Astro2110 – The Solar System

Kepler’s portrait by an unknown artist

Johannes Kepler’s(1571-1630) love for astronomy started at a young age. He had amazing mathematical prowess although challenged by poor vision which limited his ability in astronomical observation. During his prime years, he worked as an assistant to astronomer Tycho Brahe who collected numerous and accurate data of celestial positions in hope of building his own model of the universe. Tycho guarded his data closely and it was only after his death that Kepler gained full access to the data. He worked on Tycho’s observations for ten years, and found that the data perfectly fit a model of planets orbiting the Sun in an elliptical path. He published his discoveries in Astronomia nova in 1609, explaining the first two of his famous laws of planetary motion. Kepler’s ‘Third Law’, discovered a decade later, relates a planet’s distance to the Sun with its orbital period, later becoming the basis for Newton’s law of universal gravitation.

What else is going on around Kepler?

Kepler lived during the beginnings of European’s colonialism. In the 1600s, European countries began to colonize India and East Asia in direct competition with each other. For example, in 1602, the British East India Company sailed to Bantam where they set up a trading post which later became the center of British trade in Indonesia for 80 years.

In his lifetime, other astronomers are also making great discoveries. In 1610, both Galileo and Simon Marius independently observed Jupiter’s four Galilean moons, which Simon would then name Io, Europa, Ganymede and Callisto, at Kepler’s suggestions.

Other notable person living in those times?

Francis Bacon (1561-1626) was an English scientist, philosopher and writer. Through his works, he popularized scientific inquiry through inductive methodology which greatly influenced the modern scientific method we know today.

Reflection

When Kepler made his discoveries, a brand new world opened up for humanity. As if the broken mirror we saw ourselves in were fixed and polished. But Kepler was not alone, and far from the first. Many before him, among him, and after him, made discoveries that had changed the world forever. In fact, every little thing we learned had changed us, brought us to new heights and made us better, as man and as seekers of knowledge. Knowledge expands and continues to expand. The more knowledge gained, the more we realized how vast it is, and how little we know. It is perhaps somewhat similar to the universe: the more we peer out of our skies, the more we see how endless everything is.