Absolute Versus Relational Space-Time: An Outmoded Debate?

Written from a very untutored and limited viewpoint in terms of physics and mathematics, this essay ventures some thoughts that should therefore be regarded as only very tentative. Especially as they address a long established idea that sits right at the heart of the scientific discipline of physics. This is the idea of naturally moving reference systems, a notion closely linked to the classical principles of both inertia and relativity. Such inertial reference systems played a key role in some thought experiments published over a century ago, by Albert Einstein. It is a critical

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2017

The text proposes some directions of research, as based on previous works made by the author. Our purpose is to discuss the contribution of general relativity to the epistemology of space and time, in the context of a relational, and not substantial, rationality. General relativity brings us the important idea (of a relational nature) that space and time do not constitute a scene external to phenomena, but that, on the contrary, the phenomena themselves, in the first place the phenomenon of gravitation, are responsible for assessing the corresponding variables. However, this contribution does not make us progress on the "mystery" of time, that remains conceptually separated from space, even though, since the relativity theory, the values of space and time variables are related. Encouraged by general relativity, we must go further and express more strongly the link between the concepts of space and time, and their identity of substance. The relational approach must extend t...

2000

When we discover the world, neither space nor time are shown to us and named as such, and we have neither rulers nor clocks independent from it. Practically, it is within the phenomena that we choose what allows us to think and to build space (material points declared to be bound together in an immobile way), and what allows us

This paper is a brief (and hopelessly incomplete) non-standard introduction to the philosophy of space and time. It is an introduction because I plan to give an overview of what I consider some of the main questions about space and time: Is space a substance over and above matter? How many dimensions does it have? Is space-time fundamental or emergent? Does time have a direction? Does time even exist? Nonetheless, this introduction is not standard because I conclude the discussion by presenting the material with an original spin, guided by a particular understanding of fundamental physical theories, the so-called primitive ontology approach.

2016

This paper is a brief (and hopelessly incomplete) non-standard introduction to the philosophy of space and time. It is an introduction because I plan to give an overview of what I consider some of the main questions about space and time: Is space a substance over and above matter? How many dimensions does it have? Is space-time fundamental or emergent? Does time have a direction? Does time even exist? Nonetheless, this introduction is not standard because I conclude the discussion by presenting the material with an original spin, guided by a particular understanding of fundamental physical theories, the so-called primitive ontology approach.

The Routledge Handbook of Emergence, 2019

Research in quantum gravity strongly suggests that our world in not fundamentally spatiotemporal, but that spacetime may only emerge in some sense from a non-spatiotemporal structure, as this paper illustrates in the case of causal set theory and loop quantum gravity. This would raise philosophical concerns regarding the empirical coherence and general adequacy of theories in quantum gravity. If it can be established, however, that spacetime emerges in the appropriate circumstances and how all its relevant aspects are explained in fundamental non-spatiotemporal terms, then the challenge is fully met. It is argued that a form of spacetime functionalism offers the most promising template for this project. Space and time, it seems, must be part and parcel of the ontology of any physical theory; of any theory with a credible claim to being a physical theory, that is. After all, physics is the science of the fundamental constitution of the material bodies, their motion in space and time, and indeed of space and time themselves. Usually implicit, Larry has given expression to this common intuition: What could possibly constitute a more essential, a more ineliminable, component of our conceptual framework than that ordering of phenomena which places them in space and time? The spatiality and temporality of things is, we feel, the very condition of their existing at all and having other, less primordial, features... We could imagine a world without electric charge, without the atomic constitution of matter, perhaps without matter at all. But a world not in time? A world not spatial? Except to some Platonists, I suppose, such a world seems devoid of real being altogether. (45) The worry here, I take it, goes beyond a merely epistemic concern regarding the inconceivability of a non-spatiotemporal world; rather, it is that such a world would violate some basic necessary condition of physical existence. It is contended that space and time partially ground a material world. The alternative to a spatiotemporal world, it is suggested, is a realm of merely abstract entities. 1 Part of what it means to be 'physically salient' (Huggett and Wüthrich 2013) is to be in space and time. In other words, what it is to give a physical explanation of aspects of our manifest world is, among other things, to offer a theory of how objects are and move in space and time. * I thank Robin Hendry and Tom Lancaster for their insightful and challenging comments on an earlier draft of this paper. This work was partly performed under a collaborative agreement between the University of Illinois at Chicago and the University of Geneva and made possible by grant number 56314 from the John Templeton Foundation and its content are solely the responsibility of the author and do not represent the official views of the John Templeton Foundation. 1 The defenders of the claim that the world is purely abstract, formal, or mathematical-as opposed to partly abstract, formal, or mathematical-are usually referred to as 'Pythagoreans', rather than as 'Platonists'.

2016

Starting from a short review of the "classical" space problem in the sense of the 19th century (Helmholtz-Lie-Klein) it is discussed how the challenges posed by special and general relativity to the classical analysis were taken up by Hermann Weyl and Elie Cartan. Both mathematicians reconsidered the space problem from the point of view of transformations operating in the infinitesimal neighbourhoods of a manifold (spacetime). In a short outlook we survey further developments in mathematics and physics of the second half of the 20th century, in which core ideas of Weyl's and/or Cartan's analysis of the space problem were further investigated (mathematics) or incorporated into basic theories (physics).

Springer eBooks, 2009

An often repeated account of the genesis of special relativity tells us that relativity theory was to a considerable extent the fruit of an operationalist philosophy of science. Indeed, Einstein's 1905 paper stresses the importance of rods and clocks for giving concrete physical content to spatial and temporal notions. I argue, however, that it would be a mistake to read too much into this. Einstein's operationalist remarks should be seen as serving rhetoric purposes rather than as attempts to promulgate a particular philosophical position-in fact, Einstein never came close to operationalism in any of his philosophical writings. By focussing on what could actually be measured with rods and clocks Einstein shed doubt on the empirical status of a number of pre-relativistic concepts, with the intention to persuade his readers that the applicability of these concepts was not obvious. This rhetoric manoeuvre has not always been rightly appreciated in the philosophy of physics. Thus, the influence of operationalist misinterpretations, according to which associated operations strictly define what a concept means, can still be felt in present-day discussions about the conventionality of simultaneity. The standard story continues by pointing out that Minkowski in 1908 supplanted Einstein's approach with a realist spacetime account that has no room for a foundational role of rods and clocks: relativity theory became a description of a four-dimensional "absolute world." As it turns out, however, it is not at all clear that Minkowski was proposing a substantivalist position with respect to spacetime. On the contrary, it seems that from a philosophical point of view Minkowski's general position was not very unlike the one in the back of Einstein's mind. However, in Minkowski's formulation of special relativity it becomes more explicit that the content of spatiotemporal concepts relates to considerations about the form of physical laws. If accepted, this position has important consequences for the discussion about the conventionality of simultaneity.

The goal of the present paper is to reconstruct the history of Minkowski spacetime, focusing on the specific understanding that Minkowski had of his own model in the context of his worldview. To achieve it, we will first take a look at Minkowski’s personal academic history. By exploring his scientific development, certain key elements in his approach to mathematics and physics will be highlighted, so that his worldview is put into perspective and supported by evidence. Afterwards, a brief summary of Einstein’s work on special relativity is presented, with the aim to speculate on Einstein’s own way of interpreting spacetime. This will also set up the foundation for a comparison with Minkowski. Then, we will analyze the main lectures through which Minkowski presented his geometric model of spacetime to the German scientific community, focusing especially on Raum und Zeit. Here, Minkowski’s worldview is further articulated. Last but not least, we will endorse that, despite Minkowski’s work becoming crucial for Einstein and Einstein's interpretation of spacetime most likely growing closer to Minkowski's, the two scientists ultimately shared crucial differences in weltanschauung.