* 1629 – Christiaan Huygens, Dutch mathematician ( d. 1695 )

In 1691 Gottfried Leibniz, Christiaan Huygens, and Johann Bernoulli derived the equation in response to a challenge by Jakob Bernoulli.

The mathematical description was derived in 1659 by Dutch physicist Christiaan Huygens.

Augustin-Jean Fresnel did more definitive studies and calculations of diffraction, made public in 1815 and 1818, and thereby gave great support to the wave theory of light that had been advanced by Christiaan Huygens and reinvigorated by Young, against Newton's particle theory.

It was notable for containing the principles of the stereographic and the orthographic projections, and it inspired the works of Desargues and Christiaan Huygens.

* Christiaan Huygens 1629 – 1695 ( Netherlands )

Christiaan Huygens experimented with gunpowder in 1673 in an early attempt to build an internal combustion engine, but he did not succeed.

The Huygens – Fresnel principle ( named after Dutch physicist Christiaan Huygens and French physicist Augustin-Jean Fresnel ) is a method of analysis applied to problems of wave propagation both in the far-field limit and in near-field diffraction.

* Christiaan Huygens

Christiaan Huygens, prior to Newton, had hypothesized that light was a wave propagating through an aether, but Newton rejected this idea.

In 1668, Wilkins proposed using Christopher Wren's suggestion of a pendulum with a half-period of one second to measure a standard length that Christiaan Huygens had observed to be 38 Rhineland or English inches ( 997mm ) in length.

* 1655 – Saturn's largest moon, Titan, is discovered by Christiaan Huygens.

There has been some debate about who the original inventor of the magic lantern is, but the most widely accepted theory is that Christiaan Huygens developed the original device in the late 1650s.

This phenomenon was first observed by Christiaan Huygens in 1665.

Christiaan Huygens ( 1657 ) gave the earliest known scientific treatment of the subject.

File: Christiaan Huygens-painting. jpeg | Christiaan Huygens ( 1629-1695 ): studied the rings of Saturn and discovered its moon Titan, invented the pendulum clock, studied optics and centrifugal force, theorized that light consists of waves ( Huygens – Fresnel principle ) which became instrumental in the understanding of wave-particle duality.

Christiaan Huygens published a book on the subject in 1657 and in the 19th century a big work was done by Laplace in what can be considered today as the classic interpretation.

From its invention in 1656 by Christiaan Huygens until the 1930s, the pendulum clock was the world's most precise timekeeper, accounting for its widespread use.

The pendulum clock was invented in 1656 by Dutch scientist Christiaan Huygens, and patented the following year.

Optics, for instance, was revolutionized by people like Robert Hooke, Christiaan Huygens, René Descartes and, once again, Isaac Newton, who developed mathematical theories of light as either waves ( Huygens ) or particles ( Newton ).

* Christiaan Huygens writes the first book to be published on probability theory, De ratiociniis in ludo aleae (" On Reasoning in Games of Chance ").

In 1673, Christiaan Huygens published his theory of the pendulum, Horologium Oscillatorium sive de motu pendulorum.

Christiaan Huygens solved this problem in the 1650s and published it much later as a book.

The nebula was independently discovered by several other prominent astronomers in the following years, including, in 1656, Christiaan Huygens ( whose sketch was the first published, in 1659 ).

The first tables for the equation of time which accounted for its annual variations in an essentially correct way were published in 1665 by Christiaan Huygens.

* Christiaan Huygens, in his posthumously published book Kosmotheoros, argues that other planets in the solar system could contain extraterrestrial life, starting a debate that extends into the 21st century.

* Christiaan Huygens writes the first book to be published on probability theory, De ratiociniis in ludo aleae (" On Reasoning in Games of Chance ").

In 1673, 17 years after he invented the pendulum clock, Christiaan Huygens published his mathematical analysis of pendulums, Horologium Oscillatorium.

Augustin-Jean Fresnel did more definitive studies and calculations of diffraction, published in 1815 and 1818, and thereby gave great support to the wave theory of light that had been advanced by Christiaan Huygens and reinvigorated by Young, against Newton's particle theory.

" He wrote two books on the subject, one published in 1647 and the other in 1668, which cover some two or three thousand closely printed pages ; the fallacy in the quadrature was pointed out by Christiaan Huygens.

Drawing of one of his first balance springs, attached to a balance wheel, by Christiaan Huygens, inventor of the balance spring, published in his letter in the Journal des Sçavants of 25 February 1675.

Christiaan Neethling Barnard ( 8 November 1922 – 2 September 2001 ) was a South African cardiac surgeon who performed the world's first successful human-to-human heart transplant.

* 1967 – At Groote Schuur Hospital in Cape Town, South Africa, a transplant team headed by Christiaan Barnard carries out the first heart transplant on a human ( 53-year-old Louis Washkansky ).

* December 3 – Christiaan Barnard carries out the world's first heart transplant at Groote Schuur Hospital in Cape Town.

In 1656 the Dutch scientist Christiaan Huygens built the first pendulum clock.

The first engagement of this new form of warfare was at Sanna's Post on 31 March where 1, 500 Boers under the command of Christiaan De Wet attacked Bloemfontein's waterworks about east of the city, and ambushed a heavily escorted convoy, which caused 155 British casualties and the capture of seven guns, 117 wagons, and 428 British troops.

* 1967 – Christiaan Barnard performs the first human heart transplant

The couple had five children: in 1628 their first son, Constantijn Jr., in 1629 Christiaan, in 1631 Lodewijk and in 1633 Philips.

In 1673 Christiaan Huygens derived the equation for the center of oscillation and oscillation period of compound pendulums, thus making use of the general equation for the moment of inertia for the first time.

The first success was achieved on December 3, 1967, by Christiaan Barnard in Cape Town, South Africa.

The first powerful telescopes of Keplerian construction were made by Christiaan Huygens after much labor — in which his brother assisted him.

This proposal was readily accepted, and Christiaan Eijkman was appointed its first Director, at the same time being made Director of the " Dokter Djawa School " ( Javanese Medical School ) which later become University of Indonesia.

Nicolas Fatio presented the first formulation of his thoughts on gravitation in a letter to Christiaan Huygens in the spring of 1690.

Christiaan Huygens was the first person informed by Fatio of his theory, but never accepted it.

Running on the platform of self-determination and apartheid as it was termed for the first time, Prime Minister Daniel Malan and his party benefited from their support in the rural electorates, defeating General Jan Christiaan Smuts and his United Party.

* Christiaan Huygens designs the first working pendulum clock, which is sufficiently accurate to be fitted with both a minute hand and a second hand.

* The tractrix, sometimes called a tractory or equitangential curve, is first studied by Christiaan Huygens, who gives it its name.

* Christiaan Huygens publishes Systema Saturnium, including the first illustration of the Orion Nebula.

* Christiaan Huygens patents his 1656 design for a pendulum clock and the first example is made for him by Salomon Coster at The Hague.

* December 3-Dr Christiaan Barnard and a team including his brother Marius perform the first successful human heart transplant, at Groote Schuur Hospital in Cape Town, South Africa, on Louis Washkansky, who survives for eighteen days.