Changes

We often think of astronomy as a type of academic discipline or hobby subject taken up by those interested in the night sky. While this is true, astronomy has fundamentally shaped human history as it allowed the understanding of the seasons and seaborne navigation. Additionally, in order to make wider understanding of the movement of starts and celestial objects in general, a great understanding of mathematics was needed that allowed other developments, where even ideas of mapping and coordinate systems developed. The importance of astronomy to the past is attested by the fact that some ancient languages only went extinct after astronomical observations ceased. On the other hand, for the modern world, astronomy has the potential to also shape our future in guiding future space exploration and possibly new worlds to explore.

Basic observation of the night sky across most of the latitudes that people heavily occupy indicates that stars, the sun, and the night sky undergo changes during the year. This is an important pattern that many ancient societies understood, where cultures in the New and Old Worlds developed astronomical observations. This includes the ancient Maya, Aztecs, Egyptians, Babylonians, Greeks, Chinese, and others (Figure 1). Astronomy helped to distinguish seasonal changes that are important for agriculturally-based societies. Knowing when the autumn and planting season in northern latitudes, for example, indicate when it is safe to harvest and sow crops.<ref>For more examples of ancient societies with knowledge of various astronomical principles, see: Ruggles, C. L. N. (2005). <i>Ancient astronomy: an encyclopedia of cosmologies and myth.</i> Santa Barbara, Calif: ABC-CLIO.</ref>

Astronomy helped to form both lunar and solar based calendars, where ancient societies even understood that the solar year was slightly more than 365 days. Navigation of ship-borne trade before 1000 BCE was mostly confined to areas along the coast or regions that can more easily observe land. However, astronomy made it possible to navigate in open waters and during the night. Whereas early navigation depended on land features, understanding the position of stars allowed the Phoenicians and Greeks to colonize wide areas of the Mediterranean Sea in the 1st millennium BCE, spreading their cultures in wide areas. Babylon and wider Babylonia was one of the key regions for many ancient developments. This included the development of the zodiac signs, still utilized today, and even a coordinate system to identify the positioning of stars and constellations. A system for predicting eclipses was even developed, invented in Babylon, which is still utilized, called the Solaris system. The coordinate system developed was the eventual 60-based system we use to describe global navigation today.<ref>For more on calendars and observations of eclipses, see: Lawson, R. M. (2004). <i>Science in the ancient world: an encyclopedia.</i> Santa Barbara, Calif: ABC-CLIO, pg. 32.</ref>

In the Middle East and Asia, astronomy had developed and retained knowledge from ancient periods to allow the development of accurate calendars and to make accurate predictions in the movement of celestial bodies. Astrolabes and other navigation equipment became commonly used to assist in observing the positioning of stars to inform sailors of their relative position, where such technologies derived from earlier, ancient observations (Figure 2). However, in Western Europe, after the fall of Rome, astronomy had made limited or few advancements.<ref>For more on navigation and star positioning, see: Denny, M. (2012). <i>The science of navigation: from dead reckoning to GPS.</i> Baltimore: John Hopkins University Press.</ref>

This changed by the 16th-17th centuries. Advancements in optics, made in the Islamic world by the early Medieval period, and then created into a telescope used later by Galileo Galilei that could observe celestial bodies. Observations by Galileo led to him seeing moons in relation to other planets, craters on the moon, and many other observations. This, once again, led astronomy to become an important science that also led to other developments, in particular physics in the 18th century began to then be closely associated with astronomy. Phases of planets in their rotation were noticed by Galileo, leading him to support Copernicus in his observation on planetary rotation. Isaac Newton used calculus to explain gravity in relation to the planetary bodies. This helped Newton to more fully develop his theory of gravity. Mathematical laws now became the way in which planetary and celestial motion was understood, leading to the fuller development of the field of physics as well.<ref>For more on the development of telescope development and planetary motion, see : Cole, G. H. A., & Woolfson, M. M. (2013). <i>Planetary science: the science of planets around stars.</i> (2nd ed). Boca Raton: CRC Press.</ref>

Modern astronomy developed in the 19th century, where experiments and further observations led to the understanding of basic chemistry, such as understanding how hydrogen and helium formed the basic components of the universe. Major recent advances have focused understanding the expansion of the universe. This includes the understanding of the origin of the universe and big bang theory became a major discovery. These developments also led for the need for increased developments in a variety of other technologies, including in developing exploratory satellites, telescopes, and computers to process data from a variety of developed sensors.<ref>For more on 19th century and later development in astronomy, see: Krebs, R. E. (2004). <i>Groundbreaking scientific experiments, inventions, and discoveries of the Middle Ages and the Renaissance.</i> Westport, CT: Greenwood Press.</ref>

More recently, modern astronomy has led to understanding of fundamental qualities in not only physics but chemistry, where the understanding of basic component of the universe have helped to shape the Earth. Modern theories such as the big bang have now helped explain how old and expansive the universe is. Technologies for modern astronomy include satellites and computing systems that have to be developed for ever deeper understanding and observation, leading to technical developments in robotics, computing, and artificial systems as more recent developments that have derived from astronomy.