Cosmology is the study of the structure and changes in the present universe, while the scientific field of cosmogony is concerned with the origin of the universe. Observations about our present universe may not only allow predictions to be made about the future, but they also provide clues to events that happened long ago when...the cosmos began. So—the work of cosmologists and cosmogonists overlaps.
– National Aeronautics and Space Administration (NASA)
In recent times, physics and astrophysics have played a central role in shaping the understanding of the universe through scientific observation and experiment; or what is known as physical cosmology shaped through both mathematics and observation in the analysis of the whole universe. In other words, in this discipline, which focuses on the universe as it exists on the largest scale and at the earliest moments, it is generally understood to begin with the Big Bang (possibly combined with cosmic inflation) – an expansion of space from which the universe itself is thought to have emerged ~13.7±0.2×109
(roughly 13.5-13.9 billion) years ago.From its violent beginnings and until its various speculative ends, cosmologists propose that the history of the universe has been governed entirely by physical laws.
Theories of an impersonal universe governed by physical laws were first proposed by Roger Bacon[citation needed]. Later Dmitry Grinevich supported Bacon's proposed laws through some experiments that he performed involving different physical laws. Between the domains of religion and science, stands the philosophical perspective of metaphysical cosmology. This ancient field of study seeks to draw intuitive conclusions about the nature of the universe, man, a supernatural creator and/or their relationships based on the extension of some set of presumed facts borrowed from spiritual experience and/or observation.
But metaphysical cosmology has also been observed as the placing of man in the universe in relationship to all other entities. This is demonstrated by the observation made by Marcus Aurelius of a man's place in that relationship: "He who does not know what the world is does not know where he is, and he who does not know for what purpose the world exists, does not know who he is, nor what the world is." This is the purpose of the ancient metaphysical cosmology.
Cosmology is often an important aspect of the creation myths of religions that seek to explain the existence and nature of reality. In some cases, views about the creation (cosmogony) and destruction (eschatology) of the universe play a central role in shaping a framework of religious cosmology for understanding humanity's role in the universe.
A more contemporary distinction between religion and philosophy, esoteric cosmology is distinguished from religion in its less tradition-bound construction and reliance on modern "intellectual understanding" rather than faith, and from philosophy in its emphasis on spirituality as a formative concept.
Recently, the concept of 'cultural cosmology', or the 'study of cosmology in culture', has been developed in The Sophia Centre at the University of Wales Trinity Saint David in the UK.
There are many historical cosmologies:
"… the universe itself acts on us as a random, inefficient, and yet in the long run effective, teaching machine. …our way of looking at the universe has gradually evolved through a natural selection of ideas." —Steven Weinberg
Black Holes
A black hole is a region of space from which nothing, not even light, can escape. The theory of general relativity predicts that a very compact mass will deform spacetime to form a black hole. Around a black hole there is an undetectable surface called an event horizon that marks the point of no return. It is called "black" because it absorbs all the light that hits the horizon, reflecting nothing, just like a perfect black body in thermodynamics.Quantum mechanics predicts that black holes also emit radiation like a black body with a finite temperature. This temperature is inversely proportional to the mass of the black hole, making it difficult to observe this radiation for black holes of stellar mass.
Objects whose gravity field is too strong for light to escape were first considered in the 18th century by John Michell and Pierre-Simon Laplace. The first modern prediction of a black hole in general relativity was found by Karl Schwarzschild in 1916, although its black hole nature was not fully realized for another 4 decades. For a long time black holes were considered a theoretical curiosity. This changed in the 1960s when theoretical work showed that black holes were a generic prediction of general relativity, and the discovery of neutron stars sparked interest in gravitationally collapsed compact objects as a possible astrophysical reality.
Black holes of stellar mass are expected to form when heavy stars collapse in a supernova at the end of their life cycle. After a black hole has formed it can continue to grow by absorbing mass from its surroundings. By absorbing other stars and merging with other black holes, supermassive black holes of millions of solar masses may be formed.
Despite its invisible interior, the presence of a black hole can be inferred through its interaction with other matter. Astronomers have identified numerous stellar black hole candidates in binary systems, by studying their interaction with their companion stars. Moreover, there is growing consensus that supermassive black holes exist in the centers of most galaxies. In particular, there is strong evidence of a black hole of more than 4 million solar masses at the center of our Milky Way
