A critical discussion of different methods and models in Casimir effect

The Casimir-Lifshitz force acts between neutral material bodies and is due to the fluctuations (around zero) of the electrical polarizations of the bodies. This force is a macroscopic manifestation of the van der Waals forces between atoms and molecules. In addition to being of fundamental interest, the Casimir-Lifshitz force plays an important role in surface physics, nanotechnology and biophysics. There are two different approaches in the theory of this force. One is centered on the fluctuations inside the bodies, as the source of the fluctuational electromagnetic fields and forces. The second approach is based on finding the eigenmodes of the field, while the material bodies are assumed to be passive and non-fluctuating. In spite of the fact that both approaches have a long history, there are still some misconceptions in the literature. In particular, there are claims that (hypothetical) materials with a strictly real dielectric function $\varepsilon(\omega)$ can give rise to fluctuational Casimir-Lifshitz forces. We review and compare the two approaches, using the simple example of the force in the absence of retardation. We point out that also in the second (the "field-oriented") approach one cannot avoid introducing an infinitesimal imaginary part into the dielectric function, i.e. introducing some dissipation. Furthermore, we emphasize that the requirement of analyticity of $ \varepsilon(\omega)$ in the upper half of the complex $\omega$ plane is not the only one for a viable dielectric function. There are other requirements as well. In particular, models that use a strictly real $\varepsilon(\omega)$ (for all real positive $\omega)$ are inadmissible and lead to various contradictions and inconsistencies. Specifically, we present a critical discussion of the "dissipation-less plasma model". Our emphasis is not on the most recent developments in the field but on some conceptual, not fully resolved issues.

Modern materialistic understanding of the “energy” notion and the method of its systemic evaluation in chemicals

It was shown that the traditional approaches to understanding the notion of “energy” as a work or a physical quantity are outdated. For example, R. Feynman noted that “today’s physics does not know what energy is.” Therefore, even now, some researchers believe that “by and large, the concept of energy… is artificial, because unlike matter, of which we can say that it exists, energy is the fruit of human thought.” In contrast to these ideas, the authors showed that energy, like matter, objectively exists in various forms (energy continuum), which differ in structure, and is able to perform different types of work, to determine the forms of interaction and movement of matter in various material systems (substances, material bodies and megamaterial systems). A new scientific foundation for systematization and quantitative evaluation of energy characteristics of chemical compounds was proposed. It is based on a comprehensive assessment of contribution of chemical compounds’ composition and chemical bond type in line with a chemical bond’s unified model and the “System of chemical bonds and compounds” (SCBC). As a result of using this basic scientific innovation, the symbiosis of Mendeleev’s periodic table of atoms (composition – property) and SCBC (composition - chemical bond and structure – property) was realized for the first time. The foundation was laid for creating a database on systemic digitalization and evaluation of energy stored in various chemicals (natural gas, coal, oil, peat, wood, etc.) and the most effective ways of extracting it from these.

Stranger spaces: Embodiment, space and language in the collaborative life writing novel The Fortune Finder

The present study takes The Fortune Finder (2008) by Edward van de Vendel and Anoush Elman as a case in point to demonstrate how interactions between material bodies, space and power constitute some characters as strangers or, in other words, as bodies deemed out-of-place. The novel is an example of collaborative life writing and describes how a young, Afghan refugee and his family flee the Taliban regime and seek asylum in the Netherlands. Building on Sara Ahmed’s work (2000), I demonstrate how their bodies are recognised as stranger bodies through a demarcation of social spaces, which involves including or excluding particular bodies based on matters of normativity and deviance. Protagonist Hamayun and his family are implicated in shifting relationships with power and space that cause their bodies to be recognised as out-of-place in various ways, dependent on their circumstances. The notion of dwelling takes centre stage in these dynamics. It denotes the actual spaces that Hamayun and his family (are allowed to) inhabit, but it also features in a metaphor that links friendship with spaces of belonging. An implied lack thereof suggests how Hamayun eventually seems to perceive himself as a kind of stranger.

Feasting with Buddhist Women: Food Literacy in Religious Belonging

This ethnographic study shows that women’s knowledge and practices involving food in Japanese Buddhist contexts circulate as gendered currency. It emphasizes how what we term “food literacy” cultivates aesthetic and affective senses of belonging among Buddhist practitioners. We argue that this embodied knowledge helps women negotiate their experiences of Buddhism and show how these experiences articulate the complexities of their bounded and self-disciplining Buddhist selves. Women use food literacy to teach, learn, and practice the way Buddhism feels and etch it into their own and others’ emotional, social, and material bodies. By recognizing women as stewards of religion, particularly through food literacy, we also elucidate how women’s uses of mundane practices illuminate food literacy as a value carrier that generates belonging through food. Such practices can equally become sites of failure to connect if the intended recipients do not share understandings or appreciations of the aesthetic and affective dimensions of it.

On the Magnitude of the Gods in Materialist Theology and Greek Art

In this paper, I address one characteristic of Classical Greek votive reliefs that has troubled scholars: the size of the gods. The reliefs depict mortal worshippers approaching gods and goddesses who are, almost invariably, larger in stature than the mortals. Scholars have generally explained the difference in scale to be art historical, rather than theological, in significance. Either the larger scale is a visual expression of the hierarchical superiority of the gods or the images of the gods represent over-life-size statues. In addition, it is widely accepted that votive reliefs are products of unsophisticated religious belief, ignorant of the conceptualization of an imperceptible, non-corporeal deity in Classical philosophy. In this paper, I accept the artistic proposition of votive reliefs at face value: in this genre, the gods are living, visible, material bodies, most often anthropomorphic in form and always larger in magnitude than mortals. I identify one significant parallel for this interpretation within Greek and Roman thought, namely, the conception of gods within the materialist theology developed by the late Classical writer Epicurus and, in part at least, by the fifth-century BC writer Demokritos. In the writings of the Epicureans and, it appears, the atomists, as in the votive reliefs, gods are human in form, very beautiful, self-sufficient, larger than humans in size and known by mortals through visual perception.

Berkeley, Edwards, and Ramist Logic

Edwards and Berkeley sound alike because both think of minds or spiritual substances not as things modeled on material bodies but as activities by which things are identified. Those activities cannot be described using the Aristotelian subject–predicate logic on which the metaphysics of substance, properties, attributes, or modes is based, because subjects, substances, etc. are themselves initially distinguished through such acts. To think of mind as opposed to matter, or of acts of mind as opposed to mind itself, is already to assume the differentiation enacted by those acts. Even though Edwards and Berkeley refer to distinctions such as mind vs. matter, they think it is important to avoid treating mind, its acts, and its objects in terms of subject–predicate logic or substance metaphysics.

Designing of Dynamic Spectrum Shifting in Terms of Non-Local Space-Fractional Mechanics

In this paper, the applicability of the space-fractional non-local formulation (sFCM) to design 1D material bodies with a specific dynamic eigenvalue spectrum is discussed. Such a formulated problem is based on the proper spatial distribution of material length scale, which maps the information about the underlying microstructure (it is important that the material length scale is one of two additional material parameters of sFCM compared to the classical local continuum mechanics—the second one, the order of fractional continua—is treated herein as a scaling parameter only). Technically, the design process for finding adequate length scale distribution is not trivial and requires the use of an inverse optimization procedure. In the analysis, the objective function considers a subset of eigenvalues reduced to a single value based on Kreisselmeier–Steinhauser formula. It is crucial that the total number of eigenvalues considered must be smaller than the limit which comes from the ratio of the sFCM length scale to the length of the material body.

Analysis of Methods for Determining the Characteristics of a Single Spatial Electromagnetic Field

This paper analyzes the methods for determining the characteristics of a single spatial electromagnetic field; considerations combine all–electric, magnetic, and electromagnetic fields into a single electromagnetic theory of a spatial field. On the basis of the concept of a single field of force spatial interaction of material bodies, it is analytically established that in a physical vacuum only waves of its polarization actually exist, transporting in the space of a vacuum sphere its excitation energy, which when force interacting with a certain physical characteristic (electrical, magnetic or gravitational) material body, creates a dynamic response of the parameters of this body, which is recorded in the experiment as a real flow of energy with responsible of the physical nature.