Johannes Kepler was a German mathematician, astronomer and astrologer born in 1571 who made significant contributions to astronomy and optics. He is best known for his three laws of planetary motion which described that planets move in elliptical orbits with the sun at one focus, that planets sweep out equal areas in equal time periods, and that the square of a planet's orbital period is proportional to the cube of its semi-major axis. These laws helped lay the foundation for Isaac Newton's later theory of universal gravitation. Kepler had a long career working with astronomers like Tycho Brahe and held positions as a mathematics teacher and imperial mathematician.

1. Johannes Kepler

2. • Born: (1571-12-27)December 27, 1571
• Died : November 15, 1630(1630-11-15) (aged 58)
• Residence: Germany
• Nationality: German
• Fields: Astronomy, astrology, mathematics and natural
philosophy .
Institutions: University of Linz
• Known for: Kepler's laws of planetary motion
Kepler conjecture

3. • Johannes Kepler was a German mathematician, astronomer and
astrologer. A key figure in the 17th century scientific revolution, he is
best known for his eponymous laws of planetary motion, codified by
later astronomers, based on his works Astronomia
nova, Harmonices Mundi, and Epitome of Copernican Astronomy.
These works also provided one of the foundations for Isaac
Newton's theory of universal gravitation.
• During his career, Kepler was a mathematics teacher at a seminary
school in Graz, Austria, where he became an associate of Prince
Hans Ulrich von Eggenberg. Later he became an assistant to
astronomer Tycho Brahe, and eventually the imperial mathematician
to Emperor Rudolf II and his two successors Matthias and Ferdinand
II. He was also a mathematics teacher in Linz, Austria, and an
adviser to General Wallenstein. Additionally, he did fundamental
work in the field of optics, invented an improved version of the
refracting telescope (the Keplerian Telescope), and mentioned the
telescopic discoveries of his contemporary Galileo Galilei.

4. • Kepler lived in an era when there was no clear
distinction between astronomy and astrology, but
there was a strong division between astronomy (a
branch of mathematics within the liberal arts) and
physics (a branch of natural philosophy). Kepler also
incorporated religious arguments and reasoning into
his work, motivated by the religious conviction and
belief that God had created the world according to an
intelligible plan that is accessible through the natural
light of reason. Kepler described his new astronomy as
"celestial physics", as "an excursion into Aristotle's
Metaphysics", and as "a supplement to Aristotle's On
the Heavens", transforming the ancient tradition of
physical cosmology by treating astronomy as part of a
universal mathematical physics.

5. Kepler’s law of motion
In astronomy, Kepler's laws of
planetary motion are three
scientific laws describing orbital
motion, each giving a description
of the motion of planets around
the Sun.

6. Kepler's laws are:
• The orbit of every planet is an ellipse
with the Sun at one of the two foci.
• A line joining a planet and the Sun
sweeps out equal areas during equal
intervals of time.
• The square of the orbital period of a
planet is directly proportional to the
cube of the semi-major axis of its
orbit.

7. LAW OF ORBITS
All planets move in elliptical orbits, with the
sun at one focus.

8. This is one of Kepler's laws. The
elliptical shape of the orbit is a
result of the inverse square force
of gravity. The eccentricity of the
ellipse is greatly exaggerated here.

9. Orbit Eccentricity
The eccentricity of an ellipse can be
defined as the ratio of the distance
between the foci to the major axis of
the ellipse. The eccentricity is zero for
a circle. Of the planetary orbits, only
Pluto has a large eccentricity.

10. The Law of Areas
A line that connects a planet to
the sun sweeps out equal areas in
equal times.

11. This is one of Kepler's laws.This
empirical law discovered by Kepler
arises from conservation of angular
momentum. When the planet is
closer to the sun, it moves
faster, sweeping through a longer
path in a given time.

12. The Law of Periods
The square of the period
of any planet is
proportional to the cube
of the axis of its orbit.

14. This is one of Kepler's laws.This law arises from the law of gravitation.
Newton first formulated the law of gravitation from Kepler's 3rd law.

15. Kepler's Law of Periods in the
above form is an approximation
that serves well for the orbits of
the planets because the Sun's mass
is so dominant. But more precisely
the law should be written

16. In this more rigorous form it is
useful for calculation of the orbital
period of moons or other binary
orbits like those of binary stars.

17. DONE BY-
NIKHIL SAI-9TH B - 32
OMKAR-9TH B -33
KV.NO.1.UPPAL