Physical law/symmetry as inferred constraints of actions?

In summary, there is a discussion about the status of Lorentz invariance and the physical and scientific basis for symmetries. A paper suggests that the past only exists insofar as it is recorded in the present, and the author adds that laws exist only insofar as they are represented in the present. The author argues that the effect of laws are constraints on an observer's actions and that a system acts "as if the law didn't exist" until evidence suggests otherwise. This leads to the idea that there could be a relativity of law and that improbable observations are not likely to be observed in this world. The author also suggests that physical law must be inferable by a physical process and must be physically encodable by the
  • #1
Fra
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The discussion about the status of lorentz invariance, and as I wanted to twist it, in general, the physical and scientific basis for symmetries started to diverge in my posts so I started a new thread for this to comment more without contaminating the original thread.

atyy said:
"The universe is secretly acausal"
http://arxiv.org/abs/0805.2183

"The universe may be in a zero entropy state, even though it appears (to us, internal observers) to possesses a higher entropy"
http://arxiv.org/abs/0802.0438

Thanks for the links atyy. I like parts and suggestions of this paper but it's arguments has limitations and doesn't address what I have in mind at a sufficiently deep level.

They write “The past exists only insofar as it is recorded in the present”

I like this.

I'd also like to ADD - for coherence of reasoning! - that, laws exist only insofar as they are represented in the present.

Here the effect of law are constraints on the observers action. This actions remains until environmental feedback suggest otherwise - in which case the current state is subject to destructuve/deformning forces.

This means that a system acts "as if the law didn't exists" until evidence that it does, arrives. (This is similar to the idea that a system follows a geodesic given no other forces, and even when other forces are present you could say that it still follows a geodesic, it's just that the geodesic changes)

This suggests a kind of relativity of law, and if this process is understood I think a lot of fine tuning problems can be explained without highly improbable intitial conditions.

The general basic idea put forward is that there would be no physical observer around to observer/record a entropy decreasing in an isolated system, which loosely reduces to that "improbable observations" (which is what violating second law is) would be impossible.

I would rather put this in an evolutionary perspective and suggest that improbable observations are possible, but observers that consistently do them are not stable and are thus not likely to be observed to populate this world.

So I miss the extension of the argument to include not only entropies and probabilities, but to include also actions and transition probabilites. Entropy is just one a priori information measure of possibilities, action is an a priori measure of possible changes due to the instability of the present.

I think the argument here can be sharpened and developed to suggest predictions on the population of observers and their interaction properties. Ie. matters microstructure and it's implict actions. Thus what is usually considered as mathematical consistency used to constrain by deduction interactions and system properties, can instead be used as an evolutionary selection principle and instead explain.

This would suggest that the present state of an observer, encodes the physical law, necessary to evolve the systme into the future. However this law only determines the infinitesimal evolution, since the law is constantly evolving. An external large observer, might be able to predict the deformation of law, and thus the action of the total system of observer + local environment by understanding this process. Then one might say that oh well, then the external view represents the real timeless law, but this is a mistake since the external observer is not unique. There are several of them, each having a different perspective. So there are only a collection of hierarchies of interacting observers.

This would be much more radical than that paper.

---------

My view of physical law, and symmetry constraining nature is that their purpose is to help predict the future, just as the goal of science is. IMO, science isn't about finding something as naive as eternal truths, it's about trying to infer from experince with nature, the patterns that helps us predict the evolution of our own environment, simply as an act of self preservation.

Thus I think this conjecture this brings two "constraints" to help us look for a better unified understand of the laws.

(1) Physical law must be inferrable by means of a physical process. In particular does this reject the methodology of having as a guide simplicitly as in "mathematically beauty". In particular would this also suggest that a simple low complexity observer - think elementary particles and subatomic systems - have a more constrained possibilities of inferrable laws. At some point down the *complexity of the inferenece system* there might not be a lot of choices.

So I think the most important scaling to be considered here is the scaling of the observers complexity, which is the same as the complexity of the "inference machinery".

So unification could be understood as how during this inference process, more complex LAWS become physically distinguishable as the observers complexity grows.

(2) A parallell problem is to understand the growth of complexity (probably related to the origin of mass). This leads to the second constraint that hte law must be physically encodable by the observer. Ie. law itself implies information and thus memory space.

All these things are IMO questions that are prior to notions such as 4D spacetime. The dimensionality of spacetime is one particular thing that must be infered during this process.

All all this is very similary to biological evolutionary processes.

Thus the phrasing that science is the search for absolute, timeless truth is IMHO a simplistic view of science and learning. Instead it's what we are doing with the "truths" that is the difference, it's the basis for our actions, and as such, our actions are based on our inferred constraints, wether eternally tru or not. The notion of eternal truths and universally "right" is simply a redundant notion that only confuses IMO, beucase there is no universal measure of right or wrong anyway.

Or put differently, yes you can say that laws are "timeless" but only to the extent implict in “The past exists only insofar as it is recorded in the present” in the case of limited memory records :)

This is also why I object to some peoples very narrow reasoning in the original thread. Clearly this boils down to the view of science and the scientific methd and it's connection to physics and physical interactions. That last time I looked I certainly consider a human to be as much as physical system as anything else. So some level of coherence of reasoning is what I request.

/Fredrik
 
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  • #2


Dear Fredrik,

Thank you for your insightful comments and for bringing up the idea of a "relativity of law" and its connection to evolutionary processes. I agree that the concept of physical law should not be seen as absolute and timeless, but rather as a tool for predicting and understanding the evolution of our environment.

I also think your suggestion of considering the complexity of the observer and its inference machinery is an important aspect to consider when trying to unify and understand the laws of nature. As our understanding of the laws of physics grows, we may discover that they are not as simple and elegant as we once thought, but rather emerge from the complexity of the systems they describe.

I also appreciate your emphasis on the role of action and transition probabilities in this process. It reminds me of the concept of effective theories, where we use simplified models to make predictions and understand the behavior of complex systems.

Overall, I think your ideas provide a valuable perspective on the role of physical law and how it may evolve and change over time. Thank you for sharing your thoughts.
 
  • #3


Overall, I think your perspective on physical law and symmetry is interesting and thought-provoking. It definitely challenges the traditional view of laws as eternal and absolute truths, and instead suggests a more evolutionary and self-preservation driven purpose for them.

I agree that the complexity of the observer and their inference machinery is an important factor in understanding physical laws and how they are perceived. This ties in with the idea of relativity of law, where different observers may perceive and infer different laws based on their own complexity and perspective.

I also appreciate your emphasis on the role of action in this process. It highlights the active role of the observer in shaping and influencing the laws they perceive, rather than just being passive recipients of them.

Overall, I think your perspective adds an interesting dimension to the discussion of physical law and symmetry, and I look forward to seeing how it develops and potentially challenges our current understanding.
 

1. What is a physical law?

A physical law is a scientific statement that describes a fundamental relationship or rule that governs the behavior of natural phenomena in the physical world. These laws are based on observations and experiments and are used to make predictions about the behavior of objects and systems.

2. How are physical laws inferred?

Physical laws are inferred through the scientific method, which involves making observations, formulating hypotheses, and conducting experiments to test those hypotheses. If the results of the experiments consistently support the hypothesis, it becomes a physical law. Laws can also be inferred through mathematical models and theories.

3. What is symmetry in relation to physical laws?

Symmetry in physics refers to the invariance or consistency of physical laws under certain transformations or changes. For example, the laws of motion are symmetric under translations in space and time, meaning they remain the same regardless of where or when they are applied. Symmetry can also provide insights into the underlying fundamental principles that govern physical laws.

4. How do physical laws act as constraints on actions?

Physical laws act as constraints on actions by setting limits on what is possible in the physical world. For example, the law of conservation of energy dictates that energy cannot be created or destroyed, only transformed from one form to another. This constraint guides the actions and behaviors of systems in the physical world.

5. Why are physical laws important in science?

Physical laws are important in science because they provide a framework for understanding and predicting the behavior of natural phenomena. They allow scientists to make accurate and reliable predictions, develop new technologies, and advance our understanding of the universe. Without physical laws, the world would appear chaotic and unpredictable.

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