Physical Axioms and Attractive Forces

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17 years 8 months ago #16593 by Larry Burford
[nonneta] "Just to warn you in advance, when you give me your example, I'm going to show you that all you have provided is a mathematical description."

I can see the possibility of some semantic disagreements, but if any do come up we will just have to work them out. It sounds interesting. Show me how this works with sound. Some of us claim that sound energy propagation involves gas molecules colliding with each other, and passing the energy along. (There are more details available, if needed.) Using this as a starting point it is possible to come up with some equations that describe the behavior of sound waves to high precision.

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17 years 8 months ago #19486 by nonneta
Replied by nonneta on topic Reply from
So you’re saying the physical explanation for sound is that “sound energy propagation involves gas molecules colliding with each other, and passing the energy along”, and then you say “more details available, if needed”.

More details are definitely needed.

What you’ve expressed (so far) is nothing other than an extremely vague and tautological (not to mention inaccurate) mathematical description. The expression ‘energy is passed along’ is basically a synonym for ‘energy is propagated’, so the only supposedly explanatory content must be the phrase “involves gas molecules colliding with each other”, but this is neither an explanation nor a description. In fact, it isn’t even a complete enumeration of what is “involved”. Do these “gas molecules” perhaps undergo something called “motion”? Are “gas molecules” to be regarded as primitive entities in your “explanation”? What are their relevant properties? Are they of finite extent? How does a physical primitive entity differ from a mathematical primitive entity? Will the “additional details” perhaps include something called “inertia”? What does it mean for “gas molecules” to “collide”? And so on.

These questions aren’t meant to be annoying; the purpose is to get you to clearly articulate just one example of what you would regard as an actual “physical explanation” for something. This is an important exercise for a person to perform at least once in their intellectual development. The outcome will give you much food for thought.

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17 years 8 months ago #16680 by Larry Burford
[nonneta] “These questions aren’t meant to be annoying … “

It is human nature to be annoyed by questions, but I appreciate the sentiment. No annoyance taken.

[nonneta] “More details are definitely needed … “

“Do these “gas molecules” perhaps undergo something called “motion”? Are “gas molecules” to be regarded as primitive entities in your “explanation”? What are their relevant properties? Are they of finite extent? How does a physical primitive entity differ from a mathematical primitive entity? Will the “additional details” perhaps include something called “inertia”? What does it mean for “gas molecules” to “collide”? And so on.”


Obviously, we physics weenies have set a difficult task in front of ourselves. More difficult than the task the math weenies have set in front of themselves, because in addition to working out the mathematical descriptions for the behavior of a phenomenon, we also have to address the questions you mention (and others as well). The answers include physical details that often place additional constraints on the math. We can’t say something like “it’s just geometry”. If we think the answer <u>does involve</u> geometry, we have to say something like “it’s the geometry of &lt;some physical thing&gt;“. Even if we cannot yet detect that thing.

Sometimes we have to theorize about physical details, because our technology is not yet able to detect everything. Like mainstream science, we will invoke a hypothetical field of some sort, or a hypothetical particle, to fill in an observational gap. But we do not then wave our hands and try to convince anyone (especially ourselves) that this field has no physical components, or that the particle is somehow virtual rather than real.

(You know, the mainstream usually doesn’t avoid the hard parts. But that just makes the times when they do more puzzling.)

===

Earlier I asked you some questions that are similar to the questions you now ask me.

[nonneta] What does it mean for “gas molecules” to “collide”? Do these “gas molecules” perhaps undergo something called “motion”? Are “gas molecules” to be regarded as primitive entities in your “explanation”? What are their relevant properties?

[LB] What are the physical (measurable in the lab) properties of spacetime? How does matter bend spacetime? What does it mean for spacetime to tell matter how to move?


I’ll try to answer some of your questions. At some point I’d appreciate it if you tried to answer some of mine.

=== Do we regard gas molecules as primitive entities?

I guess the answer has to be yes, but you need to understand that we regard everything as both primitive entities and composed entities.

To us a primitive entity is something that can be used to build composite entities. Stars are some of the primitive entities used to build galaxies. And galaxies are some of the primitive entities used to build galactic super clusters. Each primitive entity is in turn composed of other primitive entities. Galactic clusters are composed of galaxies, galaxies are composed of stars, stars are composed of atoms, and atoms are composed of sub atomic particles. This process continues to infinity in both directions along the scale dimension. “Primitive entity” is a scale dependent concept in this view.

Another way to think of primitive entities is to say the current smallest detectable thing is “the” primitive entity from which all larger things are built. “Primitive entity” then becomes a technology dependent moving target as we learn how to see smaller and smaller things, but this view is still useful. Galactic super clusters are composed of atoms. Or of quarks, if you subscribe to the view that they are a done deal. In a few decades, however, GSCs will be composed of the newly discovered things from which quarks are then known to be built.

=== Are physical primitive-entities different from mathematical primitive-entities?

This is a really interesting question. If you focus on a particular interval along the scale dimension, then yes. Mathematical primitive (and composed) entities are allowed to have unphysical properties such as a radius of zero and a finite mass, yielding a density of infinity. Real primitive (and composed) entities are not.

But if you stand back and contemplate the infinite extent of the scale dimension, then the distinction becomes less clear. See below.

*** The local view ***

Over the particular range of scale that we are familiar with, one can detect “things” that are typically referred to as solid or physical or real. But there are aspects of the behavior of these things that appear to depend on other things that we cannot detect. In the past when we have been able to resolve such mysteries, it has turned out that the previously undetectable “other things” were just very much smaller than anything we had encountered (or even imagined) before.

<ul><li>Animals sometimes get sick. Invisibly small (until we learned how to detect them) bugs turned out to be the cause.
<li></li>Atoms sometimes break apart. They (supposedly irreducible atoms) turned out to be built of invisibly small (until we learned how to detect them) particles that can in fact be separated from one another.
</li></ul>
Some other mysteries of this sort are still awaiting resolution.

<ul><li>Matter attracts matter. In the most recent guesses as to why, a gravitational “field” is invoked. We can detect no particle or wave or anything else to account for this field, but its behavior can be described to high precision with equations. Some leave it at that, claiming that gravity isn‘t a real thing. We smile, and keep looking for the little doohickies that will turn out to be the primitive entities from which the field is built.
</li></ul>
*** The global view ***

In the grand scheme of things, however, there is no bottom, or primitive, particle. At least not that you can “hold in your hand”. The smallest (or largest) possible thing exists as a concept. Any real particle, no matter how small, can always be disassembled into its components.

Here is a place where we might come close to some kind of agreement about the ambiguity of a distinction between the physical and the mathematical. The thing we call substance, from which we hypothesize that all real things are composed, exists as a conceptual “smallest possible thing”. A real, living mathematical point, some might say. Radius zero (exactly), volume zero, mass zero, density indeterminate. (But approaching infinity or zero in the limit? Or undefined? Hmmm, probably not; last time I looked, 0/0 was indeterminate. Probably good for us. If it had to be undefined or zero or infinity, we might be in trouble.)

Nothing real can be substance, however, because real things can ALWAYS be disassembled into their components.

No matter how far you go in the direction of small, what you find is not infinitely small. You are always infinitely far from the infinitely small. No matter how far you go in the direction of large, what you find is not infinitely large. You are always infinitely far from the infinitely large. (“Stuck in the middle again … “ as the tune goes.)

But if you <u>could</u> go all the way to infinity in the small direction, you would find that strange little thing we call substance.

This is one of the postulates of our view of reality. So one could argue that you and I agree that reality is built on a mathematical / logical abstraction. At least to a certain extent.

Regards,
LB

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17 years 8 months ago #19491 by nonneta
Replied by nonneta on topic Reply from
You say

“The thing we call substance, from which we hypothesize
that all real things are composed, exists as a conceptual
‘smallest possible thing’. A real, living mathematical point,
some might say. Radius zero (exactly), volume zero, mass
zero, density indeterminate. Nothing real can be substance,
however, because real things can ALWAYS be disassembled
into their components.”

So you claim that all “real” masses are ultimately composed of “unreal” entities with zero mass, and hence something comes from nothing. This is blatent “creation ex nihilo”. Likewise you assert that all real entities of positive volume are composed of unreal entities of zero volume, and that all real entities of positive radius are composed of unreal entities of zero radius. Needless to say, no finite number of zeros (real or unreal), nor even a countably infinite number of zeros, can sum to a positive value, so you are proposing that the finite (zero) somehow becomes infinite (a continuum). All this is in blatent violation of the principles that you claim to espouse.

Furthermore, you attribute a physical property (namely, density), albeit of “indeterminate” value, to an unreal nothingness. How can nothing (or even an “unreal” something) have a real property, and what does it mean for this property of nothingness to be indeterminate? How can anything real and determinate come from something (or rather, nothing) that is unreal and indeterminate? Also, you say all physical entities are composed of a “living mathematical point”, but you don’t give even a hint of what you mean by “living” in this context. Surely you don’t mean this literally, but then how exactly is it to be interpreted? Excuse me for saying so, but what you’ve described is already pure magic (the kindest word I can use for it) - and you haven’t even begun to address the really hard questions that I was hoping to bring to your attention, such as the spatial context of your “points”, the constraints imposed by that context, the concepts of change and temporality, and the operational attributes of “mass”, notably the attribute of inertia. At this rate, I fear we will never get to these crucial topics.

By the way, neither of the two mutually exclusive definitions of “primitive” you mentioned is correct. A primitive element of a conceptual framework need not be “small”, and conversely the smallest things need not be primitive. Of course, even the concept of “size” pre-supposes a vast conceptual structure, none of which you even acknowledge, let alone “explain” in “physical” terms (which you still have yet to define). All you’ve said is that

“Mathematical [i.e., unphysical]… entities are allowed to
have unphysical properties… Real [i.e., physical]… entities
are not.”

Needless to say, this bizarre tautology is useless. Similarly your example of an unphysical thing (“an entity with a radius of zero and a finite mass”) suffers from the fact that you haven’t defined “radius” or “mass”, let alone explained why the combination of zero radius and non-zero mass is “unphysical”. And of course this example is undermined by your later contention that even your supposedly “physical” particles are actually composed of “living” mathematical “points” with no “radius”, “volume”, or “mass”, and indeterminate “density”.

At this point I could describe the dozen or so other logical fallacies and internal contradictions in your message (such as the classic about how everything has been explained mechanically - except for the things that haven’t), but perhaps this is enough to get you started thinking about how you might work towards eliminating some of the illogical and incoherent aspects of your beliefs. We can’t really get started discussing the interesting things until/unless you have freed yourself from the misconception that there is some objective distinction between mathematical descriptions and physical explanations. Hopefully some of the above observations have stirred a few brain cells into action!

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17 years 8 months ago #16630 by Larry Burford
[nonneta] "Hopefully some of the above observations have stirred a few brain cells into action!"

Did you know that it is possible to discuss technical subjects without being rude? If you had said this about someone else I would have already put you in the time out corner. But since you were talking about me, and I have a thicker skin than average, I'll give you another chance to clean up your act.

Just stick to technical content and don't talk about the skills or motives or beliefs of whomever has presented an idea.

Messages are fair game, messengers are not.

Such deviations from what is relevant make the deviator appear to be losing, and I'm not yet convinced that you are.

===

Note that I am not the only moderator here. We each operate independently, using our independent-but-similar criteria for making these decisions. If another moderator decides to pull your plug, he can.

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17 years 8 months ago #16631 by Larry Burford
[Gregg] " ... First you blow stupid, then you blow smart."

Do me a favor? See if you can find alternate wording for this. I've been thinking about asking a similar question, but have not because I'm still looking for wording that avoids the personal attack aspect.

LB

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