Physics is Just a Model

[Carl Emerson]

It is an inner knowing in the human spirit - the Greeks called it Epi-Gnosis.

 

[SelfSim]

Interesting .. this sounds like it may be some kind of 'justified true belief' definition of knowledge(?) (At least, that's how I'll relate to it).

If so, all I have to say about that is that we are in a science forum .. Justified true beliefs have nothing to do with 'scientific knowledge', which is all about justification, is sketchy on truth, and is devoid of any need for belief. So, 'knowing' in science, is choosing where you are going to place your bet, when the bet has objective consequences. Therefore, 'knowledge' boils down to 'track record', and nothing else. Certainly not 'justified true belief' .. although, I do recognise that any kind of belief, still requires a human mind.

 

[sjastro]

Here is a historical perspective of Lagrangian mechanics.
The origins did not begin with Joseph-Louise Lagrange but between brawling alpha males namely Isaac Newton and the dreaded Bernoulli brothers Jacob and Johann.
It started over who invented differential calculus Isaac Newton or Gottfried Leibnitz.

Johann posed a problem and solution in Lagrangian mechanics about fifty years before its innovation.

I, Johann Bernoulli, address the most brilliant mathematicians in the world. Nothing is more attractive to intelligent people than an honest, challenging problem, whose possible solution will bestow fame and remain as a lasting monument. Following the example set by Pascal, Fermat, etc., I hope to gain the gratitude of the whole scientific community by placing before the finest mathematicians of our time a problem which will test their methods and the strength of their intellect. If someone communicates to me the solution of the proposed problem, I shall publicly declare him worthy of praise

Given two points A and B in a vertical plane, what is the curve traced out by a point acted on only by gravity, which starts at A and reaches B in the shortest time.

The challenge was issued to Newton who not only solved the problem but in his characteristic 'humble' style replied.

"I do not love to be dunned [pestered] and teased by foreigners about mathematical things...

 

[public hermit]

'Reality' is a model.

I knew you were going to show up for this, haha! We've had this discussion a couple times.

How do you avoid a regress, so that even your own position regarding models is a model, and that itself is just a model, etc.? Maybe such a regress is not possible, but why not?

How can you say "reality is a model" as if it is certain? If physics is not a representation of reality, how can you be confident your claim about reality being a model is nothing more than your preference? Intersubjective agreement, perhaps?

 

[SelfSim]

How do you avoid a regress, so that even your own position regarding models is a model, and that itself is just a model, etc.? Maybe such a regress is not possible, but why not?

I don't see a useful need for avoiding regression. Should I? Why?
Regressing helps us notice that there are different types of models, or concepts, but they're all nonetheless, still quite demonstrably, concepts.

For example, there are scientifically accessible concepts which are demonstrably different from other concepts .. (which typically represents usefulness in the advancement of scientific knowledge).

How can you say "reality is a model" as if it is certain?

Its objectively testable and generates abundant, consistent, affirming results for the hypothesis under test (with no results for the alternatives) .. all we have to do, is to look for/at those results.
(Note: we're also having this conversation in a science forum, talking about Physics, what's more).

If physics is not a representation of reality, how can you be confident your claim about reality being a model is nothing more than your preference? Intersubjective agreement, perhaps?

Firstly its possible that physics might be a representation of something independent from the mind of the Physicist .. but thus far, there is no objective test that scientific thinkers would agree on for that alternative .. which I guess, brings us around to intersubjective agreement where the subject is science and Physics.

 

[public hermit]

I don't see a useful need for avoiding regression. Should I? Why

That was not the response I was expecting, which is pretty delightful. Cool.

objectively testable and generates abundant, consistent, affirming results for the hypothesis under test (with no results for the alternatives) .. all we have to do, is to look for/at those results

Is objectivity simply which model fits the results best?

Firstly its possible that physics might be a representation of something independent from the mind of the Physicist .. but thus far, there is no objective test that scientific thinkers would agree on for that alternative .. which I guess, brings us around to intersubjective agreement where the subject is science and Physics

Since Kant, hasn't it been pretty much settled that we can't get past phenomena, past the observable?

Couldn't objectivity be that which garners the widest intersubjective agreement? It's basically whatever model best fits the observations?

 

[SelfSim]

Is objectivity simply which model fits the results best?

More like its a type of collectively agreed thinking involving consistency .. but I don't think its likely to be able to be proven to be a 'universal' or 'absolute' form of consistency. If one understands what scientific consistency is, one will be able to be a scientist, and if one doesn't, one won't, but there's not a whole lot more that can be said on that without some basic common ground (IMO).

Since Kant, hasn't it been pretty much settled that we can't get past phenomena, past the observable?

I've seen arguments invoking 'pointers' but don't ask me to explain what these might be .. I wouldn't have a clue.

Couldn't objectivity be that which garners the widest intersubjective agreement? It's basically whatever model best fits the observations?

In Physics, say, we are trying to build a concept of reality that fits in our heads and is quantitatively successful, but our successes there, seem to go way beyond anything we've imagined our brains evolving to do. Then, we're left with the question of why are the basic physical laws of the universe so simple we can teach many of them in high school? That's a doozy!

Since the overall goal is simply to understand, and the simplest model/theory that agrees with data is the best path to understanding, then that would clearly be our best model/theory. Agreement between theoretical models and the data, is thus important to us, for this reason.

 

[Tinker Grey]

 

[durangodawood]

'Reality' is a model.

...a model of what?

 

[SelfSim]

...a model of what?

A model of our mind's perceptions.

Eg: Science investigating 'the existence of something' only ever tests its models and never tests 'the thing itself', where that 'thing' stands independent from the scientist's mind. A scientist describing something which exists independently from their mind would be a magic trick!

 

[durangodawood]

A model of our mind's perceptions.

Eg: Science investigating 'the existence of something' only ever tests its models and never tests 'the thing itself', where that 'thing' stands independent from the scientist's mind. A scientist describing something which exists independently from their mind would be a magic trick!

That^ sounds like you mean: "scientific models are models of our minds perceptions".

But reality is a model of our minds perceptions? Unless "reality" just means the models we make. In which case: what are our perceptions (however flawed), of, if not of reality?

 

[public hermit]

A model of our mind's perceptions.

Eg: Science investigating 'the existence of something' only ever tests its models and never tests 'the thing itself', where that 'thing' stands independent from the scientist's mind. A scientist describing something which exists independently from their mind would be a magic trick!

But you do admit that there is something other than mind that is being tested, right?

 

[SelfSim]

See, everything we perceive from our senses, is processed by our minds. Once described, those perceptions become concepts (or models). There are two types of models objectively testable, and untestable. Science tests the testables and is indifferent to the untestables, which can be classified as beliefs.

 

[durangodawood]

See, everything we perceive from our senses, is processed by our minds. Once described, those perceptions become concepts (or models). There are two types of models objectively testable, and untestable. Science tests the testables and is indifferent to the untestables, which can be classified as beliefs.

Makes sense. But that doesnt help me get what you were saying about "reality".

 

[SelfSim]

That^ sounds like you mean: "scientific models are models of our minds perceptions".

Of course they are.. (demonstrably objectively evidently so, eg: Einstein's GR/SR thought experiments).
The (objective) evidence for that, originates in the meanings we pass amongst ourselves via the common terms in the language we use. No scientist ever tests something which is not described using language and its meanings which have obviously been processed by our minds.

Its just a belief (or short-hand method of convenience) to give the impression that 'things' exist independently from the minds conveying descriptions of those 'things'. All we have is descriptions/models.

.. In which case: what are our perceptions (however flawed), of, if not of reality?

If the way you are meaning 'reality' there, is as being something which exists totally independently from our minds, this simply doesn't matter because that kind of reality is not accessible to us. What is accessible to us are concepts and descriptions, conveyed via the meanings behind the words we use.
The focus on some 'external reality', (meaning some kind of totally mind independent reality), is chasing at best, a belief .. which then permits any kind of belief to be (perpetually?) pursued .. just as these forums seem to actively promote!

 

[SelfSim]

But you do admit that there is something other than mind that is being tested, right?

I only have to admit that this may be possible. The abundant objective evidence, sourced from a testable mind dependent hypothesis, does not support this 'possibility' however and abdundantly supports that mind dependent models/concepts are under test.

You need to get that what I talking about here is applying the scientific method in creating a testable hypothesis and then testing it by gathering data which implies mind dependence. I'm familiar with your penchant for philosophy and this is about a consistent philsophy of science .. but its also making use of the scientific method to support its claim (which distinguishes it from being a purely philosophical claim).

 

[durangodawood]

Of course they are.. (demonstrably objectively evidently so, eg: Einstein's GR/SR thought experiments).
The (objective) evidence for that, originates in the meanings we pass amongst ourselves via the common terms in the language we use. No scientist ever tests something which is not described using language and its meanings which have obviously been processed by our minds.

Its just a belief (or short-hand method of convenience) to give the impression that 'things' exist independently from the minds conveying descriptions of those 'things'. All we have is descriptions/models.

Oh it did make sense to me, and I should have said as much up front.

If the way you are meaning 'reality' there, is as being something which exists totally independently from our minds, this simply doesn't matter because that kind of reality is not accessible to us. What is accessible to us are concepts and descriptions, conveyed via the meanings behind the words we use.
The focus on some 'external reality', (meaning some kind of totally mind independent reality), is chasing at best, a belief .. which then permits any kind of belief to be (perpetually?) pursued .. just as these forums seem to actively promote!

So the idea that our perceptions refer to anything real beyond our own minds is just a belief like any other, for example, like the belief in the resurrection of Jesus? I dont buy that, in that the reality of something real "out there" (even if its quite different than our perceptions indicate) is the baseline mode of understanding which we all share as human animals prior to the exertions required for religious or ideological belief-building.

In other words belief in the real is the opposite of a slippery slope downward to any old crazy belief. Its more like the rut we're stuck in

 

[SelfSim]

Oh .. and I'm not alone with this line of argument.

Hawking/Mlodinow were on the same track in the book: 'The Grand Design'

 

[durangodawood]

oops

 

[J_B_]

An interesting discussion, but I'm not sure how useful it is to me.

I once heard someone on this forum (and an atheist to boot) say they accept a reality apart from themselves because that's the way it appears. I found that answer very satisfying. Simple, succinct, and no other answer is any better. I may have to concede there is a possibility God doesn't exist on some "rules of logical discourse" grounds, but in no way does that possibility affect my behavior.

I live my life as if I am a thing and all other things exist apart from me, and nothing has ever challenged that as a reliable attitude.

If nothing else, this conversation is proof to me that things exist apart from me because it's not at all what I had in mind when I wrote the OP. This conversation didn't come from me. It is apart from me.