Christiaan Huygens

Astronomer horologist mathematician physicist

April 14, 1629 (age 66)

Hague, Netherlands

Huygens's first published work, on the quadrature of various mathematical curves, appeared in 1651. In addition, as a result of his study of collision phenomena between hard, elastic bodies, by 1656 he had demonstrated the incorrectness of René Descartes's laws of motion and impact, although he did not announce his conclusions until some 12 years later, and his complete study of such phenomena was published posthumously. In 1655 Christiaan Huygens spent several months in Paris. He attended the informal gatherings of the so-called Montmort Academy, an important precursor of the French Academy of Sciences and, to at least some of its members, reported on his discovery of Titan, the first of Saturn's moons to be observed. He had initially been attracted to Saturn by its apparently anomalous shape, described by Galileo as "three spheres which almost touch each other, which never change their relative positions, and are arranged in a row along the zodiac so that the middle sphere is three times as large as the others." Intrigued by this peculiar shape, Huygens realized that its resolution would depend on constructing improved telescopes, less subject to various aberrations, and more capable of producing detailed images. Upon returning from Paris, Huygens devoted full time to his efforts to construct such improved eyepieces and lens systems, and although he was unsuccessful in his attempts to produce lenses with hyperbolic or elliptical surfaces, he and his elder brother did succeed in figuring and polishing lenses with an accuracy never before attained. With telescopes utilizing these improved components, great progress was made toward solving the problem of Saturn's appearance. What had originally appeared as a "trispherical" form now appeared as simply some sort of band passing across the middle of the planet, and, early in 1656, utilizing a still better telescope, Huygens was able to clearly distinguish a thin ring surrounding the planet at a slight angle to the ecliptic. In 1659 he published his complete study of Saturn in a work entitled Systema Saturnium. Huygens's interest in improving telescopes continued throughout his life. For measuring the angular diameter of planets, he invented a type of micrometer consisting of a series of small brass plates of varying widths that could be slipped across the focal plane of the telescope. Christiaan Huygens first described his successful application of the pendulum to the escapement mechanism of the standard mechanical clock in 1658. Sometime after he had produced the first pendulum clock, Huygens became interested in its obvious application to the problem of determining longitude at sea. One of the simplest solutions to this important navigation problem involved the construction of extremely accurate timekeeping device with which local time could be compared with a standard time at, say, Paris or London. Although the pendulum clock was the most accurate such device then available, its motion was easily disturbed by the movement of the ship at sea. In an effort to overcome this difficulty, Huygens invented a pendulum whose period of oscillation was independent of the amplitude of its swing. In 1660 Huygens returned to Paris, where he again attended meetings of the Montmort Academy. By 1661 he had discovered a basic principle of mechanics which allowed him to solve with ease certain types of problems which English mathematicians at the time found especially difficult. Now fundamental, this principle stated that the center of gravity of a body or system of bodies, acting solely under the influence of gravity, cannot rise above the level from which it initially falls. The French Academy of Sciences was officially formed in 1666, and at the invitation of Louis XIV's chief minister, Huygens returned to Paris and a position as a leader and founding member of the new academy. He was one of the chief influences in guiding the early affairs of the academy and, profiting from his contacts with English men of science, he emphasized the need for careful observation and experiment. With the exception of two trips to The Hague because of illness, he remained in Paris until 1681. In the years after his return to Paris, Huygens's interests turned increasingly from astronomy to terrestrial mechanics, and as a result of his work in this field, he has rightfully been regarded as one of the founders of the science of dynamics. His earliest studies in this area dealt with impact phenomena, and although he had completed this work as early as 1656, his results were reported only in 1669, when he presented to the Royal Society a clear and concise statement of the laws governing the collision of elastic bodies. Although of great significance because of their statement of the conservation of mechanical energy in the collision of perfectly elastic bodies and because of their refutation of the incorrect laws of impact earlier presented by Descartes, Huygens's results were presented without proof, and their complete demonstration was published posthumously in 1703. One of the great scientific treatises of the 17th century, Huygens's masterpiece, Horologium oscillatorium, appeared in 1673. More than just a summary of his researches on the pendulum clock, it in fact was a general work on dynamics containing numerous original discoveries. In it, he demonstrated the isochronous nature of a body moving freely under the influence of gravity along a cycloidal path. He showed how to calculate the period of oscillation of a simple pendulum. He provided a definitive solution to the problem of a compound and physical pendulums, demonstrating how to calculate the "center of oscillation" and the length of an equivalent simple pendulum. And, in an appendix, he presented the basic laws of centrifugal force governing bodies moving with a uniform circular motion. The significance of this monumental work was immediately recognized. Perhaps the best-known of Huygens's varied pursuits is his work on physical optics and his development of the wave, or, more accurately, pulse, the theory of light. First presented before the Academy of Sciences in 1678, his Traité de la lumière (Treatise on Light) was, characteristically, not published until 1690. The theory of light put forth in it, however, was the direct result of his study of impact phenomena and represented the union of the physical and mathematical aspects of the study of optics. Other inventions by Huygens included his design of an internal combustion engine in 1680 that ran off of gunpowder, although he never actually built it. He developed the first compound eyepiece for a telescope using multiple lenses, which bore his name. These eyepieces were considered standard equipment for large telescopes for some time. Huygens also built three telescopes with focal lengths of 123 feet, 180 feet, and 210 feet, which were later presented to the Royal Society. In 1681 Huygens returned to The Hague. Although ill health was the immediate cause, additional personal and religious pressures combined to make permanent his return to his native country. He did, however, maintain his extensive correspondence, and although his mathematical and abstract studies suffered a marked diminution after 1680, the general pattern of his life remained little changed until his death on July 8, 1695.

Christiaan Huygens Edit Profile

Astronomer horologist mathematician physicist

Background

Christiaan Huygens was born on April 14, 1629, to Constantijn Huygens and Suzanna Van Baerle in The Hague, capital city of South Holland. Huygens came from a wealthy and distinguished middle-class family. Christiaan was named after his paternal grandfather.

Education

Privately tutored at home until 16, Christiaan early showed signs of intellectual brilliance, devoting much time to drawing and making mechanical models and devices as well as demonstrating exceptional skill in geometry. As a child, Huygens loved to experiment with windmills and other machines and to watch the ripples produced by throwing a stone into water.

Huygens was already in contact with leading scholars of the time, even at an early age. Mersenne, the famous French polymath, wrote to his father that his child had the potential to "even surpass Archimedes."

He studied law and mathematics at the University of Leiden and after 2 years moved on to Breda, where he completed his studies.

Education period of Christiaan Huygens in Leiden University

Career

Huygens's first published work, on the quadrature of various mathematical curves, appeared in 1651. In addition, as a result of his study of collision phenomena between hard, elastic bodies, by 1656 he had demonstrated the incorrectness of René Descartes's laws of motion and impact, although he did not announce his conclusions until some 12 years later, and his complete study of such phenomena was published posthumously.

In 1655 Christiaan Huygens spent several months in Paris. He attended the informal gatherings of the so-called Montmort Academy, an important precursor of the French Academy of Sciences and, to at least some of its members, reported on his discovery of Titan, the first of Saturn's moons to be observed. He had initially been attracted to Saturn by its apparently anomalous shape, described by Galileo as "three spheres which almost touch each other, which never change their relative positions, and are arranged in a row along the zodiac so that the middle sphere is three times as large as the others." Intrigued by this peculiar shape, Huygens realized that its resolution would depend on constructing improved telescopes, less subject to various aberrations, and more capable of producing detailed images.

Upon returning from Paris, Huygens devoted full time to his efforts to construct such improved eyepieces and lens systems, and although he was unsuccessful in his attempts to produce lenses with hyperbolic or elliptical surfaces, he and his elder brother did succeed in figuring and polishing lenses with an accuracy never before attained. With telescopes utilizing these improved components, great progress was made toward solving the problem of Saturn's appearance. What had originally appeared as a "trispherical" form now appeared as simply some sort of band passing across the middle of the planet, and, early in 1656, utilizing a still better telescope, Huygens was able to clearly distinguish a thin ring surrounding the planet at a slight angle to the ecliptic. In 1659 he published his complete study of Saturn in a work entitled Systema Saturnium.

Huygens's interest in improving telescopes continued throughout his life. For measuring the angular diameter of planets, he invented a type of micrometer consisting of a series of small brass plates of varying widths that could be slipped across the focal plane of the telescope.

Christiaan Huygens first described his successful application of the pendulum to the escapement mechanism of the standard mechanical clock in 1658.

Sometime after he had produced the first pendulum clock, Huygens became interested in its obvious application to the problem of determining longitude at sea. One of the simplest solutions to this important navigation problem involved the construction of extremely accurate timekeeping device with which local time could be compared with a standard time at, say, Paris or London. Although the pendulum clock was the most accurate such device then available, its motion was easily disturbed by the movement of the ship at sea. In an effort to overcome this difficulty, Huygens invented a pendulum whose period of oscillation was independent of the amplitude of its swing.

In 1660 Huygens returned to Paris, where he again attended meetings of the Montmort Academy. By 1661 he had discovered a basic principle of mechanics which allowed him to solve with ease certain types of problems which English mathematicians at the time found especially difficult. Now fundamental, this principle stated that the center of gravity of a body or system of bodies, acting solely under the influence of gravity, cannot rise above the level from which it initially falls.

The French Academy of Sciences was officially formed in 1666, and at the invitation of Louis XIV's chief minister, Huygens returned to Paris and a position as a leader and founding member of the new academy. He was one of the chief influences in guiding the early affairs of the academy and, profiting from his contacts with English men of science, he emphasized the need for careful observation and experiment. With the exception of two trips to The Hague because of illness, he remained in Paris until 1681.

In the years after his return to Paris, Huygens's interests turned increasingly from astronomy to terrestrial mechanics, and as a result of his work in this field, he has rightfully been regarded as one of the founders of the science of dynamics. His earliest studies in this area dealt with impact phenomena, and although he had completed this work as early as 1656, his results were reported only in 1669, when he presented to the Royal Society a clear and concise statement of the laws governing the collision of elastic bodies. Although of great significance because of their statement of the conservation of mechanical energy in the collision of perfectly elastic bodies and because of their refutation of the incorrect laws of impact earlier presented by Descartes, Huygens's results were presented without proof, and their complete demonstration was published posthumously in 1703.

One of the great scientific treatises of the 17th century, Huygens's masterpiece, Horologium oscillatorium, appeared in 1673. More than just a summary of his researches on the pendulum clock, it in fact was a general work on dynamics containing numerous original discoveries. In it, he demonstrated the isochronous nature of a body moving freely under the influence of gravity along a cycloidal path. He showed how to calculate the period of oscillation of a simple pendulum. He provided a definitive solution to the problem of a compound and physical pendulums, demonstrating how to calculate the "center of oscillation" and the length of an equivalent simple pendulum. And, in an appendix, he presented the basic laws of centrifugal force governing bodies moving with a uniform circular motion. The significance of this monumental work was immediately recognized.

Perhaps the best-known of Huygens's varied pursuits is his work on physical optics and his development of the wave, or, more accurately, pulse, the theory of light. First presented before the Academy of Sciences in 1678, his Traité de la lumière (Treatise on Light) was, characteristically, not published until 1690. The theory of light put forth in it, however, was the direct result of his study of impact phenomena and represented the union of the physical and mathematical aspects of the study of optics.

Other inventions by Huygens included his design of an internal combustion engine in 1680 that ran off of gunpowder, although he never actually built it. He developed the first compound eyepiece for a telescope using multiple lenses, which bore his name. These eyepieces were considered standard equipment for large telescopes for some time. Huygens also built three telescopes with focal lengths of 123 feet, 180 feet, and 210 feet, which were later presented to the Royal Society.

In 1681 Huygens returned to The Hague. Although ill health was the immediate cause, additional personal and religious pressures combined to make permanent his return to his native country. He did, however, maintain his extensive correspondence, and although his mathematical and abstract studies suffered a marked diminution after 1680, the general pattern of his life remained little changed until his death on July 8, 1695.

Achievements

Christiaan Huygens was a leading scientist of his time. His work included early telescopic studies of the rings of Saturn and the discovery of its moon Titan, the invention of the pendulum clock, and other investigations in timekeeping. He published major studies of mechanics and optics and pioneered work on games of chance.

Works

The Celestial Worlds Discovered: Or Conjectures Concerning The Inhabitants, Plants And Productions Of The Worlds In The Planets The Celestial Worlds Discovered: Or Conjectures Concerning The Inhabitants, Plants And Productions Of The Worlds In The Planets

Cosmotheoros: or, conjectures concerning the inhabitants of the planets. Translated from the Latin of Christian Huygens. A new edition, corrected. Cosmotheoros: or, conjectures concerning the inhabitants of the planets. Translated from the Latin of Christian Huygens. A new edition, corrected.

book
- Treatise on Light
  (The Treatise on Light of Huygens has, however, withstood ...)
  1690
- Cosmotheoros: or, conjectures concerning the inhabitants of the planets. Translated from the Latin of Christian Huygens. A new edition, corrected.
- The Celestial Worlds Discovered: Or Conjectures Concerning The Inhabitants, Plants And Productions Of The Worlds In The Planets 1722

Views

Early publications by Huygens were focused on mathematical problems, but in 1654 he turned his attention to the telescope. With the help of his brother, he came up with a better method of grinding and polishing the lenses, providing greater clarity. He turned one of his improved telescopes toward the planet Saturn, which had shown an elongated appearance in less accurate observations. Huygens determined that the distorted planet boasted several rings. Although his finding was initially not well received, further observations confirmed Saturn was indeed a ringed planet.

Huygens also discovered a large moon orbiting the planet, which he named Titan. When the European Space Agency parachuted a probe onto the moon in 2005 to study its atmosphere, they named it after the Dutch astronomer. Titan is considered one of the best possible sources for life in the solar system. Fittingly, Huygens wrote one of the earliest discussions on extraterrestrial life, published just after his death.

Huygens also focused on light and its mechanics. In the 17th century, three theories about how light functioned existed in various stages. The first suggested that the eye sent out something which registered the world around it. The second proposed that objects emitted something which hit the eye. The third advocated that a medium between the eye and the environment around it changed between the object and the eye, allowing for sight.

Light, Huygens suggested, consisted of the longitudinal vibrations of an all-pervasive ether composed of small, hard, elastic particles, each of which transmitted the impulses it received to all contiguous particles without itself suffering any permanent displacement. The propagation of light was thus reduced to the transmission of motion.

Each particle of a luminous body, such as a candle flame, sent out its own set of concentric, spherical wavelets. Formulating what is today known as Huygens's principle, he conceived of each ether particle itself as also being the source of a new wavelet, which was likewise propagated to the adjacent particles. Within the boundaries where these individual wavelets reinforced each other and formed a coherent wave envelope, light was propagated. Outside the boundaries, there is no reinforcement of the wavelets, was shadow, and no propagation of light.

Based on the third theory, Huygens proposed that light traveled in waves through a rare substance called luminiferous ether. The waves of light allegedly vibrated the ether as they traveled from the object to the eye. With this as his foundation, Huygens calculated the laws of reflection and refraction. Although his calculations remain correct, the ether itself does not exist.

His theory was rejected by Isaac Newton, who proposed that light was composed of several small bodies moving. Today, light is understood to have attributes of both waves and particles.

Huygens contributed to the understanding of mechanics when he determined that collisions between bodies neither lose nor gain momentum within the system. A single object may transfer its momentum to another object in a collision. He proposed that the object's center of gravity moves in a straight line, and calculated the formula for centrifugal force, the outward-pushing force on a rotating body.

Quotations: "I believe that we do not know anything for certain, but everything probably."

"One may conceive light to spread successively, by spherical waves."

"It is surrounded by a thin flat ring, inclined to the ecliptic, and nowhere touches the body of the planet."

Membership

In 1663, Christiaan Huygens became a Fellow of the Royal Society. He was also a member of French Academy of Sciences.

Royal Society , United Kingdom

1663
French Academy of Sciences , France

1666

Personality

Christiaan Huygens suffered from severe depression, which worsened during the last five years of his life after the death of his father in 1687.

Connections

Christiaan Huygens led a lonely life and neither married nor had children.

Father:: Constantijn Huygens
Mother:: Suzanna van Baerle
Sister:: Suzanna Huygens
Brother:: Philips Huygens
Brother:: Lodewijck Huygens
Brother:: Constantijn Huygens Jr.
tutor:: Jan Jansz de Jonge Stampioen
Acquaintance:: Rene Descartes
Acquaintance:: Marin Mersenne
Acquaintance:: Thomas Hobbes

Main Photo