Historical Astronomers in Context

Johannes Kepler (1571- 1630)

Johannes Kepler was an important contributor to astronomy after he created the three laws of planetary motion. The first law states that planets move in elliptical orbits around the sun, and the second law states that planets move faster in their orbits when closer to the sun. Lastly, the third law explains the relationship between orbit speed and distance from the sun. His discovery of elliptical orbits around the sun paved the way for many future astronomical discoveries.  

Historical Events

One major historical event that happened in the late 16th century, more specifically between 1592-98, was the Japanese invasion of Korea. Initially, the Japanese forces conquered the majority of the Korean peninsula but were driven back by Chinese reinforcements. This resulted in a stalemate, deeming the Japanese invasion a failure. Another historical event that happened around this time was the start of the Scientific Revolution. The Scientific Revolution changed the way Europeans thought by introducing the Scientific Method, a method of learning that involves heavy observation. The Scientific Revolution replaced philosophy with science and facts by starting a period of experimentation and questioning. 

Historical Figure

Another historical figure that was alive during the time of Kepler was William Shakespeare. Shakespeare was a worldwide renowned poet, famous for his works like Hamlet and Romeo and Juliet. 

Reflection

Learning about this time period and the historical figures/events during this time, opened my eyes to how long ago these observations were made. Astronomers like Kelper set the foundation for what we know today, and their experimentation has opened up tremendous avenues for astronomers who have come after them. It is incredibly interesting to see how these astronomers made such monumental discoveries with such little technology and help.

Blog 1: Our Expanding Universe

Our expanding universe is a captivating cosmic phenomenon that continues to unfold in the vastness of space. Galaxies throughout the cosmos are in a state of expansion, distancing themselves from one another as space itself expands between them. From our vantage point on Earth, nearly every galaxy beyond our Local Cluster is gradually moving away and it appears the farther away the galaxy, the faster the rate at which it expands. Scientists call the source of this acceleration and movement dark energy, however, they still aren’t completely sure how dark energy works. While these cosmic shifts are invisible to the naked eye, astronomers utilize Doppler shifts to measure them and the rate at which they are expanding accurately. 

More specifically, researchers use the wavelength of light to determine whether an object is approaching or receding from Earth. A shorter wavelength, denoted as a “blue shift,” signifies the object is moving towards Earth. Conversely, a longer wavelength, identified as a “redshift,” indicates the object is moving away from Earth. Moreover, the greater the speed of the object in its trajectory, the more drastic the shift in wavelength becomes.

Furthermore, this observational technique has allowed scientists and astronomers to estimate that our universe is approximately 14 billion years old. It is exciting to think how different our universe will look in the billions of years to come. 

The expansion of the universe from the Big Bang to the present. Digital illustration.

Sources: Photo, Dark Energy, Doppler Shift