Akeley inside the elephant: Trajectory of a taxidermic image

Abstract: As a process distinct from its poured cousin, sprayed concrete involves using compressed air to propel cement with various chemical admixtures at a surface. Used in tunnelling for rock surface stabilization, and above ground for securing slopes and fabricating fake rockeries, its chimeric character ranges from the polished landscapes of skateparks and swimming pools to mimicking cast concrete in structural repair work. The origins of this industrial process lie with taxidermist Carl E. Akeley (1864–1926), who invented it during his pioneering work in the proto-photographic field of natural habitat dioramas at the Chicago Field Museum in 1907. Further cementing André Bazin’s notion of photography as embalmment, Akeley also invented a unique 35mm cine camera during his time at the American Museum of Natural History, New York. The essay explores this historical intersection between photography, taxidermy and architecture, and its wider implications for thinking through photography’s material contingency. Keywords: sprayed concrete, taxidermy, Carl Akeley, cinematography, Paul Strand, James Tiptree Jr, realism, robotics

Unusual Nernst effect and spin density wave precursors in superconducting LaFeAsO1−xFx\rm\bf LaFeAsO_{1-x}F_x

The Nernst effect has recently proven as a sensitive probe for detecting unusual normal state properties of unconventional superconductors. Here we present a systematic study of the Nernst effect of the iron pnictide superconductor \laf with a particular focus on its evolution upon doping. For the parent compound we observe a huge negative Nernst coefficient accompanied with a severe violation of the Sondheimer cancellation in the spin density wave (SDW) ordered state. Surprisingly, an unusual and enhanced Nernst signal is also found at underdoping ($x=0.05$) despite the presence of bulk superconductivity and the absence of static magnetic order, strongly suggestive of SDW precursors at $T\lesssim150$ K. A more conventional normal state Nernst response is observed at optimal doping ($x=0.1$) where it is rather featureless with a more complete Sondheimer cancellation.Comment: 4 pages, 3 figure

A Camera on Wheels: Situating the Self-driving Car within a Photographic Teleology

Even before the long-promised arrival of self-driving cars on our roads, vehicles are already increasingly equipped with a range of optical and light-based sensors that are capturing automated images of the built environment toward a post-human photography perhaps most succinctly anticipated by Ed Ruscha’s seminal work Every Building on the Sunset Strip (1966). This paper proposes a media archaeology of autonomous vehicles by engaging with an automotive camera and its machine vision algorithms from within photographic history and discourse, drawing on research pursued at Bosch Research Campus near Stuttgart, Germany, on some of the 'situated knowledges' (Haraway) at work in one of Europe's foremost research centers on automated driving. From the bounding boxes of now classical object detection to contemporary semantic segmentation, the talk probes the technical images used to train self-driving cars and traces some of the aesthetic genealogies that might constitute machine vision’s ‘optical unconscious’ (Benjamin). This includes an analysis of the Daimler Cityscapes machine learning dataset comprising 25'000 semantically labelled photographs of urban street scenes throughout 50 European cities which is used by AI researchers at Bosch to preemptively test the capacity of machinic perception to be deceived in so-called 'universal adversarial perturbations', a form of steganography that alters what the machine 'sees' while remaining invisible to the human eye. The paper concludes by discussing the results of a creative collaboration with the AI team at Bosch to insert a reflexive piece of photographic history into this novel and uniquely machine-readable class of images, closing a loop that situates autonomous vehicles within a teleology of photography

The Paranoiac-Critical Method of Reflectance Transformation Imaging

A performative talk examining Reflectance Transformation Imaging (RTI), an open source computational photographic process that is transforming methodologies in archaeology and heritage conservation for its ability to interactively re-light artefacts within a virtual hemisphere of illumination and extrude a digital topography that is hyper-legible in space-time, from its contemporary application in facial recognition via Bertrand Tavernier's 1980 science fiction film La Mort en Direct and a return of the death mask through digital extrusion, ultimately locating a progenitor of the heightened objectivity promised by RTI paradoxically in Surrealist photography and the fugitive facialities of Salvador Dali's Paranoiac-Critical Method. As emerging imaging technologies such as RTI are seen to open novel ways of extracting latent data from historical artefacts, reassembling objects of study in a new (virtual) light, collateral opportunities provided by these technologies to re-enter archival still and moving image recordings inadvertently recalibrate their spatio-temporal ground and destabilise their indexical reading through an excessive production of new traces and signs. If methodologies can be seen to play a significant role in constructing their objects of study, then emerging computational imaging operations such as RTI have their own subjectivities to disclose: In performing a media archaeology of this digital process, the talk proposes that we not only narrate the subjects of our study but the very tools of investigation themselves

The devisive moment

This article discusses the 2019 Event Horizon Telescope (EHT) image of a black hole as an ontological question for photography, contrasting its spatially distributed operations as a planetary apparatus against its temporal inscriptions of successive histories of scientific realisms following Lorraine Daston and Peter Galison. The 'becoming photographic' of this image, this text argues, hinges on the distance it traverses from its scientific milieu to its vernacular reception, making visible the cultural calibrations that produce a consensually legible image

Determining the Short-Range Spin Correlations in Cuprate Chain Materials with Resonant Inelastic X-ray Scattering

We report a high-resolution resonant inelastic soft x-ray scattering study of the quantum magnetic spin-chain materials Li2CuO2 and CuGeO3. By tuning the incoming photon energy to the oxygen K-edge, a strong excitation around 3.5 eV energy loss is clearly resolved for both materials. Comparing the experimental data to many-body calculations, we identify this excitation as a Zhang-Rice singlet exciton on neighboring CuO4-plaquettes. We demonstrate that the strong temperature dependence of the inelastic scattering related to this high-energy exciton enables to probe short-range spin correlations on the 1 meV scale with outstanding sensitivity.Comment: 5 pages, 4 figure

Synthesis and physical properties of LaO1−xFxFeAs\rm\bf LaO_{1-x}F_xFeAs

We have prepared the newly discovered Fe-based superconducting material $\rm LaO_{1-x}F_xFeAs$ ($0\leq x\leq 0.2$) in polycrystalline form and have investigated the samples by means of structural, thermodynamic and transport measurements. Our investigations reveal a non superconducting phase at $0\leq x\lesssim0.04$ which for $x=0$ is characterized by a structural transition towards an orthorhombic distortion at $T_s\approx 160$ K and antiferromagnetic spin order at $T_N\approx138$ K. Both transitions lead to strong anomalies in various transport properties as well as in magnetization and in specific heat. Remarkably, the transition temperatures are only weakly doping dependent up $x\lesssim 0.04$. However, the transitions are abruptly suppressed at $x\geq0.05$ in favour of a superconducting phase with a critical temperature $T_c\gtrsim 20$ K. Upon further increasing the F-doping $T_c$ increases up to a maximum of $T_c=26.8$ K at $x=0.1$ which is followed by a decrease down to $T_c\approx10$ K at $x\geq0.15$

SCOPE New Photographic Practices

The photographic practices brought together for this exhibition and publication provide a broad scope of how photographic and lens based media may be used in order to have a visceral and conceptual impact. The methods on show demonstrate the way that artists might pick and choose from the approaches, processes and debates that have arisen through the medium’s history. This collection of work features film, video and photography that demand a renegotiation of the relationship between camera, subject and viewer. Visual Art Centre Gallery, Tsinghua University, Beijing, Chin