Explore the vast range of titles available.

The fragmentation of the archaeological record presents methodological challenges: as researchers analyse and construct models, they do not (and in most cases cannot and will not) know what is missing. Here, the author argues that these gaps are one of the field's greatest strengths; they force practitioners to be reflective in their understanding of, and approach to, studying the material traces of past people's lives and to make space for ways of being foreign to present reality. The uncertainty of a past in ruins is a place of possibility that empowers us all to imagine and to work towards a better future.

In this essay, we interrogate how aDNA analyses have been blended with the study of migrations in European prehistory. Genetic research into ancient populations has given archaeologists and geneticists a new and rich data-set that sparks media coverage and public fascination. Yet far right wing and racist political activists also report on and repeat the results of archaeogenetic studies because it bolsters their image of 'Fortress Europe' under threat from biologically distinct non-Europeans. We worry about the lack of action, even discussion, we perceive among archaeologists and archaeogeneticists faced with this ugly appropriation of their research. In order to address these concerns, we have taken a deliberately provocative style. Even as we realise that the politically questionable interpretive implications of aDNA research are most likely unintended, we strongly believe that we must acknowledge their power before we can ameliorate our approach.

I want to preface this response by noting that, while I think Bentley, O'Brien and I fundamentally differ in how we approach the archaeological record (2024), I am also convinced that the more perspectives on the past we can cultivate, the richer our interpretative garden will be. Moreover, the more narratives of past worlds we develop, the more nuanced and complex our image of the past will become and, hence, the messier and more human (Frieman in press). I therefore write in the hopes that we can disagree with care, so that all of our scholarship is enriched.

To start: I thank the responding authors for their generosity and thoughtfulness in engaging in this debate about ‘Attending to unproof: an archaeology of possibilities’ (Frieman 2024) and also the journal's editors for facilitating this discussion.

We characterize the ability of the Dark Energy Camera (DECam) to perform relative astrometry across its 500 Mpix, 3-deg2 science field of view and across four years of operation. This is done using internal comparisons of ∼4 × 107 measurements of high signal-to-noise ratio stellar images obtained in repeat visits to fields of moderate stellar density, with the telescope dithered to move the sources around the array. An empirical astrometric model includes terms for optical distortions; stray electric fields in the CCD detectors; chromatic terms in the instrumental and atmospheric optics; shifts in CCD relative positions of up to 10 m when the DECam temperature cycles; and low-order distortions to each exposure from changes in atmospheric refraction and telescope alignment. Errors in this astrometric model are dominated by stochastic variations with typical amplitudes of 10-30 mas (in a 30 s exposure) and 5′-10′ coherence length, plausibly attributed to Kolmogorov-spectrum atmospheric turbulence. The size of these atmospheric distortions is not closely related to the seeing. Given an astrometric reference catalog at density 0.7 arcmin − 2 , e.g., from Gaia, the typical atmospheric distortions can be interpolated to 7 mas rms accuracy (for 30 s exposures) with 1 ′ coherence length in residual errors. Remaining detectable error contributors are 2-4 mas rms from unmodelled stray electric fields in the devices, and another 2-4 mas rms from focal plane shifts between camera thermal cycles. Thus the astrometric solution for a single DECam exposure is accurate to 3-6 mas ( 0.02 pixels, or 300 nm) on the focal plane, plus the stochastic atmospheric distortion.

Brück (2021) provides an eloquent and necessary critique of an overreliance on scientific tools to understand social relationships. I enjoyed reading this debate piece and found myself agreeing enthusiastically with most of it. Rather than pulling at the details of Brück's argument, here, I would like to sharpen its edges. In particular, Brück challenges us to expand our interpretative imaginaries as we reconstruct the past using biomolecular data. I suggest, however, that we should also think more critically about these very data and how contemporary models of kinship by blood relatedness affect not just the interpretations we develop, but also the questions that we ask and the methods that we apply in answering them. In a recent article, Wolf-Meyer (2020) argues that technology is entangled in kin relations: technology, when conceived of as inextricably enmeshed in complex networks of people, things and relationships, can be kin; but it can also form a conduit that creates connections between people, making kin out of them. Salient to archaeogenetic research, Wolf-Meyer (2020: 237) points to genetic ancestry tests as one example of how technology creates kinship by “rendering bodies like one another” and creates a sense of shared identity through biological substance. Indeed, he expands this to encompass the kinship chart—a graphic technology that, he argues, “composes a connection between bodies, across space and time” (Wolf-Meyer 2020: 242). Hence, archaeogenetics does not reveal innate kin relations, but creates them. This does not mean they are not real, but that they encompass only one element of the kinship experienced by past people, and represent it in terms that are more relevant to us, as contemporary scholars, than to those past people we study. Thus, genetic kinship relations in prehistory—like prehistory in general—are invented, constructed and woven together from incomplete and biased data. Scientific studies of biological relatedness do not reveal natural relations, but create them in both a language and form that is familiar to us, rather than revelatory about the past.

In this paper we investigate how implementing machine learning could improve the efficiency of the search for Trans-Neptunian Objects (TNOs) within Dark Energy Survey (DES) data when used alongside orbit fitting. The discovery of multiple TNOs that appear to show a similarity in their orbital parameters has led to the suggestion that one or more undetected planets, an as yet undiscovered \"Planet 9\", may be present in the outer solar system. DES is well placed to detect such a planet and has already been used to discover many other TNOs. Here, we perform tests on eight different supervised machine learning algorithms, using a data set consisting of simulated TNOs buried within real DES noise data. We found that the best performing classifier was the Random Forest which, when optimized, performed well at detecting the rare objects. We achieve an area under the receiver operating characteristic (ROC) curve, (AUC) = 0.996 0.001. After optimizing the decision threshold of the Random Forest, we achieve a recall of 0.96 while maintaining a precision of 0.80. Finally, by using the optimized classifier to pre-select objects, we are able to run the orbit-fitting stage of our detection pipeline five times faster.

Scholars of the past frame the ‘origins’ or evolution of inequality, usually using archaeological or anthropological evidence as a basis for their arguments, as an intentional, inevitable, important step towards the development of states, implicitly framed as the pinnacle of human political and economic achievement. Anarchist archaeologies reject the idea of hierarchy as a positive or inevitable evolutionary outcome underlying the path to civilization. We argue instead for a radical reorientation towards archaeologies of equality. We propose a prefigurative archaeology that celebrates the myriad ways that human beings have actively undermined and resisted hierarchical social arrangements. We aim to reorient archaeology's focus towards societies that purposefully prevented or constrained the emergence of inequality. To demonstrate the potential of archaeologies of equality we present case examples from Oceania, Britain, West Asia and the American Southwest. Highlighting the accomplishments of societies of equals in the past demonstrates the contingency and problematic nature of present forms of inequality. It allows us to explore a different set of pasts and thus enact different presents as we imagine different futures.

Gravitational wave (GW) events have several possible progenitors, including black hole mergers, cosmic string cusps, supernovae, neutron star mergers, and black hole-neutron star mergers. A subset of GW events are expected to produce electromagnetic (EM) emission that, once detected, will provide complementary information about their astrophysical context. To that end, the LIGO-Virgo Collaboration has partnered with other teams to send GW candidate alerts so that searches for their EM counterparts can be pursued. One such partner is the Dark Energy Survey (DES) and Dark Energy Camera (DECam) Gravitational Waves Program (DES-GW). Situated on the 4m Blanco Telescope at the Cerro Tololo Inter-American Observatory in Chile, DECam is an ideal instrument for optical followup observations of GW triggers in the southern sky. The DES-GW program performs subtraction of new search images with respect to preexisting overlapping images to select candidate sources. Due to the short decay timescale of the expected EM counterparts and the need to quickly eliminate survey areas with no counterpart candidates, it is critical to complete the initial analysis of each night's images within 24 hours. The computational challenges in achieving this goal include maintaining robust I/O pipelines during the processing, being able to quickly acquire template images of new sky regions outside of the typical DES observing regions, and being able to rapidly provision additional batch computing resources with little advance notice. We will discuss the search area determination, imaging pipeline, general data transfer strategy, and methods to quickly increase the available amount of batch computing. We will present results from the first season of observations from September 2015 to January 2016 and conclude by presenting improvements planned for the second observing season.

Over the past 30 years, Britain’s large archaeological museums and collections have shifted their focus away from academic visitors exploring their stores and collections and toward the dynamic presentation of permanent and temporary displays. These are arranged to emphasize compelling and relevant interpretative narratives over the presentation of large numbers of objects. The shift to digitization and the online presentation of collections is a major feature of public engagement activities at many museums but also might open older and less accessible collections up to research. In this article, we consider what role digital platforms may have in the future of British museum-based archaeology, with special reference to initiatives at the British Museum. We suggest that online collections have the potential to mediate between engaging the public and allowing professional archaeologists to develop sophisticated research programs, since these platforms can present multiple narratives aimed at different audiences.