Cosmology originates from Greek word, “kosmos” which means the “world” and “logia” which means “study of”. This term was used for the first time in 1970 in Cosmologia Generalis, a work by a German philosopher Christian Wolff (Albright, 2000).
Many definitions have been given to cosmology, from “historical science”, “extreme science” to “the science of the Universe”. However, definitions from different scientists have converged on the fact that the universe is the central theme in cosmology. According to Grignon (2012), cosmology is “a prominent subset of contemporary physics” p.333. Spergel who was theoretical astrophysicist defined cosmology as “historical science” simply because of the tendency to connect the universe with its origin (Albright, 2000).Cosmology, according to Albright (2000), “is the study of the structure and origin of the entire universe” p.173.
Therefore, cosmology can be defined as scientific study of the cosmos. Cosmos is a word that is interchangeably used with “universe”. Cosmology endeavors to make use of scientific methods in order to explain the origin, nature, evolution, and ultimate end of the universe (Albright, 2000). Cosmology, like other scientific fields, involves formulation of hypothesis and theories about the universe based on scientific experiments. Prediction of certain phenomena is made and tested with observation in order to create strong arguments. Grignon (2012) asserts that cosmology helps in conveying deficiencies of the fundamental physics. Cosmology is a development of astronomy, within the category of etymologically legislative science and monothetic sciences, the branch of science that provides and sets laws.
There are other scientific fields that are closely related to cosmology; such as astronomy, astrology, and cosmogony. Cosmogony is a subsection of cosmology that deals particularly with the origin of the universe. Astronomy deals with the detailed study of features within the universe such as galaxies, stars, and planets among others. Astrology tries to explain the future in regard to the composition of the universe, such as, the position of stars.
The History of Cosmology
Before the 20th century, there were no observational and intellectual tools that are available today. Highly developed technology in the recent times has significantly supported cosmological experiments. However, this did not stop philosophers, religious leaders, and scientist from speculating about the nature of the universe. For many centuries, the “universe” meant approximately what currently is referred to as the solar system. Galileo Galilei made a significant step of assembling evidence that brought a paradigm shift, from geocentric nature to heliocentric nature of the universe (Albright, 2000). Galileo through the telescope observed the Milk Way as a collection of numerous discrete stars and refuted the speculations of a continuous stripe.
In the nineteenth century, Astronomer Sir William Herschel made discovery of the planet Uranus and also plotted a map showing Milk Way based on solid observation. In the same century the physics community held to the notion that the universe and the planet earth were in their toddler stage. 1915 was a significant year when Einstein formulated famous general theory of relativity. This theory was received with mixed reaction, with some scientist disputing the argument while majority believed it. His equation did not correspond to the idea of static universe but rather converged a sense of dynamic universe. The idea of Einstein’s general theory of relativity revolutionized general speculation about the universe. It brought the nature of space and time in a more concrete manner and explained gravity from a different perspective.
The period between 1930 and 1960 are considered great historical times in the development of cosmology. This period was marked with great deal of uncertainties with regard to basic foundational issues in development of cosmos study. Although the concept of relativistic cosmology was the most favorable theoretical framework, there was no common paradigm for what involved the methods and intensions of the science of the universe. Indeed, there was great contention on whether such a science existed (Giberson, 2015). Among the most common rival conceptions was, the steady-state theory founded by Hermann Bondi, Fred Hoyle and Thomas Gold which was popular in 1950s, Kinematic relativity founded by Edward Arthur Milne which was influential in the period between 1930 and 1940 (Albright, 2000). None of these theoretical frameworks built or supported Einstein’s theory of General relativity.
Although the concept of Arthur Stanley and Milne conveyed differences in many aspect, they had some point of convergence in the sense that they were genuine and ambitious attempts to reshape cosmological physical science found in of normal principle of a priori nature rather than observation (Folse, 2014). Through the use of simple kinematic concepts such as time and distance, Milne’s idea was a unique mixture of conventionalism, rationalism, and positivism. Milner though that observational knowledge was not vital in the understanding of universe. However, Milne admitted the fact that predictive power was paramount to formation of any scientific theory, but he ruled that acceptable theory must have some sense of philosophical fulfillment (Grignon, 2012). His cosmological model conveyed a regularly growing universe in a rather than flat space governed by the universal cosmological principles. His universe was made of infinite numbers of separate galactic regions, which depicted a kind of multiverse.
Cosmology compels a person to think deeply and widely and avoid the use of binary concept (yes or no) when answering and tackling uncertainties. This study challenges the foundation of history and shapes people’s thought about the universe. The universe is a controversial topic that has found different definition from different people. Religious people think that it is an area that was theistically created and ruled by supernatural forces, while philosophers believe it is a logical world of synthetic and analytic structures (Kragh, 2013). Even more diverse are the ideas held by people of different societies such as the Hindus, Buddhists, Polynesians, Eskimos, Chinese, Zulus, Greeks, Celtic, Norse, Mayan, Hopi, Maoris among others. Therefore, this indicates various models of the universe and a major concern on what truly define the universe. These uncertainties have compelled the need to create a major focus on the universe in order to have clarity about the universe. Therefore, cosmology creates a major focus on the cosmos, through integrating field of natural sciences, mostly physics and astrology.
There are many uncertainties in the nature of the universe that scientist have tried to uncovers since the history of human civilization. Cosmology plays a great role in offering scientific explanation to many questions that have been asked concerning the universe (Kragh, 2013). There are explanations on numerous issues concerning the universe such: the nature (captures through the dynamism, the mechanism, the atomism, and the hylomorphism), the origin (captures in monism and cosmogony), and the essence of cosmos (captured in teleology)
There are two significant aspect of cosmology today that has made it more alluring that any other time. The first aspect is the enormous data available as a result of great developments of the scientific field. There are major discoveries that have been made in the last three decades. For example, the state-of-the-art survey conducted by the Center for Astrophysics had identified 1100 galaxies in 1985 (Grignon, 2012). Today, half a million galaxies have been discovered in a 3D system survey conducted by Sloan Digital Sky Survey (Giberson, 2015).
The second aspect, which makes modern cosmology distinguishable from previous efforts, is the consistent development in theoretical framework which connects quantitatively with the data. There are theories which make predictions and can be tested through observations. Cosmological theories are not made to deviate from established concepts such as general relativity, quantum physics, fluid dynamics, thermodynamic and the interaction of light with matter (Guijarro, 2007). Indeed, cosmological theories agree perfectly with the power spectra of matter and radiation in blackbodies along with fundamental measures of the structure in the universe.
Einstein’s discovery that brought along the general relativity in the 20th century was a major breakthrough to modern cosmology. This brought out the realization that the universe was growing and was once smaller, hotter, and denser (Albright, 2000). The notion of expanding universe has been a major area of study in the modern cosmology. The scientific development in the new age has seen significant insight in the knowledge of the universe through studies such as astrobiology, multiverse cosmology, eschatological physics, and string-based pre-big bang cosmology. There are major claims of an epistemic shift paving way for new paradigm where great historical and philosophical interest are providing answers to the question about the universe (Kragh, 2013). Among the many theories in cosmology, the string theory has attracted most attention, both among philosophers and physicists. From 1990s, numerous drastic advances made transformed the view of cosmology from speculative historical science to predictive science, with major agreements between observation and theory.
In order to explain the formation and development of the universe, cosmologists have established universal law that is universally valid. Basically, the laws are mathematical relations which define the objects, form its concept, and categorically state its propositions. Cosmology has some resemblance with other historical sciences such as geology, archaeology, and biology of evolution, in the sense that it infers history from the vestiges left by the past (Grignon, 2007). However, unlike physical and monothetic sciences, it prioritizes on observations rather than experiments.
The Standard Model
The standard model of cosmology is made up of four main parts:
- The universe is expanding
- Large scale distribution of matter is close to homogeneous
- The dynamic theory that is thought to have the best description of the universe is the general theory of relativity
- The expansion of the universe found its way from the prior state that was very small, very hot and very dense (Albright, 2000).
Benefits of Cosmology
Cosmology intends to play to vital purposes which include: (1) providing laboratory testing for the laws of nature, (2) It offers vital explanation about the universe through the use of the known laws of nature. The idea of studying this field may seem void to many because of the aspect of tackling a rather complicated issues as the nature and the origin of the universe. However, the formation, development and the ultimate fate of the Universe is both challenging and interesting question, and when people engage challenging and interesting issues they end up developing new tools that impact mankind in a super way (Giberson, 2015). It was in the quest for discovery of the universe when the first website was discovered. CCD cameras were developed from cosmological craving for better tools in order to make precise observations and pictures. Cosmology provides a wide platform for scientific research where major developments are made to help space explorers. Cosmology has helped predict occurrence of certain events and as a result helped in planning and mitigation processes.
Albright, J. R. (2000). Cosmology: What one needs to know. Zygon: Journal Of Religion & Science, 35(1), 173.
Folse, H. (2014). Higher Speculations: Grand Theories and Failed Revolutions in Physics and Cosmology. Annals Of Science, 71(1), 123-127. doi:10.1080/00033790.2011.627461
Giberson, K. (2015). Cosmos from nothing? (Cover story). Christian Century, 132(12), 20-25.
Grignon, C. (2012). Is cosmology a historical science?. AIP Conference Proceedings, 1446(1), 333-337. doi:10.1063/1.4732719
Guijarro, J. F. (2007). Cosmic Origin and Theology of the Revelation. AIP Conference Proceedings, 905(1), 224-229. doi:10.1063/1.2737020
Kragh, H. (2013). “The Most Philosophically Important of All the Sciences”: Karl Popper and Physical Cosmology. Perspectives On Science, 21(3), 325-357. doi:10.1162/POSC_a_00102