Why things fall

  title={Why things fall},
  author={Olaf Dreyer},
  journal={arXiv: General Relativity and Quantum Cosmology},
  • O. Dreyer
  • Published 23 October 2007
  • Physics, History
  • arXiv: General Relativity and Quantum Cosmology
In this paper we discuss Internal Relativity, a recent program to address the problem of quantum gravity. In our approach we change the relationship between spacetime and matter. Currently we view matter as propagating on spacetime. Einstein's equations encode how spacetime curves due to the presence of matter and how spacetime, in turn, tells matter how to propagate. In internal realtivity matter and spacetime cease to exist as distinct entities, rather, they arise simultaneously from an… Expand

Figures from this paper

Paper Mentions

Analogue Models for Emergent Gravity
Gravity stands out among the fundamental interactions because of its apparent incompatibility with having a quantum description. Moreover, thermodynamic aspects of gravitation theory appears asExpand
Exploring Spacetime Phenomenology: From Lorentz Violations to Experimental Tests of Non-locality
Doctor of Philosophy Exploring Spacetime Phenomenology: From Lorentz Violations to Experimental Tests of Non-locality by Alessio BELENCHIA This thesis deals primarily with the phenomenologyExpand
Analogue gravitational phenomena in Bose-Einstein condensates
Analogue gravity is based on the simple observation that perturbations propagating in several physical systems can be described by a quantum field theory in a curved spacetime. While phenomena likeExpand
Emergence of Lorentzian signature and scalar gravity
In recent years, a growing momentum has been gained by the emergent gravity framework. Within the latter, the very concepts of geometry and gravitational interaction are not seen as elementaryExpand
Emergent Gravity : the Analogue Models Perspective
This thesis is devoted to the study of some aspects of emergent gravity scenarios, i.e. of non-gravitational systems which exhibit, under suitable conditions, the emergence of effective spacetimeExpand
Time is not the problem
Attempts to quantize general relativity encounter an odd problem. The Hamiltonian that normally generates time evolution vanishes in the case of general relativity as a result of diffeomorphismExpand
Relativistic Bose?Einstein condensates: a new system for analogue models of gravity
In this paper we propose to apply the analogy between gravity and condensed matter physics to relativistic Bose?Einstein condensates (RBECs), i.e. condensates composed by relativistic constituents.Expand
Early Universe Cosmology in Internal Relativity
We present a new approach to early universe cosmology. Inflation is replaced by a phase transition in which both matter and geometry are created simultaneously. We calculate the spectrum of metricExpand
The quantum geometric limit
In Einstein's gedankenexperiment for measuring space and time, an ensemble of clocks moving through curved spacetime measures geometry by sending signals back and forth, as in the global positioningExpand
Quantum histories and quantum gravity
This paper reviews the histories approach to quantum mechanics. This discussion is then applied to theories of quantum gravity. It is argued that the results of all measurements in suitably definedExpand


The universe from scratch
A fascinating and deep question about nature is what one would see if one could probe space and time at smaller and smaller distances. Already the 19th century founders of modern geometryExpand
Modern Canonical Quantum General Relativity
The open problem of constructing a consistent and experimentally tested quantum theory of the gravitational field has its place at the heart of fundamental physics. The main approaches can be roughlyExpand
Emergent General Relativity
We review different approaches to quantum gravity in which spacetime is emerging. We discuss in some detail the proposals by G. Volovik and S. Lloyd and show how they differ in the way they treatExpand
Analogue Models of and for Gravity
Condensed matter systems, such as acoustics in flowing fluids, light in moving dielectrics, or quasiparticles in a moving superfluid, can be used to mimic aspects of general relativity. MoreExpand
Classicality in quantum mechanics
In this article we propose a solution to the measurement problem in quantum mechanics. We point out that the measurement problem can be traced to an a priori notion of classicality in the formulationExpand
Physical Relativity: Space-Time Structure from a Dynamical Perspective
1. Overview 2. The physics of coordinate transformations 3. The relativity principle and the fable of Albert Keinstein 4. The trailblazers 5. Einstein's principle-theory route to the LorentzExpand
A theory of quantum gravity based on quantum computation
This paper proposes a method of unifying quantum mechanics and gravity based on quantum computation. In this theory, fundamental processes are described in terms of pairwise interactions betweenExpand
Spacetime geometry from algebra: spin foam models for non-perturbative quantum gravity
This is an introduction to spin foam models for non-perturbative quantum gravity, an approach that lies at the point of convergence of many different research areas, including loop quantum gravity,Expand
Speakable and Unspeakable in Quantum Mechanics: Collected Papers on Quantum Philosophy
List of papers on quantum philosophy by J. S. Bell Preface Acknowledgements Introduction by Alain Aspect 1. On the problem of hidden variables in quantum mechanics 2. On the Einstein-Rosen-PodolskyExpand
Quantum Theory of Fields
To say that this is the best book on the quantum theory of fields is no praise, since to my knowledge it is the only book on this subject. But it is a very good and most useful book. The original wasExpand