Johannes Kepler was a German mathematician, astronomer, and astrologer born in 1571 who is best known for his laws of planetary motion. He served as Tycho Brahe's assistant and was appointed as his successor as Imperial Mathematician. Although Tycho withheld some of his data from Kepler and gave him the difficult task of studying Mars, this led Kepler to formulate his three laws of planetary motion, including that planets orbit the sun in ellipses and that the relationship between a planet's period and distance from the sun is connected. Kepler used careful observation and mathematics to scientifically discover and prove his laws, changing the study of planets and influencing later scientists like Newton.

1. Johannes Kepler
By: Michael Toro

2. Background
❖ Born December 27, 1571 and
died November 15, 1630.
❖ He was a German
mathematician, astronomer,
and astrologer
❖ He is best known for his laws
of planetary motion

3. A bit more Background
❖ Kepler served as Tycho Brahe's assistant until the
latter's death in 1601 and was then appointed Tycho's
successor as Imperial Mathematician, the most
prestigious appointment in mathematics in Europe.
❖ Tycho was afraid that Kepler would surpass him, so in
an effort to keep his status, Tycho didn't show Kepler
all his data, and gave him the difficult task of studying
mars

4. Keplers Discovery
❖ Although Tycho made Kepler take on the difficult task
to study the orbit of mars, it was the key to Kepler
forming his laws
❖ Kepler formulated three laws of planetary motion.

5. Second law of planetary
motion
❖ Although it is technically the
first law he discovered, it
would later be called his
second law.
❖ This law states that a planet
orbiting the sun sweeps out
equal areas in equal times.

6. First law of planetary motion
❖ Although he discovered it
second this is his first law.
❖ This law states that planets
orbit the sun in ellipses, with
the sun at one focus.

7. Third law of planetary motion
❖ This law recognized that the relationship between the
period of two planets. The time they take to orbit the
sun is connected to their distance from the sun.

8. Use of the scientific method
❖ Kepler used the scientific method to determine his
laws.
❖ His hypothesis that the sun was at the center of the
universe with planets moving in an elliptical orbit
around the sun was proven true
❖ He used observation as his tests and used
mathematics to discover his laws which were later
confirmed by others.

9. Influences
❖ Kepler's discoveries changed the way that planets
were studied.
❖ Newton built upon the idea of the sun in the center of
the universe
❖ Newton also showed the unity of Kepler’s laws

10. Is it relevant today?
❖ Kepler’s laws are very relevant
today.
❖ The laws of planetary motion still apply.
❖ He was the first to determine that refraction drives vision in the eye,
and that using two eyes enables depth perception.
❖ He created eyeglasses for both near and farsightedness, and
explained how a telescope worked.