This short essay presents a critical cartography of the critical new materialist notion and methodology of diffraction.

This essay focuses on the possibility of adopting a representational approach for technoscience, in which representation is considered as a situated process of dynamic “intra-action” (Barad 2007 ). Re-elaborating the recent critiques of representationalism (Thrift 2008 ), my analysis begins by analysing Hayles’s situated model of representation from an early essay where she explains her definition of constrained constructivism (Hayles [ 1991 ] 1997). The essay then discusses the notions of figuration and diffraction and the way they are employed (...) by Haraway in many of her writings for her critique of technoscience (Haraway 1991 , 1997 ). Finally, after considering diffraction through Barad’s reading of this practice in the context of her theory of agential realism ( 2007 ), it shows the links that relate constrained constructivism, situated knowledge and agential realism, and the way all of them work at “diffract[ing] the rays of technoscience” (Haraway 1997 : 16) through an alternative representational practice. (shrink)

Academics should produce quality scholarly research. However, the demands of the marketised, neoliberal higher education institution and the increase in the academic’s bureaucratic and administrative tasks do not allow for adequate engagement with the deep work and slow forms of scholarship that are needed to produce cutting-edge and insightful research. Many academics find it challenging to think critically and creatively under such conditions, yet they are unwilling to fill their time with shallow work instead. Thus, they are torn between producing (...) an institutionally-determined number of research outputs, and striving towards producing quality scholarly work that advances knowledge in the academic’s discipline. Reading groups serve to rework this tension by providing a communal and scheduled place and mind-space for reading major academic works. Reading takes time and persistence. We find that setting aside time and creating creative spaces for reading groups offer an opportunity for silent revolt against the pressures of the higher education institution. In this (post)qualitative inquiry we diffractively read – “through one another” – two autoethnographical accounts to experiment with our experiences of various reading groups over a period of three years while positioning ourselves in relation to Barad’s notion of diffraction. This speculative experimentation entails a myriad of ideas and methods that serve to decentre hegemonic, monolithic knowledge systems through seeking alternative ways of knowing, and recognises the importance of the entanglement of matter and meaning in tracing (and countering) the social relations produced in neoliberalist contexts. Such (re)thinking is thus a vital counterpoint to the neoliberal obsessions of the higher education context, (re)directing the scholar to new non-autonomous and mutable landscapes. (shrink)

This article seeks to further the discussion of mimesis in the current new materialist philosophies that are charged with doubts about the potential of mimetic practices, i.e., practices of reflection, and propose a more differential /diffractive notion of mimesis. It argues that the concept of mimesis and performative approaches to knowledge making can be compatible. The figures of mimesis appear in the conceptualizations of both reflective and diffractive practices, and if mimesis is considered rather as a diffractive operation, it could (...) be seen as having a different efficacy and ethico-political function. Drawing on Karen Barad’s and Isabelle Stengers’ arguments, I start by showing why in the representationalist view of knowledge making, the tool of mimesis is dysfunctional—it is a way of separating and classifying copies of reality. Then, I introduce a diffractive notion ofmimesis in line with the mimetic re-turn in posthuman studies. From the perspective of relational understanding of knowledge making supported in Barad’s and Stengers’ ethico-political proposals, mimesis can be perceived as a tool for provoking change and thus, imply a need to do it carefully. (shrink)

In this article it is argued that the optical metaphor and critical practice of diffraction further developed by Donna Haraway and Karen Barad might be no less significant than the widely spread notion of reflection, when the questions of various practices of knowledge are addressed. By considering Paul Ramsden’s approach to learning/teaching and its underlying theory in higher education alongside Karen Barad’s methodology of diffraction, it is shown that Ramsden’s understanding of learning/teaching is rather based on the theoretical (...) assumptions of diffractive practice. His notion that teaching/learning are closely related and actively shaping each other, and that learners are not disconnected from the environment and their previous experiences with the subject matter and learning process itself, adds to Barad’s onto-epistemological position that knowers know the world at the same time as being the part of the world in its ongoing intra-activity. Ramsden’s understanding of relation is diffractive, because it is not about predefined binary entities and their fixed identities, but about layers and entanglements of various previous experiences and reactions to the learning environment. In addition, looking at learning/teaching processes through a different perspective also leads to a different approach to teaching and other ways of problem-solving. Both Ramsden and Barad distrust homologies, analogies, and causality-based conceptions of knowledge sharing. Instead, the ability to respond to an always new learning/teaching environment is assessed, which implies a diffractive type of sensitivity to the context, iterative process of re-turning, and the creation of dangerously indeterminate relationships and commitments. In this way, some of Barad’s philosophical notions, i.e., the diffraction pattern, intra-activity, returning, and others, also may acquire new practical content. (shrink)

This chapter touches upon the damaging impact of neoliberal reason on institutions of higher education, and my efforts as a teacher to help turn things around by re-vitalizing the classroom. After a critique of current neoliberal ‘borderline times’, the chapter takes the reader on a journey of diffractive re-imaginings in which I share some of my experiences of co-learning with undergraduates in an American feminist-philosophical classroom. My central argument is that the neoliberalism-induced crisis in education can be affirmatively counteracted through (...) experimentations with various posthuman and new materialist theories, and the Harawayan-Baradian methodology of diffraction in particular. Furthermore, informed by the impression that theory and pedagogical praxis go hand in hand in many contemporary feminist new materialisms, I zoom in on daily acts of resistance against the neoliberal corporatization of the American university, acts that actualized themselves as feminist new materialist pedagogies. Three examples of diffractive pedagogical strategies are then discussed in detail. (shrink)

Quantum leaps happen in texts, too. This reading of the role of the quantum leap in Karen Barad's agential realism is necessary, because arguing that the diffractive reading strategy proposed by Barad's ethico-onto-epistemology mirrors the physical phenomenon of diffraction would indeed be representationalist. Reviewing how Barad—in her own oeuvre—has transformed diffraction into an innovative reading methodology that could not only potentially challenge the epistemological underpinnings of the canonization process that is at work in feminist theory, but could also (...) radically change the canonization practice of feminist oeuvres itself, our article embarks on a detailed examination of the ways in which the oeuvres of Simone de Beauvoir and Luce Irigaray have been mistakenly categorized and canonized in a hierarchical and Oedipalized manner. This conflict-based narrative has not only paralyzed the oeuvres of Irigaray and Beauvoir, but also has had a negative impact on the canonization of sexual difference philosophy as a whole in feminist theory. By (re)reading the oeuvres diffractively, this article brings the feminist philosophies of Beauvoir and Irigaray together by invalidating the idea that the feminist canonization process always has to run along the lines of discontinuity, Oedipalization and dialectization. (shrink)

This intra-view explores a number of productive junctions between contemporary Deleuzoguattarian and new materialist praxes via a series of questions and provocations. Productive tensions are explored via questions of epistemological, ontological, ethical, and political intra-sections as well as notions of difference, transversal contamination, ecosophical practices, diffraction, and, lastly, schizoanalysis. Various irruptions around biophilosophy, transduction, becomology, cartography, power relations, hyperobjects as events, individuation, as well as dyschronia and disorientation, take the discussion further into the wild pedagogical spaces that both praxes (...) have in common. -/- . (shrink)

Through the prism of archipelicity, the artistic production of the Afro-American Diaspora reveals its diffractive potential: at once close to and far from its original origins, it unfolds in the in-between of a double consciousness. In his seminal essay, Paul Gilroy calls for the overcoming of binary oppositions in order to better apprehend the complexity of Afro-diasporic intellectual culture, which he sees as specifically transnational (Gilroy, 1993). As inclusive as this theoretical framework may seem, it is challenged by the inherent (...) transcoloniality of the artistic dynamics animating the region of the Black Island Americas. To this day, avatars of the colonial model persist in the Lesser and Greater Antilles and in the majority of the coastal nations of the Caribbean basin. To a certain extent, these schemes continue to influence the aesthetic-political choices of the region’s visual artists and performers, while providing them with symbolic codes that can be interpreted as signs of belonging to the Afro-Trans American diaspora. It is therefore a challenge to claim any form of diasporic citizenship in such a shifting and uncertain configuration. What is thought to be relevant from an individual or community perspective may prove to be institutionally subversive. In the syncretic tradition of Cuba and Brazil, the same code can be given different semiotic meanings depending on the political and pragmatic context. This article therefore takes an ethno-critical look at the contribution of such practices to the broader framework of archipelagic networks and map zones of Afro-diasporic connectivity in a trans-American context. (shrink)

Space is one of the most fundamental concepts over which scientific knowledge has been constructed. But it is also true that space concepts extrapolate by far the scientific domain, and permeate many other branches of human knowledge. Those are fascinating aspects that could di per se justify the compilation of a long bibliography. Another one is the passion for books. My interest in some physical, historical and philosophical problems concerning the concept of space in Physics, and its properties, can be (...) traced back to the early 1980. Since that time, I have being studying, with several collaborators, the influence of space dimensionality in different physical phenomena, like the Casimir Effect, neutron diffraction, Cosmic Microwave Background Radiation and the stability of Schrödinger’s and Dirac’s hydrogen atom in arbitrary number of dimensions, as well as epistemological aspects of the works of Kant, Ehrenfest an others on this particular subject. Meanwhile, I gave lectures about the History of the Concepts of Space in Physics at the Centro Brasileiro de Pesquisas Físicas (CBPF), at the Program of History of Sciences, Technics and Epistemology of the Federal University of Rio the Janeiro (UFRJ) and also at the Physics Institute of the State University of Rio de Janeiro (UERJ). As a consequence of both this interest and my love for books, I continuously bought books on space for my personal library which contains now quite one half of all the books quoted here. In 1996, Roberto Moreira and I published the Sources for the History of Space concepts in Physics: From 1845 to 1995 in the series Notas de Física of the CBPF (NF # 084/96), which is still available online. This was a first initiative to share our bibliography on space. At that time, it contained 1075 references, including 414 books entirely devoted to space, 380 articles in periodical journals and proceedings and 281 miscellaneous citations. After fifteen years, I decided to focus my attention here to collect what in my opinion are the 601 essential books which could be useful for anyone interested on learning about space. An important restriction is imposed here by language: only texts written in English, French, German, Italian, Spanish, Portuguese and Latin were considered. References are given in chronological order covering the period between 1739 and 2010. For each year, the books are listed in alphabetical order of authors’ name. An onomastic index is included at the end of the book. -/- Francisco Caruso Rio de Janeiro, October 2011 . (shrink)

Using grizzly-human encounters as a case study, this paper argues for a rethinking of the differences between humans and animals within environmental ethics. A diffractive approach that understands such differences as an effect of specific material and discursive arrangements (rather than as pre-settled and oppositional) would see ethics as an interrogation of which arrangements enable flourishing, or living and dying well. The paper draws on a wide variety of human-grizzly encounters in order to describe the species as co-constitutive and challenges (...) perspectives that treat bears and other animals as oppositional and nonagential outsides to humans. (shrink)

This article reviews the debate on ‘intersectionality’ as the dominant approach in gender studies, with an emphasis on the politics of representation. The debate on intersectionality officially began in the late 1980s, though the approach can be traced back to the institutionalization of women's studies in the 1970s and the feminist movement of the 1960s. Black and lesbian feminists have long advocated hyphenated identities to be the backbone of feminist thought. But in recent years, intersectionality has sustained criticism from numerous (...) angles within gender studies, ranging from feminist philosophy to applied political research. This article will use the theorization of ‘interference’ as a searchlight to produce an overview of this interdisciplinary debate, culminating in our affirmative answer to the question: should we move from intersectionality to interference? Our answer is based on onto-epistemological reflections, i.e., reflections in which being and knowing are always already entangled. -/- . (shrink)

The Mach-Zehnder Interferometer (MZI) is chosen to illustrate the long-standing wave-particle duality problem. Why is which-way (welcher weg) information incompatible with wave interference? How do we explain Wheeler’s delayed choice experiment? Most crucially, how can the photon divide at the first beam splitter and yet terminate on either arm with its undiminished energy? The position advanced is that the photon has two identities, one supporting particle features and the other wave features. There is photon kinetic energy that never splits (on (...) half-silvered mirrors) or diffracts (in pinholes or slits). Then there are photon probability waves that do diffract and can reinforce or cancel. Photon kinetic energy is oscillatory; its cycles require/occupy time. E = mc2 suggests that kinetic energy is physically real as occurrence in time just as rest mass is physically real as existence in space; both are quantized and both occupy/require a dimension for their occurrence or existence. Photon kinetic energy (KE) thus resides in time, but is still present/available for interactions (events) in space; rest mass (e.g., your desk) resides in space but is still present/available for interactions (events) in time. While photon probability waves progress in space and diffract there, photon KE resides in time and never diffracts in space; at reception it always arrives whole and imitates particle impact without being a particle. Photon probability waves are real; they diffract in space. Acknowledging that the photon has two identities (residing energy and progressing probability), explains photon dual nature. And wave-particle duality is central to quantum mechanics. Understanding it leads to new insights into entanglement, nonlocality and the measurement problem. A 30-minute video on nonlocality and photon dualism can be found by a google: search “youtube klevgard nonlocality”). (shrink)

Dennis Gabor devised a new concept for optical imaging in 1947 that went by a variety of names over the following decade: holoscopy, wavefront reconstruction, interference microscopy, diffraction microscopy and Gaboroscopy. A well-connected and creative research engineer, Gabor worked actively to publicize and exploit his concept, but the scheme failed to capture the interest of many researchers. Gabor’s theory was repeatedly deemed unintuitive and baffling; the technique was appraised by his contemporaries to be of dubious practicality and, at best, (...) constrained to a narrow branch of science. By the late 1950s, Gabor’s subject had been assessed by its handful of practitioners to be a white elephant. Nevertheless, the concept was later rehabilitated by the research of Emmett Leith and Juris Upatnieks at the University of Michigan, and Yury Denisyuk at the Vavilov Institute in Leningrad. What had been judged a failure was recast as a success: evaluations of Gabor’s work were transformed during the 1960s, when it was represented as the foundation on which to construct the new and distinctly different subject of holography, a re-evaluation that gained the Nobel Prize for Physics for Gabor alone in 1971. This paper focuses on the difficulties experienced in constructing a meaningful subject, a practical application and a viable technical community from Gabor’s ideas during the decade 1947-1957. (shrink)

The photon is typically regarded as a unitary object that is both particle-discrete and wave-continuous. This is a paradoxical position and we live with it by making dualism a fundamental feature of radiation. It is argued here that the photon is not unitary; rather it has two identities, one supporting discrete behavior and the other supporting continuous (wave) behavior. There is photon kinetic energy that is always discrete/localized on arrival; it never splits (on half-silvered mirrors) or diffracts (in pinholes or (...) slits). Then there is the photon’s probability wavefront that is continuous and diffractable. Acknowledging that the photon has two identities explains the photon’s dual nature. And wave-particle duality is central to quantum mechanics. Understanding it leads to new insights into the photon’s constant velocity and its entanglement with another photon. (shrink)

This study was carried out on the low-grade chromite, Gedarif state, Sudan, at Umm Saqata- Qala Elnahal to achieve full characterization for the ore via Microscopic studies for the polish section samples, X-ray diffraction analysis (XRD), X-ray Fluorescence Analysis (XRF), Scanning electron microscopic with Energy Dispersive X-ray Spectroscopy (SEM-EDX), and physical properties tests. Microscopic study revealed that the liberation size of chromite mineral is in the range (0.30-0.05) mm. also the X-ray diffraction, X-ray fluorescence and scanning electron microscope (...) with the Energy Dispersive X-ray analysis showed that main gangue of the ore is mineral silicates as Antigorite and contains 21.58-19.60% Cr2O3. The physical tests (saturated density and dry density) demonstrated that ore has low density in range 2.54-2.38 g/cm3 because it is low grade chromite ore, this can be attributed to the dominating mineral silicate (waste) which associated with chromite mineral. (shrink)

Boundary colors are observed when light from a scene is dispersed by a prism or diffraction grating. We discovered that patterns with repeating black and white stripes can produce repeating bands of boundary colors with two hues. These hues are virtually constant as measured by chromaticity or CIELAB. We found seven cases of this kind using a new appearance model for boundary colors. The model correctly predicts that green and magenta bands recur as stripe widths and dispersion strength vary. (...) The first green/magenta case in the sequence traces out an accurate ellipse in XYZ color space. Green and magenta bands are prominent in supernumerary rainbows and interference rings, and we explain why that might be the case. The explanation is based on an interesting property of the visible spectrum. In addition to the green/magenta cases, the other cases are orange/cyan, yellowish-green/purple, and yellow/violet. The success of the boundary color appearance model implies that bands are perceived as if the wavelength responses of the cones were essentially independent, which contradicts the actual behavior of cones. (shrink)

Boundary colors are observed when light from a scene is dispersed by a prism or diffraction grating. We discovered that patterns with repeating black and white stripes can produce repeating bands of boundary colors with two hues. These hues are virtually constant as measured by chromaticity or CIELAB. We found seven cases of this kind using a new appearance model for boundary colors. The model correctly predicts that green and magenta bands recur as stripe widths and dispersion strength vary. (...) The first green/magenta case in the sequence traces out an accurate ellipse in XYZ color space. Green and magenta bands are prominent in supernumerary rainbows and interference rings, and we explain why that might be the case. The explanation is based on an interesting property of the visible spectrum. In addition to the green/magenta cases, the other cases are orange/cyan, yellowish-green/purple, and yellow/violet. The success of the boundary color appearance model implies that bands are perceived as if the wavelength responses of the cones were essentially independent, which contradicts the actual behavior of cones. (shrink)

We think of kinetic energy (KE) as a quantity possessed by rest mass in motion. But somehow electromagnetic (EM) radiation transports KE across space without any rest mass. In addition, a single photon passing through a double slit diffracts into multiple paths in space without affecting its KE. This is hard to explain. Quantum theories that confront the double slit problem do not address these two issues directly. The ontology of radiation KE is examined which leads to some new ideas (...) as to the nature of KE transmission by radiation. (shrink)

Abstract: Samples of LaxSr1-xMnO3 (x = 0.5, 0.55, 0.6, 0.66, and 0.7) were prepared by the citrate-nitrate autocombustion method. The prepared nano-particles were investigated and characterized using X-Ray diffraction (XRD) and Transmission Electron Microscopy (TEM) to confirm the formation of the samples in single phase without any impurities and to calculate the particle size. The magnetic susceptibility χM was measured as a function of temperature and magnetic field intensity. From χM(T) and M(H) the saturation magnetization (Ms), remanent magnetization (Mr) (...) and coercivity (Hc) of the samples were estimated. The correlation among physical properties and the ratio of divalent cation substitution was discussed and reported to shed more light on technological applications of the investigated samples. (shrink)

The MgAl2O4 spinel doped with Eu2+ ions powder phosphor was prepared at temperature as low as 500 oC using the combustion route. A structural property of the powder was characterized by X-ray diffraction (XRD). This XRD pattern shows the well crystallized cubic phase, Fd-3m space group of MgAl2O4. The estimated average crystalline size is about 36 and 30 nm for MgAl2O4 and Eu doped MgAl2O4 particles respectively. The photoluminescent property of prepared powder was investigated using excitation and emission spectroscopy (...) at room temperatures. Energy levels scheme is proposed for emission from MgAl2O4: Eu2+. (shrink)

Omnicide: Mania, Fatality and Future-in-Delirium (2019) finds Iranian-American philosopher and comparative literature theorist Jason Bahbak Mohaghegh carving the figure of the diffracted neo-Bedouin wanderer, whose mania we tail through the book’s haunted pages. The book’s namesake, “omnicide,” refers to the complete and total erasure of the Earth--the term has most recently been generally applied in ecological contexts, most markedly in regards to the Anthropocene and futurology. However, it is the explicitly poetic and literary intersection between mania and the grotesque that (...) Mohaghegh inches us towards, lifting omnicide from its proscriptive use in the Western philosophical/sociological tradition and goading it towards an unfamiliar cryptic terrain. Surveying ten contemporary Middle Eastern poets and fiction writers, including Sadeq Hedayat (Iran), Réda Bensmaia (Algeria), Samuel Adonis (Syria), Joyce Mansour (Egypt), Forugh Farrokhzad (Iran), Ibrahim al-Koni (Libya), Ahmad Shamlu (Iran), Ghada Samman (Lebanon), Mahmoud Darwish (Palestine) and Hassim Blasim (Iraq), Mohaghegh parses curious stanzas and plucks spectral paragraphs from myriad texts so as to navigate the largely occluded and excised narratives of the contemporary Middle Eastern philosophical-literary canon. Not only does Mohaghegh acuminate the multifaceted question of mania and its variegated networks, chambers, byways and sunken burrows--so as to juxtapose two different world literatures (East and West)--but Mohaghegh also illuminates this oeuvre to affront the Western psychoanalytic treatment of mania as an exclusionary vessel. Thus, despite Mohaghegh avoiding any explicit references to Western philosophers and scientists, both the codified dictum of the medical decree and the hyper-genealogical superlative tradition of Georges Canguilhem, Michel Foucault and their contemporaries rankle Omnicide’s annals. (shrink)