Joomla! site syndication http://scienceomatica.com Wed, 20 Aug 2008 14:53:10 +0100 FeedCreator 1.7.2 http://scienceomatica.com/images/M_images/joomla_rss.png http://scienceomatica.com Joomla! site syndication http://scienceomatica.com/content/view/86/28/ It seems necessary to apply the quantum theory to describe the pre-inflation universe, which is the essence of the quantum cosmology. However, quantum cosmology has not been treated seriously until the 80s, when the classical attempts at description of the early universe eventually failed. In the classical theory, when moving back in time, the size of the universe tends to zero, while the gravitational field intensity, density of matter and temperature tend to infinity. At the time t 10-35 s, when the process of inflation started, the size of the universe was much smaller than that of an atom. As follows from the experiments of atomic physics, in such a small scale the classical physical theories fail and the quantum theory has to be employed. . It indicates that the universe emerged from a certain initial singularity – a spherical space of infinite curvature and infinite density of energy at which the known laws of physics do not work. This singularity is not a question of assumption of a certain convention or a consequence of a purely formal property of the models of the universe. It is a result of the famous theorems on singularities proved in the 60s by Stephen Hawking and Roger Penrose. According to these theorems, each model of expanding universe when considered back in time meets the initial singularity. At this initial singularity it is impossible to formulate the equations of the general theory of relativity, so the general theory of relativity foresees its failure because it shows that the beginning of the universe or its evolution cannot be predicted from it. If cosmology is to be a science, the laws of physics must be valid also at the moment of the universe origin, so the classical theory of gravitation should be replaced by a better - quantum one. Main Category - The basics of scienceomatic Wed, 07 May 2008 13:13:15 +0100 http://scienceomatica.com/content/view/85/28/ In an attempt at answering these questions in this work, we have to leave the territory of physical cosmology and enter the field of philosophy. We shall consider the properties of the universe on the four levels: the level of facts obtained from direct astronomical observations by physical methods, the classical and quantum theories of Big Bang and the metaphysical level. The latter lead to a certain general model of reality and this model can provide answers to the fundamental existential questions. Moreover, the model offers a holistic and consistent view of the reality, in full agreement with contemporary physics. However, because astronomically large numbers appear rather a lot, the power notation has been used: for instance a milliard (american - billion) seconds is written as 109 s, and one millionth fraction of a meter is 10-6 m. One of the most profound questions of science is that about the origin, evolution and structure of the universe. It has been for ages the subject of interest of philosophers and theologians, but the answer was far beyond science. Only the rapid development of sciences in the 20th century has made it possible to attempt at answering it in a consistent and general way. The 20th century witnessed the birth of a new field of science – cosmology (known also as physical cosmology) – concerned with the study of the universe as a whole. Unfortunately, cosmology, which is a science based on empirical and mathematical methodology of physics, cannot provide answers to such fundamental questions as: Is there any sense in the existence of the universe? What was before the universe came into being? Why is the universe rational? What is the man’s position in the universe? Main Category - The basics of scienceomatic Wed, 07 May 2008 13:09:34 +0100 http://scienceomatica.com/content/view/87/28/ Quantum cosmology explains the emergence of the universe as a spontaneous creation from ‘nothing’, however, this notion in the quantum cosmology is not the equivalent of the common meaning. The explanation assumes that from the very beginning there were quantum theory principles admitting spontaneous appearance of a fluctuation from which after a few milliard years the cosmos as we know it today formed. Moreover, the basis for everything should have been the omnipresent world of mathematics and logic. Thus, the fundamentals of quantum cosmology need the developed structure of rationality, which we will look for in the following. When constructing technical devices man very often, more or less deliberately, copies the solutions found in nature. In particular we have recently witnessed a great development of devices simulating the reality, among them digital devices creating the so-called virtual reality. The principle of operation of these devices is the only possible simulation of reality, so the key assumption is that the natural physical reality functions on similar principles as the devices creating virtual reality. In other words, we assume that the constructors of devices creating virtual reality unconsciously copied nature. The devices usually are connected to two people wearing special uniforms responding to the movements of their bodies and equipped with a microphone, stereoscopic monitors and headphones generating spatial sound field. The uniforms are connected to a computer and through a communication system supply the computer with data on the position of their bodies and sound information. The computer by means of these uniforms passes the appropriate visual and sound information the people wearing them. Appropriate computer programming makes the people believe that they are in a certain virtual reality different from that in which they actually are. For instance the computer can give them the impression that they are fencing while in reality they are far from each other. Main Category - The basics of scienceomatic Wed, 07 May 2008 13:18:22 +0100 http://scienceomatica.com/content/view/84/28/ The control of access to consciousness is inherently metacognitive. That is, it requires knowledge about our ownmental functioning, and about the material that is to be selected or rejected. Voluntary attention would seem to require conscious metacognition, or the ability to have conscious access to and control over the different things that can become conscious. Metacognition is a major topic in its own right, one we can only touch on here. It is widely believed that knowledge of one's own performance is required for successful learning. Among students in school, good learners continually monitor their own progress; poor learners seem to avoid doing so, as if fearing that the results might be too awful to contemplate. But by avoiding conscious knowledge of results, they lose the ability to guide their own learning in the most effective way. We have previously maintained that consciousness is involved especially in the learning of new things, those that demand more adaptation. If that is so, then attention (as metacognitive control of consciousness) seems to be necessary for voluntary, purposeful learning. Many of the most important uses of consciousness are metacognitive. Normal access to Short Term Memory involves metacognitive control of retrieval, rehearsal, and report. Long Term Memory retrieval is equally metacognitive. One cannot know consciously why or how one did something in the past without metacognitive access. One cannot deliberately repeat an action by evoking its controlling goal image without metacognition, nor can one construct a reasonably accurate and acceptable self concept without extensive metacognitive operations. All these functions require sophisticated, and partly conscious, metacognitive access and control, which inevitably becomes a major theme of this book from here on. One of our main concerns in this chapter is the role of conscious metacognition in voluntary attention. One cannot choose consciously between two alternative conscious topics without anticipating something about the alternatives. That is, one must represent to oneself what is to be gained by watching the football game on television rather than reading an interesting book. Main Category - The basics of scienceomatic Wed, 30 Apr 2008 15:35:43 +0100 http://scienceomatica.com/content/view/82/28/ What is wrong with complementarity as based on philosophical principles ? If it is to be defended at all, Bohr’s principle of complementarity, that stands at the heart of his interpretation, has to make sense as a principle that was plausible and accessible to his readers at the time. It will not do to read it as based on esoteric philosophical principles; it will not do to justify it by mathematical or physical arguments that were then unfamiliar. The answer had better lie more on the surface of his writings.? The answer is not only that it would then have hardly had much appeal among physicists; it is that it would have had too broad a scope, and pilot-wave theory refutes it. As we shall see, the principle needs to be read as anchored in the phenomena if it is to stand any hope of escaping this objection. Only on one point was it reasonable to commit to any a priori (or dogmatic) principle, in the absence (at the time) of any worked out view to the contrary, and that was the irreplaceability of classical concepts (agreed on by Bohr, Einstein and de Broglie). The old quantum theory was of course also based on classical concepts; Bohr was as much concerned to make sense of the old quantum theory as the new. Broadly philosophical presuppositions can be allowed, so long as they were genuinely community-wide. Anti-realism and idealism are not in this category, but a mildly operationalist outlook is. Bohr was concerned with experiments and with the operational definitions of concepts, as were most of his contemporaries. A broad and shallow form of operationalism is perfectly compatible with realism (“realism with a cautious face”). Finally, since our concern is with Bohr’s influence on the wider scientific community in the inter-war period, it is only his views and writings at this time that matter. Three stand out as especially important. It was the centre piece of his collection Atomtheorie und Naturbeschreibung published in 1931, translated as Atomic Theory and Human Knowledge in 1934. In the Como lecture Bohr first set out his theory of complementarity, following two years of almost complete public silence (the two years that covered the explosive discovery of the new mechanics). The second is the preface to this collection, the “Introductory Survey”, first published in 1929 (in Danish) as an accompaniment to the Danish translations of these articles. In the German and English translations this was read almost as widely as the Como lecture itself. And the third is Bohr’s response to Einstein, Podolski, and Rosen (the EPR argument), published in 1935; that followed several years of debate with Einstein over foundations and in effect marked their conclusion. Any account of Bohr’s interpretation of quantum mechanics that is not clearly embodied in these three texts is worthless for our purposes. Main Category - The basics of scienceomatic Fri, 25 Apr 2008 04:04:20 +0100