15 research outputs found

    The contribution of VM Slipher to the discovery of the expanding universe

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    A brief history of the discovery of the expanding universe is presented, with an emphasis on the seminal contribution of VM Slipher. It is suggested that the well-known Hubble graph of 1929 could also be known as the Hubble-Slipher graph. It is also argued that the discovery of the expanding universe matches the traditional view of scientific advance as a gradual process of discovery and acceptance, and does not concur with the Kuhnian view of science progressing via abrupt paradigm shifts.Comment: 13 pages, 2 figures. Accepted for publication in the proceedings of the conference "Origins of the Expanding Universe: 1912-1932", M. J. Way & D. Hunter, eds., ASP Conf. Ser., Vol. 471 in pres

    A new perspective on Einstein's philosophy of cosmology

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    The recent discovery that Einstein once attempted - and quickly abandoned - a steady-state model of the expanding universe sheds new light on his philosophical journey from static to dynamic cosmologies.Comment: Revised book chapter. To be published in 'The Philosophy of Cosmology:Foundations and Perspectives'. Eds J.Silk and J.Barrow (Cambridge University Press

    A new perspective on steady-state cosmology: from Einstein to Hoyle

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    We recently reported the discovery of an unpublished manuscript by Albert Einstein in which he attempted a 'steady-state' model of the universe, i.e., a cosmic model in which the expanding universe remains essentially unchanged due to a continuous formation of matter from empty space. The manuscript was apparently written in early 1931, many years before the steady-state models of Fred Hoyle, Hermann Bondi and Thomas Gold. We compare Einstein's steady-state cosmology with that of Hoyle, Bondi and Gold and consider the reasons Einstein abandoned his model. The relevance of steady-state models for today's cosmology is briefly reviewed.Comment: To be published in the 'Proceedings of the 2014 Institute of Physics International Conference on the History of Physics', Cambridge University Press. arXiv admin note: substantial text overlap with arXiv:1504.02873, arXiv:1402.013

    Einstein's cosmology review of 1933: a new perspective on the Einstein-de Sitter model of the cosmos

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    We present a first English translation and analysis of a little-known review of relativistic cosmology written by Albert Einstein in late 1932. The article, which was published in 1933 in a book of Einstein papers translated into French, contains a substantial review of static and dynamic relativistic models of the cosmos, culminating in a discussion of the Einstein-de Sitter model. The article offers a valuable contemporaneous insight into Einstein's cosmology in the 1930s and confirms that his interest lay in the development of the simplest model of the cosmos that could account for observation, rather than an exploration of all possible cosmic models. The article also confirms that Einstein did not believe that simplistic relativistic models could give an accurate description of the early universe.Comment: Accepted for publication in the European Physical Journal (H). Includes an English translation of a little-known review of cosmology written by Albert Einstein in 1933. 20 pages, 4 figure

    One Hundred Years of the Cosmological Constant: from 'Superfluous Stunt' to Dark Energy

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    We present a centennial review of the history of the term known as the cosmological constant. First introduced to the general theory of relativity by Einstein in 1917 in order to describe a universe that was assumed to be static, the term fell from favour in the wake of the discovery of the expanding universe, only to make a dramatic return in recent times. We consider historical and philosophical aspects of the cosmological constant over four main epochs: (i) the use of the term in static cosmologies (both Newtonian and relativistic); (ii) the marginalization of the term following the discovery of cosmic expansion; (iii) the use of the term to address specific cosmic puzzles such as the timespan of expansion, the formation of galaxies and the redshifts of the quasars; (iv) the re-emergence of the term in today's Lamda-CDM cosmology. We find that the cosmological constant was never truly banished from theoretical models of the universe, but was sidelined by astronomers for reasons of convenience. We also find that the return of the term to the forefront of modern cosmology did not occur as an abrupt paradigm shift due to one particular set of observations, but as the result of a number of empirical advances such as the measurement of present cosmic expansion using the Hubble Space Telescope, the measurement of past expansion using type SN 1a supernovae as standard candles, and the measurement of perturbations in the cosmic microwave background by balloon and satellite. We give a brief overview of contemporary interpretations of the physics underlying the cosmic constant and conclude with a synopsis of the famous cosmological constant problem.Comment: 60 pages, 6 figures. Some corrections, additions and extra references. Accepted for publication the European Physical Journal (H

    Semiconductor physics at WIT and Trinity College

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    A WIT research group that studies the physics of semiconductors is coordinated by Dr. Cormac O’Raifeartaigh of the School of Science. Experimental research is carried out at the electron spin resonance (ESR) laboratory at Trinity College Dublin (TCD) in collaboration with Dr. Robert Barklie of TCD. Research data are analysed at WIT with theoretical support provided by Dr. Mohammad Alhourani and Mr. Frank Leonard. The group has participated in research projects funded by WIT (BEHEST Programme), Enterprise Ireland and the EU (5th Framework Programme), with the results published in international science journals

    Einstein and the Atomic Theory

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    In the year 1905, a young Albert Einstein published a number of scientific papers that changed physics forever. The best known of these, the Special Theory of Relativity, quickly established the young Einstein as a scientist of note (see J.IEI vol. 59:6) and led to Einstein’s General Theory of Relativity, one of the pillars of modern physics. In a second paper, Einstein published a controversial proposal concerning the nature of light that later formed a cornerstone of quantum theory, the revolutionary theory that underpins much of modern science and technology (see J.IEI vol. 59:7). Incredibly, the young Einstein made a third ground-breaking advance in 1905. He published an analysis that pointed the way towards a crucial test of the reality of atoms, and of the validity of the laws of thermodynamics. The outcome of that test now underpins much of modern science, from our view of the atomic nature of matter to our understanding of meteorology and other complex systems
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