C ULTURAL P ROJECT : T HE E ARTH & T HE S UN : W HAT R EVOLVES A ROUND W HAT ? Physics 001 By: Emily Pambianco, Paige McManus, & Sarah Bomrad

EARLY THINKING  It was not until the 16 th century that people became aware that Earth, and all other planets, revolved around the Sun.  Before this, in 150 AD, the philosophy of Claudius Ptolemeus was the most widely used theory explaining the structure of the solar system. Ptolemeus was an astronomer, mathematician, and geographer who had created this early model which assumed that the Earth was not only the center of our solar system, but the center of our universe.  The Ptolemaic Model explained the motions of the planets in a different way. He described the universe as “nesting circles”. This idea assumes that “each planet moved on a small sphere or circle, that moved on a larger sphere or circle” ( This movement described is called an epicycle, moving on a larger sphere called a deferent.

Diagram of an Epicycle

E ARLY T HINKING  Another concept thought of in these days was the concept of the stars in the sky.  Early astronomers were under the perception that the Sun, moon, planets and other celestial beings orbited around the Earth.  Before telescopes were invented, this was thought of to be true by the common people since the naked eye was the only way in which this could be judged. In these times, we obviously didn’t have the technology we have today, so people basically believed everything that an intelligent individual had theorized.  (

D ISCOVERY Galileo Galilei changed the way we think about he universe. He studied the sun, the earth, and the moon. Scientist, Nicolaus Copernicus, in 1543, published a new theory stating the earth revolves around the sun. This is known as the Copernican theory. This theory was considered a serious challenge to the Ptolemaic theory (which was discussed in the previous slides). Copernicus died before he could prove his theory. Unfortunately, before he could prove his theory of the Earth revolving around the sun, Copernicus died. When he passed, Galilei took over and studied the Copernicus Theory and set out to prove or disprove it. To do this he used the telescope.

G ALILEO G ALILEI

T HE M OONS OF J UPITER Galileo made an important discovery about the planet Jupiter in He noticed four “stars” revolving around Jupiter, and then realized that these “stars” were not actually stars, but moons. “Galileo's discovery of four moons revolving around Jupiter proved one object in space can revolve around a second object in space while the second object revolves around a third object in space.” ( ) To be put more simply, this observation proved the moon can revolve around the earth while the earth revolves around the sun. This is the observation that helped prove the Copernican Theory that the Earth revolves around the sun.

I MPACT ON S OCIETY ( MODERN SCIENCE ) Due to Galileo’s discovery, he is responsible for the birth of modern science. Due to Galileo’s astronomical discoveries, other scientific endeavors and principles are named after him and include: The Galileo spacecraft (first spacecraft to enter orbit around Jupiter) Galileo global satellite navigation system (a system of satellites that provide autonomous geo-spatial positioning with global coverage) Galilean transformation (used to transform between the coordinates of two set of axes which only differ by constant relative motion) The Gal (a non-SI unit of acceleration)

I MPACT ON S OCIETY (M ODERN S CIENCE ).. CONTINUED In 2009, it was the fourth centenary of Galileo’s first recorded astronomical observations with the telescope The United Nations dedicated this year to Galileo and it was named the International year of Astronomy. The International year of Astronomy was to be a worldwide celebration of how astronomy has contributed to society and culture The goal of The international year of Astronomy was used to gain worldwide interest not just in astronomy but science in general. It was aimed towards younger people.

I MPACT ON S OCIETY ( IN ARTISTIC AND POPULAR MEDIA ) Galileo features prominently in the song ”Galileo” performed by the Indigo Girls Many 20 th century plays have been written on Galileo’s life including: Life of Galileo (1943) by German playwright Bertolt Bercht (a film adaption in 1975) Lamp at Midnight (1947) Galileo Galilei (2008)

I MPACT ON S OCIETY (I N A RTISTIC AND P OPULAR M EDIA.... CONTINUED ) In 2009 * Kim Robinson wrote a science fiction novel, Galileo’s Dream. *Galileo was selected to be on a collectors’ coin known as the International Year of Astronomy commemorative coin * The Galileoscope was also released *The Galileoscope is a mass-produced cheap telescope with high quality.

B IBLIOGRAPHY m m scope/