14065 research outputs found
Sort by
23 open problems in the philosophy of physics
Full text linkI present 23 open problems in the Philosophy of Physics. Based upon a talk given at the launch event of the Radboud Centre for Natural Philosophy, Nijmegen, NL, held 9th-10th January 2025
Scientific Theory and Possibility
Full text linkIt is plausible that the models of scientific theories correspond to possibilities. But how do we know which models of which scientific theories so correspond? This paper provides a novel proposal for guiding belief about possibilities via scientific theories. The proposal draws on the notion of an effective theory: a theory that applies very well to a particular, restricted domain. We argue that it is the models of effective theories that we should believe correspond, at least in part, to possibilities. It is thus effective theories that should guide modal reasoning in science
The Talking of the Bot with Itself: Language Models for Inner Speech
Full text linkIn this essay, I explore the idea of using large language models (LLMs) not as full models of general artificial intelligence themselves, but as components that can help bootstrap cognitive architectures comprised of other components to greater degrees of cognitive flexibility and agency. In particular, I explore the idea that LLMs could perform some of the roles that inner speech plays in human cognitive development and adult problem-solving. Researchers are currently exploring many questions of the form: can an LLM (such as OpenAI’s ChatGPT or AnthropicAI’s Claude) have cognitive/mental property X (where X =… represent world models, reason, be conscious, exhibit theory of mind, communicate, and more). If instead of evaluating language models themselves as the sole bearer of X, we instead tried to use LLMs to play the role in the developmental process of acquiring X played by inner speech—as an internal, linguistically-vehicled coordinator and scaffold for diverse other processes—then the significance of research on LLMs as a path towards AI deserves fresh reevaluation, and a different research agenda for philosophically-motivated, deep-learning-based AI comes into focus
Can a time varying but spatially uniform electric scalar potential shift the energy levels of a quantum system? A critical look at the new Aharonov-Bohm effect proposed by Chiao et al
Full text linkRecently Chiao and his collaborators proposed a new version of the electric Aharonov-Bohm effect [Phys. Rev. A 107, 042209 (2023)]. They argued that a quantum system confined in a Faraday cage with a time varying but spatially uniform electric scalar potential can pick up the Aharonov-Bohm phase, and the observable consequence is the energy level shift of the quantum system. In this paper, I argue that Chiao et al's analysis is problematic, and a time varying, spatially uniform electric scalar potential cannot result in observable energy level shift of quantum systems. A possible explanation of this seemingly puzzling result is also given based on the one true gauge principle
Not the Measurement Problem's Problem: Black Hole Information Loss with Schrödinger's Cat
Full text linkRecently, several philosophers and physicists have increasingly noticed the hegemony of unitarity in the black hole information loss discourse and are challenging its legitimacy in the face of the measurement problem. They proclaim that embracing non-unitarity solves two paradoxes for the price of one. Though I share their distaste over the philosophical bias, I disagree with their strategy of still privileging certain interpretations of quantum theory. I argue that information-restoring solutions can be interpretation-neutral because the manifestation of non-unitarity in Hawking's original derivation is unrelated to what's found in collapse theories or generalized stochastic approaches, thereby decoupling the two puzzles
Equivalent Gravities and Equivalence Principle: Foundations and experimental implications
Full text linkThe so-called Geometric Trinity of Gravity includes General Relativity (GR), based on spacetime curvature; the Teleparallel Equivalent of GR (TEGR), which relies on spacetime torsion; and the Symmetric Teleparallel Equivalent of GR (STEGR), grounded in nonmetricity. Recent studies demonstrate that GR, TEGR, and STEGR are dynamically equivalent, raising questions about the fundamental structure of spacetime, the under-determination of these theories, and whether empirical distinctions among them are possible. The aim of this work is to show that they are equivalent in many features but not exactly in everything. In particular, their relationship with the Equivalence Principle (EP) is different. The EP is a deeply theory-laden assumption, which is assumed as fundamental in constructing GR, with significant implications for our understanding of spacetime. However, it introduces unresolved conceptual issues, including its impact on the nature of the metric and connection, its meaning at the quantum level, tensions with other fundamental interactions and new physics, and its role in dark matter and dark energy problems. In contrast, TEGR and STEGR recover the EP but do not rely on it as a foundational principle. The fact that GR, TEGR, and STEGR are equivalent in non-trivial predictions, but the EP is not necessary for TEGR and STEGR, suggests that it may not be a fundamental feature but an emergent one, potentially marking differences in the empirical content of the three theories. Thus, the developments within the Geometric Trinity framework challenge traditional assumptions about spacetime and may help to better understand some of the unresolved foundational difficulties related to the EP
Nothing Matters
Full text linkOne challenge to relationism in general relativity is that the metric field is underdetermined by the stress-energy tensor. This is manifested in the existence of distinct vacuum solutions to Einstein's equations. In this paper, I reformulate the problem of underdetermination as a problem from vacuum solutions. I call this the vacuum challenge and identify the gravitational degrees of freedom (associated with the Weyl tensor) as the "source" of the challenge. The Weyl tensor allows for gravitational effects that something outside of a system exerts on the system. I provide a relationist response to the vacuum challenge
Operational equivalence and causal structure
Full text linkIn operational quantum mechanics two measurements are called operationally equivalent if they yield the same distribution of outcomes in every quantum state and hence are represented by the same operator. In this paper, I will show that the ontological models for quantum mechanics and, more generally, for any operational theory sensitively depend on which measurement we choose from the class of operationally equivalent measurements, or more precisely, which of the chosen measurements can be performed simultaneously. To this goal, I will take first three examples––a classical theory, the EPR-Bell scenario and the Popescu-Rochlich box; then realize each example by two operationally equivalent but different operational theories––one with a trivial and another with a non-trivial compatibility structure; and finally show that the ontological models for the different theories will be different with respect to their causal structure, contextuality, and fine-tuning
Perspectives in and on Quantum Theory
Full text linkI take a pragmatist perspective on quantum theory. This is not a view of the world described by quantum theory. In this view quantum theory itself does not describe the physical world (nor our observations, experiences or opinions of it). Instead, the theory offers reliable advice—on when to expect an event of one kind or another, and on how strongly to expect each possible outcome of that event. The event’s actual outcome is a perspectival fact—a fact relative to a physical context of assessment. Measurement outcomes and quantum states are both perspectival. By noticing that each must be relativized to an appropriate physical context one can resolve the measurement problem and the problem of nonlocal action. But if the outcome of a quantum measurement is not an absolute fact, then why should the statistics of such outcomes give us any objective reason to accept quantum theory? One can describe extensions of the scenario of Wigner’s friend in which a statement expressing the outcome of a quantum measurement would be true relative to one such context but not relative to another. However, physical conditions in our world prevent us from realizing such scenarios. Since the outcome of every actual quantum measurement is certified at what is essentially a single context of assessment, the outcome relative to that context is an objective fact in the only sense that matters for science. We should accept quantum theory because the statistics these outcomes display are just those it leads us to expect
Explanation, Understanding, and the Methodological Problem in Consciousness Science
Full text linkPhilosophers of mind and philosophers of science have markedly different views on the relationship between explanation and understanding. Reflecting on these differences highlights two ways in which explaining consciousness might be uniquely difficult. First, scientific theories may fail to provide a psychologically satisfying sense of understanding—consciousness might still seem mysterious even after we develop a scientific theory of it. Second, our limited epistemic access to consciousness may make it difficult to adjudicate between competing theories. Of course, both challenges may apply. While the first has received extensive philosophical attention, in this paper I aim to draw greater attention to the second. In consciousness science, the two standard methods for advancing understanding—theory testing and refining measurement procedures through epistemic iteration—face serious challenges