Does gravity have mass?

[inocente]

I think you have the wrong idea of a nature or essence ( or substance ). The nature or essence cannot be seen. What is seen is material structure ( external and interior ), behavior, powers, etc. The nature of an elephant is known by the latter notes from which they flow, it is their sourse. The nature is inerior to everything else. The behavior and powers of a substance are not and cannot be determined by the interior cells, atoms, etc. because they are clearly organized for a different purpose in every substance in which they exist. In some substances they give rise to horses, in others cows, in others trees, etc. So there must be an organizing factor, a controlling factor which directs the same cells, atoms, etc to form a different type of substance. This controlling factor Aristotle calls a nature/essence/substance. " Horseness " is the nature or controlling factor of a horse. Human nature is the controlling factor of man.

Sorry but this is alien to modern science. First, nothing in nature is capable of assigning purpose. We might interpret something as having or giving a purpose, but that’s metaphysics or theology, not science (no experiment can test whether we’re correct).

Then, even philosophers disagree on what “substance” and “essence” mean and whether they exist, (e.g. see here). Science can’t be based on such flimsy ideas.

I think “substance” is only used by chemists (as a shorthand for “an element or compound”) and “essence” to mean an essential oil (an oil with a distinctive smell).

We might loosely talk about human nature or horsy nature, but horse is a species of animal, and all three underlined words are human classifications, so they only tell us about how humans divide up the the world, and talking that way isn’t useful if we’re interested in the world as it really is.

 

[inocente]

The notion of natures as understood by Aristotle is just as valid today as it was in Aristotle’s day. Nobody denies that things have natures such as human beings, lions, tigers, oak trees, or elements. Although Aristotle thought that natures apply more to living things, it can be used in a wide sense to apply to inanimate things. The nature of something is simply the essence of something which is equivalent to the definition of a thing.
Aristotle held that material substances are composed of two essential principles, i.e., form and matter. It is the form of things that determines the nature or essence of things while the matter is what individuates things. For example, the element of carbon would have the form of carbon while its matter is composed of a certain number of protons, nuetrons, and electrons. The union of form and matter is what makes up a substance. Carbon has other qualities or properties as well which are derived from the form or matter of carbon and which are called accidents such as what science calls electrical charges or electromagnatism, strong and weak forces, and gravity. Protons, neutrons, and electrons are not the substance of carbon per se, but its proper quantitative accident for quantity, which is the first accident of a material substance, extends matter into parts and three dimensional space.

Please see post #139 above on natures, substances and essences. Unless you can think of an experiment which shows that they exist in an objective sense, I can’t see any use for the notions in science.

Dividing up the world into matter and form doesn’t seem to serve any explanatory purpose. How could you test that the world is really like that? Is a photon matter? What is a photon’s form? Is a neutron matter or is it the form of three quarks?

Then, for instance, charge would seem to me to not be an accidental property - unless charge-less electrons exist it’s an essential property. But again, is there any use for this way of thinking, does it tell us anything? It just seems to be an attempt to graft on that method of analysis to make it sound scientific, but all it does is add unnecessary complication.

There is of course a hypothesis which says there is no matter and everything is form, but it’s only science if it can be tested.

(Please Note: This uploaded content is no longer available.)
xkcd.com/171/

 

[inocente]

Hecd2 has rejected my explanation of the bending of light near a gravitational mass …]

I think everything in your post has already been covered on this thread, so it may not help to go over it again.

hecd2 might like to debate whether your ideas are better than Einstein’s, but I’d suggest there’s no point until after you’ve tested them against the same one hundred years’ of empirical evidence which tested Einstein’s theory. He passed with flying colors, including all the stuff you don’t like. Good luck testing!

 

[hecd2]

First, to say, " I reject a physical theory (GR) which predicts everything that we can currently observe about gravity and the nature of spacetime in favour of one (Newtonian mechanics) which demonstrably fails to predict some observations correctly and which is therefore a less accurate description of reality " is not my position at all

Indeed it is your position - the theory is a description of reality. By rejecting the foundation of GR which is that spacetime curvature is what gives rise to gravitational effects, you are de facto rejecting the theory in favour of one in which space is universally Euclidean and which makes poorer predictions - ie is a less accurate description of reality.

As regards the theory of ( GR ) I make no more judgment than scientists make, it seems to work. So I do not reject the theory, I reject its interpretation - that space and time curve and that photons have no mass.

Since GR is based on the concept that spacetime is curved by the presence of mass-energy, your claim that you accept the theory but reject its interprtetation is a distinction without a difference.

Hecd2 has made a is a value judgment without merit. Are we to think then that the " bending of space, the bending of time " are applicable only to light?

Of course not - why would we think that? The Einstein field equations which embody the concept of spacetime curvature predict everything that Newtonian mechanics and Special Relativity predicted and more - so is more accurate under certain conditions and this applies to all bodies.

But if it applies to all objects in space, then it would seem that every solar system would have its own pecular system of curved space and time. Would this mean that all curved space-time is purely local?

Exactly so, spacetime is locally curved by the influence of all massive bodies in the universe, but the influence of nearby bodies is greatest. The curvature varies from place to place.

As Lord Whimsy might say, " Very odd indeed. "

What Lord Whimsy says or thinks about this is entirely irrelevant to whether it is so or not.

And wouldn’t there be, somewhere in the universe, conflicting paths of this curved space-time, as between solar systems or between galaxies?

I don’t know what you mean by paths, but GR predicts that far away from massive bodies spacetime tends to the average geometry of the Universe, which has been measured to be flat or nearly so.

Under Hecd2’s explanation, we would have to discard the notion that gravitational bodies, such as any object larger than a photon, are governed not by the attraction and repelling of gravitaty but by the bending of space-time!!

It’s not my explanation but that of General Relativity. But the curvature of spacetime is an explanation (which is correct as far as it has been measured) for why we observe the attraction of gravity (gravity doesn’t repel).

It is more consistent with the nature of things to recognize that we can have a mathematical formula which gives the correct outcome but does not reflect the nature of things.

Only if you insist that your preconceived intuition is right in the face of contrary evidence.

So it is more logical to say that nature always remains the same, irregardless of a particular mathematical formula, that space does not bend and that time does not bend and that photons have mass like every other body in space, and that the mass of photons is overcome by the gravitational mass of other greater gravitational masses?

No, and the idea that one mass is “overcome” by another is bizarrely wrong, even according to Newton.

Furthermore, are space and time real substances like a stick or a fishing rod that can bend?

The foundational idea of GR is that space is a three dimensional manifold (like a sphere is a two dimensional manifold), which can be flat (locally parallel lines are always the same distance apart and the sum of the angles of a triangle add up to 180 degrees and so on), or not flat (locally parallel lines can meet or diverge, angles of a triangle are more or less than 180 degrees etc, as they are on a sphere in the two dimesnsional example) and that the curvature of spacetime is determined by the presence of mass-energy.

And did Einstein actually say that space curves and that time curves? If it wasn’t him, who first made that philosophical interpretation?

It’s not a philosphical interpretation - it’s built into the foundation of the theory in the Einstein Field Equations which is where he said it first.

 

[hecd2]

The notion of natures as understood by Aristotle is just as valid today as it was in Aristotle’s day. Nobody denies that things have natures such as human beings, lions, tigers, oak trees, or elements. Although Aristotle thought that natures apply more to living things, it can be used in a wide sense to apply to inanimate things. The nature of something is simply the essence of something which is equivalent to the definition of a thing.
Aristotle held that material substances are composed of two essential principles, i.e., form and matter. It is the form of things that determines the nature or essence of things while the matter is what individuates things. For example, the element of carbon would have the form of carbon while its matter is composed of a certain number of protons, nuetrons, and electrons. The union of form and matter is what makes up a substance. Carbon has other qualities or properties as well which are derived from the form or matter of carbon and which are called accidents such as what science calls electrical charges or electromagnatism, strong and weak forces, and gravity. Protons, neutrons, and electrons are not the substance of carbon per se, but its proper quantitative accident for quantity, which is the first accident of a material substance, extends matter into parts and three dimensional space.

I think that this sort of description of the natural world has no explanatory power at best and is actually misleading at worst.

For example to say that the essence of a lion is its lionness doesn’t tell me a single thing about lions and moreover falls into the fallacy that classification is somehow absolute, rather than being a human construct that depends on culture. Where the classification is obvious it might seem to be absolute but by looking at cases where the classification is less obvious it becomes clear that it is not. Two examples: lions and tigers are quite closely related and at some tiime, not so long ago, had a common ancestor. At what point, as we go back generation by generation does a lion cease to be a lion and become something else (the answer to this, by the way, is complex, and depends on your definition of what you mean by lion). Second example: until the 20th century fish, dolphins and other marine mammals were regarded as fish - in fact living whalers call them fish. Are they fish? Depends on how you define fish, and for what purpose (or porpoise ).

But your example of carbon shows how the concepts can actually be misleading. You say that the form of carbon is carbon, and the matter is protons, neutrons and electrons and that attributes like fundamental forces are accidents which proceed from its form. I would say that you have this almost exactly back to front. Carbon is defined by the number of protons in its nucleus and its form is a consequence of what the fundamental forces cause in terms of, for example, the energies of the electrons in the carbon atom, which in turn give rise to its thermal and electrical conductivity, its magnetism, its density, its melting point, etc etc. But what is more, the element carbon has three distinct naturally occurring forms at room temperature: amorphous carbon, graphite and diamond which have radically different physical properties and the reason why the forms are so different is well known - and yet all of these forms are carbon. In fact there are several orther exotic forms of carbon such as fullerenes. It is almost certain that Aristotle would have regarded diamond and graphite as fundamentally different in nature, but a physicist would not.

 

[Linusthe2nd]

Sorry but this is alien to modern science. First, nothing in nature is capable of assigning purpose. We might interpret something as having or giving a purpose, but that’s metaphysics or theology, not science (no experiment can test whether we’re correct).

I didn’t mention purpose, would you like me to? You surely are not suggesting that only science can make a positive statement about something, a statement that is true. That would certainly reduce Faith based on Divine Revelation to mere superstition or mythology.

Then, even philosophers disagree on what “substance” and “essence” mean and whether they exist, (e.g. see here). Science can’t be based on such flimsy ideas.

In the case of Aristotle and Thomas Aquinas, the meaning can be gleaned from the context in which thay occur. Both speak of first substance and second substance, with first substance being the thing you see, touch, etc. and second substance being the underlying reality which makes a thing to be what it is and that makes it to exist…

I think “substance” is only used by chemists (as a shorthand for “an element or compound”) and “essence” to mean an essential oil (an oil with a distinctive smell).

That may be true. But they assume that an underlying, organizing factor or nature exists. Without this underlying, organizing factor or nature science would be impossible, human life would be impossible.

We might loosely talk about human nature or horsy nature, but horse is a species of animal, and all three underlined words are human classifications, so they only tell us about how humans divide up the the world, and talking that way isn’t useful if we’re interested in the world as it really is.

You surely aren’t suggesting that everything that exists is simply a conglomerate of freely floating atoms, electrons, etc. There must be an organizing factor and this is what Aristotle calls a nature. It is the reason a horse is different from a rose bush. And I will point out that science texts, at least in my youth, did speak about human nature - at least the ones I used. Of course I went to Catholic schools all the way.

And this is precisely the way the world is. You can neglect it of course or even reject it.

" And God said, ’ Let us make man in our image and likeness. ’ " In other words, man is not a simple conglomerate of freely floating atoms, electrons, etc. That image God made in us is our organizing factor, our substantial form, which in union with our bodies is our human nature.

Linus2nd

 

[hecd2]

The behavior and powers of a substance are not and cannot be determined by the interior cells, atoms, etc. because they are clearly organized for a different purpose in every substance in which they exist. In some substances they give rise to horses, in others cows, in others trees, etc. So there must be an organizing factor, a controlling factor which directs the same cells, atoms, etc to form a different type of substance. This controlling factor Aristotle calls a nature/essence/substance.

I think we call it DNA.

" Horseness " is the nature or controlling factor of a horse. Human nature is the controlling factor of man.

And what explanatory power could the statement “The nature/essence/substance of a horse is horseness” ever possibly have.

 

[Linusthe2nd]

I think everything in your post has already been covered on this thread, so it may not help to go over it again.

hecd2 might like to debate whether your ideas are better than Einstein’s, but I’d suggest there’s no point until after you’ve tested them against the same one hundred years’ of empirical evidence which tested Einstein’s theory. He passed with flying colors, including all the stuff you don’t like. Good luck testing!

Come now, I never said my ideas were better than Einstein’s. I’m looking at the thing from a different point of view.

I’m not worried, man has lived for billions of years on my view of things.

Linus2nd

 

[Linusthe2nd]

Indeed it is your position - the theory is a description of reality. By rejecting the foundation of GR which is that spacetime curvature is what gives rise to gravitational effects, you are de facto rejecting the theory in favour of one in which space is universally Euclidean and which makes poorer predictions - ie is a less accurate description of reality.
Since GR is based on the concept that spacetime is curved by the presence of mass-energy, your claim that you accept the theory but reject its interprtetation is a distinction without a difference.
Of course not - why would we think that? The Einstein field equations which embody the concept of spacetime curvature predict everything that Newtonian mechanics and Special Relativity predicted and more - so is more accurate under certain conditions and this applies to all bodies.Exactly so, spacetime is locally curved by the influence of all massive bodies in the universe, but the influence of nearby bodies is greatest. The curvature varies from place to place. What Lord Whimsy says or thinks about this is entirely irrelevant to whether it is so or not. I don’t know what you mean by paths, but GR predicts that far away from massive bodies spacetime tends to the average geometry of the Universe, which has been measured to be flat or nearly so.

I mean it is difficult to see how we can isolate the curved space-time between systems and they must logically conflict with one another to some degree. After all, light travels clear accross the universe, so it is unreasonable to suppose that the space-time curvature of one system is completely isolated from that of another.

It’s not my explanation but that of General Relativity. But the curvature of spacetime is an explanation (which is correct as far as it has been measured) for why we observe the attraction of gravity (gravity doesn’t repel).

So you do admit that gravity attracts? Good, but then why posit a curving space-time? Are you saying that the gravity mass of a smaller body does offer an opposing force to the gravity mass of a larger body?

Only if you insist that your preconceived intuition is right in the face of contrary evidence.

I don’t think the interpretation offered by science is compelling. Points on a four dimensional graph do not represent reality in a three dimensional world.

No, and the idea that one mass is “overcome” by another is bizarrely wrong, even according to Newton.

I have just explained why I don’t think that is ture.

The foundational idea of GR is that space is a three dimensional manifold (like a sphere is a two dimensional manifold), which can be flat (locally parallel lines are always the same distance apart and the sum of the angles of a triangle add up to 180 degrees and so on), or not flat (locally parallel lines can meet or diverge, angles of a triangle are more or less than 180 degrees etc, as they are on a sphere in the two dimesnsional example) and that the curvature of spacetime is determined by the presence of mass-energy.
It’s not a philosphical interpretation - it’s built into the foundation of the theory in the Einstein Field Equations which is where he said it first.

Don’t we live in a three dimensional world?

---

And I heartily reject your conclusions here. At the time of Newton it was assumed that his laws reflected the nature of things ( though that was not universally held). Now comes along Einstien and it is assumed that his theories reflect the nature of things. And of course the next theory that comes along will be said to reflect the nature of things. So it would seem that the nature of things is always changing - a very strange state of affairs.

And you did not answer these important questions:

Furthermore, are space and time real substances like a stick or a fishing rod that can bend? I don’t see how they can be regarded as actually existing things. Show me an object you call space, another that you call time. Put them under a microscope, or show them to me on an oscilloscope.

And did Einstein actually say that space curves and that time curves? If it wasn’t him, who first made that philosophical interpretation?

Linus2nd

 

[Linusthe2nd]

I think we call it DNA.

Exactly. But why is the DNA of one living thing different from that of another? The fact that they are different suggests an organizing factor that accounts for the different DNA structure in each. And this organizing factor is the different nature of each. And what would you point to as the organizing factor in inanimate things? It certainly couldn’t be DNA.

And what explanatory power could the statement “The nature/essence/substance of a horse is horseness” ever possibly have.

Of course you would have to explain what was meant by nature first of all and go on from there as I have to some extent. Once a person understands what nature means, he should see that it explains the differences that exist between genuses and between species and how it explains the differences between individuals even.

Linus2nd

 

[inocente]

I didn’t mention purpose, would you like me to?

You did, and I quoted where you did:

IThe nature is inerior to everything else. The behavior and powers of a substance are not and cannot be determined by the interior cells, atoms, etc. because they are clearly organized for a different purpose in every substance in which they exist. In some substances they give rise to horses, in others cows, in others trees, etc.

You surely are not suggesting that only science can make a positive statement about something, a statement that is true. That would certainly reduce Faith based on Divine Revelation to mere superstition or mythology.

Don’t know where you got that from in what I said.

In the case of Aristotle and Thomas Aquinas, the meaning can be gleaned from the context in which thay occur. Both speak of first substance and second substance, with first substance being the thing you see, touch, etc. and second substance being the underlying reality which makes a thing to be what it is and that makes it to exist…

Fine but that hypothesizes that there is an underlying reality which makes a thing to be what it is and which makes it to exist. Which isn’t testable, so it’s unscientific. You can believe it if you like, you can debate round the campfire long into the night, but it’s metaphysics, not science.

That may be true. But they assume that an underlying, organizing factor or nature exists. Without this underlying, organizing factor or nature science would be impossible, human life would be impossible.

Organizing implies an organizer, so that’s theology, or at the least it’s anthropomorphizing.

*You surely aren’t suggesting that everything that exists is simply a conglomerate of freely floating atoms, electrons, etc. There must be an organizing factor and this is what Aristotle calls a nature. It is the reason a horse is different from a rose bush. And I will point out that science texts, at least in my youth, did speak about human nature - at least the ones I used. Of course I went to Catholic schools all the way.

And this is precisely the way the world is. You can neglect it of course or even reject it.

" And God said, ’ Let us make man in our image and likeness. ’ " In other words, man is not a simple conglomerate of freely floating atoms, electrons, etc. That image God made in us is our organizing factor, our substantial form, which in union with our bodies is our human nature.*

But you can’t test God, so that’s not science, it’s theology. I said we might loosely talk of human nature, meaning the collection of traits which all humans share, but in science we wouldn’t mean that it’s intended or designed, it’s just a system we invented for classifying and categorizing. These natures of which you speak don’t exist outside of some books.

 

[inocente]

Come now, I never said my ideas were better than Einstein’s. I’m looking at the thing from a different point of view.

I’m saying that unless your ideas stack up against the evidence, logically they must be wrong.

I’m not worried, man has lived for billions of years on my view of things.

You seem to specialize in beliefs unique to yourself.

 

[hecd2]

Exactly. But why is the DNA of one living thing different from that of another? The fact that they are different suggests an organizing factor that accounts for the different DNA structure in each.

The DNA is different in different living things because of that subject of which we may not speak on this forum - let’s just say descent with modification, recombination and random disjunction in anaphase…And this organizing factor is the different nature of each.

And what would you point to as the organizing factor in inanimate things? It certainly couldn’t be DNA.

Physics and chemistry generally. So, to take rocks as an example, they are classified according to their physical formation, their chemical constituents and their chemical annd physical history. I see no reason to posit any other metaphysical “organising principle”.

Of course you would have to explain what was meant by nature first of all and go on from there as I have to some extent.

Have you? I haven’t seen you suggest any concept around nature or essence or substance that explains anything at all. These concepts, as you describe them, add absolutely nothing to our understanding.

Once a person understands what nature means, he should see that it explains the differences that exist between genuses and between species and how it explains the differences between individuals even.

Really? How does it do that then? To take a very broad inanimate example, how does “nature” as you understand it, explain the difference between igneous and metamorphic rocks. For example. Or to take a biological example, how does it explain the difference between a Cox’s Orange Pippin and a Bramley. Can you even define what species means?

Linus2nd

 

[hecd2]

I mean it is difficult to see how we can isolate the curved space-time between systems and they must logically conflict with one another to some degree. After all, light travels clear accross the universe, so it is unreasonable to suppose that the space-time curvature of one system is completely isolated from that of another.

I haven’t the slightest idea why you think they need to be isolated. Curvature varies continously from point to point across space according to the conditions pertaining at each point as described by the Einstein field equations. You are arguing against General Relativity without even understanding a layman’s description of it in words. You can’t be credible arguing against a theory that you don’t understand.

So you do admit that gravity attracts? Good, but then why posit a curving space-time?

Because physics is a quantitative science. Just saying that gravity attracts doesn’t even get you as far as Newton. Curvature of spacetime was posited becuase Newtonian gravity in Euclidean did not correspond to experiment - it didn’t predict the rihght answer - nearly but not quite. Einstein proposed that gravitational effects are caused by spacetime curvature because he needed a theory in which accceleration and gravitation are unified, and the specific theory he came up with fits experimental results exactly. In a way that flat space and Newtonian theory does not. That’s why.

Are you saying that the gravity mass of a smaller body does offer an opposing force to the gravity mass of a larger body?

I’m not saying that because that statement is incoherent.

I don’t think the interpretation offered by science is compelling.

I know you’ve said that many times. But nature does not care what you think or what you like.

…the idea that one mass is “overcome” by another is bizarrely wrong, even according to Newton.

I have just explained why I don’t think that is ture.

I don’t think you have because there isn’t a physical theory of gravitation in existence that posits that one mass is overcome by another

Don’t we live in a three dimensional world?

Yes, and…?

And I heartily reject your conclusions here.

Yes, but you can’t tell me why you do rationally or logically because my conclusions (that of GR actually) fits the observed world better than your preferred model.

At the time of Newton it was assumed that his laws reflected the nature of things ( though that was not universally held). Now comes along Einstien and it is assumed that his theories reflect the nature of things. And of course the next theory that comes along will be said to reflect the nature of things. So it would seem that the nature of things is always changing - a very strange state of affairs.

I think you know that it is our understanding of nature that is changing (and improving) not nature itself. By they way it is not assumed that Einstein’s theories closely reflect reality - science doesn’t assume these things - we think GR is good theory because we demonstrate that it correctly predicts reality.

And you did not answer these important questions:

Furthermore, are space and time real substances like a stick or a fishing rod that can bend?

I explained what scientists mean by curvature of space. If you choose not understand it or accept it, nature still doesn’t care - it just goes on doing what it does.

I don’t see how they can be regarded as actually existing things.

I don’t see hoyw your personal incredulity is evidence for anything or carrioes any weight in this or any other debate.

And did Einstein actually say that space curves and that time curves?

And I replied to that directly - but to make it even more concise, yes.

Now we’ve been rouind the houses twice and I don’t see any prospect o our views getting any closer so perhaps it’s time to say adios and have a good weekend.

 

[Linusthe2nd]

I haven’t the slightest idea why you think they need to be isolated. Curvature varies continously from point to point across space according to the conditions pertaining at each point as described by the Einstein field equations. You are arguing against General Relativity without even understanding a layman’s description of it in words. You can’t be credible arguing against a theory that you don’t understand.
Because physics is a quantitative science. Just saying that gravity attracts doesn’t even get you as far as Newton. Curvature of spacetime was posited becuase Newtonian gravity in Euclidean did not correspond to experiment - it didn’t predict the rihght answer - nearly but not quite. Einstein proposed that gravitational effects are caused by spacetime curvature because he needed a theory in which accceleration and gravitation are unified, and the specific theory he came up with fits experimental results exactly. In a way that flat space and Newtonian theory does not. That’s why. I’m not saying that because that statement is incoherent.
I know you’ve said that many times. But nature does not care what you think or what you like.
I don’t think you have because there isn’t a physical theory of gravitation in existence that posits that one mass is overcome by another
Yes, and…?
Yes, but you can’t tell me why you do rationally or logically because my conclusions (that of GR actually) fits the observed world better than your preferred model. I think you know that it is our understanding of nature that is changing (and improving) not nature itself. By they way it is not assumed that Einstein’s theories closely reflect reality - science doesn’t assume these things - we think GR is good theory because we demonstrate that it correctly predicts reality.

I explained what scientists mean by curvature of space. If you choose not understand it or accept it, nature still doesn’t care - it just goes on doing what it does. I don’t see hoyw your personal incredulity is evidence for anything or carrioes any weight in this or any other debate.
And I replied to that directly - but to make it even more concise, yes.

Now we’ve been rouind the houses twice and I don’t see any prospect o our views getting any closer so perhaps it’s time to say adios and have a good weekend.

No, I doubt we will arrive at a rapprochement’. Nevertheless, I have made a good case for the reader to consider.

Pax
Linus2nd

 

[Linusthe2nd]

The DNA is different in different living things because of that subject of which we may not speak on this forum - let’s just say descent with modification, recombination and random disjunction in anaphase…And this organizing factor is the different nature of each. Physics and chemistry generally. So, to take rocks as an example, they are classified according to their physical formation, their chemical constituents and their chemical annd physical history. I see no reason to posit any other metaphysical “organising principle”.
Have you? I haven’t seen you suggest any concept around nature or essence or substance that explains anything at all. These concepts, as you describe them, add absolutely nothing to our understanding. Really? How does it do that then? To take a very broad inanimate example, how does “nature” as you understand it, explain the difference between igneous and metamorphic rocks. For example. Or to take a biological example, how does it explain the difference between a Cox’s Orange Pippin and a Bramley. Can you even define what species means?

Linus2nd

I don’t think its worth commenting here. I have made my case and its validity doesn’t depend on anyone’s opinion. It is simply for people to consider. I’m not looking for standing any where, I am looking for the truth of things or as Aristotle would say the true cause of all things in the metaphysical sense.

Linus2nd.

 

[Linusthe2nd]

You did, and I quoted where you did:

Your point, sorry.

Don’t know where you got that from in what I said.

Form statements like this from the same post: " Fine but that hypothesizes that there is an underlying reality which makes a thing to be what it is and which makes it to exist. Which isn’t testable, so it’s unscientific. You can believe it if you like, you can debate round the campfire long into the night, but it’s metaphysics, not science. "

So according to your view there is no objective truth unless it has passed the gauntlet of scientific verification. Is that not empiricism, which would exclude all philosophical and Divine truth? It is a view I do not share.

Fine but that hypothesizes that there is an underlying reality which makes a thing to be what it is and which makes it to exist. Which isn’t testable, so it’s unscientific. You can believe it if you like, you can debate round the campfire long into the night, but it’s metaphysics, not science.

You just stubbed your toe. You are affirming the very thing you just denied.

Organizing implies an organizer, so that’s theology, or at the least it’s anthropomorphizing

No, it is philosophy. And it points to the importance of philosophy.

But you can’t test God, so that’s not science, it’s theology.

So belief in God is not credible?

I said we might loosely talk of human nature, meaning the collection of traits which all humans share, but in science we wouldn’t mean that it’s intended or designed,

But science takes it for granted, it is assumed. And of course it implies the existence of a Being who creates each nature or essence, which is " designed " to carry out the tasks of its creator.

… it’s just a system we invented for classifying and categorizing. These natures of which you speak don’t exist outside of some books.

Again, you are expressing an attitude of scientism which you have just deined above.

Linus2nd

 

[Linusthe2nd]

I’m saying that unless your ideas stack up against the evidence, logically they must be wrong.

Again you are pleading scientism. You faith is at risk if that is true.

You seem to specialize in beliefs unique to yourself.

How could that be, billions of people have agreed with me ?

Linus2nd

 

[Richca]

Please see post #139 above on natures, substances and essences. Unless you can think of an experiment which shows that they exist in an objective sense, I can’t see any use for the notions in science.

Dividing up the world into matter and form doesn’t seem to serve any explanatory purpose. How could you test that the world is really like that? Is a photon matter? What is a photon’s form? Is a neutron matter or is it the form of three quarks?

Then, for instance, charge would seem to me to not be an accidental property - unless charge-less electrons exist it’s an essential property. But again, is there any use for this way of thinking, does it tell us anything? It just seems to be an attempt to graft on that method of analysis to make it sound scientific, but all it does is add unnecessary complication.

There is of course a hypothesis which says there is no matter and everything is form, but it’s only science if it can be tested.

http://imgs.xkcd.com/comics/string_theory.png
xkcd.com/171/

All one has to do is look at the external world around him/her to know that substances and natures or essences are real. A substance in its primary meaning is an individual existing thing. Now it is obvious to our sense experience that there are individual existing things in the world. It is also obvious to our sense experience that these substances are of a certain kind or nature such as human beings, dogs, trees, gold or what have you. The form answers the question what is it? The matter is what makes a thing be this dog Lassie, for example, and not some other dog and of course, the matter is the material constituent of the dog.

In my view, to know that a particular substance is a dog, for example, has more explanatory value then to say that it is a conglomeration of protons, neutrons, electrons and quarks, etc. which hardly explains the dog.

Is a photon matter? Well, according to the Wikipedia article, it is an elementary particle so maybe it is made out of matter, though supposedly, it possesses wave and particle like properties. I don’t think light is a substance though, rather it is a qualitative accident of a substance such as the sun or of substances such as helium or hydrogen and their fission or fusion. It is caused by a light source. A photon’s form is photon.

If we speak of neutrons as particles of elementary atoms, then neutrons are accidental forms composed of matter for they exist in the substantial forms of the elements such as carbon. If neutrons can be further divided into quarks, then these quarks are also accidental forms of the substantial forms of the elements.

The explanatory value of a philosophical system such as St Thomas Aquinas, who drew much from Aristotle and some from Plato and other philosphers as well, is that we can arrive at an ultimate explanation and cause of the universe which of course is God. The natural sciences have no such system or explanatory value nor can they because they study only some part or aspect of reality, not the totality of reality.

 

[inocente]

I mean it is difficult to see how we can isolate the curved space-time between systems and they must logically conflict with one another to some degree. After all, light travels clear accross the universe, so it is unreasonable to suppose that the space-time curvature of one system is completely isolated from that of another.

Whoa! That book you have must not be much good at all.

We can’t picture four dimensions, so the standard teaching aid is a big rubber sheet stretched out like a table, with weights placed on it representing planets or stars. They distort the sheet forming “gravity wells”. It’s interesting how many things it can demonstrate.

Here’s a teacher showing other teachers what students can learn from this: youtube.com/watch?v=MTY1Kje0yLg

Jim - this is a really good demo.