scholarly journals Thinking about Spacetime

2021 ◽  
pp. 129-153
Author(s):  
David Yates
Keyword(s):  
Quantum Gravity ◽  
Philosophy Of Mind ◽  
Fundamental Theory ◽  
True Nature ◽  
Fundamental Ontology ◽  
Fundamental Structure ◽  
Space And Time ◽  
Spacetime Structure ◽  
Research Programmes ◽  
Emergent Spacetime

Several different quantum gravity research programmes suggest, for various reasons, that spacetime is not part of the fundamental ontology of physics. This gives rise to the problem of empirical coherence, which I frame in terms of entailment: how could a non-spatiotemporal fundamental theory entail spatiotemporal evidence propositions? Solutions to this puzzle can be classified as realist or antirealist, depending on whether or not they posit a non-fundamental spacetime structure grounded in or caused by the fundamental structure. These approaches place different constraints on our everyday concepts of space and time. Applying lessons from the philosophy of mind, I argue that only realism is both conceptually plausible and suitable for addressing the problem at hand. I suggest a role-functionalist version of realism, which is consistent with both grounding and causation, and according to which our everyday concepts reveal something of the true nature of emergent spacetime.

scholarly journals When the Actual World Is Not Even Possible

2020 ◽  
pp. 233-254
Author(s):  
Christian Wüthrich
Keyword(s):  
Quantum Gravity ◽  
Actual World ◽  
Possible Worlds ◽  
Fundamental Theory ◽  
Fundamental Level ◽  
Fundamental Structure ◽  
Space And Time ◽  
Mere Existence ◽  
Spatiotemporal Relations

Approaches to quantum gravity often involve the disappearance of space and time at the fundamental level. The metaphysical consequences of this disappearance are profound, as is illustrated with David Lewis’s analysis of modality. As Lewis’s possible worlds are unified by the spatiotemporal relations among their parts, the non-fundamentality of spacetime—if borne out—suggests a serious problem for his analysis: his pluriverse, for all its ontological abundance, does not contain our world. Although the mere existence—as opposed to the fundamentality—of spacetime must be recovered from the fundamental structure in order to guarantee the empirical coherence of the non-spatiotemporal fundamental theory, it does not suffice to salvage Lewis’s theory of modality from the charge of rendering our actual world impossible.

scholarly journals On the Foundation of Space and Time by Quantum-Events

2021 ◽  
Vol 52 (1) ◽  
Author(s):  
Andreas Schlatter
Keyword(s):  
Quantum Gravity ◽  
Cosmological Constant ◽  
Natural Philosophy ◽  
True Nature ◽  
Modern Times ◽  
Space And Time ◽  
Einstein's Equation ◽  
Material Systems ◽  
Spatio Temporal

AbstractThe true nature of space and time has been a topic of natural philosophy, passed down since the presocratic era. In modern times reflection has particularly been inspired by the physical theories of Newton and Einstein and, more recently, by the quest for a theory of quantum gravity. In this paper we want to specify the idea that material systems and their spatio-temporal distances emerge from quantum-events. We will show a mechanism, by which quantum-events induce a metric field between material systems, which is governed by Einstein's equation including a cosmological constant.

scholarly journals Functionalist explanation of spacetime

2019 ◽  
Vol 62 (2) ◽  
pp. 119-131
Author(s):  
Radmila Jovanovic-Kozlowski
Keyword(s):  
Quantum Gravity ◽  
Functional Role ◽  
Physical Theory ◽  
Classical Mechanics ◽  
Fundamental Theory ◽  
Emergent Spacetime ◽  
New Interpretation ◽  
New Research ◽  
Philosophical Debates ◽  
Real Challenge

In contemporary physics, from General relativity and Quantum mechanics to new research programs of Quantum gravity, we can find a vast variety of spacetime structures, which makes the interpretation of this concept a real challenge. Recently, a group of authors advanced a new interpretation of spacetime called ?spacetime functionalism?, with the idea that spacetime should be defined via its functional role in the physical theory, in other words, ?spacetime is what spacetime does?. A material field or an object are spatiotemporal if they play a defined role in a physical theory. The approach is meant to be widely applicable, from classical mechanics to possible new theories of Quantum gravity, where spacetime might not appear at the fundamental theory level. Functionalism can be well combined with the emergent spacetime. It should also shed a new light on traditional philosophical debates between substantivists and relationists and between realists and anti-realists.

Introduction

2021 ◽  
pp. 1-15
Author(s):  
Christian Wüthrich ◽  
Baptiste Le Bihan ◽  
Nick Huggett
Keyword(s):  
Quantum Gravity ◽  
Philosophical Work ◽  
Material World ◽  
Fundamental Structure ◽  
The Third ◽  
Space And Time ◽  
Methodological Challenges ◽  
Fertile Ground

Quantum gravity offers a fertile ground for philosophical work, particularly through its suggestion that spacetime may not be fundamental but merely a derivative structure. As such, theories of quantum gravity stand in a long tradition of physical theories with deep implications for the nature of space and time, and indeed the fundamental structure of our material world. This Introduction summarizes the contributions to this collection by structuring them around three themes. The first group of chapters analyses various aspects of the search of lost spacetime in quantum gravity. The second group studies metaphysical and epistemological aspects of the emergence in play in quantum gravity. The third group widens the investigations to several key methodological challenges arising in the context of quantum gravity.

Causal Powers

2017 ◽  
Keyword(s):  
Philosophy Of Science ◽  
Philosophy Of Mind ◽  
Scientific Practice ◽  
Laws Of Nature ◽  
Causal Powers ◽  
Important Work ◽  
Space And Time ◽  
Metaphysics Of Mind

This collection brings together new and important work by both emerging scholars and those who helped shape the field on the nature of causal powers, and the connections between causal powers and other phenomena within metaphysics, philosophy of science, and philosophy of mind. Contributors discuss how one who takes causal powers to be in some sense irreducible should think about laws of nature, scientific practice, causation, modality, space and time, persistence, and the metaphysics of mind.

scholarly journals Dust as a standard of space and time in canonical quantum gravity

1995 ◽  
Vol 51 (10) ◽  
pp. 5600-5629 ◽  
Author(s):  
J. David Brown ◽  
Karel V. Kuchař
Keyword(s):  
Quantum Gravity ◽  
Space And Time ◽  
Canonical Quantum Gravity ◽  
Canonical Quantum

scholarly journals Quantum gravity as a metaphysical problem

2017 ◽  
Vol 1 (5) ◽  
pp. 163-170
Author(s):  
Ilja Schmelzer
Keyword(s):  
Field Theory ◽  
Quantum Gravity ◽  
Degrees Of Freedom ◽  
Einstein Equations ◽  
Absolute Space ◽  
Quantum Theories ◽  
Approximation Techniques ◽  
Metaphysical Problem ◽  
Space And Time ◽  
Important Argument

The problem with quantum gravity is usually presented as if it would be difficult to construct even a single quantum theory of relativistic gravity. This is shown to be wrong. A straightforward approach using standard, well-studied methods allows to construct mathematically well-defined quantum theories which give, in a certain classical limit, the Einstein equations of GR: GR may be transformed into a field theory on a fixed background by breaking diffeomorphism symmetry using harmonic coordinates. The resulting field theory may be regularized using standard lattice approximation techniques. The result is a well-defined canonical theory with a finite number of degrees of freedom, which can be quantized without problems in a canonical way. Why such a straightforward way to quantize gravity is simply ignored? We identify missing explanation of relativistic symmetry as an important argument, and propose a solution. evaluate possible explanations why this simple possibility to construct a theory of quantum gravity is ignored. While a lot of different metaphysical and sociological reasons play a role, we identify as a main point a preference of the scientific community for the relational philosophy behind the spacetime interpretation of GR, in opposition to the Newtonian concept of absolute space and time (substantivalism). We conclude that the quantization of gravity is not a problem of physics, but a metaphysical problem. It is a problem of the relational philosophy of space and time in the tradition of Descartes and Leibniz, which is the base of the spacetime interpretation of GR, because this philosophy is incompatible with the known examples of theories of quantum gravity.

Finding Space in a Non-Spatial World

2021 ◽  
pp. 154-181
Author(s):  
David J. Chalmers
Keyword(s):  
Philosophy Of Mind ◽  
Perceptual Experience ◽  
Functional Role ◽  
Recent Literature ◽  
Cartesian Skepticism ◽  
Scientific Image ◽  
Emergent Spacetime ◽  
Manifest Image

What is the relation between space in the manifest image of perceptual experience and in the scientific image of physics? I will argue that we have moved from spatial primitivism (on which space is understood as a primitive conception that we are acquainted with) to spatial functionalism (on which space is picked out by its functional role). I investigate different forms of spatial functionalism on which the relevant roles are experiential (involving effects on our experience) and non-experiential (involving patterns of causal interactions). I draw connections to functionalism in the philosophy of mind, to Cartesian skepticism, and to recent literature on spacetime functionalism and emergent spacetime.

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