Pierre Simon Laplace is a scientist and a man. School encyclopedia

P. Laplace was born in the north of France into a peasant family. The boy's outstanding abilities prompted wealthy neighbors to help him graduate from the school of the Benedictine Order. It is difficult to say what knowledge P. Laplace took away from the institution of the Holy Fathers. But there is no doubt that it was after school that he became a convinced atheist. At the age of 17 he becomes a teacher high school in his hometown of Beaumont and writes several mathematical articles.

Then, having secured letter of recommendation, goes to Paris to J. d’Alembert. However, the famous mathematician was skeptical about provincial patronage. Then P. Laplace writes a work on the fundamentals of mechanics in a few days and sends it to J. d’Alembert again. Justice has prevailed; and soon the young ambitious man finds himself accepted into the teaching staff of the Paris High School.

Having barely established himself, P. Laplace wrote one after another and sent his works to the Paris Academy of Sciences. Rare persistence combined with a certain mathematical talent led to the fact that at the age of 24 he became an adjunct, and at the age of 36 - a full member of the academy.

P. Laplace, like no one else, knew how to highlight the main thing in the problem under consideration; was able to present complex natural phenomena in mathematical form, formulate the conditions of the problem and select an original method for solving it.

It is difficult to list the works of P. Laplace - there are so many of them, and they are so diverse. However, despite basic research in mathematics and physics, the bulk of his work relates to astronomy.

P. Laplace proved the stability of the structure of the solar system, that is, the constancy of orbits and the invariability of the average distances of the planets from the Sun. Discovered the causes of periodic inequalities in the motion of Jupiter and Saturn and solved another one for this special case the famous "three body problem". Considering the theory of the motion of Jupiter's satellites, he derived the laws that received his name and significantly supplemented the lunar theory. We can say that P. Laplace actually completed it, giving a complete theoretical calculation of the movement of the Moon. Of course, he finished in the sense and at the level that the state of his contemporary science allowed.

As a result of his astronomical works, one should name the five-volume “Treatise on Celestial Mechanics”, in which in a sequential presentation he combined the works of I. Newton, L. Euler, J. d'Alembert and A. Clairaut and in which P. Laplace himself gives a complete mathematical explanation of the movement of solar system bodies.

“At the end of the last century,” he writes in the preface to the first volume, “I. Newton published his discovery of universal gravitation. Since then, mathematicians have managed to reduce all known phenomena of the universe to this great law of nature and thus achieve unexpected accuracy in astronomical theories and tables. My goal is to present from a single point of view the theories scattered throughout various works, combining together all the results on the equilibrium and motion of solid and liquid bodies from which our solar system and similar systems spread out in the vastness of the universe are built, and to build in this way through celestial mechanics."

This treatise became a classic during P. Laplace’s lifetime. To this day, many of the ideas of this excellent work form the basis of theoretical astronomy, and the method of presentation serves as a model for the approach to solving theoretical problems. They say his last words before his death were: “How insignificant is what we know compared to the boundless area of ​​the unknown.” P. Laplace, of course, was an outstanding scientist, a great scientist, a great mathematician.

What a pity that an assessment of his personality and human dignity cannot be made in the same words. P. Laplace had a very unpleasant character. Extremely vain, arrogant and rude towards people below him on the social ladder and towards his colleagues, he could not stand the delicate J. Lagrange and quarreled with A. Lavoisier. Perhaps the only person in the academy whom he treated more or less decently was J. d’Alembert.

P. Laplace supported the republic, extolling freedom, equality and fraternity. But when Napoleon became first consul, the astute mathematician begged him for the position of home secretary. Dismissed after six weeks for his inability to do this work, he was, as a consolation, appointed a member of the Senate. P. Laplace dedicated the third volume of his “Celestial Mechanics” to the “Heroic Pacificator of Europe”, having achieved the title of count from Emperor Napoleon. But a few years later he voted for the deposition of his idol and joyfully welcomed the restoration of Louis XVIII. Ready to admit and deny anything for the sake of another order, he later received the title of Marquis and the peerage of France from the king.

What we know is so insignificant compared to what we don't know.

Pierre Simon Laplace

Pierre Simon Laplace (23 March 1749 - 5 March 1827) - an outstanding French mathematician, physicist and astronomer; known for his work in the field of celestial mechanics, differential equations, one of the creators of probability theory. Laplace's merits in the field of pure and applied mathematics and especially in astronomy are enormous: he improved almost all departments of these sciences.

Pierre Simon Laplace was born in the town of Beaumont-en-Auge, in the Norman department of Calvados, into the family of a poor peasant. Subsequently, the Count and Marquis Laplace was ashamed of his humble origins, so about his childhood and youth very little is known. Pierre showed his outstanding abilities early, brilliantly graduated from the Benedictine school and was left there, in Beaumont, as a mathematics teacher at a military school. At the age of seventeen he wrote his first scientific work. The memoir “Sur le calcul intégral aux différences infiniment petites et aux différences finies” (1766) that he sent to Turin and published there attracted the attention of scientists, and Laplace was invited to Paris.

Life in provincial Beaumont weighed heavily on Laplace, and in 1766 he went to Paris. There, with the help of D'Alembert, he received a position as a mathematics teacher at the Military School of Paris.

In 1772, Laplace attempted to enter the Paris Academy of Sciences, but failed in the elections. D’Alembert tried to get his protégé into the Berlin Academy and wrote a letter to its president Lagrange: “This young man is eager to study mathematics, and I think he has enough talent to excel in this field.” But Lagrange politely refused. He replied that the conditions at the Berlin Academy of Sciences are bad, and he does not advise entering it.

At the beginning scientific career Laplace immediately began the assault " main problem celestial mechanics": study of stability solar system.

Some irregularities were observed in the movement of the Moon and planets. They could mean that the planet is moving further and further away from the Sun. Back in 1695, Halley discovered that over the course of several centuries Jupiter gradually accelerates and approaches the Sun, while Saturn, on the contrary, slows down and moves away from the Sun. Some scientists believed that Jupiter would eventually fall into the Sun.

In 1773, masterfully using mathematical analysis, Laplace proved that the irregularities observed in the velocities of Jupiter and Saturn are periodic in nature, therefore the motion of these two planets is stable. Even Newton and Euler were not sure about this.

In 1773, Laplace became an adjunct of the Paris Academy.

In 1778, Laplace married Charlotte de Courty - beautiful woman with a good character and was happy in his personal life. The wife loved her husband, worshiped him and did everything to protect him from household worries and worries, so that he could devote all his time to science. Family life Laplace, according to the recollections of contemporaries, flowed smoothly and pleasantly. He had a daughter and a son - later General Laplace.

In 1785, Laplace became a full member of the Paris Academy of Sciences. In the same year, during one of the exams, Laplace highly evaluates the knowledge of the 17-year-old applicant Bonaparte. Subsequently, their relationship was invariably warm.

In 1779 - 1784, Laplace, together with Lavoisier, studied physical issues, in particular, the heat of fusion of bodies. The Great French Revolution interrupted Laplace's work in this area.

After the popular uprising of 1793, a Jacobin dictatorship was established in France. Soon the revolution began to decline. On August 8, 1793, by decree of the Convention, the Academy of Sciences, among all other royal institutions, was abolished, and Laplace was dismissed from the Commission on Weights and Measures due to “insufficient republican virtues and too weak hatred of kings.”

In 1794, the Convention created the Normal School, designed to train teachers, and the Central School of Public Works, which was later renamed the Polytechnic School. Laplace was a professor in both of these schools. An outstanding institution of higher education was the Polytechnic School, about which contemporaries said that it was “an institution without a rival and without a model, an institution that is the envy of all of Europe, the first school in the world.” In addition to Laplace, such famous scientists as Monge, Lagrange, and Carnot taught there.

In 1795, instead of the abolished Academy of Sciences, the Convention created National Institute sciences and arts. Laplace becomes a member of the Institute and heads the Bureau of Longitudes, which was engaged in measuring the length of the earth's meridian.

At all stages of the turbulent political life of the then France, Laplace never came into conflict with the authorities, who almost invariably showered him with honors. Laplace's common origin not only protected him from the repressions of the revolution, but also allowed him to occupy high positions.

The day after the coup of the 18th Brumaire, Napoleon, who came to power, appointed Laplace Minister of the Interior. The scientist held this post for only six months and was replaced by Napoleon's brother Lucien Bonaparte. In order not to offend the scientist, Bonaparte appointed Laplace a member of the Senate and sent him a polite letter.

In 1803, Napoleon made Laplace vice-president of the Senate, and a month later - chancellor. In 1804, the scientist received the Order of the Legion of Honor.

From 1801 to 1809, Laplace was elected a member of the royal societies in Turin and Copenhagen, and the academies of sciences in Göttingen, Berlin and Holland. On October 13, 1802, Laplace became an honorary member of the St. Petersburg Academy of Sciences.

Napoleon, who very correctly judged people, wrote about Laplace on the island of St. Helena in his memoirs: “The great astronomer sinned by considering life from the point of view of infinitesimals.” Indeed, everything that did not relate to science was infinitesimal for Laplace. Strict and demanding of himself when it came to science, in everyday life Laplace sometimes acted well, sometimes badly, depending on the circumstances, neglecting all this as infinitesimal, in the name of the main cause of his life - scientific creativity. For the sake of science, he even changed his beliefs. Apparently, it is worth treating some moments in Laplace’s life as infinitesimal in comparison with the great and significant that the scientist created in science.

Laplace devoted his entire life to astronomy, and, no matter what area of ​​mathematics he studied, he was primarily interested in the application of the results obtained to astronomy. They say that in his manuscripts Laplace often omitted the difficult stages of the proof, replacing them with a brief remark: “It is not difficult to see that...” One thing is beyond doubt - Laplace really had no time for detailing the proofs, he was in a hurry to move on to astronomical applications. Numerous fundamental results obtained by Laplace in mathematics were nothing more than by-products of his titanic work in the field of natural science. For Laplace, mathematics was a language and a means of understanding and describing the natural world. Laplace famously said:

State of the Universe in this moment can be seen as the result of its past and as the cause of its future. An intelligent being who at any moment would know all the driving forces of nature and mutual arrangement of the creatures that form it, could - if his mind were broad enough to analyze all this data - express in one equation the movement and most large bodies in the Universe, and the smallest atoms.

Scientific achievements of the 18th century were collected and embodied by Laplace in one of his masterpieces scientific literature- five-volume “Celestial Mechanics”, published in 1799-1825.

Raised in the spirit of Catholicism, Laplace was an agnostic and resolutely rejected the idea of ​​God as the creator of the mathematical plan of the Universe. The following story is told:

When Laplace presented Napoleon with a copy of his “Celestial Mechanics” as a gift, he remarked: “Monsieur Laplace, they say you wrote this thick book about the system of the world without mentioning the creator in a single word.” To which Laplace allegedly replied: “I didn’t need this hypothesis.”

Ironically, Laplace, who firmly believed that natural phenomena are strictly determined in accordance with mathematical laws, becomes one of the fathers of statistical and probabilistic methods in mathematics. The reasons causing this or that phenomenon, Laplace believed, are not always known, and observations have limited accuracy. To determine the most likely causes and the most likely results, the theory of probability should be used. In 1812, the grandiose “Analytical Theory of Probability” was published, in which Laplace also summarized all his and others’ results. Laplace's "Analytic Theory of Probability" was published three times during the author's lifetime (1812, 1814, 1820), and is rightfully considered a classic work on this branch of mathematics.

When solving applied problems, Laplace developed methods of mathematical physics that are widely used in our time. Particularly important results relate to potential theory and special functions. He introduced spherical functions into mathematics, which are used to find a general solution to Laplace's equation and to solve problems of mathematical physics for areas limited by spherical surfaces. He advanced linear algebra far; in particular, Laplace gave an expansion of the determinant in minors. Laplace expanded and systematized the mathematical foundation of probability theory and introduced generating functions. Despite the fact that before Laplace, the theory of probability was studied, in particular, by Fermat and Bernoulli, it was Laplace who was largely the author of the mathematical theory of probability, and he was responsible for improving the methods of proof. The first book of "Analytic Theory of Probability" is devoted to mathematical foundations; the theory of probability itself begins in the second book, in application to discrete random variables. There is also a proof of the limit theorems of Moivre-Laplace and applications to the mathematical processing of observations, population statistics and the “moral sciences”. Laplace also developed the theory of errors and approximations by the method least squares.

A number of outstanding achievements belong to Laplace in astronomy, in addition to the already mentioned proof of the stability of the Solar system. Laplace proposed the first mathematically substantiated cosmogonic hypothesis for the formation of all bodies in the Solar System, called after him: the Laplace hypothesis.

According to Laplace's hypothesis, the solar system formed from a primordial nebula, consisting of hot gas and extending far beyond the orbit of the most distant planet. The rotational motion of the cooling and contracting nebula caused its flattening. In the process of this flattening, a centrifugal force arose, under the influence of which rings of gaseous matter were separated from the nebula along its edge, which then gathered into lumps and gave rise to planets and their satellites.

His hypothesis was generally accepted in science for a century. Over time, it came into conflict with the newly discovered patterns in the solar system and was abandoned.

Laplace was the first to suggest that some nebulae observed in the sky are in fact galaxies similar to our Milky Way.

Laplace advanced perturbation theory far and convincingly showed: all deviations of the positions of the planets from those predicted by Newton’s laws (more precisely, predicted by the solution of the two-body problem) are explained by the mutual influence of the planets, which can be taken into account using the same Newton’s laws. Before Laplace's discoveries, many scientists tried to explain the deviations of the theory from observations by the movement of the ether, the final speed of gravity and other non-Newtonian factors; Laplace buried such attempts for a long time. He, as Clairaut had earlier, proclaimed: in celestial mechanics there are no forces other than Newtonian ones, and he substantiated this thesis with arguments.

Laplace discovered that the acceleration in the movement of the Moon, which perplexed all astronomers (secular inequality), is also a periodic change in the eccentricity of the lunar orbit, and it arises under the influence of gravity major planets. The displacement of the Moon calculated by him under the influence of these factors was in good agreement with observations.

Using inequalities in the motion of the Moon, Laplace clarified the compression of the Earth's spheroid. In general, the studies carried out by Laplace on the movement of our satellite made it possible to compile more accurate tables of the Moon, which, in turn, contributed to solving the navigation problem of determining longitude at sea.

Laplace was the first to construct an accurate theory of the motion of the Galilean satellites of Jupiter, the orbits of which, due to mutual influence, constantly deviate from Keplerian ones. He also discovered a relationship between the parameters of their orbits, expressed by two laws called “Lapplace’s laws.”

Having calculated the equilibrium conditions for Saturn's ring, Laplace proved that they are possible only when the planet rotates rapidly about its axis, and this was indeed proven later by the observations of William Herschel. Laplace concluded that Saturn's ring could not be continuous, otherwise it would be unstable; predicted the compression of Saturn at the poles.

Laplace developed the theory of tides using twenty years of observations of sea level in Brest.

In physics, Laplace is responsible for the barometric formula that relates air density, altitude, humidity, and the acceleration of gravity. Laplace published a number of works on the theory of capillarity and established a law for capillary pressure. In 1809, Laplace dealt with problems of acoustics; he derived a formula for the speed of sound in air.

Undoubtedly, Laplace was a great scientist. His scientific heritage is enormous. Information about him as a person is very contradictory.

Laplace is especially criticized for being apolitical. He always left the losers and went over to the side of the winners. Thus, in 1814, Laplace was one of the first to vote for the deposition of Napoleon. But we must remember that the main thing in Laplace’s life was not politics, but science. He devoted himself to her with all his passion, he served her faithfully, in her he was honest, frank and principled to the end. Sometimes he was mistaken. For example, he did not accept the wave theory of light and insisted on its corpuscular nature. But other great scientists also suffered from errors of this kind.

Laplace was a widely educated man. He knew languages, history, philosophy, chemistry and biology, not to mention astronomy, mathematics and physics. He loved poetry, music, painting. He had an excellent memory and old age I recited entire pages from Racine by heart.

After the restoration of the monarchy, Laplace enjoyed the favor of Louis XVIII. The king made him a peer of France and granted him the title of marquis. In 1816, the scientist was appointed a member of the commission for the reorganization of the Polytechnic School. In 1817 Laplace became a member of the newly created French Academy, i.e. one of the forty immortals.

Pierre Simon Laplace died after a short illness on March 5, 1827. His last words were: “What we know is so insignificant compared to what we don’t know.”

The following mathematical objects are named after Laplace:

• Laplace integral
• Laplace operator (Laplacian)
• vector Laplace operator (vector Laplacian)
• Laplace's limit formula
• Laplace transform
• Laplace distribution
• local Laplace theorem
• Laplace's theorem on calculating the determinant
• Laplace's equation
• Laplace function
• Laplace method

Based on materials from the books by D. Samin “100 Great Scientists” (M.: Veche, 2000) and “Rank of Great Mathematicians” (Warsaw, published by Nasha Ksengarnia, 1970), the site tonnel.ru and Wikipedia.

>> Pierre Simon Laplace

Biography of Pierre Simon Laplace (1749-1827)

Short biography:

Education: University of Caen Basse-Normandie

Place of Birth: Beaumont-en-Auge, Calvados

A place of death: Paris

– French astronomer: biography with photos, discoveries, celestial mechanics, the movement of Jupiter’s satellites, the birth of the Solar system from a nebula.

Pierre Simon Laplace - physicist, mathematician and astronomer, member of the Paris Academy of Sciences, was born on March 28, 1749 in a peasant family in Beaumont-en-Auge (Normandy), France. He studied at the school of the Order of Benedictine monks, but even in his youth Laplace took the position of convinced atheism. Was in the military educational institution in Beaumont-en-Auge as a mathematics teacher. Laplace moved to Paris in 1766. There he published famous mathematical works in the famous "Turin Papers", which were founded by Lagrange. Since 1771, Laplace became a professor at the Paris Military School. After the revolution in France, the scientist became one of the organizers of the Ecole Normale Supérieure and the Ecole Polytechnique. In 1790, Laplace became chairman of the Chamber of Weights and Measures, where he introduced the new metric system. Since 1795, the scientist has been the head of the Bureau of Longitudes. During the revolution in France, he sympathized with the Republicans. After Napoleon Bonaparte came to power, Laplace served as Minister of the Interior and received the title of Count. During the Bourbon restoration, he received a peerage and the title of marquis.

Laplace's main theoretical works were devoted to problems of celestial mechanics. This term was first used by Laplace in the title of a grandiose work of five volumes - “Treatise on Celestial Mechanics”. In this scientific field, the scientist brought to a significant degree of perfection the implementation of various ideas and methods of Newton, outlined by him in the “Mathematical Principles of Natural Philosophy.” Using the methods of analytical mechanics created by Euler and Lagrange, he considered many important issues from the theory of the motion of celestial bodies, as well as their equilibrium figures. Laplace showed that the law of universal gravitation exhaustively explains the movement of bodies in the solar system; he introduced disturbances mathematical series and successfully proved the periodicity of disturbances. Laplace showed that the apparent deviations in the trajectory of Jupiter and Saturn from the law of universal gravitation constitute one of its most surprising evidence. In 1789, Laplace explained, on the basis of perturbation theory, the peculiarities of the motion of Jupiter's satellites. The scientist’s undoubted merit was the study of the reasons for the acceleration of the Earth’s satellite.

He proved that the speed of the geocentric trajectory of the Moon directly depends on the eccentricity of the Earth's orbit. The latter changes under the influence of planetary disturbances. This disturbance is quite periodic in nature. This period is long, so after a certain period of time the Earth's satellite will begin to move more slowly. Laplace, having analyzed the features of movement, which also depend on the compression of our planet, determined the magnitude of the compression and designated it as 1/305. This figure is close actual value. The proof given by scientists of the stability of the entire solar system seems very important. The most important place in the history of cosmogonic ideas is occupied by Laplace’s famous hypothesis about how the Solar system arose from a rotating gas nebula. These ideas were expressed by the scientist in the work “Exposition of the World System” (1796). This hypothesis was called nebular. Engels gave a high assessment of this research, which is an improvement of Kant’s hypothesis. He noted that Kant’s work had no direct result until Laplace and Herschel did not develop his ideas and did not substantiate them in detail, thereby preparing the gradual acceptance of the “nebular hypothesis.”

Laplace owns a number of important works in mathematics and mathematical physics. Basically, these are works on the theory of differential equations. For example, he derived the partial differential equation that bears his name. It has great importance for theories of potential, electrostatics and hydrodynamics. Laplace contributed to the development of important probability theory, as well as error theory and the method of least squares. He also created the theory of spherical functions. Laplace proposed a formula for the dependence of air density indicators on altitude earth's surface(the so-called barometric formula). Currently, it is used in a variety of studies of the Earth's atmosphere and the atmospheres of other planets.

In his philosophical views, Laplace was inclined towards materialism. His interesting answer to Napoleon’s question is known: why is God not mentioned at all in the Treatise on Celestial Mechanics? The scientist's answer was: "I did not need this hypothesis." But Laplace's materialism was rather limited and mechanistic. He believed that everything natural phenomena It is possible to explain and predict only based on the laws of mechanics. In celestial mechanics, Laplace saw only a certain exemplary form of scientific knowledge.

• Normal school [d]
• Bureau of Longitude

Pierre-Simon, Marquis de Laplace(French Pierre-Simon de Laplace; March 23 - March 5) - French mathematician, mechanic, physicist and astronomer; known for his work in the field of celestial mechanics, differential equations, and one of the creators of probability theory. Laplace's merits in the field of pure and applied mathematics and especially in astronomy are enormous: he improved almost all sections of these sciences.

Laplace was a member of six academies of sciences and royal societies, including the St. Petersburg Academy (1802), and a member of the French Geographical Society. His name is included in the list of the greatest scientists of France, placed on the first floor of the Eiffel Tower.

Biography

Born into a wealthy peasant family in Beaumont-en-Auge, Normandy. Laplace's father was the mayor of this town for some time. There was also in the family elder sister Marie-Anne. The boy studied at the Benedictine school, from which he emerged, however, as a convinced atheist. Wealthy neighbors helped the talented young man enter the University of Caen in 1765.

In 1785, Laplace was elected a full member of the Paris Academy of Sciences. In the same year, at one of the exams, Laplace highly appreciated the knowledge of the 16-year-old applicant Bonaparte. Subsequently, their relationship was invariably warm. 12 years later, Laplace recommended General Bonaparte to the Institute of France (as the Academy of Sciences was then called).

From 1795, Laplace lectured on probability theory at the newly opened École Normale, where he was invited as professor of mathematics, together with Lagrange, by decree of the National Convention.

In 1796, “Exposition of the World System” was published - a popular outline of the results later published in Celestial Mechanics, without formulas and vividly presented; The book became widely known, during the author’s lifetime alone it was reprinted 4 times and translated into many languages ​​of the world. In 1799, the first two volumes of Laplace’s main work, the classic “Celestial Mechanics” (it was Laplace who introduced this term), were published. This book outlines the movement of planets, their possible forms, and the theory of tides. Work on the monograph lasted 26 years: volume III was published in 1802, volume IV in 1805, volume V in 1823-1825. The presentation style was too concise; the author replaced many statements with the words “it’s easy to see that...”. However, the depth of analysis and richness of content made this work a reference book for astronomers of the 19th century. In one of the notes, Laplace casually outlined the famous hypothesis about the origin of the solar system from a gaseous nebula, previously expressed by Kant. In the third edition of Celestial Mechanics (1813), Laplace significantly expanded the presentation of his cosmogonic hypothesis.

Laplace in the 1820s

In 1812, the last monograph of the 63-year-old Laplace appeared - the grandiose “Analytical Theory of Probability”, in which Laplace also summarized all his and other people’s results. In 1814 he published a popular exposition of this work: An Essay on the Philosophy of the Theory of Probability, the second and fourth editions of which served as an introduction to the second and third editions of the Analytical Theory of Probability. “An Experience in the Philosophy of Probability Theory” was published in Russian translation in 1908 and republished in 1999.

He advanced linear algebra far; in particular, Laplace gave an expansion of the determinant in minors.

Laplace expanded and systematized the mathematical foundation of probability theory and introduced generating functions. The first book of "Analytic Theory of Probability" is devoted to mathematical foundations; Probability theory itself begins in the second book, as applied to discrete random variables. There is also a proof of the limit theorems of Moivre-Laplace and applications to the mathematical processing of observations, population statistics and the “moral sciences”.

Astronomy

In Celestial Mechanics, Laplace summed up both his own research in this area and the work of his predecessors, starting with Newton. He gave a comprehensive analysis of the known movements of the bodies of the Solar System on the basis of the law of universal gravitation and proved its stability in the sense of the practical invariability of the average distances of the planets from the Sun and the insignificance of fluctuations in the remaining elements of their orbits. Along with the mass of special results concerning the movements of individual planets, satellites and comets, the figure of the planets, the theory of tides, etc., the most important was the general conclusion that refuted the opinion (which Newton also shared) that maintaining the present appearance of the solar system requires the intervention of some some extraneous supernatural forces.

Laplace proved the stability of the solar system, which consists in the fact that due to the movement of the planets in one direction, small eccentricities and small mutual inclinations of their orbits, there should be an invariability of the average distances of the planets from the Sun, and the fluctuations of other elements of the orbits should be contained within very tight limits.

Laplace proposed the first mathematically substantiated cosmogonic hypothesis for the formation of all bodies in the Solar System, called after him: Laplace's hypothesis. He was also the first to suggest that some nebulae observed in the sky are actually galaxies similar to our Milky Way.

Before Laplace's discoveries, many scientists tried to explain the deviations of the theory from observations by the movement of the ether, the final speed of gravity and other non-Newtonian factors; Laplace buried such attempts for a long time. He, as Clairaut had earlier, proclaimed: in celestial mechanics there are no forces other than Newtonian ones, and he substantiated this thesis with arguments.

Laplace discovered that the acceleration in the movement of the Moon, which perplexed all astronomers ( centuries-old inequality), is also a periodic change in the eccentricity of the lunar orbit, and it occurs under the influence of the attraction of large planets. The displacement of the Moon calculated by him under the influence of these factors was in good agreement with observations.

Using inequalities in the motion of the Moon, Laplace clarified the compression of the Earth's spheroid. In general, the studies carried out by Laplace on the movement of our satellite made it possible to compile more accurate tables of the Moon, which, in turn, contributed to solving the navigation problem of determining longitude at sea.

Laplace was the first to construct an accurate theory of the motion of the Galilean satellites of Jupiter, the orbits of which, due to mutual influence, constantly deviate from Keplerian ones. He also gave an explanation of the "Wargentin relation" between the orbital angles of satellites in terms of Newton's laws. This explanation is called "Laplace resonance".

Having calculated the equilibrium conditions for the ring of Saturn, Laplace proved that they are possible only when the planet rotates rapidly about its axis, and this was indeed proven later by the observations of William Herschel.

Ahead of his time, Laplace actually predicted “black holes” in his Exposition of the System of the World (1796):

If the diameter of a luminous star with the same density as the Earth were two hundred and fifty times greater than the diameter of the Sun, then, due to the attraction of the star, not a single ray emitted by it could reach us; therefore, it is possible that the largest of the luminous bodies are invisible for this reason.

- Laplace P.S., 1795, Le Systeme du Monde, vol.II, Paris]

However, this bold hypothesis was removed from the fourth edition.

Physics

Philosophical views

The dialogue between Laplace and Napoleon is widely known:

You wrote such a huge book about the system of the world and never mentioned its Creator!
- Sire, I did not need this hypothesis.

Original text (French)

"M. La place, on me dit que vous avez écrit ce volumineux ouvrage sur le système de l’Univers sans faire une seule fois mention de son Créateur.”

“Sire, je n’ai pas eu besoin de cette hypothèse.”

Dialogue between Laplace and Napoleon

M. Arago assured me that Laplace, who was warned shortly before his death that the story was about to be published in a biographical collection, asked him to demand the publisher to remove it. It was necessary to either explain it or remove it, and the second way was the simplest. But, unfortunately, it was not removed or explained.

Nevertheless, Laplace had a strong reputation as an atheist. Several sources cite the continuation of Napoleon's conversation with Laplace; According to them, Napoleon later retold Laplace's response to Lagrange: God is an excellent hypothesis, it explains a lot. Laplace responded dryly: “This hypothesis, sir, actually explains everything, but does not allow us to predict anything.”

Laplace was a supporter of absolute determinism. He argued that if any sentient being could have all the particles in the world at a certain moment, it could accurately predict all world events. Such a hypothetical creature was subsequently called Laplace's demon. The fallacy of such predetermination was noted long before the advent of probabilistic quantum mechanics - at the beginning of the 20th century, Henri Poincaré discovered fundamentally unpredictable processes in which an insignificant change in the initial state causes, over time, arbitrarily large deviations in the final state.

Personal qualities

Contemporaries noted Laplace's goodwill towards young scientists and his constant readiness to help. His attitude towards his colleagues was much more restrained; contemporaries often reproached Laplace for arrogance and disregard for issues of priority - in his works he often did not refer to the discoverers.

Laplace was one of the outstanding figures of French Freemasonry. He was Honorary Grand Master of the Grand Orient of France.

Awards

• Order of the Legion of Honor:
  • Grand Cross (22 May 1825)
  • grand officer (14 June 1804 (25 Prairial XII))
  • Knight (October 2, 1803 (9 Vendemier XII))
• Order of Reunification, Grand Cross (3 April 1813)
• Title of Marquis (1817)

Memory

Laplace's grave

Named in honor of the scientist:

• asteroid (4628) Laplace;
• numerous concepts and theorems in mathematics.

Laplace was buried at

Pierre-Simon Laplace is an outstanding French mathematician, physicist and astronomer who improved almost every section of these sciences. The scientist’s main achievement is the proposed nebular hypothesis, which states that the solar system is formed from large quantity rotating gas.

The future scientist was born in northern France in the small town of Beaumont-en-Auge (department of Calvados, Normandy) on March 23, 1749. Later, although Pierre received the titles of count and marquis, he continued to be ashamed of his humble origins, so practically nothing is known about his youth.

The peasant family was of average income, but an influential neighbor helped the smart boy get an education and sent him to study at a Benedictine school, and after graduation to enter the University of Caen. After graduating from school, Laplace became a convinced adherent of atheism.

He graduated from school with honors and an offer to stay in the city military school as a mathematics teacher. At the age of 17, Laplace wrote his first scientific work related to the theory of gambling. Subsequently, the method used in the calculations became one of the most common in statistics.

The level of knowledge and opportunities in a small town did not suit the guy, so at the first opportunity in 1766 he moved to Paris, where for the first three years he intensively studied mathematics and published his works. After 5 years of living in the capital, friends helped him get a professorship at the Military School.

In 1778 he married Charlotte de Courti, who bore him two children.

Career

In 1773 he became an adjunct of the Paris Academy of Sciences for his study of the stability of planetary orbits. Since 1785 - an active member of the Academy of Sciences. 5 years after receiving membership in the academy, Laplace was elected Chairman of the Chamber of Weights and Measures, who was tasked with introducing new system measures

After the Jacobins came to power in 1793, the Academy of Sciences was abolished, and Laplace was dismissed from his position in the Commission on Weights and Measures. A year later, the Higher Normal School and the Polytechnic School were created, where the scientist became a professor. Instead of the Academy of Sciences, they created the National Institute of Sciences and Arts, where Pierre was invited as a member and head of the Bureau of Longitudes.

The new ruler of France, Napoleon, already on the second day after the revolution appointed Laplace Minister of the Interior. He was later promoted to member of the Senate. In 1803, the scientist became vice-president of the Senate, and later chancellor.

Major scientific achievements

Laplace made his first scientific achievements in collaboration with Lavoisier. Their general work became the basis for the development new science called thermochemistry. Based on their research, scientists have proven that the amount of heat that is used to decompose a compound is equal to the amount of heat released during the formation of such a compound.

Laplace is a fairly versatile scientist. But most of his fundamental discoveries were made in three directions - mathematics, physics and astronomy.

His main achievements in mathematics:

• Fundamental developments in the field of differential equations;
• Introduction to the science of spherical functions;
• Developed methods of mathematical physics;
• Significantly expanded the foundation of linear algebra with a theorem on the representation of determinants by the sum of products of additional minors, probability theory - introduced generating functions;
• Developed the theory of errors and approximations using the least squares method.

Laplace achieved no less outstanding successes in physics:

1. He derived a formula for calculating the speed of sound in air.
2. Invented the ice calorimeter.
3. Established a law for capillary pressure.
4. He developed a barometric formula based on which air density can be calculated.

But the greatest amount of the scientist’s research relates to celestial mechanics. The main work of his life bears a similar name - “Celestial Mechanics”. In his works, Laplace proved the stability of the solar system, which had previously been refuted.

In 1780, he proposed a completely innovative method for calculating the orbits of celestial bodies. Another important achievement scientist - in 1787 he showed that average speed The Moon's orbit depends on the eccentricity of the Earth's orbit, which changes under the influence of the gravitational pull of the planets. Based on the latter theory, the scientist determined the amount of compression of the Earth at the poles. He also developed the dynamic theory of tides.