History of Astronomy

History of Astronomy Project by Polly Adams Maggie Aldworth Avery Sheiner

Link to Astrology: • In ancient times many peoples, such as the Greek saw shapes in the stars and decided to tie meanings to them. These meanings turned into the idea of Astrology, and many peoples believed that they could find ideas on their futures by looking to the heavens.

People Finding Meanings in the Stars • The beginnings of astronomy was not scientific nor religious in nature, instead it was practical and very down to Earth. Seafarers needed to navigate their vessels and farmers had to know when to plant their crops during the year. In a very real sense, human survival depended on knowledge of the heavens.

As a result, • The ability to predict the arrival of the season as well as other astronomical events was undoubtedly a highly prized skill to possess.

When one knows the stars… • The humans ability to perceive patterns in the stars lead to the “invention” of constellations as a convenient means of labeling regions of the celestial sphere.

And so, Astrology was born! Or gave birth? • Some argue that Astronomy was born out of Astrology, or even the other way around. Astrology is the study of stars that was started thousands of years ago, that is based off of the belief that shapes made from stars as their vertices mean something about a person’s personality or even future. Astronomy, on the other hand, is a natural study of celestial objects looking at them scientifically rather than metaphorically, and finds scientific results rather than finding shapes in the sky and making meaning of them.

Astronomy in Early Cultures • Many separate cultures all over the world built large and elaborate structures to serve as primitive calendars. In some cases these were also used for religious rites, like some place now in the use of Astrology.

Such as… • Stonehenge is located on Salisbury Plain, England. It is believed that this structure was an early kind of 3D calendar or almanac, enabling it’s builders and their descendants to identify important dates by means of specific celestial events.

Or Also… • The big horn medicine wheel in Wyoming is similar to Stonehenge in design, and presumably, intent. It’s alignment with the rising and setting of the sun and with some other bright stars, indicates that the Plains Indians had much more than a passing familiarity with the changing of the night sky.

And One Final Example… • Caracol Temple, built by the Mayans around 1000 A.D. in Mexico’s Yucatan Peninsula, is much more sophisticated than Stonehenge. It’s windows built specially to allign with the sunrise and sunsets at the solstices and equinoxes, as well as the rising and setting of the planet Venus as to help them understand the seasons and how to plant crops year round.

Links Between Time • The Arab influence on modern Astronomy is subtle, but quite pervasive. For instance, many of the mathematical techniques involved in trigonometry were developed by Muslim Astronomers in response to very practical problems.

In Ancient Greece, • To the Greeks, the universe was basically the solar system, namely the Sun, Earth and planets known at the time. They believe that many stars beyond our solar system were fixed in one position.

Continued: • Greeks also saw the movements of the Earth, Sun and Moon as simple- apposed to the movements of other planets.

Skipping a Few Hundred Years… • During the time span between the Greeks and the Renaissance, ideas about the stars and night sky didn’t seem to develop as much as they did during the beginning years of the Renaissance.

The Renaissance and Astronomy • Moving from Ancient Astronomy to the Renaissance, the idea of the sky changed greatly in the sense that people’s knowledge of the universe expanded so that they saw it as an expansion of the Earth rather than a practical map used only to determine the seasons. • Western thought moved away from the passive acceptance of ancient dogma and static believes towards critical thinking and observational testing.

Some of these thoughts were thought by great thinkers…like these “founding fathers” • Plato • Aristotle • Nicholas Copernicus • Galileo Galilei • All of these influential historical figures not only contributed to the ideas of modern astronomy, but also popular theorems and new ideas in their time period.

Plato’s ideas turned into Play Dough… for other astronomers. • Under the mentorship of Socrates, Plato was one of the earliest to determine that the other planets in the solar system would have to always “orbit the Earth” in a circle. This idea would continue to be “molded” and refined into the understanding of planetary motion that we have today.

Aristotle • As the student of Plato, Aristotle was highly influential through his models of the solar system. Despite the fact that he believed the planets still orbited the Earth, he was correct in in his observations about

Copernicus’ work • Copernicus rediscovered the model of the solar system making it so that the Earth revolved around the sun instead of the other way around. He made the discovery that is accepted in the world today as complete fact that the only thing orbiting the Earth is in fact the moon. • His major motivation was simplicity towards the mapping out of our solar system. However, he still did not quite grasp the fact that other planets did not orbit in concentric circles around the sun as he knew that the Earth did.

Yo, Galileo! • Copernicus’s work had little affect on the general public of the time because of his contradictions to the popular believes of religion. So, after Copernicus’s death, that sly dog Galileo popularized his ideas and in turn got most of the credit for discovering them. • Galileo was a very famous Italian mathematician and philosopher. Because he was very willing to perform his experiments to test his ideas, the knew technology of the telescope which he recreated himself and used in his investigations, he revolutionized the way science was conducted that he is now commonly known as the “Father” of experimental science

Speaking of using telescopes… • The telescope was one of the first instruments used to aid the exploration of the stars. First invented in Holland by Hans Lippershay in 1608, this early design consisted of a convex objective lens and a concave eyepiece. In the following year Galileo Gelilei used the same design idea to create a tool to help him with his exploration of the stars. This tool was one of the windows leading to modern day astronomy.

Combining Physics and Astronomy • When the idea of physics became more popular and advanced as time went on, it was of course applied to modern astronomy. Using new technologies and theorems scientists were allowed to make many big guesses about the universe we live in.

Such as…. • Using physics and scientific method people moved onwards in the pursuit of knowledge linked to astronomy. This lead to many facts that we find very obvious and true fact today, like that our solar system has 8 planets all revolving around the same star, what we have learned to call the sun.

History of Astronomy