Yuri Balashov

Enduring and Perduring Objects in Minkowski Space-Time

I examine the issue of persistence over time in thecontext of the special theory of relativity (SR). Thefour-dimensional ontology of perduring objects isclearly favored by SR. But it is a different questionif and to what extent this ontology is required, andthe rival endurantist ontology ruled out, by thistheory. In addressing this question, I take theessential idea of endurantism, that objects are whollypresent at single moments of time, and argue that itcommits one to unacceptable conclusions regardingcoexistence, in the context of SR. I then propose anddiscuss a plausible account of coexistence forperduring objects, which is free of these defects. This leaves the endurantist room for some maneuvers. I consider them and show that they do not really helpthe endurantist out. She can accommodate the notionof coexistence in the relativistic framework only atthe cost of renouncing central endurantist intuitions.

Persistence and spacetime

1. Background and Assumptions 2. Persistence, Location and Multilocation in Spacetime 3. Classical and Relativistic Spacetime 4. Persisting Objects in Classical Spacetime 5. Persisting Objects in Minkowski Spacetime 6. Coexistence in Spacetime 7. Strange Coexistence? 8. Shapes and Other Arrangements in Minkowski Spacetime References

Resource Letter AP‐1: The anthropic principle

This Resource Letter provides a guide to the literature on the anthropic principle. The letter E after an item indicates elementary level or material of general interest to persons becoming informed in the field. The letter I, for intermediate level, indicates material of somewhat more specialized nature. The annotation A indicates rather specialized or advanced material.

Zero-Value Physical Quantities

To state an important fact about the photon, physicists use such expressions as (1) “the photon has zero (null, vanishing) mass” and (2) “the photon is (a) massless (particle)” interchangeably. Both (1) and (2) express the fact that the photon has no non-zero mass. However, statements (1) and (2) disagree about a further fact: (1) attributes to the photon the property of zero-masshood whereas (2) denies that the photon has any mass at all. But is there really a difference between saying that something has zero mass (charge, spin, etc.) and saying that it has no mass (charge, spin, etc.)? Does the distinction cut any physical or philosophical ice? I argue that the answer to these questions is yes. Put briefly, the claim of this paper is that some zero-value physical quantities are not mere “privations”, “absences” or “holes in being”. They are respectable properties in the same sense in which their non-zero partners are. This, I will show, has implications for the debate between two rival views of the nature of property, dispositionalism and categoricalism.

Restricted Diachronic Composition, Immanent Causality, and Objecthood: A Reply to Hudson

Composition, persistence, vagueness, and more constitute an interconnected network of problems. My criticism of Hud Hudson’s provocative claims made in a recent paper (Hudson 2002) was focused almost exclusively on the issue of diachronic composition (Balashov 2003). Hudson’s response (2003) has highlighted the dangers of such isolationism. But I want to hold to my strategy to the end. Part of the reason is to evade the appalling responsibility of presenting a full-blown theory of all the above phenomena; I must confess that I do not have such a theory. At the same time, I contend that diachronic composition can be profitably carved out from the medley of the surrounding issues more or less at the joints provided by nature itself. And I do subscribe to some sort of realism about the joints of nature. The most important of them is a broadly causal relation between successive stages of material objects that is revealed in mark transmission. Following Hudson’s suggestion (2003, 17)—and thus to avoid prejudging any important issues—let us refer to this relation as immanent causality rather than genidentity. I believe immanent causality places a natural restriction on diachronic composition and, hence, demarcates real perduring physical objects from ‘separate and loose’ series of temporal parts that do not compose anything. Hudson thinks, on the contrary, that whereas some line between these two cases has to be

Temporal Parts and Superluminal Motion

Abstract Hud Hudson has recently suggested a scenario intended to show that, assuming the doctrine of temporal parts and a sufficiently liberal view of composition, there are material objects that move faster than light. I accept Hudsons conditional but contend that his modus ponens is less plausible than the corresponding modus tollens. Reversed in this way, the argument stemming from the scenario raises the cost of mereological liberalism and advances the case for a principled restriction on diachronic composition.

On vagueness, 4D and diachronic universalism

I offer a new criticism of the argument from vagueness to four-dimensionalism [Sider 2001. The argument is modelled after an older argument for mereological universalism [Lewis 1986 and may be looked upon as a tightened-up and extended version of the latter. While I agree with other critics [Koslicki 2003; Markosian 2004 that the argument from vagueness fails precisely because of this affinity, my recipe for dealing with it is different. I reject the assumption, shared by Sider with his opponents, that synchronic composition and ‘minimal diachronic fusion’ are sufficiently similar to use considerations inspired by the analysis of the former to bear on the latter. My objection to a crucial premise of the argument from vagueness turns on the relevant aspect of dissimilarity between these two cases.

Einstein Studies in Russia

Einstein and Friedmann, Viktor Frenkel the problem of conservation laws in general relativity - an historical and methodological analysis, Gennady Gorelik the role played by Machs ideas in the genesis of the general theory of relativity, Vladimir Vizgin Hermann Weyl and large numbers in relativistic cosmology, Gennady Gorelik laws of physics and the universe, Yuri Balashov Vsevolod Frederiks, pioneer of relativism and liquid crystal physics, Vladimir Vizgin and Viktor Frenkel Einsteins fluctuation formula and the wave-particle duality, Alexei Kojevnikov Diracs quantum electrodynamics, Alexei Kojevnikov Einsteins Zurich colloquium, Boris Yavelov what may happen to a man who thinks a great deal but reads very little, Victor Frenkel and Boris Yavelov.

Chapter 4 Persistence and Multilocation in Spacetime

The chapter attempts to make the distinctions among the three modes of persistence—endurance, perdurance and exdurance—precise, starting with a limited set of notions. I begin by situating the distinctions in a generic spacetime framework. This requires, among other things, replacement of classical notions such as ‘temporal part’, ‘spatial part’, ‘moment of time’ and the like with their more appropriate spacetime counterparts. I then adapt the general definitions to Galilean and Minkowski spacetime and consider some illustrations. Finally, I respond to an objection to the way in which my generic spacetime framework is applied to the case of Minkowski spacetime.

On Stages, Worms, and Relativity

Four–dimensionalism, or perdurantism, the view that temporally extended objects persist through time by having (spatio-)temporal parts or stages, includes two varieties, the worm theory and the stage theory. According to the worm theory, perduring objects are four–dimensional wholes occupying determinate regions of space–time and having temporal parts, or stages, each of them confined to a particular time. The stage theorist, however, claims, not that perduring objects have stages, but that the fundamental entities of the perdurantist ontology are stages. I argue that considerations of special relativity favor the worm theory over the stage theory.