Cosmological Ideas Research Articles

Ancient prototypes of the big bang and the Hot Universe (to the prehistory of some fundamental ideas in cosmology)

Abstract Gamov's cosmological (as a matter of fact, cosmophysical!) Hot Universe theory, which shocked the astrophysics by its unusual universality at first, had “predecessors” in the antiquity. In spite of the ancient natural philosophers' poor scientific knowledge, their apprehension of the world as a whole helped them to catch some profound analogies and to express some surprising guesses concerning the process of the birth of the Universe.

String cosmology and the dimension of spacetime

The implications of string theory for understanding the dimension of uncompactified spacetime are investigated. Using recent ideas in string cosmology, a new model is proposed to explain why three spatial dimensions grew large. Unlike the original work of Brandenberger and Vafa, this paradigm uses the theory of random walks. A computer model is developed to test the implications of this new approach. It is found that a four-dimensional spacetime can be explained by the proper choice of initial conditions.

Quantum cosmology with Yang-Mills fields

We examine an extension of the ideas of quantum cosmology and, in particular, the proposal of Hartle and Hawking for the boundary conditions of the Universe, to models which incorporate Yang-Mills fields. Inhomogeneous perturbations about a homogeneous, isotropic minisuperspace background model are considered, by expanding the Yang-Mills fields in harmonics of the spatial directions which are taken to be three-spheres. The expansions are made explicit for SO(N) gauge fields thereby obtaining formulae compatible with the formalism conventionally used in quantum cosmology. We apply these results to the gauge group SO(3) and derive the Lagrangian and the semi-classical wave function for this special case.

Facts and ideas in modern cosmology

A review of the principles of observational testing of cosmological theories is given with a special emphasis on the distinction between observational facts and theoretical hypotheses. A classification of modern cosmological theories and possible observational tests for these theories is presented. The main rival cosmological models are analyzed from the point of view of observational testing of their initial hypothesis. A comparison of modern observational data with theoretical predictions is presented. In particular we discuss in detail the validity of the two basic assumptions of modern cosmology that are the Cosmological Principle and the Expanding Space Paradigm. It is found that classical paradigms need to be reanalyzed and that it is necessary to develop crucial cosmological tests to discriminate alternative theories.

Science, Religion, and Mormon Cosmology

If cosmology connotes an understanding of the structure of both a physical and a transcendent universe, contends Erich Robert Paul, it is virtually impossible to understand Mormonism outside the dimensions of cosmological thinking. This unique study examines how Mormonism shaped its cosmic vision by using and developing cosmological ideas, and what this process says about science, religion, and Mormonism itself.

Inflation after the cosmic background explorer (COBE)

Abstract The success of the standard picture of the Hot Big Bang scenario, emphasizing the assumptions that have to be made in the initial conditions, is reviewed. A possible model which could account for these is then described. The inflationary universe scenario is one of the most exciting theoretical ideas in cosmology, because it offers the opportunity of explaining much of the observed large scale structure. These observations and the constraints they imply for the scenario are discussed, with emphasis being placed on the recent remarkable results from the COsmic Background Explorer (COBE).

Ptolemy's universe: the natural philosophical and ethical foundations of Ptolemy's astronomy

Universe is a modern examination of the cosmological and philosophical dimensions of Ptolemy's thought as presented in his astronomical works. Claudius Ptolemy (second century AD) ranks as one of the most important figures in the history of science, especially renowned for his contribution to mathematical astronomy. Within astronomical works such as The Mathematical Syntaxis, Ptolemy presented some of his views on natural philosophy, epistemology and ethics, and explained their pertinence to his astronomy. While much has been written about Ptolemy's mathematical work, few attempts have been made to understand his philosophical and cosmological ideas. In this book, Dr Taub shows how Ptolemy's conception of the celestial bodies as divine beings shaped his philosophical thinking, and how this in turn influenced his study of the heavens. Dr Taub's examination of the place of Ptolemy's ideas within the broader context of Greek philosophy, mathematics and culture, provides insights into the nature of Greek scientific thought.

The Concepts of “Beginning” and “Creation” In Cosmology

The paper is inspired by the arguments raised recently by Grünbaum criticizing the current approaches of many cosmologists to the problem of spacetime singularity, matter creation and the origin of the universe. While agreeing with him that the currently favored cosmological ideas do not indicate the biblical notion of divine creation ex nihilo, I present my viewpoint on the same issues, which differs considerably from Grünbaum's. First I show that the symmetry principle which leads to the conservation law of energy is violated when the time axis is terminated at t = 0. Next I discuss why this epoch (t = 0) is more a mathematical artifact whose supposed significance may disappear when one goes beyond the classical relativistic cosmology. This is illustrated by the example of quantum cosmology.

Fermions in quantum cosmology.

This paper considers the extension of the ideas of quantum cosmology and, in particular, the proposal of Hartle and Hawking for the boundary conditions of the Universe, to models which incorporate fermions in a realistic manner. We consider inhomogeneous fermionic perturbations about a homogeneous, isotropic minisuperspace background model, by expanding the fermion fields in spinor harmonics on the spatial sections, taken to be three-spheres. The Dirac action is thus found to take the form of an infinite sum of terms, each describing a time-dependent Fermi oscillator. On quantization, we find that the Wheeler-DeWitt equation for the wave function of the Universe may be decomposed into a set of time-dependent Schroumldinger equations, one for each fermion mode, and a background minisuperspace Wheeler-DeWitt equation, which includes a term in its potential describing the back reaction of the fermionic perturbations on the homogeneous modes. Our quantization procedure employs the holomorphic representation for the fermion modes, which permits them to be treated in a manner very similar to the case of bosonic perturbations considered by Halliwell and Hawking. We set initial conditions for the Schr\odinger equations by applying the proposal of Hartle and Hawking that the quantum state of the Universe is defined by a path integral over compact four-metrics and regular matter fields. We find this to imply that the fermion modes start out in their ground state. Particles are created in the subsequent (inflationary) evolution, and their number, defined with respect to instantaneous Hamiltonian diagonalization, is calculated and is found to be finite. We calculate the back-reaction term and find, after regularization, that its effect is negligible. We construct a model of a fermionic particle detector and, in the case of an exact de Sitter background, examine its response to the state picked out by the Hartle-Hawking proposal. We show that it experiences a thermal spectrum at the de Sitter temperature, with a distribution of the Fermi-Dirac form, although the distribution does not have the correct density-of-states factor to be precisely Planckian.

Conceptions of traditional cosmological ideas among literate and nonliterate Nigerians

AbstractThis paper examines the nature of selected traditional cosmological concepts among literate and nonliterate Nigerians. An analysis of the data reveals that the subjects, irrespective of their level of education, class, sex, age, religion, tribe, or locality, hold in varying degrees certain traditional as well as scientific concepts about the natural phenomena. An exposure of some of the subjects to an history/philosophy of science course appears to enhance their preference for a scientific worldview vis a vis a traditional point‐of‐view. The implications of these findings for traditional societies deserve a closer consideration.

New ideas in cosmology and new solutions in general relativity

New ideas in cosmology that have become popular in recent years include matter production, inflation and bubbles in the early Universe. New solutions in general relativity include Friedmann/Robertson/Walker ones which start in Minkowski space, and spherically-symmetric ones with expanding, singular hypersurfaces which are spherical in ordinary space. The ideas in cosmology and the solutions which describe them are reviewed. In particular, Einstein's equations are given in forms suitable for finding other solutions; and certain recent solutions are quoted in forms suitable for working out astrophysical consequences. It is hoped that the present review will serve as a stimulus to further research in this field.

Isotropic singularities in cosmological models

Motivated by the ideas of quiescent cosmology and Penrose's Weyl tensor hypothesis concerning the 'big bang', the authors give a geometric (and hence coordinate-independent) definition of the concept of 'isotropic singularity' in a spacetime. The definition generalises previous work on 'quasi-isotropic' and 'Friedman-like' singularities. They discuss simple consequences of the definition. In particular it is shown that an isotropic singularity is a scalar polynomial curvature singularity at which the Weyl tensor is dominated by the Ricci tensor. Finally they impose the Einstein field equations with irrotational perfect fluid source. This enables them to give a detailed description of the geometric structure of an isotropic singularity.

The assimilation of christianity in the thai culture

The anthropological theorist, Mary Douglas, has developed tile Durkheimian thesis that certain aspects of religion and cosmology tend to reflect the social structures of the society in which they are found. She has argued that the type of cosmology in a society tends to correlate with the amount of pressure on individuals to conform to the wishes of social leaders or to general social expectations and regulations, and to the extent to which there is a shared system &classifications in the society. For example, Douglas suggests that in societies in which there is a strong emphasis on the position and role of the individual in the social system, and in which there is a rigid system of classification defining how the individuals are to view the world, the cosmology tends to be highly structured. The world is seen as morally just, in which individuals are invariably punished sooner or later for their misdeeds, and in which they are rewarded for their virtues. On the other hand, in societies in which the structures are loose, and there is a, constant struggle for individual power, the cosmology tends to be seen as the open arena for the struggle of powers. Douglas has argued that these basic cosmological ideas are absorbed by the child in socialization part ly through the social control system as it operates throug h discipline in the family and the community. She has developed a principle origifially formulated by Basil Bernstein:

Frank Peddle, Thought and Being; Hegel's Criticism of Kant's System of Cosmological Ideas. Washington, DC, University of America Press, 1980, pp. xiii, 190, hardback $16.75, paperback $8.95.

An abstract is not available for this content so a preview has been provided. Please use the Get access link above for information on how to access this content.

Ökologie als existentiales Problem im Viererschema der biologischen Wissenschaften

A “quadruple scheme” of the biological sciences is developed, which encloses four fundamental disciplines, morphology, physiology, taxonomy and ecology, marked by two polarized axes: the first “form—function” represents the antagonism of morphology/taxonomy contrary to physiology/ecology, the second, “unity — multiplicity” means that of morphology/physiology contrary to axonomy/ecology (Fig. 1). In this system ecology appears as science of “existential clarification” ("Daseinserhellung” by Heidegger). Every special science may be arranged into the scheme as a part-, collective- or borderdiscipline (Fig. 2). In the philosophy of human knowledge the quadruple scheme is founded on the table of the categorical “four cosmological ideas” by K ant . It has also a logical basis (Fig. 4), and is equivalent to the “quadruple structure of the inductive method” by M. H artmann (Fig. 5). In the psychology of the human personality the polarity of the axis “form—function” corresponds to the “function-types” “feeling/thinking” by C. G. J ung , the polarity “unity — multiplicity” corresponds to the “attitude-types” “introvert/extrovert” (Fig. 6). An analysis of the individuslities of G oethe , L inné , H ales and S prengel demonstrates these relations. Moreover are discussed the principles of the biology and its history sinco the oldest times of tho Jonian philosophy. In modern definition, they are “constituted materia” and “harmonic balance of powers". The biological use of a principle “teleology” is only of heuristic value. Notes on the valuation of the subject—object axis, the extent of validity and the futuro prospect of the quadruple scheme are given.

Cosmology and the arrow of time

THE arrow of time manifests itself in three distinct ways: through the approach to equilibrium in closed systems containing a large number of interacting particles; through the phenomenon of memory in certain open systems; and through the expansion of the observable Universe. The approach to equilibrium in closed systems can occur through a wide variety of physical processes, including not only molecular transport processes like diffusion and conduction but also macroscopic processes like turbulence which convert ordered fields and motions into less highly ordered ones and ultimately into heat. All such processes generate entropy. By contrast, the accumulation and preservation of information about previous states of a system depend upon processes tha t generate information (negative entropy). As for the entropy changes associated with cosmic evolution, it can be argued tha t these too must be negative-in spite of the fact tha t the Universe is, by definition, a closed system, l~or, as will be explained below, there are reasons for believing tha t the structure of the Universe was simpler in the past than it is now. Thus it is clear tha t the second law of thermodynamics does not afford a sufficiently broad framework for an understanding of the arrow of time in all its aspects. I t is equally clear, however, tha t these aspects must be related, for irreversible processes in closed systems, memory in certain open systems, and the evolution of cosmic structure all define the same arrow. And there are indications tha t the three kinds of process are physically connected. For example, it is obvious tha t we cannot hope to understand why different systems show the same arrow so long as we confine our attention to isolated systems. Interactions with the environment play an essential par t in determining the initial conditions for closed systems, and some authors have suggested tha t they continue to play an essential par t in the subsequent development of what are regarded nominally as closed systems. The present communication outlines a unified theory of the arrow of time. Although it requires a ra ther drastic departure from currently accepted cosmological ideas, this theory is consistent with theories of the kind tha t have been developed by van Hove (:) and Prigogine (2) to describe the approach to equilibrium in closed systems. In fact, it clarifies certain assumptions in these theories tha t have previously been regarded as ambiguous or obscure. To fix ideas, let us recall how the transition from a reversible microscopic description to an irreversible macroscopic description is accomplished in non-equilibrium statistical mechanics. In the first place, it is necessary to suppose tha t the microscopic state of the system under consideration is specified by a probability distribution {10k} or, more generally, by a density matrix ~. The information associated with this description is defined by

New Evidence on the Life of ‘Abdullāh B. Yāsīn and the Origins of the Almoravid Movement

The Qāḍli ‘Iyāḍ in his biography of ‘Abdullāh b. Yāsīn confirms many details in al-Bakri's record of the rise of the Almoravids. His account differs in a few important respects, and furnishes new information which is valuable in reassessing the life of ‘Abdullāh b. Yāsīn. Since no insular ribāṭ is mentioned, its historicity is increasingly suspect, and in the light of Maghribī cosmological ideas it is better regarded as a myth, and not as a historical fact. This text is the earliest surviving one to mention the Dār al-Murābiṭīn of Wajjāj b. Zalwī al-Lamṭī.The Qāḍī ‘Iyāḍ states that Jawhar, a character who appears to have been confused with Yaḥyā b. Ibrāhīm al-Gudālī, the Ṣānhaja chief who reputedly brought ‘Abdullāh b. Yāsīn to the Sahara, is none other than al-Jawhar b. Sakkum, the Gudāla jurist who was later executed by ‘Abdullāh b. Yāsīn. The cause of the execution appears to have been a combination of religious differences and a struggle for power, probably after the death of Yaḥyā b. Ibrāhīm al-Gudālī. This event may prove to have been a turning point in the Almoravid movement, the main reason for the dominance of the Lamtūna and the eventual withdrawal of the Gudāla from the Almoravid cause, possibly for their militant opposition to it. The confusion in the accounts over the early phase of the stay of ‘Abdullāh b. Yāsīn among the Ṣanhāja casts grave doubts as to how much reliance can be placed on them as historical evidence. The myth may be a good deal more than the ‘island story’.

The relevance of tribal studies

WE ALL have the same human body, with the same number of orifices, using the same energies and seeking the same biological satisfactions. Yet tribal rituals are highly selective in their treatment of these themes. I cannot think of any physical condition of which the ritual treatment is constant across the globe. Even fear of the dead, even corpse pollution which Malinowski thought to be a universal human experience, has not been taken up universally in ritual. There are cultures, such as the Mae Enga of the New Guinea Highlands, where contact with corpses does not have to be ritually cleansed, though they cleanse themselves from sex pollution [l]. While in other parts, say among the Nyakyusa of Tanzania, elaborate washings, seclusions and fumigations are necessary to make the mourners and burial party fit for normal society again [2]. The same for menstruation: in tribal society it is not universally hedged with ritual taboos. Each primitive culture makes its own selection of bodily functions which it emphasizes as dangerous or good. The problem then is to understand the principles of selection. Another point to consider is that rituals are not fixed from time immemorial. They are not unchanging hard cores of some mystic cosmology. It is a mistake to think of people as being set somewhere below and apart from their cosmological ideas. To some extent they themselves (or we, ourselves) get this feeling of being controlled by an external, fixed environment of ideas. But the feeling is an illusion. People are living in the middle of their cosmology, down in amongst it; they are energetically manipulating it, evading its implications in their own lives if they can, but using it for hitting each other and forcing one another to conform to something they have in mind. If we can realize how much a language changes in a lifetime, without the speakers recognizing their own contribution, we can realize how rituals and beliefs change. They are extremely plastic. These two points should be taken together: first, that rituals select some bodily conditions and ignore others, second that they are being manipulated by people trying to live together. Jointly they provide a clue to the interpretation of ritual, for we should look for circumstances that are not universal, not common to all mankind to discover the principles of selection, and we are likely to find these in the social environment, the dimension in which people are using everything they can, particularly mystic ideas, to influence one another. The next stage is to distinguish various levels of meaning. Take a common bodily condition and consider the range of rites which seek to control it: there will be several psychological meanings, by which I mean meanings for the person undergoing that

Homocentric Spheres in de caelo

It is commonly assumed that Aristotle's starting point in the development of his cosmological ideas was the Platonic system described in the Timaeus, and this seems a natural assumption to make. But it is not clear at what stage Aristotle abandoned this system for the theory of homocentric spheres propounded by Eudoxus and Callippus,l nor is the development of this theory itself certain. We must not assume without reason that Aristotle had already adopted the theory at the time when he wrote De Caelo; but in one chapter at any rate, Bi 2, there is clear evidence that he had done so,2 and I wish first to consider the form which the theory takes in that chapter. In Metaphysics A 3Aristotle mentions three versions of the theory: that of Eudoxus, that of Callippus and his own. It is generally agreed that while the first two of these differ from one another only in detail, the third differs in principle from them both. The theory as originally formulated by Eudoxus was purely an abstract mathematical construction representing the paths followed by the heavenly bodies; Aristotle gave it an entirely new character by turning it into a mechanical system of physically existing spheres by means of which the celestial motions are produced.4

Reviews of Books

Book reviewed in this article:THE HISTORY OF MISSIONS IN AFRICA: The Planting of Christianity in Africa. Volume 2. 1840–1878. Volume 3. 1878–1914. By C. P. Groves.Stanley: Lettres Inédites. By Albert Maurice. Illustrated.A Handbook of Tswana Law and Custom. By I. Schapera. Map. London: Oxford University Press. 30s. 1955.African Worlds: Studies in the Cosmological Ideas and Social Values of African Peoples. Edited by Daryll Forde.Baba of Karo: A Woman of the Muslim Hausa. By Mary Smith.Representative Government in South‐east Asia. By Rupert Emerson.The Church Faces the Challenge. The report of the Church of Scotland Commission on Communism.Amida: Aspects du Bouddhisme. By Henri de Lubac, S.J. Paris: Editions du Seuil.Par‐delà l'Est et l'Ouest. By John Wu. Translated by Franz Weyergans.When Iron Gates Yield. By Geoffrey T. Bull.AN ENGLISH TRANSLATION OF THE SEPTUAGINT: The Septuagint Bible. The Oldest Version of the Old Testament in the translation of Charles Thomson … edited, revised and enlarged by C. A, Muses.Kirche der Inseln: Eine Reise nach Ost‐Indonesien. By Th. Müller‐Krüger.