• Introduction

Throughout the history of our existence, mankind has always looked to heavens and pondered over what it was that lit the night skies. They have given names and shapes to the numerous stars, as well as histories, backgrounds which reflected their own cultures. While the stars and their constellations remained constant, the stories behind them have morphed and changed with our views of the world around us and the skies beyond. From pre-civilization to the great Roman Empire, and up until our modern day, the night sky has proven an integral part of our development as sentient beings. Its sheer vastness can be daunting, unsettling, but how can one resist its tantalizing beauty? The inherent enigma of its existence serves only to whet this curiosity, and so we have weaved such intricate tales, symbolism, and now even scientific research, around it.

Humans have seemingly always been intrigued by the sky. Although they may not have immediately had logical theories, they were theories none-the-less, and the beginning of astronomy. Although people had long thought that their gods lived in the sky, they also used the stars to determine seasons. The ancient Egyptians used the recurring appearance of Sirius to tell them when the Nile River would rise. Although the Greeks are most commonly thought of when thinking of constellations representing gods, the Egyptians did this as well, the constellation Orion represented their god Osiris, the god of death, rebirth and the afterlife. In fact, some of the figures in the sky were so important that they had gods of their own. There was a sun god, who died every day (the blood from his death caused the sky to turn red at sunset) and the "imperishable ones" were the personifications of the stars that were visible in the Northern sky. The ancient Egyptians and their grand empire put a lot of faith in the sky, and it defined a lot of who they were.

Aristarchus' calculation of the distance ratio between the sun and moon

The sky was used as a tool to tell when to harvest and for sailing the ocean, for all seafaring cultures, including of course the Greeks. The Greeks are credited for a lot of the progress made in ancient astronomy, as they started to separate religion and the science of astronomy. Though people attached gods to the heavens for a very long time (in fact, many still do), people started to view the sky more scientifically surprisingly early, with the theories of Plato, who theorized that the sun, moon and planets move in circular motions. Plato also encouraged his colleagues to help him prove his theories, and Eudoxus built models to represent our solar system and found that the sun does trace a circular path within a year. Many Greeks later improved on these theories, from Aristarchus (the first to theorize that we revolved around the sun, rather than vice-versa) to Ptolemy. But before all of this, Thales of Miletus predicted when eclipses would occur (he probably observed that eclipses tend to occur about every 18 years), something that had been thought of before as entirely decided by the gods. After Thales, Pythagoras recognized that the earth was a sphere and he also recognized that the orbit of the moon was inclined to the equator of the Earth. Pythagoras definitely did not separate science from religion, though; in fact, math and science became a sort of religion. The followers of Pythagoras became known as Pythagoreans, and this group was/is thought of as a cult. So instead of gods ruling over science, science became the gods (for Pythagoreans only, of course). Pythagoreans theorized that the Earth was not the center of the universe, not entirely for scientific reasons, but rather for the fact that the Earth was not “divine”, and though they did not theorize that the Sun was the center of the universe, this seems to be some sort of progress (progress that would not stay for long, with the Christian ideas of the solar system).
Galileo's sketch of the phases of the moon

Although a lot of credit for the progress in astronomy goes to the Greeks, astronomy was very important in ancient India as well. The first known reference to astronomy in India is from about 2000 B.C. The book in which this reference was found is called Rig Veda. The word for astronomy in the rig veda is "Khagola-shastra" "khagola" refers to the cosmos and "shastra" means science. So although the cosmos were still religiously tied for the Indians, it was thought of as a science as well. Vedic Aryans (the ancient Indians whose people wrote the Rig Vadra) worshiped the sun, stars and comets as deities. Astronomy was interwoven with astrology in India, but they made some great scientific bounds as well. Ancient Indian astronomers theorized that the stars were the same as the sun, and also theorized that the sun was the center of the solar system (something that the Polish astronomer Copernicus was later credited as discovering).

After the Copernican Revolution, there was a movement to unite both physics and astronomy. The first person to attempt to derive mathematical predictions of celestial motions from assumed physical causes was Johannes Kepler, a German mathematician, astronomer, and astrologer. He discovered the three laws of planetary motion (which are named after him) around 1605 based on the naked-eye observations of Tycho Brahe, which were unprecedentedly accurate. Kepler’s three laws are as follows:
1. “The orbit of every planet is an ellipse with the sun at a focus.”
2. “A line joining a planet and the sun sweeps out equal areas during equal intervals of time”
3. “The square of the orbital period of a planet is directly proportional to the cube of the semi-major axis of its orbit.”
Source from http://physics.uwyo.edu

Another famous physicist, Isaac Newton, further developed ties between physics and astronomy through his law of universal gravitation. During his studies, he had come to realize that the same force which attracted objects to Earth simi
Sir Isaac Newton
larly held the moon in orbit around Earth- a force known as gravity.

Ironically, it was a discrepancy in the orbit of Mercury that helped point out flaws in Newton’s theory. This was, however, resolved in 1915 by Albert Einstein’s New Theory of Relativity. In his infamous theory, Einstein unifies special relativity and Newton’s law of universal gravitation. It defines gravity as a property of the geometry of space and time (spacetime). The equations founded in Einstein’s theory are still used today, with highly accurate results. No experimental test has yet been able to discredit the theory, but there are strong indications that the theory is, as of yet, incomplete.

In our modern age, the study of space has taken to the field of science, rather than religion. We study the stars and planets with advancing technology and advancing philosophies. In the last hundred years alone we have made leaps and bounds in our knowledge about space. We now know infinitely more about the reality of what lies in the vastness of space. The discovery of planets, redefining of satellites and moons, and even the revelation of dark matter are just a few of the numerous new findings. We use technology in projects such as SETI, the Search for Extra-Terrestrial Intelligence, in our search for other intelligent beings, a field of research which never fails to intrigue us. Humans will always yearn to find that they are not alone in the vast cosmos of existence.
Source from http://www.resonancepub.com

Yet there is, of course, much more for us to learn. Countries the world over are advancing their means of space study competitively. Human beings, by nature, yearn to know where they are from, where they are headed, and where they belong in the cosmos. Our curiosity is insatiable, and so we build and create the means by which we may explore the universe, from telescopes to space stations. The more we learn, the more we want to know, and so we turn our eyes to the heavens, and, aided by satellites, computer systems, and mathematics, we observe.

  • Conclusion

Although people have always been intrigued by the sky and have theorized about it's properties, and the meaning of it's vastness there theories have changed drastically over time. For eons, the sky evoked mostly religious reactions, but as people slowly thought of the sky as more of a scientific thing and less of a religious one, we progressed to out theories and thoughts of today. Looking back on all the ideas had about the cosmos we can say that they were primitive and illogical, something we can assume is possible for the future people looking back on us. But we can be almost positive that as long as human beings live on earth, they will try to solve as many mysteries about the universe as possible.
  • Bibliography

What Remains To Be Discovered, John Maddox (1998)
Astronomy Ancient and Modern, John Holmes (1751)
Tycho Brahe’s Copernican Campaign, Journal for the History of Astronomy, 29(1998): 2-34, Owen Gingerich and James R. Voelkel
Philosiphiæ Naturalis Principia Mathematica, Isaac Newton (1687)