Scientific realists often say that there should be belief in the approximate truth of ‘our best scientific theories.’ It is hard to hear the phrase ‘our best scientific theories’ without thinking of quantum mechanics and quantum field theories. But as numerous chapters in this collection make clear, it is unclear that some experts even know how to make sense of being a realist about quantum theories. They provide recipes for calculating incredibly precise predictions for observations, but beyond the recipes, they do not seem to offer a clear-cut or unambiguous picture of what physical reality is like at the fundamental level. After giving an overview of the problems that beset any attempt to believe in the truth or approximate truth of quantum theories, Chapter 2 turns to the question of how to protect scientific realism from the ills of the quantum. The aim is to show that it is possible to quarantine the worst of those ills, freeing us to adopt a robustly realistic attitude toward many other extremely successful areas of contemporary science, such as (parts of) geology, microbiology, and chemistry. The quarantine barrier may be imperfect and permeable in places, but is strong enough (the chapter argues) to help the cause of scientific realism.
Scientific realists often say that there should be belief in the approximate truth of ‘our best scientific theories.’ It is hard to hear the phrase ‘our best scientific theories’ without thinking of quantum mechanics and quantum field theories. But as numerous chapters in this collection make clear, it is unclear that some experts even know how to make sense of being a realist about quantum theories. They provide recipes for calculating incredibly precise predictions for observations, but beyond the recipes, they do not seem to offer a clear-cut or unambiguous picture of what physical reality is like at the fundamental level. After giving an overview of the problems that beset any attempt to believe in the truth or approximate truth of quantum theories, Chapter 2 turns to the question of how to protect scientific realism from the ills of the quantum. The aim is to show that it is possible to quarantine the worst of those ills, freeing us to adopt a robustly realistic attitude toward many other extremely successful areas of contemporary science, such as (parts of) geology, microbiology, and chemistry. The quarantine barrier may be imperfect and permeable in places, but is strong enough (the chapter argues) to help the cause of scientific realism.
Scientific realism has traditionally maintained that our best scientific theories can be regarded as more or less true and as representing the world as it is (more or less). However, one of our very best current theories—quantum mechanics—has famously resisted such a realist construal, threatening to undermine the realist stance altogether. The chapters in this volume carefully examine this tension and the reasons behind it, including the underdetermination generated by the multiplicity of formulations and interpretations of quantum physics, each presenting a different way the world could be. Authors in this volume offer a range of alternative ways forward: some suggest new articulations of realism, limiting our commitments in one way or another; others attempt to articulate a ‘third way’ between traditional forms of realism and antirealism, or are critical of such attempts. Still others argue that quantum theory itself should be reconceptualised, or at least alternative formulations should be considered in the hope of evading the problems faced by realism. And some examine the nature of these issues when moving beyond quantum mechanics to quantum field theory. Taken together they offer an exciting new set of perspectives on one of the most fundamental questions in the philosophy of modern physics: how can one be a realist about quantum theory, and what does this realism amount to?
According to scientific realism, science gives us an approximately true description of what the world is like. But what does it mean? In this chapter, we focus on the ontological and metaphysical aspects of this discussion. That is, we are concerned with the following questions: what there is, according to our best scientific theories? And how are these things that theories say exist? We start from the assumption that a genuine scientific realism must deal with these issues. Taking non-relativistic quantum mechanics as a case study, we discuss some of the challenges currently faced by a genuinely realistic stance. We argue, first, that in the ontological aspect, realists are in the same boat as science, that is, without sufficient epistemic justification to adopt the belief in the entities postulated by a single quantum theory, given that experience (currently) is not able to decide between rival theories; in the metaphysical aspect, realists also encounter problems with theory choice, given the possibility of associating more than one metaphysical theory with the description of the entities postulated by each quantum theory. The same goes for structuralist alternatives, since, even if we accept that scientific theories are committed to the existence of structures, but not objects, we still do not know what structures are, metaphysically. Finally, we move forward in the discussion with the meta-Popperian method, which serves to reduce the metaphysical alternatives associated with the ontological postulates of scientific theories. We may not know what the correct alternative is, but we have been able to progressively check which metaphysical alternatives are incompatible with each scientific theory.
Quantum mechanics has always presented a problem for scientific realists.For it does not seem to offer a coherent picture of the world.I think it does, and that there is a viable quantum mechanical model of reality.But it cannot be constructed, given the continuity constraints that we usually place on realistic models.To be a quantum mechanical realist, one has to be willing to accept that there are two fundamentally different kinds of processes occurring in nature: continuous, but quantum mechanically indeterminate, energy transfer processes and discontinuous, but spatially extended, changes of state.The unwillingness of philosophers to accept that there is such a distinction has caused many of them to doubt the reality of Schrodinger waves, and the processes of their generation and collapse.I am fully aware that I am treading on well-trodden territory, and that the technical difficulties that must be faced by anyone who is not a specialist in the field are immense.Nevertheless, I think there is a fairly clear metaphysical position on these issues derivable from the kind of essentialist realism outlined in the previous chapter, and I ask readers to bear with me.First, realism about Schrodinger waves requires the belief that particles are always transmitted as quantum mechanically indeterminate 1.
Quantum mechanics has always presented a problem for scientific realists. For it does not seem to offer a coherent picture of the world. I think it does, and that there is a viable quantum mechanical model of reality. But it cannot be constructed, given the continuity constraints that we usually place on realistic models. To be a quantum mechanical realist, one has to be willing to accept that there are two fundamentally different kinds of processes occurring in nature: continuous, but quantum mechanically indeterminate, energy transfer processes and discontinuous, but spatially extended, changes of state. The unwillingness of philosophers to accept that there is such a distinction has caused many of them to doubt the reality of Schrödinger waves, and the processes of their generation and collapse. I am fully aware that I am treading on well-trodden territory, and that the technical difficulties that must be faced by anyone who is not a specialist in the field are immense. Nevertheless, I think there is a fairly clear metaphysical position on these issues derivable from the kind of essentialist realism outlined in the previous chapter, and I ask readers to bear with me. First, realism about Schrödinger waves requires the belief that particles are always transmitted as quantum mechanically indeterminate waves, but always act as classically determinate particles on whatever absorbs them. The probability of absorption by a given absorbing object (e.g. measuring instrument) at a given location is determined by the value of the Ψ-function at this point.
Scientific realists believe, of successful scientific theories, that they’re at least approximately true. Quantum mechanics (QM) lays credible claim to being the most successful theory in the history of human science. But what does a scientific realist believe when she believes QM? And what can we learn about the scientific realism debate from the fact that that debate, conducted in abstraction, appears incapable of settling what a realist about QM should believe when she believes QM? This contribution explores both questions.
Much has been discussed in the philosophy of science about how we should understand the scientific enterprise. On the one hand, scientific realists believe that empirically adequate theories can be supplemented by interpretations that can mirror reality-as-it-is; on the other hand, anti-realists argue that this is not the case, as long as scientific theories make sufficiently accurate experimental predictions the addition of narratives is irrelevant for the scientific enterprise, and regarding narratives, it is preferable to remain agnostic. In this paper, we argue that realism was never really at stake in this debate.