In this chapter I will discuss Karl Popper’s notion of metaphysical research programmes (MRPs) and apply it to contemporary cosmology. While Popper was extremely critical of Big Bang cosmology, his work on MRPs provides a potentially fruitful way of understanding the discipline in a different light. I will suggest that while cosmology does fail to meet the criteria Popper sets for a mature science, the standard model of cosmology (also known as ΛCDM) could be seen as an example of a (...) MRP. I will examine the Cosmological Principle as well as the dark matter hypothesis as prospective parts of this MRP. Finally, I will go beyond Popper’s own views and evaluate ΛCDM and its main rival, Modified Newtonian Dynamics (MOND), with the help of two methodological tools: the correspondence principle as formally explicated by E. K. Voishvillo, and Ilkka Niiniluoto’s measures of truthlikeness. The conclusion I will draw from this is that MOND is a viable and in some respects superior alternative to ΛCDM. (shrink)

Dark matter is a fundamental component of the standard cosmological model, but in spite of four decades of increasingly sensitive searches, no-one has yet detected a single dark-matter particle in the laboratory. An alternative cosmological paradigm exists: MOND (Modified Newtonian Dynamics). Observations explained in the standard model by postulating dark matter are explained in MOND by proposing a modification of Newton's laws of motion. Both MOND and the standard model have had successes and failures – but only MOND has repeatedly (...) predicted observational facts in advance of their discovery. In this volume, David Merritt outlines why such predictions are considered by many philosophers of science to be the 'gold standard' when it comes to judging a theory's validity. In a world where the standard model receives most attention, the author applies criteria from the philosophy of science to assess, in a systematic way, the viability of this alternative cosmological paradigm. (shrink)

Truth-makers are the dark matter of metaphysics. On the one hand, truth-makers seem obvious and necessary: if there are truths then there must be something that makes these truths true. On the other hand, it’s proven difficult to say exactly what these truth-makers are. Even defenders disagree about what sort of entity truth-makers are or whether all truths have truth-makers. Skeptics have questioned whether truth-makers are actually so obvious and necessary, or even whether they exist at all. Here I offer (...) an account of this unhappy state of affairs and a modest proposal. First, I argue that not only are there no good arguments for truth-makers but it’s unlikely that there ever will be. Second I point to how much can be done without resorting to truth-makers in the first place: they are not as essential as often assumed. Finally, I conclude that we needn’t jettison the concept of truth-makers entirely. Understood in a modest and pragmatic spirit we can hold on to truth-makers while recognizing their inherent limitations. (shrink)

While $$\Lambda $$ Λ CDM has emerged as the standard model of cosmology, a small group of physicists defends modified newtonian dynamics (MOND) as an alternative view on cosmology. Exponents of MOND have employed a broad, at times explicitly philosophical, conceptual perspective in arguing their case. This paper offers reasons why that MONDian defense has been ineffective. First, we argue that the defense is ineffective according to Popperian or Lakatosian views–ostensibly the preferred philosophical views on theory assessment of proponents of (...) MOND. Second, we argue that the defense of MOND can instead best be reconstructed as an instance of meta-empirical theory assessment. The formal employment of meta-empirical assessment by MONDians is unconvincing, however, because it lacks a sufficient epistemic foundation. Specifically, the MONDian No Alternatives Argument relies on falsifiability or explanation conditions that lack epistemic relevance, while the argument from Unexpected Explanatory Success fails since there is a known alternative to MOND. In the last part of the paper, we draw some lessons for applications of meta-empirical assessment more generally. (shrink)

We critically analyze the rationale of arguments from finetuning and naturalness in particle physics and cosmology, notably the small values of the mass of the Higgs-boson and the cosmological constant. We identify several new reasons why these arguments are not scientifically relevant. Besides laying out why the necessity to define a probability distribution renders arguments from naturalness internally contradictory, it is also explained why it is conceptually questionable to single out assumptions about dimensionless parameters from among a host of other (...) assumptions. Some other numerological coincidences and their problems are also discussed. (shrink)

Problems of scientific cosmology only rarely occur in the works of Karl Popper. Nevertheless, it was a subject that interested him and which he occasionally commented on. What is more important, his general claim of falsifiability as a criterion that demarcates science from non-science has played a significant role in periods of the development of modern physical cosmology. The paper examines the historical contexts of the interaction between cosmology and Popperian philosophy of science. Apart from covering Popper’s inspiration from Einstein (...) and his views on questions of cosmology, it focuses on the impact of his thoughts in two periods of controversy of modern cosmology, the one related to the steady state theory and the other to the recent multiverse proposal. It turns out that the impact has been considerable, and continues to be so, but also that the versions of Popperian methodology discussed by cosmologists are sometimes far from what Popper actually thought and wrote. (shrink)

Measuring the rate at which the universe expands at a given time–the ‘Hubble constant’– has been a topic of controversy since the first measure of its expansion by Edwin Hubble in the 1920s. As early as the 1970s, Sandage and de Vaucouleurs have been arguing about the adequate methodology for such a measurement. Should astronomers focus only on their best indicators, e.g., the Cepheids, and improve the precision of this measurement based on a unique object to the best possible? Or (...) should they “spread the risks”, i.e., multiply the indicators and methodologies before averaging over their results? Is a robust agreement across several uncertain measures, as is currently argued to defend the existence of a ‘Hubble crisis’ more telling than a single 1% precision measurement? This controversy, I argue, stems from a misconception of what managing the uncertainties associated with such experimental measurements require. Astrophysical measurements, such as the measure of the Hubble constant, require a methodology that permits both to reduce the known uncertainties and to track the unknown unknowns. Based on the lessons drawn from the so-called Hubble crisis, I sketch a methodological guide for identifying, quantifying and reducing uncertainties in astrophysical measurements, hoping that such a guide can not only help to re-frame the current Hubble tension, but serve as a starting point for future fruitful discussions between astrophysicists, astronomers and philosophers. (shrink)