Johannes Kepler
Johannes Kepler was born on December 27, 1571, in the Holy Roman Empire of German Nationality. He was the one who determined to prove to the world that Copernicus was right and that Ptolemy’s geocentric theory was wrong. Kepler bought a telescope from Galileo and went to work as an assistant for Tycho Brahe. By that time, Brahe’s health was having deterioration in health. On his deathbed, he gave out his life’s work of calculations and star maps to young Kepler reluctantly. With the documents that Brahe has given and with his own sharp intuition, he has made three profound conclusions. These conclusions are known today as Kepler’s Laws of Planetary Motion:
1. The planets travel in elliptical orbits and not in circles around an off-centre Sun. The Sun is at one focal point.
2. The speed of planet’s orbit depends on its distance from the Sun. Which means that the closet planet to the Sun moves the fastest and when a planet is farther away from the Sun, it moves slower than the planets that are closer to the Sun.
3. More distant planets and dwarf planets have longer years than closer ones. For example, Earth’s year is about 365 quarter days, Pluto’s year is about 91000 Earth days which is 248 years, and Sedna’s year would be about 10000 Earth years.
1. The planets travel in elliptical orbits and not in circles around an off-centre Sun. The Sun is at one focal point.
2. The speed of planet’s orbit depends on its distance from the Sun. Which means that the closet planet to the Sun moves the fastest and when a planet is farther away from the Sun, it moves slower than the planets that are closer to the Sun.
3. More distant planets and dwarf planets have longer years than closer ones. For example, Earth’s year is about 365 quarter days, Pluto’s year is about 91000 Earth days which is 248 years, and Sedna’s year would be about 10000 Earth years.