Light in Einstein's Universe: The Role of Energy in Cosmology and Relativity

ISBN-13: 9789401089029 / Angielski / Miękka / 2011 / 222 str.

R. Prokhovnik

Opis

The tremendous progress in astronomical observations over the past sixty years has revealed a vast structured universe whose fundamental parti cles are galaxies, and clusters thereof. The interpretation of the new astronomical evidence owes much to Einstein's insights and deductions. All our knowledge of the world derives from the light, more generally the energy, which reaches us from near and far. Einstein recognised the vital role of energy as the solE basis of our information about the workings of nature; his Special Theory of Relativity showed how our understanding of space and time Is linked with measurements involving reflecting light signals. He further demonstrated that matter exists in two interchangeable forms - a mass form and an energy form - which interact closely at all levels. His General Theory of Relativity dealt with the nature of this interaction in the context of gravitational fields, and led to a view of the universe which was soon observationally confirmed. Einstein's methods and results form the theoretical basis of modern cosmology which has spawned many 'models' of the universe; how ever, they all deal with an Einstein-type universe and they all employ his geometric approach to describe it.

Recenzje

`An original, timely and stimulating book: do not miss it.' Foundations of Physics (1986)

Spis treści

1. The Observable Universe.- 1.1 Introduction.- 1.2 The Origins of Modern Cosmology.- 1.3 The Scale of the Universe.- 1.4 The Large-scale Features of the Universe.- 1.5 Recent Observational Developments.- 1.6 Strange and Wonderful Objects.- Exercises and Problems.- 2. The Bases of Modern Cosmology.- 2.1 The Significance of the Hubble Law.- 2.2 The Interpretation of Cosmological Red-Shifts.- 2.3 The Nature of a Mathematical Model.- 2.4 Basic Assumptions and Definitions.- 2.5 The Case for a Uniform Rate of Expansion.- 2.6 The Puzzle of Light Propagation.- Exercises and Problems.- 3. The Principle of Relativity.- 3.1 Motion According to Galileo.- 3.2 Newton’s System of the World.- 3.3 The Basis of Special Relativity.- 3.4 The Lorentz Transformation and its Implications.- 3.5 The Relativity of Time and Length Observations.- 3.6 The Relativistic Metric.- Exercises and Problems.- 4. Light Propagation in an Expanding Universe.- 4.1 The Cosmological Metric.- 4.2 The Geometry of Light Paths.- 4.3 Astronomical Implications.- 4.4 The Equivalence of Fundamental Observers.- Exercises and Problems.- 5. The Effects of Movement Relative to the Fundamental Frame.- 5.1 The Cosmological Acceleration Field.- 5.2 The Primary Anisotropy Effect.- 5.3 The Retarded Potential Law for ‘Moving’ Bodies.- 5.4 The Effect of Motion on Length and Mass.- Exercises and Problems.- 6. Special Relativity as a Cosmological Theory.- 6.1 The Basic Effects of Anisotropy.- 6.2 Observational Consequences.- 6.3 The Balance of Anisotropy Effects.- 6.4 Some Further Consequences.- Exercises and Problems.- 7. Gravitation in a Unique Universe.- 7.1 A Cosmological Basis for Gravitation.- 7.2 Einstein’s Very General Theory.- 7.3 Fock’s Particular Formulation of General Relativity.- 7.4 The Universe as a Mass-Energy System.- Exercises and Problems.- 8. The Space, time and Matter of our Universe.- 8.1 Relative or Absolute?.- 8.2 The Status of the Cosmological Substratum.- 8.3 The Nature of Time.- 8.4 The Matter of our Universe.- 8.5 The Essence and Basis of the Argument.- Exercise and Problems.- Appendices.- Appendix 1: The Steady State Syndrome.- Appendix 2: The Status of Einstein’s Stationary System.- Appendix 3: The Black Hole Deduction.- Appendix 4: The Lorentz-Equivalence of Fundamental Observers — General Proof.- Appendix 5: Derivation of the Retarded Potential Field Law — General Case.- Appendix 6: Synchronisation of Clocks By Slow Transport.- Appendix 7: The Relativistic Doppler and Aberration Furmulae.- Comments on the Exercises and Problems.- 1–1 Movement relative to the cosmic background radiation?.- 1–2 Newtonian black holes?.- 2–1 Why do some galaxies exhibit blue-shifts?.- 2–2(a) The velocity space of a steady-state universe.- 2–2(b) The velocity space of a uniformly-expanding universe.- 2–3 Observational indicators of cosmic time.- 3–1 The practical significance of Einstein’s measurement conventions.- 3–2 Derivation of a transformation involving Einstein co-ordinate measures.- 3–3 The influence of Einstein’s new approach.- 3–4 The velocities transformation and the conditions for its employment.- 3–5 The invariance of the out-and-return journey result.- 3–6 The invariance of the order of events within a time-like interval.- 4–1 Two-dimensional representations of an expanding reference frame.- 4–2 The composition of recession velocities.- 4–3 The extent of the universe?.- 4–4 The limits of observation?.- 4–5 Are there any fundamental observers in the universe?.- 5–1 The speed of light relative to a moving system.- 5–2 Derivation of the retarded potential result for a point directly behind the moving source-body.- 5–3 Derivation of the general length-contraction formula.- 6–1 The observation of length contraction.- 6–2 The time-dilation result for arbitrarily-oriented light-clocks.- 6–3 The puzzle of the balanced lever.- 6–4 The group properties of the Lorentz transformation.- 7–1 The universe as a mass-energy system.- 7–2 A changing universe as the source of gravity?.- 8–1 Eddington’s table.- 8–2 The faces of the Moon.- 8–3 The twin tendencies of evolution and dissolution in our universe.- List of References.