How to Formulate the Laws of Physics to Fit the Dynamic Production Account

核心概念

The dynamic production account, which posits that the laws of nature actively produce the future from the past, requires a specific formulation of physical laws to be tenable, particularly in light of challenges posed by the need for temporal locality and compatibility with special relativity.

要約

This article is a research paper (though it does not include all of the sections that you might expect, like a methodology section).

Bibliographic Information: Sebens, C.T. (2024). How do Laws Produce the Future? [Preprint]. arXiv:2407.00210v2 [physics.hist-ph]

Research Objective: To determine whether the dynamic production account of laws can be made precise and to defend it from challenges related to (a) how the laws produce the future, and (b) whether that production is compatible with special relativity.

Methodology: This paper takes the form of a philosophical analysis of the laws of classical mechanics and electromagnetism, exploring how those laws might be formulated to fit the dynamic production account.

Key Findings:

• The dynamic production account requires laws of nature to fit a specific "time evolution paradigm" where dynamical laws connect properties of the present and arbitrarily-short past to changes into the arbitrarily-short future.
• Newton's laws of classical mechanics and the laws of classical electromagnetism can be formulated to fit this time evolution paradigm.
• In relativistic theories like electromagnetism, a stricter "relativistic time evolution paradigm" can be imposed, requiring the dynamical laws to be spatiotemporally local, connecting past and future light-cones.

Main Conclusions:

• By carefully defining the inputs and outputs of dynamical laws, the dynamic production account can be made precise and can address concerns about how the laws produce the future.
• The dynamic production account can be made compatible with special relativity by requiring the dynamical laws to be spatiotemporally local.

Significance: This paper clarifies the requirements for physical theories to be compatible with the dynamic production account, a leading account of laws of nature. It also defends that account from important recent criticisms.

Limitations and Future Research: This paper focuses on classical mechanics and electromagnetism. Further work is needed to determine whether more advanced physical theories, such as quantum field theory and general relativity, can also be formulated to fit the dynamic production account.

統計

引用

"The universe, as well as all the smaller parts of it, is made: it is an ongoing enterprise, generated from a beginning and guided towards its future by physical law.” - Maudlin (2007, pg. 182)
“. . . equations depicting causal relations between physical phenomena must, in general, be equations where a present-time quantity (the effect) relates to one or more quantities (causes) that existed at some previous time.” - Jefimenko (2000, pg. 4)
“The universe started out in some particular initial state. The laws of temporal evolution operate, whether deterministically or stochastically, from that initial state to generate or produce later states.” - Maudlin (2007, pg. 174)

抽出されたキーインサイト

How do Laws Produce the Future?

by Charles T. S... 場所 arxiv.org 10-14-2024

https://arxiv.org/pdf/2407.00210.pdf

深掘り質問

Can the laws of quantum physics, which may involve non-locality and indeterminism, be formulated in a way that is compatible with the dynamic production account?

Quantum physics presents unique challenges to the dynamic production account due to its inherent features of non-locality and indeterminism. Let's break down these challenges:

Non-locality: Bell's theorem, supported by experimental evidence, suggests that quantum mechanics violates local realism. This means events at one spacetime point can instantaneously influence events at spacelike separated points, seemingly contradicting the relativistic time evolution paradigm where influences should be confined to the future light-cone.

Possible Reconciliation: Some interpretations of quantum mechanics, like Bohmian mechanics, maintain a form of determinism and attempt to reconcile non-locality with a clear picture of dynamic production. However, this often comes at the cost of introducing non-local hidden variables, which are themselves controversial.

Indeterminism: Quantum mechanics is inherently probabilistic, meaning the outcome of a measurement is not pre-determined but governed by probabilities. This clashes with the deterministic picture of dynamic production where laws uniquely determine future states.

Stochastic Dynamic Production: The dynamic production account can accommodate stochastic laws, where probabilities govern the production of future states. However, this requires a careful understanding of how probabilistic laws can still be seen as "producing" the future. Some argue that the probabilistic nature of quantum mechanics reflects a fundamental randomness in the universe, while others propose interpretations where probabilities arise from our limited knowledge of a deterministic underlying reality.
Formulating Quantum Physics for Dynamic Production:

Stochastic Dynamical Laws: One approach is to formulate quantum mechanics with spatiotemporally local dynamical laws that are stochastic. This would involve laws that take the quantum state at a spacetime point and probabilistically determine its evolution within the future light-cone. This approach aligns with interpretations like Consistent Histories or Stochastic Collapse theories.
Preferred Foliation: To address non-locality, one might adopt a preferred foliation of spacetime, as Maudlin suggests. This would introduce a preferred frame of reference and allow for a sequential picture of dynamic production even with non-local influences. However, this approach faces challenges in reconciling with the general covariance of general relativity.
Alternative Frameworks: Exploring alternative frameworks beyond the standard Hilbert space formalism of quantum mechanics might offer new avenues for compatibility with dynamic production. For example, path integral formulations or approaches based on quantum information theory could provide different perspectives on the relationship between laws and time evolution.

The compatibility of quantum physics with the dynamic production account remains an open question. Further research into the foundations of quantum mechanics and its interpretation is crucial to determine whether a satisfactory reconciliation is possible.

If the best systems account can also accommodate temporally local dynamical laws, as Callender (2017) argues, is there any empirical way to decide between the best systems account and the dynamic production account?

This is a crucial question that highlights the philosophical depth of the debate. While both the best systems account and the dynamic production account can accommodate temporally local dynamical laws, they fundamentally differ in their interpretation of these laws and their role in the universe. This difference makes it challenging to find a definitive empirical test to decide between them.
Challenges for Empirical Differentiation:

Laws as Descriptive or Productive: The core difference lies in how each account views the nature of laws. The best systems account sees laws as descriptive summaries of the overall mosaic of events in the universe, while the dynamic production account views laws as fundamental entities that actively produce or govern the unfolding of events. This difference is primarily metaphysical and not directly testable through observations.
Underdetermination of Laws by Data: Even if we grant that the laws we discover are incredibly successful in predicting and explaining phenomena, they are ultimately underdetermined by the finite amount of empirical data we have access to. Multiple sets of laws, potentially with different metaphysical interpretations, could be compatible with the same observational data.
Possible Avenues for Exploration:
Despite the challenges, there might be indirect ways to gain insights into the plausibility of each account:

Fruitfulness in Guiding Research: One could argue that the account that provides more fruitful guidance for scientific research and leads to new discoveries might be considered more plausible. For example, if the dynamic production account motivates the search for specific types of laws or mechanisms that are then empirically confirmed, it would lend support to its validity.
Coherence with Other Domains: The coherence of each account with our understanding of other domains, such as metaphysics, philosophy of mind, or even ethics, could provide further support. For instance, if the dynamic production account offers a more compelling explanation for agency or free will, it might be considered more favorable.
Theoretical Virtues: Philosophers of science often appeal to theoretical virtues like simplicity, elegance, or explanatory power when evaluating competing theories. If one account consistently demonstrates a higher degree of these virtues across various domains of physics, it could be considered more likely to be true.

The Verdict:
Ultimately, the debate between the best systems account and the dynamic production account might not be resolvable through purely empirical means. It requires careful philosophical analysis, weighing the strengths and weaknesses of each account based on theoretical virtues, coherence with other domains, and their potential to guide future scientific inquiry.

If we are living in a block universe where the past, present, and future all equally exist, as special relativity seems to suggest, in what sense can we say that anything is really being produced at all?

The idea of a block universe, where the past, present, and future all coexist, seems to challenge our intuitive notion of production or becoming. If the future is already "out there," it seems strange to say that it is being produced. This tension lies at the heart of the debate between the block universe view and dynamic accounts of time.
Reconciling Production with the Block Universe:

Perspective of Time: The key is to recognize the different perspectives involved. From an outside-of-time, "God's eye" perspective, the block universe picture might hold, and all events might be equally real. However, our experience of time is inherently internal and temporal. We experience the flow of time and the distinction between past, present, and future.
Production as a Temporal Process: Production, in this context, should be understood as a process that unfolds within time. While the future might exist in the block universe, it is not yet realized from the perspective of an observer within time. The laws of nature, in the dynamic production account, can be seen as the mechanisms that govern this unfolding or realization of the future from within time.
Analogy to a Story: Imagine reading a novel. The entire story, from beginning to end, exists within the pages of the book. However, as you read, the plot unfolds, and events are "produced" in your mind as you progress through the narrative. Similarly, in the block universe, the entire history of the universe might be "written," but the experience of time and the production of events occur as we move along our worldlines.

Production is Not Creation:
It's crucial to distinguish between production and creation. The dynamic production account does not claim that the laws of nature are creating the future out of nothing. Instead, they are seen as governing the transition from one state of the universe to the next, even if those states already exist within the block universe framework.
The Illusion of Passage:
Some philosophers argue that the feeling of temporal passage and the notion of production are merely illusions arising from our limited perspective within time. However, even if this is the case, the laws of nature, as described by the dynamic production account, would still play a crucial role in explaining the precise nature of this illusion and how the universe appears to unfold in time.
In Conclusion:
Living in a block universe does not necessarily invalidate the idea of production. By recognizing the distinction between the outside-of-time and within-time perspectives, we can understand production as a process that occurs within the block universe, governed by the laws of nature. The debate about the nature of time and the reality of production remains a complex philosophical issue, but the block universe picture does not render the dynamic production account incoherent.