Abstract Teleparallel Gravity (TPG) is an alternative, but empirically equivalent, spacetime theory to General Relativity. In its modern formulation, TPG purports to be both a gauge theory of translations (G), as well as locally Lorentz-invariant (L). However, the reasoning invoked in order to implement (L) and (G) is often involved. As such, clarification of the reasoning upon which TPG proponents rely in constructing their theory is sorely needed. The present paper will address this need. It will also offer a succinct methodolog ical assessment of TPG as a theory per se .

Pursuing a scientific idea is often justified by the promise associated with it. Philosophers of science have proposed various ways of unpacking this idea of promise, including more specific indicators. Economic models in particular emphasise the trade-off between an idea’s benefits and its costs. Taking up this Peirce-inspired idea, we spell out the metaphor of such a cost-benefit analysis for scientific ideas. It fruitfully urges a set of salient meta-methodological questions that accounts of scientific pursuit-worthiness ought to address. In line with such a meta-methodological framework, we also articulate and explore an appealing and auspicious concretisation—what we shall dub “the virtue-economic account of pursuit-worthiness”: cognitive benefits and costs of an idea, we suggest, should be characterised in terms of an idea’s theoretical virtues, such as empirical adequacy, explanatory power, or coherence. Assessments of pursuit-worthiness are deliberative judgements in which scientifically competent evaluators weigh and compare the prospects of such virtues, subject to certain rationality constraints that ensure historical and contemporary scientific circumspection, coherence and systematicity. The virtue-economic account, we show, sheds new light on the normativity of scientific pursuit, methodological pluralism in science, and the rationality of historical science.

What constitutes a scientific discovery? What role do discoveries play in science, its dynamics and social practices? The paper explores these questions by first critically examining extant philosophical explications of scientific discovery—the models of scientific discovery, propounded by Kuhn, McArthur, Hudson, and Schindler. As an alternative, we proffer the “change-driver model”. In a nutshell, it conceives of discoveries as problems or solutions to problems that have epistemically advanced science. Here we take a problem to be generated by a datum that we want to account for and make sense of—by putting it in contact with our wider web of scientific knowledge and understanding. The model overcomes the shortcomings of its precursors, whilst preserving their insights. We demonstrate its intensional and extensional superiority, especially with respect to the link between scientific discoveries and the dynamics of science, as well as with respect to its reward system. Both as an illustration, and as an application to a recent scientific and political controversy, we apply the considered models of discovery to one of the most momentous discoveries of science: the expansion of the universe. We oppose the 2018 proposal of the International Astronomical Union as too simplistic vis-à-vis the historical complexity of the episode, and as problematically reticent about the underlying—and in fact crucial—philosophical-conceptual presuppositions regarding the notion of a discovery. The change-driver model yields a more nuanced and circumspect verdict: (i) The redshift-distance relation shouldn’t be named the “Hubble-Lemaître Law”, but “Slipher-Hubble-Humason Law”; (ii) Its interpretation in terms of an expanding universe, however, Lemaître ought to be given credit for; (iii) The Big Bang Model, establishing the expansion of the universe as an evidentially fully warranted result in the 1950s or 1960s (and a communal achievement, rather than an individually attributable one), doesn’t qualify as a discovery itself, but was inaugurated by, and in turn itself led to, several discoveries.

The paper examines the nature of scientific progress through the lens of the history of modern cosmology (i.e. from Einstein’s, 1917 static universe to the present-day Standard (ΛCDM) model of cosmology). We distil three novel lessons, germane to the debate between the two main accounts of scientific progress (the noetic and the epistemic one, respectively). First, it’s difficult to sharply locate—to precisely pinpoint the locus of—the epistemic content of scientific knowledge. Cosmology displays stark epistemic holism: epistemic content and evidence are typically inextricably distributed over a wider “web of beliefs”. Secondly, cosmologists employ a variety of justificatory practices and modes of reasoning. More often than not, they fall short of the fastidious standards of traditional epistemology. Thirdly, cosmological claims typically defy easy and unambiguous characterisation in terms of truth. These three lessons are shown to pose grave challenges to the epistemic account of scientific progress (on which progress consists in the accumulation of knowledge). By contrast, the rivalling noetic account (which characterises progress in terms of improved understanding) can naturally accommodate those lessons.

The paper revisits Janssen’s proposal of Common Origin Inferences (COIs), a powerful and scientifically fruitful inference pattern that (causally) traces striking coincidences back to a common origin. According to Janssen, COIs are a decisive engine for rational theory change across disciplines and eras. After a careful reconstruction of Janssen’s central tenets, we critically assess them, highlighting three key shortcomings: its strong realist and ontological commitments, its restriction to (or strong penchant for) causal/ontic explanations, and its intended employment for conferring evidential-epistemic status. To remedy these shortcomings, we moot a natural generalisation and amelioration of Janssen’s original conception—COI*s: Constraint-Omnivorous Inferences. COI*s warrant inference to pursuit-worthy hypotheses: it is rational to further study, work on, elaborate/refine or test hypotheses that account for multiple constraints in one fell swoop. As a demonstration of the utility of COI* reasoning, we finally show how it sheds light on, and dovetails, the three most significant breakthroughs in recent cosmology: the Dark Matter hypothesis, the Dark Energy postulate, and the theory of cosmic inflation.

The paper examines the nature of scientific progress through the lens of the history of modern cosmology (i.e. from Einstein’s, 1917 static universe to the present-day Standard (ΛCDM) model of cosmology). We distil three novel lessons, germane to the debate between the two main accounts of scientific progress (the noetic and the epistemic one, respectively). First, it’s difficult to sharply locate—to precisely pinpoint the locus of—the epistemic content of scientific knowledge. Cosmology displays stark epistemic holism: epistemic content and evidence are typically inextricably distributed over a wider “web of beliefs”. Secondly, cosmologists employ a variety of justificatory practices and modes of reasoning. More often than not, they fall short of the fastidious standards of traditional epistemology. Thirdly, cosmological claims typically defy easy and unambiguous characterisation in terms of truth. These three lessons are shown to pose grave challenges to the epistemic account of scientific progress (on which progress consists in the accumulation of knowledge). By contrast, the rivalling noetic account (which characterises progress in terms of improved understanding) can naturally accommodate those lessons.

This paper argues that we ought to conceive of the Dark Energy problem—the question of how to account for observational data, naturally interpreted as accelerated expansion of the universe—as a crisis of underdetermined pursuit-worthiness. Not only are the various approaches to the Dark Energy problem evidentially underdetermined; at present, no compelling reasons single out any of them as more likely to be true than the other. More vexingly for working scientists, none of the approaches stands out as uncontroversially preferable over its rivals in terms of its rationally warranted promise, i.e. the reasons to further work on, explore, and develop it. We demonstrate this claim by applying a Peircean economic model of pursuit-worthiness in terms of a cognitive cost/benefit estimate—with the instantiation of theory virtues as key indicators of cognitive gains—to the four main Dark Energy proposals (the cosmological constant approach, modified gravity, quintessence, and inhomogeneous cosmologies). According to our analysis, these approaches do not admit of an unambiguous, or uncontroversial, ranking with respect to which ansatz deserves distinguished attention and research efforts. The overall methodological counsel that our analysis underwrites recommends a pragmatic double research strategy forward: to encourage and foster theory pluralism and the search for tests—with the goal of enhancing the testability of the Λ CDM model and “testing it to destruction".

Geometric underdetermination (i.e., the underdetermination of the geometric properties of space and time) is a live possibility in light of some of our best theories of physics. In response to this, geometric conventionalism offers a selective anti-realism, refusing to assign truth values to variant geometric propositions. Although often regarded as being dead in the water by modern philosophers, in this article we propose to revitalise the programme of geometric conventionalism both on its own terms, and as an attractive response to the above-mentioned live cases of geometric underdetermination. Specifically, we (1) articulate geometrical conventionalism as we conceive it, (2) anticipate various objections to the view, and defend it against those objections, and (3) demonstrate how geometric conventionalism plays out in the context of a wide variety of spacetime theories, both classical and relativistic.

This paper critically examines the models of scientific discovery propounded by Kuhn, McArthur, Hudson, and Schindler. As an alternative, we proffer the x201cchangex2013driver modelx201c. It conceives of discoveries as problems or solutions to problems that have epistemically advanced science. Here we take a problem to be generated by a datum that we want to account for and make sense ofx2013by putting it in contact with our wider web of scientific knowledge and understanding. The model overcomes the shortcomings of its precursors, whilst preserving their insights. We demonstrate its intensional and extensional superiority, especially with respect to the link between scientific discoveries and the dynamics of science. Both as an illustration, and as an application to a recent scientific and political controversy, we apply the considered models of discovery to one of the most momentous discoveries of science: the expansion of the universe.

The paper re-examines the principal methodological questions, arising in the debate over the cosmological standard model's postulate of Dark Matter vs. rivalling proposals that modify standard (Newtonian and general relativistic) gravitational theory, the so-called Modified Newtonian Dynamics (MOND) and its subsequent extensions. What to make of such seemingly radical challenges of cosmological orthodoxy? In the first part of our paper, we assess MONDian theories through the lens of key ideas of major 20th century philosophers of science (Popper, Kuhn, Lakatos, and Laudan), thereby rectifying widespread misconceptions and misapplications of these ideas common in the pertinent MOND-related literature. None of these classical methodological frameworks, which render precise and systematise the more intuitive judgements prevalent in the scientific community, yields a favourable verdict on MOND and its successors-contrary to claims in the MOND-related literature by some of these theories' advocates; the respective theory appraisals are largely damning. Drawing on these insights, the paper's second part zooms in on the most common complaint about MONDian theories, their ad-hocness. We demonstrate how the recent coherentist model of ad-hocness captures, and fleshes out, the underlying-but too often insufficiently articulated-hunches underlying this critique. MONDian theories indeed come out as severely ad hoc: they do not cohere well with either theoretical or empirical-factual background knowledge. In fact, as our complementary comparison with the cosmological standard model's Dark Matter postulate shows, with respect to ad-hocness, MONDian theories fare worse than the cosmological standard model.

The paper investigates the historical and contemporary pursuit-worthiness of cosmic inflation-the rationale for working on it (rather than necessarily the evidential support for claims to its approximate truth): what reasons existed, and exist, that warrant inflation's status as the mainstream paradigm studied, explored, and further developed by the majority of the cosmology community? We'll show that inflation exemplifies various salient theory virtues: explanatory depth, unifying/integrative power, fertility and positive heuristics, the promotion of understanding, and the prospect (and passing) of novel benchmark tests. This, we'll argue, constitutes inflation's auspicious promise. It marks inflation as preferable over both the inflation-less Hot Big Bang Model, as well as rivals to inflation: inflation, we maintain, rightly deserved, and continues to deserve, the concerted research efforts it has enjoyed.

This article revisits Karl Popper’s falsificationist methodology with respect to three tasks. The first is to illuminate and systematize Popper’s methodological views in light of his core epistemological commitments. A second and related objective is to gauge which aspects of falsificationism should be identified as “conventionalist”—a label that Popper himself uses (albeit with qualifications) but that is compromised by and, thus, stands in need of elucidation because of Popper’s idiosyncratic understanding of conventionalism. Third, by elaborating Popper’s virtue-epistemological, dialogical model of rationality, I show how Popper’s conventionalism, fallibilism, and critical rationalism form a coherent system. This system allows Popper to accord science the status of a privileged source of knowledge—without naïve appeal to authority. My systematization of Popper’s views yields an intrinsically and exegetically more satisfactory reading of Popper’s falsificationism than usual presentations. Thanks to its marked flexibility and methodological liberalism, it bypasses many standard objections but still offers sound and relevant methodological advice. With its “virtue-methodological” thrust, Popper sketches an original and promising approach to methodology, the fertility of which deserves further exploration for contemporary debates.

The present paper revisits conventionalism about the geometry of classical and relativistic spacetimes. By means of critically examining a recent evaluation of conventionalism, we clarify key themes of, and rectify common misunderstandings about, conventionalism. Reichenbach's variant is demarcated from conventionalism simpliciter, associated primarily with Poincaré. We carefully outline the latter's core tenets-as a selective anti-realist response to a particular form of theory underdetermination. A subsequent double defence of geometric conventionalism is proffered: one line of defence employs (and thereby, to some extent, rehabilitates) a plausible reading of Reichenbach's idea of universal forces; another consists in independent support for conventionalism, unrelated to Reichenbach. Conventionalism, we maintain, remains a live option in contemporary philosophy of spacetime physics, worthy of serious consideration.

The paper takes up Bell's (1987) "Everett (?) theory" and develops it further. The resulting theory is about the system of all particles in the universe, each located in ordinary, 3-dimensional space. This many-particle system as a whole performs random jumps through 3N-dimensional configuration space - hence "Tychistic Bohmian Mechanics" (TBM). The distribution of its spontaneous localisations in configuration space is given by the Born Rule probability measure for the universal wavefunction. Contra Bell, the theory is argued to satisfy the minimal desiderata for a Bohmian theory within the Primitive Ontology framework (for which we offer a metaphysically more perspicuous formulation than is customary). TBM's formalism is that of ordinary Bohmian Mechanics (BM), without the postulate of continuous particle trajectories and their deterministic dynamics. This "rump formalism" receives, however, a different interpretation. We defend TBM as an empirically adequate and coherent quantum theory. Objections voiced by Bell and Maudlin are rebutted. The "for all practical purposes"-classical, Everettian worlds (i.e. quasi-classical histories) exist sequentially in TBM (rather than simultaneously, as in the Everett interpretation). In a temporally coarse-grained sense, they quasi-persist. By contrast, the individual particles themselves cease to persist.

f(R) Gravity is the most natural extension of General Relativity within Riemannian Geometry. Due to (inter alia) its potential capacity for a unified treatment of early and late-time cosmic expansion, it has enjoyed recent attention in astrophysics and cosmology. I critically examine three inter-related claims found in the pertinent physics literature, of general interest to the philosopher of science. 1. f(R) Gravity is equivalent to a particular Brans-Dicke Theory. 2. The spacetime geometry underpinning f(R) Gravity has substantial conventional elements. 3. f(R) Gravity is an instance of a theory in which the distinction between matter and spacetime is conventional. Whilst the first claim can be vindicated in precise terms, the remaining two claims, I submit, are unwarranted - at least for the reasons usually adduced. On different grounds, though, the case for conventionalism about spacetime geometry in f(R) Gravity (as well as General Relativity) turns out to be considerably stronger.

The paper re-examines Nordström's scalar theory of gravity (NG) – arguably the most convincing relativistic theory of gravity before the advent of General Relativity. It exists in two different formulations. In Nordström's original one (1913), NG appears to describe a scalar gravitational field on Minkowski spacetime. In Einstein and Fokker’s (1914) version, NG seems to be a spacetime theory: It reconceptualises gravitational effects as manifestations of non-Minkowskian inertial structure. Both variants of NG give rise to three contradictory verdicts on the status and validity of fundamental principles: the Weak Equivalence Principle, the existence of gravitational energy, and energy conservation. Given the putative equivalence of both variants of NG, this ambiguity seems paradoxical to the spacetime realist. I'll proffer a resolution from the perspective of integrable Weyl geometry: The paradoxes rest on the failure to recognise a more apposite spacetime setting for NG.

The paper investigates the status of gravitational energy in Newtonian Gravity (NG), developing upon recent work by Dewar and Weatherall. The latter suggest that gravitational energy is a gauge quantity. This is potentially misleading: its gauge status crucially depends on the spacetime setting one adopts. In line with Møller-Nielsen’s plea for a motivational approach to symmetries, we supplement Dewar and Weatherall’s work by discussing gravitational energy–stress in Newtonian spacetime, Galilean spacetime, Maxwell-Huygens spacetime, and Newton–Cartan Theory (NCT). Although we ultimately concur with Dewar and Weatherall that the notion of gravitational energy is problematic in NCT, our analysis goes beyond their work. The absence of an explicit definition of gravitational energy–stress in NCT somewhat detracts from the force of Dewar and Weatherall’s argument. We fill this gap by examining the supposed gauge status of prima facie plausible candidates—NCT analogues of gravitational energy–stress pseudotensors, the Komar mass, and the Bel-Robinson tensor. Our paper further strengthens Dewar and Weatherall’s results. In addition, it sheds more light upon the subtle link between sufficiently rich inertial structure and the definability of gravitational energy in NG.

The present paper revisits the debate between realists about gravitational energy in GR (who opine that gravitational energy can be said to meaningfully exist in GR) and anti-realists/eliminativists (who deny this). I re-assess the arguments underpinning Hoefer's seminal eliminativist stance, and those of their realist detractors' responses. A more circumspect reading of the former is proffered that discloses where the so far not fully appreciated,realchallenges lie for realism about gravitational energy. I subsequently turn to Lam and Read's recent proposals for such a realism. Their arguments are critically examined. Special attention is devoted to the adequacy of Read's appeals to functionalism, imported from the philosophy of mind.

I review and critically examine the four textbook arguments commonly taken to establish that gravitational waves (GWs) carry energy-momentum: 1. the increase in kinetic energy that a GW confers on a ring of test particles, 3.Bondi/Feynman's Sticky Bead Argument of a GW heating up a detector, 3. nonlinearities within perturbation theory, construed as the gravity's contribution to its own source, and 4. the Noether Theorems, linking symmetries and conserved quantities. As it stands, each argument is found to be either contentious, or incomplete in that it presupposes substantive assumptions which the standard exposition glosses over. I finally investigate the standard interpretation of binary systems, according to which orbital decay is explained by the system's energy being dissipated via GW energy-momentum transport. I contend that for the textbook treatment of binary systems an alternative interpretation, drawing only on the general-relativistic equations of motions and the Einstein Equations, is available. It's argued to be even preferable to the standard interpretation. Thereby an inference to the best explanation for GW energy-momentum is blocked. I conclude that a defence of the claim that GWs carry energy can't rest on the standard arguments.