biographical introduction to Kirchhoff's life, an analysis of the reception to Kirchhoff's paper through the ages, a discussion on why Kirchhoff's theory manages to produce accurate predictions in spite of being 'wrong', and views on the theory as well as its predecessor and subsequent developments. This anthology will make all English-speaking scientists, engineers, historians, and interested laymen aware of the great fecundity of Kirchhoff's thought and historical context.
Publisher: World Scientific
ISBN: 9813147164
Category : Science
Languages : en
Pages : 166
Book Description
'Although the editors admit that they cannot present an unequivocal explanation for the strange resilience of Kirchhoff’s flawed theory, their book is an admirable effort to meet this challenge … It is a concerted effort to resolve a persistent riddle in the history of physics — and an example of how expert knowledge from different specialties may be focused on a target of common interest.'ISIS JournalThe 1882 paper by the mathematical physicist Gustav Robert Kirchhoff on diffraction theory is still being discussed to this day, but has never been translated into English. This volume contains the first English translation of the Kirchhoff treatise, as well as background and commentary on it. Included are a biographical introduction to Kirchhoff's life, an analysis of the reception to Kirchhoff's paper through the ages, a discussion on why Kirchhoff's theory manages to produce accurate predictions in spite of being 'wrong', and views on the theory as well as its predecessor and subsequent developments. This anthology will make all English-speaking scientists, engineers, historians, and interested laymen aware of the great fecundity of Kirchhoff's thought and historical context.
Ether and Modernity
Author: Jaume Navarro
Publisher: Oxford University Press
ISBN: 0192517791
Category : Science
Languages : en
Pages : 263
Book Description
Ether and Modernity offers a snapshot of the status of an epistemic object, the "ether" (or "aether"), in the early twentieth century. The contributed papers show that the ether was often regarded as one of the objects of modernity, hand in hand with the electron, radioactivity or X-rays, and not simply as the stubborn residue of an old-fashioned, long-discarded science. The prestige and authority of scientists and popularisers like Oliver Lodge and Arthur Eddington in Britain, Phillip Lenard in Germany or Dayton C. Miller in the USA was instrumental in the preservation, defence or even re-emergence of the ether in the 1920s. Moreover, the consolidation of wireless communications and radio broadcasting, indeed a very modern technology, brought the ether into audiences that would otherwise never have heard about such an esoteric entity. The ether also played a pivotal role among some artists in the early twentieth century: the values of modernism found in the complexities and contradictions of modern physics, such as wireless action or wave-particle puzzles, a fertile ground for the development of new artistic languages; in literature as much as in the pictorial and performing arts. Essays on the intellectual foundations of Umberto Boccioni's art, the linguistic techniques of Lodge, and Ernst Mach's considerations on aesthetics and physics witness to the imbricate relationship between the ether and modernism. Last but not least, the ether played a fundamental part in the resurgence of modern spiritualism in the aftermath of the Great War. This book examines the complex array of meanings, strategies and milieus that enabled the ether to remain an active part in scientific and cultural debates well into the 1930s, but not beyond. This portrait may be easily regarded as the swan song of an epistemic object that was soon to fade away as shown by Paul Dirac's unsuccessful attempt to resuscitate some kind of aether in 1951, with which this book finishes.
Publisher: Oxford University Press
ISBN: 0192517791
Category : Science
Languages : en
Pages : 263
Book Description
Ether and Modernity offers a snapshot of the status of an epistemic object, the "ether" (or "aether"), in the early twentieth century. The contributed papers show that the ether was often regarded as one of the objects of modernity, hand in hand with the electron, radioactivity or X-rays, and not simply as the stubborn residue of an old-fashioned, long-discarded science. The prestige and authority of scientists and popularisers like Oliver Lodge and Arthur Eddington in Britain, Phillip Lenard in Germany or Dayton C. Miller in the USA was instrumental in the preservation, defence or even re-emergence of the ether in the 1920s. Moreover, the consolidation of wireless communications and radio broadcasting, indeed a very modern technology, brought the ether into audiences that would otherwise never have heard about such an esoteric entity. The ether also played a pivotal role among some artists in the early twentieth century: the values of modernism found in the complexities and contradictions of modern physics, such as wireless action or wave-particle puzzles, a fertile ground for the development of new artistic languages; in literature as much as in the pictorial and performing arts. Essays on the intellectual foundations of Umberto Boccioni's art, the linguistic techniques of Lodge, and Ernst Mach's considerations on aesthetics and physics witness to the imbricate relationship between the ether and modernism. Last but not least, the ether played a fundamental part in the resurgence of modern spiritualism in the aftermath of the Great War. This book examines the complex array of meanings, strategies and milieus that enabled the ether to remain an active part in scientific and cultural debates well into the 1930s, but not beyond. This portrait may be easily regarded as the swan song of an epistemic object that was soon to fade away as shown by Paul Dirac's unsuccessful attempt to resuscitate some kind of aether in 1951, with which this book finishes.
Symplectic Geometry
Author: Helmut Hofer
Publisher: Springer Nature
ISBN: 3031191110
Category : Mathematics
Languages : en
Pages : 1158
Book Description
Over the course of his distinguished career, Claude Viterbo has made a number of groundbreaking contributions in the development of symplectic geometry/topology and Hamiltonian dynamics. The chapters in this volume – compiled on the occasion of his 60th birthday – are written by distinguished mathematicians and pay tribute to his many significant and lasting achievements.
Publisher: Springer Nature
ISBN: 3031191110
Category : Mathematics
Languages : en
Pages : 1158
Book Description
Over the course of his distinguished career, Claude Viterbo has made a number of groundbreaking contributions in the development of symplectic geometry/topology and Hamiltonian dynamics. The chapters in this volume – compiled on the occasion of his 60th birthday – are written by distinguished mathematicians and pay tribute to his many significant and lasting achievements.
Einstein, Picasso
Author: Arthur I Miller
Publisher: Basic Books
ISBN: 0786723130
Category : Science
Languages : en
Pages : 370
Book Description
The most important scientist of the twentieth century and the most important artist had their periods of greatest creativity almost simultaneously and in remarkably similar circumstances. This fascinating parallel biography of Albert Einstein and Pablo Picasso as young men examines their greatest creations -- Picasso's Les Demoiselles d'Avignon and Einstein's special theory of relativity. Miller shows how these breakthroughs arose not only from within their respective fields but from larger currents in the intellectual culture of the times. Ultimately, Miller shows how Einstein and Picasso, in a deep and important sense, were both working on the same problem.
Publisher: Basic Books
ISBN: 0786723130
Category : Science
Languages : en
Pages : 370
Book Description
The most important scientist of the twentieth century and the most important artist had their periods of greatest creativity almost simultaneously and in remarkably similar circumstances. This fascinating parallel biography of Albert Einstein and Pablo Picasso as young men examines their greatest creations -- Picasso's Les Demoiselles d'Avignon and Einstein's special theory of relativity. Miller shows how these breakthroughs arose not only from within their respective fields but from larger currents in the intellectual culture of the times. Ultimately, Miller shows how Einstein and Picasso, in a deep and important sense, were both working on the same problem.
George Gabriel Stokes
Author: Mark McCartney
Publisher: Oxford University Press
ISBN: 0192555707
Category : Science
Languages : en
Pages : 264
Book Description
George Gabriel Stokes was one of the most important mathematical physicists of the 19th century. During his lifetime he made a wide range of contributions, notably in continuum mechanics, optics and mathematical analysis. His name is known to generations of scientists and engineers through the various physical laws and mathematical formulae named after him, such as the Navier-Stokes equations in fluid dynamics. Born in Ireland into a family of academics, clergymen and physicians, he became the longest serving Lucasian Professor of Mathematics at Cambridge. Impressive as his own scientific achievements were, he made an equally important contribution as a sounding board for his contemporaries, providing good judgement and mathematical rigour in his wide correspondence and during his 31 years as Secretary of the Royal Society where he played a major role in the direction of British science. Outside his own area he was a distinguished public servant and MP for Cambridge University. He was keenly interested in the relation between science and religion and wrote at length on their interaction. Stokes was a remarkable scientist who lived in an equally remarkable age of discovery and innovation. This edited collection of essays brings together experts in mathematics, physics and the history of science to cover the many facets of Stokes's life in a scholarly but accessible way to mark the bicentenary of his birth.
Publisher: Oxford University Press
ISBN: 0192555707
Category : Science
Languages : en
Pages : 264
Book Description
George Gabriel Stokes was one of the most important mathematical physicists of the 19th century. During his lifetime he made a wide range of contributions, notably in continuum mechanics, optics and mathematical analysis. His name is known to generations of scientists and engineers through the various physical laws and mathematical formulae named after him, such as the Navier-Stokes equations in fluid dynamics. Born in Ireland into a family of academics, clergymen and physicians, he became the longest serving Lucasian Professor of Mathematics at Cambridge. Impressive as his own scientific achievements were, he made an equally important contribution as a sounding board for his contemporaries, providing good judgement and mathematical rigour in his wide correspondence and during his 31 years as Secretary of the Royal Society where he played a major role in the direction of British science. Outside his own area he was a distinguished public servant and MP for Cambridge University. He was keenly interested in the relation between science and religion and wrote at length on their interaction. Stokes was a remarkable scientist who lived in an equally remarkable age of discovery and innovation. This edited collection of essays brings together experts in mathematics, physics and the history of science to cover the many facets of Stokes's life in a scholarly but accessible way to mark the bicentenary of his birth.
Last Thoughts
Author: Henri Poincaré
Publisher: MultiMedia Publishing
ISBN: 6060332919
Category : Science
Languages : en
Pages : 99
Book Description
Henri Poincaré is a mathematician, physicist, philosopher and engineer, born April 29, 1854 in Nancy and died July 17, 1912 in Paris. He has carried out works of major importance in optics and in infinitesimal calculus. His advances on the problem of the three bodies make him a founder of the qualitative study of systems of differential equations and chaos theory; he is also a major precursor of the theory of special relativity and the theory of dynamical systems. Henri Poincaré is considered one of the last great universal scholars, mastering all branches of mathematics of his time and some branches of physics. This book gathers here various articles and lectures that Henri Poincaré himself intended to form the fourth volume of his works of philosophy of science. All the previous ones had already appeared in this collection. It would be useless to recall their prodigious success. The most illustrious of modern mathematicians has been an eminent philosopher, one of those whose books profoundly influence human thought. It is probable that if Henri Poincaré himself had published this volume, he would have modified certain details, removed some repetitions. But it seemed to us that the respect due to the memory of this great death forbade any editing of his text.
Publisher: MultiMedia Publishing
ISBN: 6060332919
Category : Science
Languages : en
Pages : 99
Book Description
Henri Poincaré is a mathematician, physicist, philosopher and engineer, born April 29, 1854 in Nancy and died July 17, 1912 in Paris. He has carried out works of major importance in optics and in infinitesimal calculus. His advances on the problem of the three bodies make him a founder of the qualitative study of systems of differential equations and chaos theory; he is also a major precursor of the theory of special relativity and the theory of dynamical systems. Henri Poincaré is considered one of the last great universal scholars, mastering all branches of mathematics of his time and some branches of physics. This book gathers here various articles and lectures that Henri Poincaré himself intended to form the fourth volume of his works of philosophy of science. All the previous ones had already appeared in this collection. It would be useless to recall their prodigious success. The most illustrious of modern mathematicians has been an eminent philosopher, one of those whose books profoundly influence human thought. It is probable that if Henri Poincaré himself had published this volume, he would have modified certain details, removed some repetitions. But it seemed to us that the respect due to the memory of this great death forbade any editing of his text.