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SpookyKitty

What are the particulars of gravity?

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3 hours ago, SpookyKitty said:

So if you don't believe something, it is invalid to question it or consider its existence?

I have no idea how you got this from what I said.

 

3 hours ago, SpookyKitty said:

But no, the two things are not the same, because gravity is not a metaphysical concept but a physical one.

Yes, but you are questioning both for the same reasons. You don't see how gravity is differentiated from anything because you see it as ubiquitously present in everything you can point at. (blue sphere or a cup makes no difference)

3 hours ago, SpookyKitty said:

You have misunderstood the nature of the question. If epistemology claims that all valid concepts arise from distinctions among entities (concrete or abstract) and if you have a valid concept (in this case, gravity) which does not arise in that way, then there is a problem. Either the account is false and must be modified, or gravity is an invalid concept. (Or gravity is a valid concept consistent with the standard account of concept formation, in which case it must be proven that it is).

Your claim that this is not the case is a denial of simple logic.

First, axiomatic concepts are not formed the same way as other concepts and that is the type of concept you were struggling with how to form previously. You see what appears to you a similarity with gravity. Second, It is you who are making a logical error. If you need epistemology to tell you if gravity is a valid concept you cannot use gravity to tell if your epistemology is valid because you need to know what a valid concept is first...

3 hours ago, SpookyKitty said:

Hierarchy inversion is when epistemology is used to prove or disprove an empirical claim or vice versa. But gravity is not an empirical claim. It is a concept that is used to explain emirical facts, and its validity is open to philosophical scrutiny.

Gravity is not an empirical claim? You are more confused than I thought. Even philosophical concepts are empirically based. What on earth is your definition of empirical then? All concepts are open to philosophical scrutiny concerning validity. Its the availability of the facts that differentiate a concept as related to one science or the other, because the methods used are necessarily different, given the availability of the facts.  

3 hours ago, SpookyKitty said:

Yes, exactly. A scientific concept can fail to be valid, in which case it would not contradict the epistemological claim. If gravity is an invalid concept, then there is no problem.

But you cannot determine if gravity is valid without knowing what the standard of validity is! How do you not see the self refuting nature of your statement?

3 hours ago, SpookyKitty said:

Well General Relativity considers them as such, so tough luck.

Oh and mass-energy actually curves spacetime, so there's that.

Heh, this is a refutation of your repeated claim to embrace the special vs general distinction between philosophy and science!

"Relativity says these concepts are causes so the philosophical science that is responsible for defining what constitutes a valid cause is out of luck" 

I think I'm wasting my time here...

Edited by Plasmatic

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50 minutes ago, Eiuol said:

Which part isn't necessary? I am only trying to show that it didn't seem like you understood the Objectivist position of the way a concept is reduced to perception. It doesn't mean finding the particular (if by particular you mean a concrete object) of the concept unless it is first-level (as in things like apple, firetruck, dog, etc). We aren't looking for a "gravity particle" necessarily for example.

This is a very confused statement. All reduction terminates in perception, which is always of particulars.

Second, why do you think scientist are looking for "gravitons"?

Edited by Plasmatic

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Right, and it's not that the abstraction -itself- is a particular. As I said before, there is no "red particular"; likewise, there is no "gravity particular".

I did not say I think scientists are looking for "gravitons" or anything like it. It'd be wrong to look for it. I said "not necessarily looking for" because in principle we know particles can cause things, there's just no reason to say there is a gravity particle. We don't need a "graviton" for gravity to be valid, either.

Edited by Eiuol

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So after spending some time with Google, I've discovered that a floating abstraction is not necessarily an invalid concept.

And Eiuol makes a good point in that, just because it may be hard to reduce a concept, doesn't mean it's impossible.

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15 minutes ago, SpookyKitty said:

So after spending some time with Google, I've discovered that a floating abstraction is not necessarily an invalid concept.

Who said that, I'm wondering? I mean, a floating abstraction is not a "good" thing, so it's definitely erroneous or at least not-yet-validated. I could hold gravity as a floating abstraction, but then fix it later.

 

Edited by Eiuol

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36 minutes ago, SpookyKitty said:

So after spending some time with Google, I've discovered that a floating abstraction is not necessarily an invalid concept.

And Eiuol makes a good point in that, just because it may be hard to reduce a concept, doesn't mean it's impossible.

You are right. People can employ a "floating abstraction", but this does not mean that the particular abstraction is invalid.  It just means that they don't understand it very well.

Edited by New Buddha

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Think of this first in terms of your fire truck and grass.  A firetruck, stop sign, drop of blood, evening sky, cherry, and hot piece of steel (but not too hot) can be isolated from other objects according to a specific characteristic and united by a specific definition.  I.e., "red."  

Likewise, grass, a lime, a "go" light, a flame from burning copper and a piece of jade are isolated and united by the definition "green."  

Given enough examples of things that have a similar, but different characteristic, we can abstract the abstractions "green" and "red" (and blue, orange, magenta, gray, etc.) isolate them from other characteristics, and unite them with the specific definition "color."

Why do objects have colors?  Given scientific insight and experiments, the colors can be explained by light theory, absorption and reflection, and wavelength, all valid concepts, even though every object absorbs and reflects electromagnetic waves "in precisely the same way."

Gravity is similar.  Go to your concretes: a brick, a feather, a helium balloon.  Group bricks with stones, sacks of potatoes, your Uncle Mike, a bar of gold - all of them "heavy."  Feathers, with balsa wood, whipped cream, a pumice stone and your Aunt Helen, all of them "light."  Now you have two characteristics that are similar but different, and you isolate them and unite them with the definition "weight."  Now observe that things with weight fall.  (The helium balloon will have to wait till later in your abstraction process...)

Now, why do things have weight, and why do they fall?  Isaac and Albert, over to you...

Edited by calzonie

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I'm just a layperson when it comes to physics, but gravity has interested me. It is not a phoney concept because we observe "gravity" around us - it is a concept based on our experience of reality.

A greater mass is said to exert a greater gravitational effect than a lesser mass. According to Objectivist philosophy, it is entities which act. The law of causality is the law of identity applied to action. So when we associate the gravitational effect with mass, we must say (in order to avoid contradicting ourselves) that gravity is an inherent action-characteristic of all masses, and it is a consequence of two or more masses interacting. All masses of equal measure exert an equal gravitational pull. This seems to suggest gravity is a universal property of mass regardless of the attributes of the particular masses? If so it makes gravity different from other attributes such as thermal properties or conductivity which seems very specific to the type of mass in question.

The effect of gravity can be disturbed outside of a vacuum too. For instance, dropping two equal masses onto the Earth where one is a lead ball and the other feathers, then the feathers will interact with air etc. and take much longer to reach the surface. So gravity does function in different ways depending on the nature of the entity and the nature of its interaction - e.g. in the presence of air masses or not. Two equal masses do not behave the same gravitationally in all situations, which suggests the attributes of the mass - e.g. how well the mass is bound together, its aerodynamic qualities, it's energetic content - does have a bearing on say its rate of descent despite equal gravitational forces acting upon it.  

I'm not well educated in physics so I am probably making an idiot of myself, but I do find something so obvious as gravity a little bit mysterious - it is supposedly a universal property of all masses but can't be observed directly (e.g. gravitons).

It seems like there is evidence to contradict our understanding of how gravity works at a universal level - but again excuse my ignorance. For example I have read that galaxies spin in a way which defies the mass effect - the velocity effect measured by Rubin which suggests there must be a lot of unidentified mass, or our calculations and understanding of gravity is wrong. I know the idea of dark matter was developed to save the hypothesis, but it all feels like a bit of a fudge, albeit very cleverly done.  

Edited by Jon Southall

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3 hours ago, Jon Southall said:

Two equal masses do not behave the same gravitationally in all situations, which suggests [other] attributes of the mass ... do have a bearing on say its rate of descent despite equal gravitational forces acting upon it.  

In fact, in all situations the gravitational force is the same. In the presence of the air there is simply an additional force, which represents the interaction of the body with the air, and that one depends on the body's form, material, speed, as well as on the air characteristics', such as density, viscosity. 

The gravitational force is independent of any other forces: it is always proportional with the masses and inversely proportional with the square of their distance, in any environment, that is independent of any other additional forces. In fact, this is not unique to the gravity: it is the property of all fundamental forces like electromagnetic, etc.

 

Quote

[Gravity] is supposedly a universal property of all masses but can't be observed directly (e.g. gravitons).

No, in fact it can be easily observed directly, for example if you let a body fall to the ground. If you are bothered by the fact that it also interacts with the air, there are other examples in which you may observe the action of gravity only: the celestial bodies, like the Moon, Sun, planets, comets and so on. You don't need for this to observe the graviton, as you don't need the photon to observe the effects of the electromagnetic forces (besides, neither play a role if the forces are static).

Quote

galaxies spin in a way which defies the mass effect ...I know the idea of dark matter was developed to save the hypothesis, but it all feels like a bit of a fudge, albeit very cleverly done.

No, quite the contrary: the idea is very natural.

If you observe that a body doesn't move quite as it should, given the forces you know about, you will automatically assume the there should be one or more other forces which you didn't take into account. As the only force that act on galaxies is gravity, the unknown force comes from a mass one did not observe yet. It was provisionally called "dark mass", dark meaning invisible with telescopes; the visible masses are the stars, gases and dust.

For a similar reason the cosmologists assume there is a "dark energy"; that one is assumed for explaining the accelerating expansion of the Universe.

 

Edited by AlexL

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Our senses cannot perceive cosmic rays, or genes, or electrons, or ultraviolet but each of these concepts is reducible to perceptual data.

They have no direct referents on the perceptual level of awareness but each can be grasped by following a long antecedent chain of concepts that ultimately reduce to first-level concepts that can be pointed at.

Gravity is an abstract concept; not a first-level concept like a dog that can be pointed at. Abstract = farther from perceptual reality.  

 

 

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On 5/11/2016 at 10:08 PM, SpookyKitty said:

Even if you were to reduce the concept of force to perceptual particulars, that would not help the situation, because, at the end of the day, gravity is defined as nothing more than a force, but the question remains, a force of what?

Actually, that question hasn't really been answered. We know how gravity works but we still don't know why it works. That's what many of our best and brightest physicists are currently trying to answer. That's why String Theory is such a big deal.

Of course, if we knew that gravitational force was caused by subatomic energy filaments, that would leave us with the open question of where those strings came from and why they behave that way. That's just the way knowledge works.

 

On 5/11/2016 at 8:48 PM, SpookyKitty said:

An abstraction is precisely the collection of its particulars. That is, "red" is precisely the collection of all red things.

Not quite. A concept is open-ended and it consists of the type of thing it refers to, regardless of how many there are. It's an important point to bear in mind.

 

On 5/12/2016 at 11:35 AM, Nicky said:

As for the current subject, OP dialing down the mindless arrogance, and paying a little attention to people with the ability to use logic and meaningful language, is all that would be needed to settle it.

This exact question plagued me at one point, too. If "gravity" applies equally to everything then how can we ever study it? It would be axiomatic. And yet we can study it in ways that you just can't study "existence" or "identity" - but how?

 

This is exactly the sort of question that will occur to anyone who's actually trying to digest, integrate and understand what we're all reading. I don't know whether or not this accurately describes SpookyKitty and I really don't care; the question, itself, is a good one.

I emphatically agree with every other point you've made.

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The stumbling-block here is that gravity doesn't reduce to any entity, at all.

 

Imagine the motion of balls along a pool table. When one is at rest, it'll stay at rest until something happens to it. When one is rolling in a straight line, it will continue along that line until it either hits something or gradually comes to rest. When one ball directly strikes another, the resting ball is pushed down the same path and at the same speed as the rolling ball, which stops. They trade places.

So it makes sense to talk about them exchanging "force" when that happens, even though there's no such entity; it allows us to think more clearly about what the balls are doing.

 

Now, suppose you've studied this "force" thing in great detail. You know all of the different ways it's usually transferred between moving objects; you know how it works with mathematical precision and can almost predict what any given *thing* will do, under any given circumstances, but not quite. There's this funny little wobble or bounce (or something) that sometimes happens, which doesn't fit anywhere into your equations.

 

That would be the perceptual observation that allows you to discover gravity, electromagnetism, or any other kind of "force". The differentia is every other kind of motion.

 

That is what makes a number of concepts from physics difficult to fit into our theory of concepts: they aren't about any *thing*, but what anything *does*.

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5 hours ago, Harrison Danneskjold said:

You know all of the different ways it's usually transferred between moving objects; you know how it works with mathematical precision and can almost predict what any given *thing* will do, under any given circumstances, but not quite.

Force is not transferred between moving objects.  Newtons Third Law:

When one body exerts a force on a second body, the second body simultaneously exerts a force equal in magnitude and opposite in direction on the first body.

The Scholastics thought of causation in much that same way that you do. Their view goes under various names, (Physical Influx).  The view that force is transferred led to the Infinite Regress and Immovable/Prime Mover problem(s). 

The equations used in Newtonian Mechanics make no reference at all to whether Ball A strikes Ball B.  To model such an collision, you set your Horizontal and Vertical vectors for both balls (the vector's magnitudes are established by mass, acceleration, friction coefficient) and all vectors will cancel to zero.

And under the Mechanics of Relativity the notion that Ball A transfers a force to Ball B makes even less sense, and you must take into account your (the Observers) frame of reference when modeling any such event.

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22 hours ago, Nicky said:

That's a loaded question, and the premise is not true.

Correct. 

 

I do not believe that gravity is some incomprehensible, ineffable sort of magick, nor am I in the habit of advocating what I know to be false (at least not on Mondays ;) ). My only intention was to demonstrate how plausible that error might seem, particularly to a newbie. Please recall what I was responding to:

Quote

As for the current subject, OP dialing down the mindless arrogance, and paying a little attention to people with the ability to use logic and meaningful language, is all that would be needed to settle it.

My first response to that little treasure was actually not very civilized. However, just as SK's question might reflect nothing more than her not knowing any better, so might your errors (or whatever the Hell prompted that post) be innocent.

I tried to remind you of that possibility without actually explaining the fact of human fallibility. I was certain that I'd made my point clearly, coherently and dispassionately. 

Obviously, I failed.

 

 

 

I'm not going to go into my "let's play nice together" mantra, again. You've heard it all before, it's already derailed plenty of threads and I'm sick of repeating it. Instead, the next pearl I find which you've written in your usual manner, I will respond to in your usual manner.

If you truly don't understand what I find offensive about it, PM me and I'll be happy to explain it to you.

 

Otherwise, that's all I have to say about it.

Edited by Harrison Danneskjold
Clarity

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7 hours ago, Harrison Danneskjold said:

If you truly don't understand what I find offensive about it, PM me and I'll be happy to explain it to you.

I have no idea what you find offensive and why. I also don't care.

And if you keep replying to me with unintelligible nonsense, I'll just put you on ignore.

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