598
9 Variational Principles in Mechanics and Their Applications
9.11 Introduction to the Famous Scientists
Kepler (Johannes, 1571.12.27–1630.11.15) German mathematician, astronomer and
physicist. Born in Free Imperial City of Weil der Stadt, died in Regensburg. Graduated from the University of Tübingen, obtained a master’s degree in literature in
1591. Became a mathematics and astronomy teacher at a seminary school in Graz,
Austria in 1594. Then using geometry image to descript the planetary orbit, Results
except Jupiter were that the error was less than 5%. Was invited to work at the
Benatek observatory near Prague in 1600, held an assistant to astronomer Tycho
Brahe (1546.12.14–1601.10.24). Inherited died Tycho Brahe’s work in 1601, at the
same time inherited the position of the royal mathematicians. Main achievements
were that he proposed the three laws of planetary motion, laid the foundation of
celestial mechanics, was acclaimed as “the sky’s legislator”. Also laid the foundation
of geometrical optics. The works had Mysterium Cosmographicum (1596), Astronomiae Pars Optica (1604), Astronomia nova (1609), Harmonices Mundi (1619) and
Rudolphine Tables (1629) etc.
Maupertuis (Pierre Louis Moreau de, 1698.9.28–1759.7.27) French mathematician,
physicist, biologist and philosopher. Born in Saint-Malo, died in Basel, Switzerland.
Had been a musketeer in the army when he was young. Served as a mathematics
teacher of the French Academy of Sciences in 1723. Was twice elected a member
of the French Academy of Sciences in 1723 and 1743, was elected a member of the
Royal Society in 1728, served as the President of the Prussian Academy of Sciences
from 1746 to 1753. Led an expedition to the Swedish Lapland region to measure the
meridian of earth in 1735, confirmed the validity of the flat earth theory. Proposed
that the integral of the mass of a body multiplied by its velocity and the path passed
through was a minimum, namely the principle of least action in 1744, and generalized
it to the conservative system with n degrees of freedom, later, Euler further clarified
the principle, Lagrange and Hamilton developed the principle. Published the paper
about the natural evolution in 1744, later studied the cause of biology embryo for
many times. The works had Sur la figure de la terre (1738), Discours sur la figure des
astres (1742), Essai de cosmologie (1750) and Œeuvres de Maupertuis (4 volumes,
1756) etc.
D’Alembert (Jean Le Rond, 1717.11.16–1783.10.29) French mathematician,
mechanician, physicist and philosopher. Born and died in Paris. Graduated from
the Collège Mazarin in 1735. Was elected into the French Academy of Sciences
in 1741, served as an assistant member of astronomy. Served as a deputy editor of
the French Encyclopedia in 1746, and wrote a lot of important items for it, became
a vice member in mathematics in the same year. Published the Réflexions sur la
cause générale des vents in 1746, won the grand prize of the French Academy of
Sciences. Became a fellow of the Royal Society in 1748. Was elected a member
of the French Academy of Sciences in 1754, served as the secretary for life to
the Academy in 1772. Was also member of the Berlin Academy of Sciences and
many other European countries’ academies of sciences. Made contributions to mathematics, mechanics and astronomy etc. many fields, the founder of the planetary
9 Variational Principles in Mechanics and Their Applications
9.11 Introduction to the Famous Scientists
Kepler (Johannes, 1571.12.27–1630.11.15) German mathematician, astronomer and
physicist. Born in Free Imperial City of Weil der Stadt, died in Regensburg. Graduated from the University of Tübingen, obtained a master’s degree in literature in
1591. Became a mathematics and astronomy teacher at a seminary school in Graz,
Austria in 1594. Then using geometry image to descript the planetary orbit, Results
except Jupiter were that the error was less than 5%. Was invited to work at the
Benatek observatory near Prague in 1600, held an assistant to astronomer Tycho
Brahe (1546.12.14–1601.10.24). Inherited died Tycho Brahe’s work in 1601, at the
same time inherited the position of the royal mathematicians. Main achievements
were that he proposed the three laws of planetary motion, laid the foundation of
celestial mechanics, was acclaimed as “the sky’s legislator”. Also laid the foundation
of geometrical optics. The works had Mysterium Cosmographicum (1596), Astronomiae Pars Optica (1604), Astronomia nova (1609), Harmonices Mundi (1619) and
Rudolphine Tables (1629) etc.
Maupertuis (Pierre Louis Moreau de, 1698.9.28–1759.7.27) French mathematician,
physicist, biologist and philosopher. Born in Saint-Malo, died in Basel, Switzerland.
Had been a musketeer in the army when he was young. Served as a mathematics
teacher of the French Academy of Sciences in 1723. Was twice elected a member
of the French Academy of Sciences in 1723 and 1743, was elected a member of the
Royal Society in 1728, served as the President of the Prussian Academy of Sciences
from 1746 to 1753. Led an expedition to the Swedish Lapland region to measure the
meridian of earth in 1735, confirmed the validity of the flat earth theory. Proposed
that the integral of the mass of a body multiplied by its velocity and the path passed
through was a minimum, namely the principle of least action in 1744, and generalized
it to the conservative system with n degrees of freedom, later, Euler further clarified
the principle, Lagrange and Hamilton developed the principle. Published the paper
about the natural evolution in 1744, later studied the cause of biology embryo for
many times. The works had Sur la figure de la terre (1738), Discours sur la figure des
astres (1742), Essai de cosmologie (1750) and Œeuvres de Maupertuis (4 volumes,
1756) etc.
D’Alembert (Jean Le Rond, 1717.11.16–1783.10.29) French mathematician,
mechanician, physicist and philosopher. Born and died in Paris. Graduated from
the Collège Mazarin in 1735. Was elected into the French Academy of Sciences
in 1741, served as an assistant member of astronomy. Served as a deputy editor of
the French Encyclopedia in 1746, and wrote a lot of important items for it, became
a vice member in mathematics in the same year. Published the Réflexions sur la
cause générale des vents in 1746, won the grand prize of the French Academy of
Sciences. Became a fellow of the Royal Society in 1748. Was elected a member
of the French Academy of Sciences in 1754, served as the secretary for life to
the Academy in 1772. Was also member of the Berlin Academy of Sciences and
many other European countries’ academies of sciences. Made contributions to mathematics, mechanics and astronomy etc. many fields, the founder of the planetary