 384BC322BC
 Aristotle
 310BC230BC
 Aristarchus of Samos proposed the Heliocentric theory.
 190BC120BC
 Hipparchus of Rhodes measured the angular height of the star
Alpha Virginis above the ecliptic and compared it with 150yrold
Babylonian observations. From the change of 2 degrees,
he deduced that the Earth's axis precesses at 47 arcseconds per year.
He also made detailed observations of the moon and
estimated the earthmoon distance with similar accuracy.
 150AD
 Ptolemy knocks heliocentricity on the head because
it violates Aristotle's ideas.
Building on Hipparchus's work, he
wrote a detailed mathematical theory of the motions of
the Sun, Moon, and planets.
 15641642
 Galileo
 15461601
 Tycho Brahe
 15711630
 Johannes Kepler
 16291695
 Christiaan Huygens [In 1656 he patented the first pendulum clock and applied it to longitude determination.]
 16431727 (16691687)
 Newton (Lucasian Professor in Cambridge)
 16931776
 John Harrison. Master clockmaker.

 17361813
 Lagrange. Had 10 younger siblings only one of whom survived infancy.
His father, a military man, wasted his earnings; Lagrange viewed this
as good fortune: "Had I been rich, I might never have known
Mathematics". He founded the Turin Academy of Sciences.
 1729.
 Laplace born. "The Newton of France." He published from 17661817.
Among his many achievements,
he put the (gamma1)/gamma into the speed of sound.
 1762
 Lagrange Method of Variations
 1766
 Lagrange moved to Berlin (where Euler had been).
Won prizes for work on moon, Jupiter,
3body problem and comets. Wrote "Analytical Mechanics", which
contained no diagrams.
 1775

 1787
 Lagrange moved to Paris and became depressed.
 1787
 publication commences of "Celestial Mechanics", Laplace's peak.
Biot assisted with the galleys.

 Laplace is president of board of Longitudes.
Went into politics where he was useless. Was replaced
by Bonaparte.
 1812
 Laplace's work on probability published. (Generating functions; inference)
 1889, 1892
 Poincaré. Poincaré was first to consider the possibility of chaos in a deterministic system, in his work on planetary orbits.
Little interest was shown in this work until the modern study of chaotic dynamics began in 1963.




