Foundation of the laws of physics

[Twodogs]

The “Laws of Physics” arise from and reflect the lawful regularity of the physical universe. Absent that underlying lawful regularity there would be no laws of physics.Is it true that the laws of physics are descriptive of that underlying order, but are silent on the nature of its origin, of how is it achieved uniformly across each far-flung increment of time and space?Does someone know of a resource where this question is discussed or put to rest?Much obliged.

 

[fresh_42]

Is it true that the laws of physics are descriptive of that underlying order, ...

Yes. But these descriptions are also tested via experiments. Within the framework of an experiment, they are axiomatic, i.e. deductive.

... but are silent on the nature of its origin, of how is it achieved ...

Yes. However, it isn't the laws which are silent, it's the underlying principles like conservation, symmetries and optimizations which are silent. The laws are only the consequences.

... uniformly across each far-flung increment of time and space?

This is an assumption. We can only test this to a certain degree, but there have never been found evidence that physical laws are only valid locally - at least if we leave simplifications due to approximations out of consideration.

Your question provokes a counterquestion: What are your expectations on an answer as to "how"? Any answer here will necessarily lead to a reason, and then again you can ask how, etc. This means in return that there cannot be a final answer. See

 

[Twodogs]

Excellent, I love Feynman. Thank you for the considered reply. I will ponder and get back.

 

[Twodogs]

So yes, where do you stop the questioning of a four-year-old in which each answer provokes the question, “Why?”. And yet, there are still plenty of questions out there.

The assumptions accompanying my question are:

1) The “Laws of Physics” are hard-won symbolic abstractions describing the underlying lawfulness of the physical world.

2) The “Laws of Physics” may be applied universally because the underlying physical lawfulness is universal ( At least in so far as to calculate an atmospheric entry angle of 12º and successfully land the Insight spacecraft on the surface of Mars.)

3) The twelve significant-digit agreement between theoretical and experimental result in the measurement of the electron g-factor is testament to both our theory and the underlying, precisely governed regularity of the physical universe.

4) The standard model and accompanying field theories are descriptive of the underlying, precisely governed regularity of the physical universe but do not speak to its origin, the how and why of it. How, in each fraction of a second and across its vast volume does the universe stay precisely on track. Metaphorically, do the laws of physics describe the motions of the pendulum while disregarding the arch from which it hangs?My question: Does anyone know of a reference to an established body of thought where this notion is discussed or put to rest?My thanks: Truly.

 

[fresh_42]

My question: Does anyone know of a reference to an established body of thought where this notion is discussed or put to rest?

Charles Popper has written a book: The Logic of Scientific Discovery. I'm not a big fan of it, but that is possibly due to the fact that I consider it from a physical point of view whereas it probably should be read from a philosophical point of view. Wittgenstein tried to solve the question of an ultimate truth by a reduction to language, resp. symbolism (from Wikipedia):

It was during this time that Wittgenstein began addressing what he considered to be a central issue in Notes on Logic, a general decision procedure for determining the truth value of logical propositions which would stem from a single primitive proposition. He became convinced during this time that “[a]ll the propositions of logic are generalizations of tautologies and all generalizations of tautologies are generalizations of logic. There are no other logical propositions.” Based on this, Wittgenstein argued that propositions of logic express their truth or falsehood in the sign itself, and one need not know anything about the constituent parts of the proposition to determine it true or false. Rather, one simply need identify the statement as a tautology (true), a contradiction (false), or neither.

Mathematicians are widely Platonists, for which everything that can be thought exists and reality is like a projection of these existences - a way out that physicists don't have, as physical existence is ultimately coupled to measurability, enforcing a sort of realism.

Metaphorically, do the laws of physics describe the motions of the pendulum while disregarding the arch from which it hangs?

I think they do both. The reason is, that physical laws usually describe a behaviour, a change in time. This means their goal is to predict what will happen, and it also means, that you can focus on the pendulum, or on the static of the arch from which it hangs, or on the arch which it describes. Three viewpoints, three mathematical concepts, but only one principle: The principle of least action (energy).

 

[Twodogs]

Thanks. You come at it from a broad perspective and there are certainly multiple things here to consider. I will do that.

 

[Auto-Didact]

My question: Does anyone know of a reference to an established body of thought where this notion is discussed or put to rest?My thanks: Truly.

I recommend:
The Foundations of Science, by Henri Poincaré

The Singular Universe and the Reality of Time, by Lee Smolin and Roberto M. Unger

 

[Twodogs]

Fresh-42,

Thanks, I appreciate the dialogue on a subject that intrigues me.

I would be interested in a philosophical parsing of my question and its assumptions, but I would most keen to understand it from a “physical point of view.” Similarly, for the discipline of logic, it is necessary to know where one makes an unsupported step in argument. And yet, with regard to logical systems, there is always the reminder, a bumper sticker version of Gödel, “No matter how you come to know truth, there will be truth you do not recognize.”

The principle of least action is a physical law describing an invariant physical behavior of the universe: (roughly) “the path actually followed by a physical system is that for which the action is minimized.” This dictum apparently has far reaching consequence in theoretical physics.

But, my four-year-old is tugging at my sleeve, “Why?” Why are physical dynamics universally and precisely constrained in this manner? How is the universe thus informed?

To that end, may we consider path as the salient observable attribute in physical dynamics? Thus, imagine a large, inflated beach ball rolling down a rocky hillside on a breezy day. Its path is a graphic record of each constituent action impulse and the configuration space of imposed constraints. So, may we say as a rule-of-thumb that path emerges “between” action and constraint?

Once again, I appreciate working though this and am also keen to know of a reference to an established body of thought where this notion is discussed or put to rest?

Regards.

 

[Twodogs]

Auto_Didact
Will track those down. Appreciate your referral.

 

[Auto-Didact]

No problem. Now that I think about it, Feynman of course spends some time on such issues as well, both in his Lectures on Physics and in The Character of Physical Law (available on YouTube).

 

[Ian J Miller]

There are a number of points raised here, but the most important is not, and that is we are on a journey of discovery, and we are nowhere near finished. We simply do not know it all, and we do not even know what we have yet to discover. Having said that, we do know enough to get hints. We can look at the spectra of stars from a very great distance in both time and space, and leaving aside the red shift, the spectra are the same as we see here. That strongly suggests the laws of electromagnetism, quantum mechanics, gravity, thermodynamics, etc are the same over time and space. If we accept that if I do an experiment here and you do one there at some different time we should get the same result, i.e. our experiments are reproducible, from Nöther's theorem we can get the conservation laws. So we do ave some idea as to the foundations, but your question is oddly enough around the wrong way. Thus the conservation laws come from the fact that physics is the same over time and space. Relativity is based on the same propositions. Of course there is a lot we don't know about the foundations, and as someone has mentioned Feynman's discussion on why questions, we cannot answer why at the most fundamental level because why refers to something else. You can only deduce from principles that either have to be considered as givens, or be induced from nature. As an aside, that concept was first stated by Aristotle.

 

[Lindsayforbes]

Today it is called physics, but when I was at university 50 years ago the department was called Natural Philosophy. That's progress?

 

[Twodogs]

Okay, thanks, I think I have a better understanding. The particular path of "least action" is constrained by the potential gradients of the underlying fields. One must look to the fields as cause of the universe's explicate order. I suppose one could then ask, “Why fields?’