Philosophy of Physics, Miscellaneous

Dynamics of complex systems is often hierarchically organized on different time scales. To understand the physics of such hierarchy, here Brownian motion of a particle moving through a fluctuating medium with slowly varying temperature is studied as an analytically tractable example, and a kinetic theory is formulated for describing the states of the particle. What is peculiar here is that the (inverse) temperature is treated as a dynamical variable. Dynamical hierarchy is introduced in conformity with the adiabatic scheme. Then, a (...) new analytical method is developed to show how the Fokker–Planck equation admits as a stationary solution the Maxwellian distribution modulated by the temperature fluctuations, the distribution of which turns out to be determined by the drift term. A careful comment is also made on so-called superstatistics. (shrink)

What justifies the allocation of funding to research in physics when many would argue research in the life and social sciences may have more immediate impact in transforming our world for the better? Many of the justifications for such spending depend on the claim that physics enjoys a kind of special status vis-a-vis the other sciences, that physics or at least some branches of physics exhibit a form of fundamentality. The goal of this paper is to articulate a conception of (...) fundamentality that can support such justifications. I argue that traditional conceptions of fundamentality in terms of dynamical or ontic completeness rest on mistaken assumptions about the nature and scope of physical explanations. (shrink)

A truly Galilean-class volume, this book introduces a new method in theory formation, completing the tools of epistemology. It covers a broad spectrum of theoretical and mathematical physics by researchers from over 20 nations from four continents. Like Vigier himself, the Vigier symposia are noted for addressing avant-garde, cutting-edge topics in contemporary physics. Among the six proceedings honoring J.-P. Vigier, this is perhaps the most exciting one as several important breakthroughs are introduced for the first time. The most interesting breakthrough (...) in view of the recent NIST experimental violations of QED is a continuation of the pioneering work by Vigier on tight bound states in hydrogen. The new experimental protocol described not only promises empirical proof of large-scale extra dimensions in conjunction with avenues for testing string theory, but also implies the birth of the field of unified field mechanics, ushering in a new age of discovery. Work on quantum computing redefines the qubit in a manner that the uncertainty principle may be routinely violated. Other breakthroughs occur in the utility of quaternion algebra in extending our understanding of the nature of the fermionic singularity or point particle. There are several other discoveries of equal magnitude, making this volume a must-have acquisition for the library of any serious forward-looking researchers. (shrink)

In Every Thing Must Go James Ladyman and Don Ross argue for a radical version of naturalistic metaphysics and propose that contemporary analytic metaphysics is detached from science and should be discontinued. The present article addresses the issues of whether science and metaphysics are separable, intuitions and understanding should be excluded from scientific theory, and Ontic Structural Realism satisfies the criteria of the radical version of naturalism advanced by Ladyman and Ross. The point underlying those topics is that successful scientific (...) research presupposes metaphysics, and that basic epistemic virtues common to metaphysics and science may allow us—as opposed to what Ladyman and Ross suggest—to increase our understanding of the world and to put constraints on allowable metaphysical theories. (shrink)

A part of relativistic dynamics is axiomatized by simple and purely geometrical axioms formulated within first-order logic. A geometrical proof of the formula connecting relativistic and rest masses of bodies is presented, leading up to a geometric explanation of Einstein’s famous E = mc 2. The connection of our geometrical axioms and the usual axioms on the conservation of mass, momentum and four-momentum is also investigated.

We prove existence and uniqueness of entropy solutions for the Neumann problem for the quasilinear elliptic equation $u - \mathrm{div} \, \mathbf{a} = v$, where $v\!\in \! L^1$, $\mathbf{a} = \nabla _\xi f$, and $f$ is a convex function of $\xi $ with linear growth as $\Vert \xi \Vert \rightarrow \infty $, satisfying other additional assumptions. In particular, this class includes the case where $f = \varphi \psi $, $\varphi > 0$, $\psi $ being a convex function with linear growth (...) as $\Vert \xi \Vert \rightarrow \infty $. In the second part of this work, using Crandall-Ligget’s iteration scheme, this result will permit us to prove existence and uniqueness of entropy solutions for the corresponding parabolic problem with initial data in $L^1$. (shrink)

can prevent non-contact interactions in Newtonian collision mechanics. The proposal is weakened by the apparent arbitrariness of what will be shown as the requirement of only an odd number of sets of some ex nihilo-created self-exciting particles. There is, however, an initial condition such that, without the ex nihilo self-exciting particles, either there is a contradictory outcome, or there is a non-contact configuration law, or there are odds versus evens indeterminacies. With the various odds versus evens arbitrarinesses and other such (...) difficulties, there seems to be an ontological unsatisfactoriness in the speed-unbounded Newtonian collision system. Introduction Taking self-excitations very seriously A problematic initial condition Another alternative. (shrink)

This dissertation reconstructs some aspects of the historical development of the concept of the electron from 1891, when the term "electron" was introduced, to 1925, when the notion of spin was put forward, in the light of the relevant historiographical and philosophical problems. The central historiographical tool employed is Karl Popper's notion of a problem situation. Furthermore, some of the historical episodes are reconstructed in terms of a "biographical" approach to theoretical entities that portrays them as active agents that participate (...) in the development of scientific knowledge. Their agency is due to the heuristic resources that they embody and to the resistance that they exhibit to manipulation. The historical analysis begins with a reconceptualization of the "discovery" of the electron and aims at situating the principal historical actors within the wider process which led to the acceptance of the electron as an element of the ontology of physics. I continue with a reconstruction of the discovery of the Zeeman effect in the light of recent work on the history and philosophy of experimental science. The next three chapters are devoted to a reading of the development of the old quantum theory of the atom , which aimed at understanding the behavior and distribution of electrons bound within the atom, from the perspective of the electron's biography. Furthermore, I discuss the chemists' representation of the electron and contrast it with its physical counterpart. The main philosophical problem examined concerns the implications of meaning change for scientific realism . I discuss in detail that issue and argue against the widespread view that meaning variance is incompatible with scientific realism. Thus, I provide a way out for the aspiring realist, without however committing myself to a realist position. Finally, I argue that the historical development of the concept of the electron from 1896 to 1925 is compatible with a realist construal of its ontological status. (shrink)

An $L^1$-existence theorem is proved for the nonlinear stationary Boltzmann equation for soft and hard forces in $\mathbb{R}^{n}$ with given indata on the boundary, when the collision operator is truncated for small velocities.