Brief biography of Christian Huygens. Huygens, Christians Interesting facts from the life of Huygens

Huygens Christian (1629-1695), Dutch physicist, mathematician, mechanic, astronomer.

Born April 14, 1629 in The Hague. At the age of 16 he entered the University of Leiden, two years later he continued his studies at the University of Breda. Mostly lived in Paris; was a member of the Paris Academy of Sciences.

Huygens became known as a brilliant mathematician. However, fate decreed that he was a contemporary of I. Newton, which means that he was always in the shadow of someone else's talent. Huygens was one of the developers of mechanics after Galileo and Descartes. He belongs to the leadership in the creation of pendulum clocks with an escapement. He managed to solve the problem of determining the center of oscillation of a physical pendulum, to establish the laws that determine the centripetal force. He also investigated and deduced the regularities of the collision of elastic bodies.

Before Newton, Huygens developed the wave theory of light. Huygens' principle (1678) - the mechanism he discovered for the propagation of light - is applicable today. Based on his theory of light, Huygens explained a number of optical phenomena, measured the geometric characteristics of Icelandic spar with great accuracy and discovered double refraction in it, then he saw the same phenomenon in quartz crystals. Huygens introduced the concept of "crystal axis", discovered the polarization of light. He worked with great success in the field of optics: he significantly improved the telescope, designed an eyepiece, and introduced diaphragms.

Being one of the creators of the Paris Observatory, he made a significant contribution to astronomy - he discovered the 8th ring of Saturn and Titan, one of the largest satellites in the solar system, distinguished the polar caps on Mars and the bands on Jupiter. The scientist with great interest designed the so-called planetary machine (planetarium) and created a theory of the figure of the Earth. He was the first to come to the conclusion that the Earth is compressed near the poles, and proposed the idea of ​​measuring the force of gravity with the help of a second pendulum. Huygens came close to discovering the law of universal gravitation. His mathematical methods are still used in science today.

Plan:

Introduction

• 1 Biography
• 2 Scientific activity
  • 2.1 Mathematics and mechanics
  • 2.2 Astronomy
  • 2.3 Optics and wave theory
  • 2.4 Other achievements
• 3 Major writings
• 4 Notes
Literature
• 5.1 Huygens' works in Russian translation
• 5.2 Literature about him

Introduction

Portrait by Kaspar Necher (1671), oil, Boerhaave Museum, Leiden

Christian Huygens (listen (inf.)) van Zeulichem(Dutch. Christiaan Huygens, IFA: [ˈkrɪstijaːn ˈɦœyɣə(n)s], April 14, 1629, The Hague - July 8, 1695, ibid) - Dutch mechanic, physicist, mathematician, astronomer and inventor.

1. Biography

Huygens was born in The Hague. His father Konstantin Huygens (Huygens), secret adviser to the princes of Orange, was a remarkable writer who also received a good scientific education.

The young Huygens studied law and mathematics at the University of Leiden, then decided to devote himself to science.

Together with his brother, he improved the telescope, bringing it to 92x magnification, and began to study the sky. The first fame came to Huygens when he discovered the rings of Saturn (Galileo also saw them, but could not understand what they were) and the satellite of this planet, Titan.

In 1657 Huygens received a Dutch patent for a pendulum clock design. In the last years of his life, Galileo tried to create this mechanism, but progressive blindness prevented him. Huygens' clock really worked and provided excellent accuracy for that time. The central element of the design was the anchor invented by Huygens, which periodically pushed the pendulum and maintained undamped oscillations. Designed by Huygens, an accurate and inexpensive pendulum clock quickly became widely used throughout the world.

In 1665, at the invitation of Colbert, he settled in Paris and was accepted as a member of the Academy of Sciences. In 1666, at the suggestion of the same Colbert, he became its first president. Huygens led the Academy for 15 years.

In 1673, under the title "Pendulum Clock", an exceptionally informative work on the kinematics of accelerated motion was published. This book was a desktop book for Newton, who completed the construction of the foundation of mechanics begun by Galileo and continued by Huygens.

1681: in connection with the intended repeal of the Edict of Nantes, Huygens, not wanting to convert to Catholicism, returned to Holland, where he continued his scientific research.

Named after Huygens:

• a crater on the moon;
• mountain Mons Huygens on the moon;
• crater on Mars
• asteroid 2801 Huygens;
• the European space probe that reached Titan;
• Huygens Laboratory: laboratory at Leiden University, The Netherlands.

2. Scientific activity

Lagrange wrote that Huygens "was destined to perfect and develop the most important discoveries of Galileo".

2.1. Mathematics and mechanics

Christian Huygens
Engraving from a painting by Caspar Necher by G. Edelink, 1684-1687.

Christian Huygens began his scientific activity in 1651 with an essay on the quadrature of the hyperbola, ellipse and circle. In 1654 he discovered the theory of evolutes and evolvents.

In 1657, Huygens published a description of the design of the clock he invented with a pendulum. At that time, scientists did not have such a device necessary for experiments as an accurate clock. Galileo, for example, when studying the laws of falling, counted the beats of his own pulse. Clocks with wheels driven by weights have been in use for a long time, but their accuracy was unsatisfactory. Since the time of Galileo, the pendulum has been used separately for accurate measurement of small periods of time, and it was necessary to count the number of swings. Huygens' clock had good accuracy, and the scientist then repeatedly, for almost 40 years, turned to his invention, improving it and studying the properties of the pendulum. Huygens intended to use a pendulum clock to solve the problem of determining longitude at sea, but did not achieve significant progress. A reliable and accurate marine chronometer appeared only in 1735 (in Great Britain).

In 1673, Huygens published the classic mechanical work The Pendulum Clock. Horologium oscillatorium, sive de motu pendulorum an horologia aptato demonstrationes geometrica"). The modest name should not be misleading. In addition to the theory of clocks, the work contained many first-class discoveries in the field of analysis and theoretical mechanics. Huygens also quadratures a number of surfaces of revolution there. This and his other writings had a profound effect on the young Newton.

In the first part of the work, Huygens describes an improved, cycloidal pendulum that has a constant swing time regardless of amplitude. To explain this property, the author devotes the second part of the book to the derivation of the general laws of motion of bodies in a gravitational field - free, moving along an inclined plane, rolling down a cycloid. It must be said that this improvement has not found practical application, since with small fluctuations the increase in accuracy from the cycloidal weight gain is insignificant. However, the research methodology itself entered the gold fund of science.

Huygens derives the laws of uniformly accelerated motion of freely falling bodies, based on the assumption that the action imparted to the body by a constant force does not depend on the magnitude and direction of the initial velocity. Deriving the relationship between the height of the fall and the square of time, Huygens makes the remark that the heights of the falls are related as the squares of the acquired velocities. Further, considering the free movement of a body thrown upwards, he finds that the body rises to the greatest height, having lost all the speed communicated to it, and acquires it again when returning back.

Galileo allowed without proof that when falling along differently inclined straight lines from the same height, bodies acquire equal speeds. Huygens proves this as follows. Two straight lines of different inclination and equal height are attached with their lower ends one to the other. If a body lowered from the upper end of one of them acquires a greater speed than that launched from the upper end of the other, then it can be launched along the first of such a point below the upper end so that the speed acquired below is sufficient to lift the body to the upper end of the second straight line; but then it would turn out that the body rose to a height greater than the one from which it fell, and this cannot be.

From the motion of a body along an inclined straight line, Huygens proceeds to motion along a broken line and then to motion along some curve, and he proves that the speed acquired when falling from any height along the curve is equal to the speed acquired during free fall from the same height along a vertical line, and that the same speed is required to lift the same body to the same height in both a vertical straight line and a curve. Then, passing to the cycloid and considering some of its geometric properties, the author proves the tautochronism of the motions of the heavy point along the cycloid.

In the third part of the work, the theory of evolutes and evolvents, discovered by the author as early as 1654, is presented; here he finds the form and position of the cycloid's evolute.

The fourth part presents the theory of the physical pendulum; here Huygens solves the problem that was not given to so many contemporary geometers - the problem of determining the center of oscillations. It is based on the following proposition:

If a complex pendulum, having left rest, has completed a certain part of its swing, more than a half-swing, and if the connection between all its particles is destroyed, then each of these particles will rise to such a height that their common center of gravity will be at that height, at which he was at the exit of the pendulum from rest.

This proposition, not proved by Huygens, appears to him as a basic principle, while now it is a simple consequence of the law of conservation of energy.

The theory of the physical pendulum was given by Huygens in quite a general form and applied to bodies of various kinds. Huygens corrected Galileo's mistake and showed that the isochronism of the pendulum oscillations proclaimed by the latter takes place only approximately. He also noted two more errors of Galileo in kinematics: uniform motion in a circle is associated with acceleration (Galileo denied this), and centrifugal force is proportional not to speed, but to the square of speed.

In the last, fifth part of his work, Huygens gives thirteen theorems on centrifugal force. This chapter gives for the first time an exact quantitative expression for the centrifugal force, which subsequently played an important role in the study of the motion of the planets and the discovery of the law of universal gravitation. Huygens gives in it (verbally) several fundamental formulas:

In 1657 Huygens wrote an appendix " About gambling settlements” to the book of his teacher van Schooten “Mathematical Etudes”. It was a meaningful exposition of the beginnings of the then emerging theory of probability. Huygens, along with Fermat and Pascal, laid its foundations. From this book, Jacob Bernoulli got acquainted with the theory of probability, which completed the creation of the foundations of the theory.

Title page of Huygens' popular astronomical and philosophical treatise Cosmotheoros

2.2. Astronomy

Huygens improved the telescope on his own; in 1655 he discovered Saturn's moon Titan and described Saturn's rings. In 1659, he described the entire system of Saturn in a work he published.

In 1672, he discovered an ice cap at the South Pole of Mars.

He also discovered the Orion Nebula and other nebulae, observed binary stars, estimated (quite accurately) the period of rotation of Mars around its axis.

The last book "ΚΟΣΜΟΘΕΩΡΟΣ sive de terris coelestibus earumque ornatu conjecturae" (in Latin; published in The Hague in 1698) is a philosophical and astronomical reflection on the Universe. He believed that other planets are also inhabited by people. Huygens' book was widely distributed in Europe, where it was translated into English (in 1698), Dutch (1699), French (1702), German (1703) and Swedish (1774). It was translated into Russian by decree of Peter I by Yakov Bruce in 1717 under the title "The Book of the World View". It is considered the first book in Russia that describes the heliocentric system of Copernicus.

2.3. Optics and wave theory

• Huygens participated in contemporaneous disputes about the nature of light. In 1678 he published A Treatise on Light, an outline of the wave theory of light. Another remarkable work he published in 1690; there he presented the qualitative theory of reflection, refraction and double refraction in Icelandic spar in the same form as it is now presented in physics textbooks. Formulated the so-called. Huygens' principle, which makes it possible to investigate the motion of a wave front, which was subsequently developed by Fresnel and played an important role in the wave theory of light and the theory of diffraction.

• He owns the original improvement of the telescope used by him in astronomical observations and mentioned in the paragraph on astronomy. He is also the inventor of the diascopic projector - the so-called. "magic lantern"
• Invented the Huygens eyepiece, consisting of two plano-convex lenses.

2.4. Other achievements

Pocket mechanical watch

• The theoretical discovery of the oblateness of the Earth at the poles, as well as an explanation of the influence of centrifugal force on the direction of gravity and on the length of the second pendulum at different latitudes.
• Solution of the issue of collision of elastic bodies, simultaneously with Wallis and Wren.
• One of the solutions to the question of the form of a heavy homogeneous chain in equilibrium: (chain line).
• The invention of the clock spiral, replacing the pendulum, is extremely important for navigation; The first clock with a spiral was designed in Paris by the watchmaker Thuret in 1674.
• In 1675 he patented a pocket watch.
• The first called for choosing a universal natural measure of length, which he proposed as 1/3 of the length of the pendulum with a period of oscillation of 1 second (this is about 8 cm).

3. Main works

• Horologium oscillatorium, 1673 (Pendulum clock, in Latin).
• Kosmotheeoros. (English translation of the 1698 edition) - Huygens' astronomical discoveries, hypotheses about other planets.
• Treatise on Light (Treatise on Light, English translation).

4. Notes

1. According to the Dutch-Russian practical transcription, it is more correct to reproduce this name and surname in Russian as Christian Huygens .
2. Gindikin S. G. Stories about physicists and mathematicians - www.mccme.ru/free-books/gindikin/index.html. - third edition, expanded. - M .: MTSNMO, 2001. - S. 110. - ISBN 5-900916-83-9
3. Kuznetsov B. G. Galileo Galilei. - M.: Nauka, 1964, pp. 165, 174.
4. Everything about the planet Mars - x-mars.narod.ru/investig.htm

Literature

5.1. Huygens' works in Russian translation

• Guens H. The book of worldview and opinion about the heavenly-terrestrial globes and their decorations. Per. Jacob Bruce. St. Petersburg, 1717; 2nd ed., 1724 (in the Russian edition, the name of the author and the name of the translator are not indicated)
• Archimedes. Huygens. Legendre. Lambert. About squaring the circle. With an appendix of the history of the question, compiled by F. Rudio. Per. S. N. Bernstein. Odessa, Mathesis, 1913. (Reprint: M.: URSS, 2002)
• Huygens H. A treatise on light, which explains the reasons for what happens to it during reflection and refraction, in particular during the strange refraction of the Icelandic crystal. M.-L.: ONTI, 1935.
• Huygens H. Three memoirs on mechanics. - publ.lib.ru/ARCHIVES/G/GYUYGENS_Christian/Gyuygens_H._Tri_memuara_po_mehanike.(1951)..zip M.: Ed. Academy of Sciences of the USSR, 1951. Series: Classics of Science.
  • Pendulum clock.
  • On the motion of bodies under the influence of impact.
  • About centrifugal force.
  • APPS:
    • K. K. Baumgart. Christian Huygens. Brief biographical sketch.
    • K. K. Baumgart. Works of Christian Huygens on mechanics.
  • Name index.

5.2. Literature about him

• Veselovsky I. N. Huygens. Moscow: Uchpedgiz, 1959.
• History of mathematics, edited by A. P. Yushkevich in three volumes, M .: Nauka, Volume 2. Mathematics of the 17th century. (1970) - ilib.mccme.ru/djvu/istoria/istmat2.htm
• Gindikin S. G. Stories about physicists and mathematicians. - www.mccme.ru/free-books/gindikin/index.html M: MTsNMO, 2001.
• Costabel P. The invention of the cycloidal pendulum by Christian Huygens and the craft of a mathematician. Historical and mathematical research, issue. 21, 1976, p. 143-149.
• Mah E. Mechanics. Historical-critical sketch of its development. Izhevsk: RHD, 2000.
• Frankfurt U. I., Frank A. M. Christian Huygens. Moscow: Nauka, 1962.
• Shawl, Michel. Historical Review of the Origin and Development of Geometric Methods - en.wikisource.org/wiki/Historical_Review of the Origin_and_Development of Geometric_Methods/Huygens. T. 1, n. 11-14. M., 1883.
• John J. O'Connor And Edmund F. Robertson. Huygens, Christian - www-groups.dcs.st-and.ac.uk/~history/Mathematicians/Huygens.html (English) on the MacTutor archive.
• Works by Christiaan Huygens - www.gutenberg.org/author/Christiaan Huygens at Project Gutenberg

Great Soviet Encyclopedia: Huygens, Christian Huygens (April 14, 1629, The Hague - July 8, 1695, ibid.), Dutch mechanic, physicist and mathematician, creator of the wave theory of light. The first foreign member of the Royal Society of London (since 1663). G. studied at the universities of Leiden and Breda, where he studied law and mathematics. At the age of 22, he published a work on determining the length of the arcs of a circle, an ellipse, and a hyperbola. In 1654, his work On the Determination of the Size of a Circumference appeared, which was the most important contribution to the theory of determining the ratio of the circumference to the diameter (calculation of the number p). This was followed by other significant mathematical treatises on the study of the cycloid, logarithmic and catenary, etc. His treatise "On calculations when playing dice" (1657) is one of the first studies in the field of probability theory. G. together with R. Hooke established the constant points of the thermometer - the melting point of ice and the boiling point of water. During these years, Mr.. working on improving the lenses of astronomical tubes, trying to increase their aperture ratio and eliminate chromatic aberration. With their help, G. discovered in 1655 the satellite of the planet Saturn (Titan), determined the period of its revolution and established that Saturn is surrounded by a thin ring, nowhere adjacent to it and inclined to the ecliptic. All observations are given by G. in the classic work "System of Saturn" (1659). In the same work, G. gave the first description of the nebula in the constellation of Orion and reported on the bands on the surfaces of Jupiter and Mars.
Astronomical observations required accurate and convenient measurement of time. In 1657 G. invented the first pendulum clock equipped with an escapement; G. described his invention in the work "Pendulum Clock" (1658). The second, expanded edition of this work was published in 1673 in Paris. In the first 4 parts of her G. explored a number of problems associated with the movement of the pendulum. He gave a solution to the problem of finding the center of swing of a physical pendulum - the first problem in the history of mechanics about the motion of a system of connected material points in a given force field. In the same work, G. established the tautochronism of motion along the cycloid and, having developed the theory of the evolution of plane curves, proved that the evolution of the cycloid is also a cycloid, but differently located relative to the axes.
In 1665, at the founding of the French Academy of Sciences, G. was invited to Paris as its chairman, where he lived almost without a break for 16 years (1665-81). In 1680, G. worked on the creation of a "planetary machine" - a prototype of the modern planetarium - for the construction of which he developed a fairly complete theory of continued, or continuous, fractions. This is the last work he did in Paris.
In 1681, returning to his homeland, G. again engaged in optical work. In 1681-87, he produced grinding lenses with huge focal lengths of 37, 54.63 m. The entire cycle of G.'s optical work ends with the famous Treatise on Light (1690). In it, for the first time, the wave theory of light is presented in a completely distinct form and applied to the explanation of optical phenomena. In chapter 5 of the "Treatise on Light" G. gave an explanation of the phenomenon of double refraction, discovered in the crystals of Icelandic spar; the classical theory of refraction in optically uniaxial crystals is still expounded on the basis of this chapter.
To the "Treatise on Light" G. added as an application the argument "On the Causes of Gravity", in which he came close to the discovery of the law of universal gravitation. In his last treatise Kosmoteoros (1698), published posthumously, G. is based on the theory of the plurality of worlds and their habitability. In 1717 the treatise was translated into Russian. language by order of Peter I.

Christian Huygens is a Dutch scientist, mathematician, astronomer and physicist, one of the founders of wave optics. In 1665-81 he worked in Paris. Invented (1657) a pendulum clock with an escapement, gave their theory, established the laws of oscillation of a physical pendulum, laid the foundations for the theory of impact. Created (1678, published 1690) the wave theory of light, explained birefringence. Together with Robert Hooke, he established the constant points of the thermometer. Improved the telescope; designed an eyepiece named after him. Discovered the ring of Saturn and its satellite Titan. Author of one of the first works on the theory of probability (1657).

Early awakening of talents

The ancestors of Christian Huygens occupied a prominent place in the history of his country. His father Konstantin Huygens (1596-1687), in whose house the future famous scientist was born, was a well-educated person, knew languages, was fond of music; after 1630 he became an adviser to Wilhelm II (and later William III). King James I elevated him to the rank of knight, and Louis XIII granted him the Order of Saint Michael. His children - 4 sons (the second - Christians) and one daughter - also left a good mark on history.

Christian's giftedness manifested itself at an early age. At the age of eight, he already studied Latin and arithmetic, learned to sing, and at the age of ten he became acquainted with geography and astronomy. In 1641, his tutor wrote to the child's father: "I see and almost envy the remarkable memory of Christian," and two years later: "I confess that Christian must be called a miracle among boys."

And Christian at this time, having studied Greek, French and Italian and having mastered the game on the harpsichord, became interested in mechanics. But not only that: he willingly engages in swimming, dancing and horseback riding. At the age of sixteen, Christian Huygens, together with his older brother Konstantin, entered the University of Leiden for training in law and mathematics (the latter was more willing and successful; the teacher decides to send one of his works to Rene Descartes).

After 2 years, the elder brother begins to work for Prince Frederik Henrik, and Christian and his younger brother move to Breda, to the Orange College. His father also prepared Christian for public service, but he had other aspirations. In 1650, he returned to The Hague, where his scientific work was hindered only by headaches that had haunted him for some time.

First scientific works

The range of scientific interests of Christian Huygens continued to expand. He is fond of the works of Archimedes on mechanics and Descartes (and later of other authors, including the English Newton and Hooke) on optics, but does not stop studying mathematics. In mechanics, his main research relates to the theory of impact and to the problem of designing clocks, which at that time was of exceptionally important applied importance and always occupied one of the central places in Huygens's work.

His first achievements in optics can also be called "applied". Together with his brother Constantine Christian Huygens is engaged in the improvement of optical instruments and achieves significant success in this area (this activity does not stop for many years; in 1682 he invents a three-lens eyepiece, which still bears his name. While improving telescopes, Huygens, however, in the Diopter ” wrote: “... a person: who could invent a telescope, based only on theory, without the intervention of chance, would have to have a superhuman mind”).

New instruments allow important observations to be made: On March 25, 1655, Huygens discovers Titan, the largest satellite of Saturn (whose rings he had been interested in for a long time). In 1657, another work by Huygens appeared, “On Calculations when Playing Dice,” one of the first works on the theory of probability. He writes another essay "On the Impact of Bodies" for his brother.

In general, the fifties of the 17th century were the time of the greatest activity of Huygens. He gains notoriety in the scientific world. In 1665 he was elected a member of the Paris Academy of Sciences.

"Huygens principle"

H. Huygens studied Newton's optical works with unflagging interest, but did not accept his corpuscular theory of light. Much closer to him were the views of Robert Hooke and Francesco Grimaldi, who believed that light has a wave nature.

But the concept of light-wave immediately gave rise to many questions: how to explain the rectilinear propagation of light, its reflection and refraction? Newton gave seemingly convincing answers to them. Rectilinearity is a manifestation of the first law of dynamics: light corpuscles move uniformly and rectilinearly if no forces act on them. Reflection was also explained as an elastic rebound of corpuscles from the surfaces of bodies. The situation with refraction was somewhat more complicated, but even here Newton offered an explanation. He believed that when a light corpuscle flies up to the boundary of the body, an attraction force from the side of the substance begins to act on it, imparting acceleration to the corpuscle. This leads to a change in the direction of the velocity of the corpuscle (refraction) and its magnitude; therefore, according to Newton, the speed of light in glass, for example, is greater than in vacuum. This conclusion is important, if only because it allows for experimental verification (experiment later refuted Newton's opinion).

Christian Huygens, like his predecessors mentioned above, believed that all space is filled with a special medium - ether, and that light is waves in this ether. Using the analogy with waves on the surface of water, Huygens came up with the following picture: when the front (i.e., the leading edge) of the wave reaches a certain point, i.e., the oscillations reach this point, then these oscillations become the centers of new waves diverging in all directions , and the movement of the envelope of all these waves gives a picture of the propagation of the wave front, and the direction perpendicular to this front is the direction of wave propagation. So, if the wave front in the void at some point is flat, then it always remains flat, which corresponds to the rectilinear propagation of light. If the front of a light wave reaches the boundary of the medium, then each point on this boundary becomes the center of a new spherical wave, and, having constructed the envelopes of these waves in space both above and below the boundary, it is easy to explain both the law of reflection and the law of refraction (but at In this case, one has to accept that the speed of light in a medium is n times less than in vacuum, where it is n - the same refractive index of the medium, which is included in the law of refraction recently discovered by Descartes and Snell).

It follows from the Huygens principle that light, like any wave, can also go around obstacles. This phenomenon, which is of fundamental interest, does exist, but Huygens considered that the "side waves" that arise during such an envelope do not deserve much attention.

Christian Huygens' ideas about light were far from modern. So, he believed that light waves are longitudinal, i.e. that the directions of oscillations coincide with the direction of wave propagation. This may seem all the more strange since Huygens himself apparently already had an idea of ​​the phenomenon of polarization, which can only be understood by considering transverse waves. But this is not the main thing. Huygens' principle had a decisive influence on our ideas not only about optics, but also about the physics of any oscillations and waves, which now occupies one of the central places in our science. (V. I. Grigoriev)

More about Christian Huygens:

Christian Huygens von Zuylichen - the son of the Dutch nobleman Constantine Huygens "Talents, nobility and wealth were, apparently, hereditary in the family of Christian Huygens," wrote one of his biographers. His grandfather was a writer and dignitary, his father was a secret adviser to the princes of Orange, a mathematician, and a poet. Faithful service to their sovereigns did not enslave their talents, and it seemed that Christian was destined for the same enviable fate for many. He studied arithmetic and Latin, music and versification. Heinrich Bruno, his teacher, could not get enough of his fourteen-year-old pupil:

“I confess that Christian must be called a miracle among boys ... He deploys his abilities in the field of mechanics and construction, makes amazing machines, but hardly necessary.” The teacher was wrong: the boy is always looking for the benefits of his studies. His concrete, practical mind will soon find schemes of machines that people really need.

However, he did not immediately devote himself to mechanics and mathematics. The father decided to make his son a lawyer and, when Christian reached the age of sixteen, he sent him to study law at the University of London. Being engaged in legal sciences at the university, Huygens at the same time is fond of mathematics, mechanics, astronomy, and practical optics. A skilled craftsman, he grinds optical glasses on his own and improves the pipe, with the help of which he will later make his astronomical discoveries.

Christian Huygens was the immediate successor of Galileo-Galilei in science. According to Lagrange, Huygens "was destined to improve and develop the most important discoveries of Galileo." There is a story about how for the first time Huygens came into contact with the ideas of Galileo. Seventeen-year-old Huygens was going to prove that bodies thrown horizontally move along parabolas, but, having found the proof in the book of Galileo, he did not want to "write the Iliad after Homer."

After graduating from the university, Christian Huygens becomes an adornment of the retinue of the Count of Nassau, who, on a diplomatic mission, is on his way to Denmark. The count is not interested in the fact that this handsome young man is the author of curious mathematical works, and he, of course, does not know how Christian dreams of getting from Copenhagen to Stockholm to see Descartes. So they will never meet: in a few months Descartes will die.

At the age of 22, Christian Huygens publishes Discourses on the Square of the Hyperbola, Ellipse, and Circle. In 1655, he builds a telescope and discovers one of Saturn's satellites, Titan, and publishes New Discoveries in the Size of a Circle. At the age of 26, Christian writes notes on dioptrics. At the age of 28, his treatise “On Calculations when Playing Dice” was published, where one of the first ever research in the field of probability theory is hidden behind a seemingly frivolous title.

One of Huygens' most important discoveries was the invention of the pendulum clock. He patented his invention on July 16, 1657 and described it in a short essay published in 1658. He wrote about his watch to the French king Louis XIV: “My automata, placed in your apartments, not only amaze you every day with the correct indication of time, but they are suitable, as I hoped from the very beginning, for determining the longitude of a place on the sea.” Christian Huygens was engaged in the task of creating and improving clocks, especially pendulum clocks, for almost forty years: from 1656 to 1693. A. Sommerfeld called Huygens "the most brilliant watchmaker of all time."

At the age of thirty, Christian Huygens reveals the secret of Saturn's ring. The rings of Saturn were first noticed by Galileo as two lateral appendages "supporting" Saturn. Then the rings were visible, like a thin line, he did not notice them and did not mention them again. But Galileo's pipe did not have the necessary resolution and sufficient magnification. Watching the sky with a 92x telescope. Christian discovers that the ring of Saturn was taken as side stars. Huygens solved the riddle of Saturn and for the first time described its famous rings.

At that time Christian Huygens was a very handsome young man with large blue eyes and a neatly trimmed mustache. The reddish curls of the wig, coolly curled in the fashion of that time, fell to the shoulders, lying on the snow-white Brabant lace of an expensive collar. He was friendly and calm. No one saw him especially agitated or confused, in a hurry somewhere, or, on the contrary, immersed in slow thoughtfulness. He did not like to be in the “light” and rarely appeared there, although his origin opened the doors of all the palaces of Europe to him. However, when he appeared there, he did not look at all awkward or embarrassed, as often happened to other scientists.

But in vain the charming Ninon de Lanclos seeks his company, he is invariably friendly, no more, this convinced bachelor. He can drink with friends, but not much. Sneak a little, laugh a little. A little bit of everything, a very little bit, so that as much time as possible is left for the main thing - work. Work - an unchanging all-consuming passion - burned him constantly.

Christian Huygens was distinguished by extraordinary dedication. He was aware of his abilities and sought to use them to the fullest. “The only entertainment that Huygens allowed himself in such abstract works,” one of his contemporaries wrote about him, “was that he was engaged in physics in between. What for an ordinary person was a tedious task, for Huygens was entertainment.

In 1663 Huygens was elected a Fellow of the Royal Society of London. In 1665, at the invitation of Colbert, he settled in Paris and the following year became a member of the newly organized Paris Academy of Sciences.

In 1673, his work "Pendulum Clock" was published, where the theoretical foundations of Huygens' invention were given. In this work, Huygens establishes that the cycloid has the property of isochronism, and analyzes the mathematical properties of the cycloid.

Investigating the curvilinear motion of a heavy point, Huygens, continuing to develop the ideas expressed by Galileo, shows that a body, when falling from a certain height along various paths, acquires a finite velocity that does not depend on the shape of the path, but depends only on the height of the fall, and can rise to a height equal (in the absence of resistance) to the initial height. This proposition, which essentially expresses the law of conservation of energy for motion in a gravitational field, is used by Huygens for the theory of the physical pendulum. He finds an expression for the reduced length of the pendulum, establishes the concept of the swing center and its properties. He expresses the formula of a mathematical pendulum for cycloidal motion and small oscillations of a circular pendulum as follows:

"The time of one small oscillation of a circular pendulum is related to the time of falling down twice the length of the pendulum, as the circumference of a circle is related to the diameter."

It is significant that at the end of his essay the scientist gives a number of proposals (without a conclusion) about the centripetal force and establishes that the centripetal acceleration is proportional to the square of the speed and inversely proportional to the radius of the circle. This result prepared the Newtonian theory of the motion of bodies under the action of central forces.

From the mechanical research of Christian Huygens, in addition to the theory of the pendulum and centripetal force, his theory of the impact of elastic balls is known, which he presented for a competitive task announced by the Royal Society of London in 1668. Huygens' impact theory is based on the law of conservation of living forces, momentum and Galileo's principle of relativity. It was not published until after his death in 1703. Huygens traveled quite a lot, but he was never an idle tourist. During the first trip to France, he studied optics, and in London he explained the secrets of making his telescopes. Fifteen years he worked at the court of Louis XIV, fifteen years of brilliant mathematical and physical research. And in fifteen years - only two short trips to his homeland to heal

Christian Huygens lived in Paris until 1681, when, after the repeal of the Edict of Nantes, he returned to his homeland as a Protestant. While in Paris, he knew Römer well and actively assisted him in the observations that led to the determination of the speed of light. Huygens was the first to report Römer's results in his treatise.

At home, in Holland, again not knowing fatigue, Huygens builds a mechanical planetarium, giant seventy-meter telescopes, describes the worlds of other planets.

Huygens' work in Latin appears on light, corrected by the author and republished in French in 1690. Huygens' Treatise on Light entered the history of science as the first scientific work on wave optics. This "Treatise" formulated the principle of wave propagation, now known as Huygens' principle. Based on this principle, the laws of reflection and refraction of light were derived, and the theory of double refraction in Icelandic spar was developed. Since the speed of propagation of light in a crystal is different in different directions, the shape of the wave surface will not be spherical, but ellipsoidal.

The theory of propagation and refraction of light in uniaxial crystals is a remarkable achievement of Huygens' optics. Christian Huygens also described the disappearance of one of the two rays when they pass through the second crystal with a certain orientation relative to the first. Thus, Huygens was the first physicist to establish the fact of light polarization.

Huygens' ideas were highly valued by his successor Fresnel. He ranked them above all discoveries in Newton's optics, arguing that Huygens' discovery "is perhaps more difficult to make than all Newton's discoveries in the field of light phenomena."

Huygens does not consider colors in his treatise, as well as the diffraction of light. His treatise is devoted only to the justification of reflection and refraction (including double refraction) from the wave point of view. This circumstance was probably the reason why Huygens' theory, despite its support in the 18th century by Lomonosov and Euler, did not receive recognition until Fresnel resurrected the wave theory on a new basis in the early 19th century.

Christian Huygens died on June 8, 1695, when KosMoteoros, his last book, was being printed in the printing house. (Samin D.K. 100 great scientists. - M .: Veche, 2000)

More about Christian Huygens:

Huygens (Christian Huyghensvan Zuylichem) is a mathematician, astronomer, and physicist whom Newton recognized as great. His father, signor van Zuylichem, secretary of the princes of Orange, was a remarkable writer and scientifically educated.

Christian Huygens began his scientific activity in 1651 with an essay on the quadrature of the hyperbola, ellipse and circle; in 1654 he discovered the theory of evolute and involute, in 1655 he found the satellite of Saturn and the type of rings, in 1659 he described the system of Saturn in a work he published. In 1665, at the invitation of Colbert, he settled in Paris and was accepted as a member of the Academy of Sciences.

Clocks with wheels driven by weights have been in use for a long time, but the regulation of such clocks was unsatisfactory. Since the time of Galileo, the pendulum has been used separately for accurate measurement of small periods of time, and it was necessary to count the number of swings. In 1657, Christian Huygens published a description of the design of the clock he invented with a pendulum. Later, published by him in 1673, in Paris, the famous work Horologium oscillatorium, sive de mota pendulorum an horologia aptato demonstrationes geometrica, which contains a presentation of the most important discoveries in dynamics, in its first part also contains a description of the structure of the clock, but with the addition improvements in the way the pendulum gains, making the pendulum cycloidal, which has a constant swing time, regardless of the magnitude of the swing. In order to explain this property of the cycloidal pendulum, the author devotes the second part of the book to the derivation of the laws of falling of bodies free and moving along inclined straight lines, and finally along a cycloid. Here, for the first time, the beginning of the independence of motions is clearly expressed: uniformly accelerated, due to the action of gravity, and uniform due to inertia.

Christian Huygens proves the laws of uniformly accelerated motion of freely falling bodies, based on the beginning that the action imparted to the body by a force of constant magnitude and direction does not depend on the magnitude and direction of the speed that the body already possesses. Deriving the relationship between the height of the fall and the square of time, Huygens makes the remark that the heights of the falls are related as the squares of the acquired velocities. Further, considering the free movement of a body thrown upwards, he finds that the body rises to the greatest height, having lost all the speed communicated to it and acquires it again when returning back.

Galileo allowed without proof that when falling along differently inclined straight lines from the same height, bodies acquire equal speeds. Christian Huygens proves this as follows. Two straight lines of different inclination and equal height are attached with their lower ends one to the other. If a body launched from the upper end of one of them acquires a greater speed than that launched from the upper end of the other, then it can be launched along the first of such a point below the upper end so that the speed acquired below is sufficient to lift the body to the upper end of the second straight line, but then it would turn out that the body rose to a height greater than the one from which it fell, but this cannot be.

From the motion of a body along an inclined straight line, H. Huygens proceeds to motion along a broken line and then to motion along any curve, and he proves that the speed acquired when falling from any height along the curve is equal to the speed acquired in free fall from the same height in a vertical line, and that the same speed is required to lift the same body to the same height, both in a vertical straight line and in a curve.

Then, passing to the cycloid and considering some of its geometric properties, the author proves the tautochronism of the motions of the heavy point along the cycloid. In the third part of the work, the theory of evolutes and evolvents, discovered by the author as early as 1654, is presented; here Christians find the form and position of the evolution of the cycloid.

The fourth part presents the theory of the physical pendulum, here Christian Huygens solves the problem that was not given to so many contemporary geometers - the problem of determining the center of swings. It is based on the following proposition: “If a complex pendulum, having left rest, completed some part of its swing, a larger half-swing, and if the connection between all its particles is destroyed, then each of these particles will rise to such a height that their common center of gravity at the same time will be at the height at which it was when the pendulum came out of rest. This proposition, not proved by Christian Huygens, appears to him as a basic principle, while now it represents the application of the law of conservation of energy to the pendulum. The theory of the pendulum of the physical is given by Huygens in a completely general form and in application to bodies of various kinds. In the last, fifth part of his work, the scientist gives thirteen theorems on centrifugal force and considers the rotation of a conical pendulum.

Another remarkable work of Christian Huygens is the Theory of Light, published in 1690, in which he expounds the theory of reflection and refraction and then of double refraction in Icelandic spar, in the same form as it is now presented in the textbooks of physics. Of the others discovered by H. Huygens, we will mention the following.

Discovery of the true appearance of Saturn's rings and its two satellites, made with a ten-foot telescope, which he himself arranged. Together with his brother Christian Huygens, he was engaged in the manufacture of optical glasses and significantly improved their production. Open theoretically the ellipsoidal form of the earth and its compression at the poles, as well as an explanation of the influence of centrifugal force on the direction of gravity and on the length of the second pendulum at different latitudes. Solution of the issue of collision of elastic bodies simultaneously with Wallis and Brenn.

Christian Huygens owns the invention of the clock spiral, which replaces the pendulum, the first clock with a spiral was made in Paris by the watchmaker Thuret in 1674. He also owns one of the solutions to the question of the form of a heavy homogeneous chain in equilibrium.

CHRISTIAN HUYGENS

Christian Huygens von Zuylichen - the son of the Dutch nobleman Constantine Huygens, was born on April 14, 1629. “Talents, nobility and wealth were, apparently, hereditary in the family of Christian Huygens,” wrote one of his biographers. His grandfather was a writer and dignitary, his father was a secret adviser to the princes of Orange, a mathematician, and a poet. Faithful service to their sovereigns did not enslave their talents, and it seemed that Christian was destined for the same enviable fate for many. He studied arithmetic and Latin, music and versification. Heinrich Bruno, his teacher, could not get enough of his fourteen-year-old pupil: “I confess that Christian must be called a miracle among boys ... He develops his abilities in the field of mechanics and structures, makes amazing machines, but hardly necessary.”

The teacher was wrong: the boy is always looking for the benefits of his studies. His concrete, practical mind will soon find schemes of machines that people really need.

However, he did not immediately devote himself to mechanics and mathematics. The father decided to make his son a lawyer and, when Christian reached the age of sixteen, he sent him to study law at the University of London. Being engaged in legal sciences at the university, Huygens at the same time is fond of mathematics, mechanics, astronomy, and practical optics. A skilled craftsman, he grinds optical glasses on his own and improves the pipe, with the help of which he will later make his astronomical discoveries.

Christian Huygens was Galileo's immediate successor in science. According to Lagrange, Huygens "was destined to improve and develop the most important discoveries of Galileo." There is a story about how for the first time Huygens came into contact with the ideas of Galileo. Seventeen-year-old Huygens was going to prove that bodies thrown horizontally move along parabolas, but, having found the proof in the book of Galileo, he did not want to "write the Iliad after Homer."

After graduating from the university, he becomes an adornment of the retinue of the Count of Nassau, who, on a diplomatic mission, is on his way to Denmark. The count is not interested in the fact that this handsome young man is the author of curious mathematical works, and he, of course, does not know how Christian dreams of getting from Copenhagen to Stockholm to see Descartes. So they will never meet: in a few months Descartes will die.

At the age of 22, Huygens published Discourses on the Square of the Hyperbola, Ellipse, and Circle. In 1655, he builds a telescope and discovers one of Saturn's satellites, Titan, and publishes New Discoveries in the Size of a Circle. At the age of 26, Christian writes notes on dioptrics. At the age of 28, his treatise “On Calculations when Playing Dice” was published, where one of the first ever research in the field of probability theory is hidden behind a seemingly frivolous title.

One of Huygens' most important discoveries was the invention of the pendulum clock. He patented his invention on July 16, 1657 and described it in a short essay published in 1658. He wrote about his watch to the French king Louis XIV: “My automata, placed in your apartments, not only amaze you every day with the correct indication of time, but they are suitable, as I hoped from the very beginning, for determining the longitude of a place on the sea.” Christian Huygens was engaged in the task of creating and improving clocks, especially pendulum clocks, for almost forty years: from 1656 to 1693. A. Sommerfeld called Huygens "the most brilliant watchmaker of all time."

At thirty, Huygens reveals the secret of Saturn's ring. The rings of Saturn were first noticed by Galileo as two lateral appendages "supporting" Saturn. Then the rings were visible, like a thin line, he did not notice them and did not mention them again. But Galileo's pipe did not have the necessary resolution and sufficient magnification. Watching the sky with a 92x telescope, Christian discovers that the ring of Saturn was taken as side stars. Huygens solved the riddle of Saturn and for the first time described its famous rings.

At that time Huygens was a very handsome young man with large blue eyes and a neatly trimmed mustache. The reddish curls of the wig, coolly curled in the fashion of that time, fell to the shoulders, lying on the snow-white Brabant lace of an expensive collar. He was friendly and calm. No one saw him especially excited or confused, in a hurry somewhere, or, on the contrary, immersed in slow thoughtfulness. He did not like to be in the “light” and rarely appeared there, although his origin opened the doors of all the palaces of Europe to him. However, when he appeared there, he did not look at all awkward or embarrassed, as often happened with other scientists.

But in vain the charming Ninon de Lanclos seeks his company, he is invariably friendly, no more, this convinced bachelor. He can drink with friends, but not much. Sneak a little, laugh a little. A little bit of everything, a very little bit, so that as much time as possible is left for the main thing - work. Work - an unchanging all-consuming passion - burned him constantly.

Huygens was distinguished by extraordinary dedication. He was aware of his abilities and sought to use them to the fullest. “The only entertainment that Huygens allowed himself in such abstract works,” one of his contemporaries wrote about him, “was that he was engaged in physics in between. What for an ordinary person was a tedious task, for Huygens was entertainment.

In 1663 Huygens was elected a member of the Royal Society of London. In 1665, at the invitation of Colbert, he settled in Paris and the following year became a member of the newly organized Paris Academy of Sciences.

In 1673, his work "Pendulum Clock" was published, where the theoretical foundations of Huygens' invention were given. In this work, Huygens establishes that the cycloid has the property of isochronism, and analyzes the mathematical properties of the cycloid.

Investigating the curvilinear motion of a heavy point, Huygens, continuing to develop the ideas expressed by Galileo, shows that a body, when falling from a certain height along various paths, acquires a finite velocity that does not depend on the shape of the path, but depends only on the height of the fall, and can rise to a height equal (in the absence of resistance) to the initial height. This proposition, which essentially expresses the law of conservation of energy for motion in a gravitational field, is used by Huygens for the theory of the physical pendulum. He finds an expression for the reduced length of the pendulum, establishes the concept of the swing center and its properties. He expresses the formula of a mathematical pendulum for cycloidal motion and small oscillations of a circular pendulum as follows: "The time of one small oscillation of a circular pendulum is related to the time of falling along the double length of the pendulum, as the circumference of a circle is related to the diameter."

It is significant that at the end of his essay, the scientist gives a number of proposals (without a conclusion) about the centripetal force and establishes that the centripetal acceleration is proportional to the square of the speed and inversely proportional to the radius of the circle. This result prepared the Newtonian theory of the motion of bodies under the action of central forces.

From the mechanical research of Huygens, in addition to the theory of the pendulum and centripetal force, his theory of the impact of elastic balls is known, which he presented for a competitive task announced by the Royal Society of London in 1668. Huygens' impact theory is based on the law of conservation of living forces, momentum and Galileo's principle of relativity. It was not published until after his death in 1703.

Huygens traveled quite a lot, but he was never an idle tourist. During the first trip to France, he studied optics, and in London he explained the secrets of making his telescopes. Fifteen years he worked at the court of Louis XIV, fifteen years of brilliant mathematical and physical research. And in fifteen years - only two short trips to his homeland to heal.

Huygens lived in Paris until 1681, when, after the repeal of the Edict of Nantes, he, as a Protestant, returned to his homeland. While in Paris, he knew Römer well and actively assisted him in the observations that led to the determination of the speed of light. Huygens was the first to report Römer's results in his treatise.

At home, in Holland, again not knowing fatigue, Huygens builds a mechanical planetarium, giant seventy-meter telescopes, describes the worlds of other planets.

Huygens' work in Latin appears on light, corrected by the author and republished in French in 1690. Huygens' Treatise on Light entered the history of science as the first scientific work on wave optics. This "Treatise" formulated the principle of wave propagation, now known as Huygens' principle. Based on this principle, the laws of reflection and refraction of light were derived, and the theory of double refraction in Icelandic spar was developed. Since the speed of propagation of light in a crystal is different in different directions, the shape of the wave surface will not be spherical, but ellipsoidal.

The theory of propagation and refraction of light in uniaxial crystals is a remarkable achievement of Huygens' optics. Huygens also described the disappearance of one of the two rays when they pass through the second crystal with a certain orientation relative to the first. Thus, Huygens was the first physicist to establish the fact of light polarization.

Huygens' ideas were highly valued by his successor Fresnel. He ranked them above all discoveries in Newton's optics, arguing that Huygens' discovery "is perhaps more difficult to make than all Newton's discoveries in the field of light phenomena."

Huygens does not consider colors in his treatise, as well as the diffraction of light. His treatise is devoted only to the justification of reflection and refraction (including double refraction) from the wave point of view. This circumstance was probably the reason why Huygens' theory, despite its support in the 18th century by Lomonosov and Euler, did not receive recognition until Fresnel resurrected the wave theory on a new basis in the early 19th century.

Huygens died on July 8, 1695, when Kosmoteoros, his last book, was being printed in the printing house.