Fundamental source of gravity?

[TCorp]

The gravitational force between planets and stars is often depicted as curvatures in space-time but the reason why matter causes space to warp usually isn't explained. About 2 months ago I set out to visualize and write down why matter -the accumulation of particles- bends space to the extent that "large" chunks of particles (stars, planets, people,...) attract each other. I'm not sure if my way of visualizing gravity is completely correct, so I thought I'd put it to the physics forum.

I start by visualizing particles, ever so minutely pinching space towards them, simply by occupying space. The accumulation of particles in large objects (people, planets, stars) constitute an accumulation of spaces being pinched, causing these objects to attract through each other's accumulated pinches (warped space). The effect of this collective pinching is visualized on a larger scale as "gravity", the bending of space around stars, planets and galaxies.

So,...am I close?

 

[Pengwuino]

What in the world do you mean by "pinching" space?

 

[TCorp]

What in the world do you mean by "pinching" space?

I visualize a pinch very much how gravity is visualized on a larger scale. Spacing being pulled on all sides by a particle to an extent that is equivalent to its mass.

 

[ZapperZ]

The gravitational force between planets and stars is often depicted as curvatures in space-time but the reason why matter causes space to warp usually isn't explained. About 2 months ago I set out to visualize and write down why matter -the accumulation of particles- bends space to the extent that "large" chunks of particles (stars, planets, people,...) attract each other. I'm not sure if my way of visualizing gravity is completely correct, so I thought I'd put it to the physics forum.

I start by visualizing particles, ever so minutely pinching space towards them, simply by occupying space. The accumulation of particles in large objects (people, planets, stars) constitute an accumulation of spaces being pinched, causing these objects to attract through each other's accumulated pinches (warped space). The effect of this collective pinching is visualized on a larger scale as "gravity", the bending of space around stars, planets and galaxies.

So,...am I close?

You complained that physics doesn't "explain" why matter causes space to warp (which actually is wrong because matter causes spacetime to 'warp'). Yet, we can apply the same complain to your "visualization". Why would space get pinched by such particles? What causes such pinching?

I see no advantage gained by your visualization. How does this help in understanding GR? Furthermore, the description given in GR is not just "visualization", but rather contains very clear and unambiguous mathematical description. It means that GR give not just qualitative description, but also quantitative description that can be checked against measurement. Because of that, the GR's description and visualization are clearer than yours and offers more advantageous.

Zz.

 

[TCorp]

I'm not arguing against GR here. GR is great for describing interactions at certain scales and speeds. I'm just trying to get an intuitive understanding of gravity that is valid from the particle scale of interactions all the way to larger objects.

 

[ZapperZ]

I'm not arguing against GR here. GR is great for describing interactions at certain scales and speeds. I'm just trying to get an intuitive understanding of gravity that is valid from the particle scale of interactions all the way to larger objects.

Still, you didn't answer on why your visualization is any better, considering that you made a mistake on what is actually getting warped. You will note that you didn't offer any better "explanation" on why such-and-such happens, which was your original complain about GR.

Zz.

 

[TCorp]

Still, you didn't answer on why your visualization is any better, considering that you made a mistake on what is actually getting warped. You will note that you didn't offer any better "explanation" on why such-and-such happens, which was your original complain about GR.

Zz.

In the original post I wrote "pinching space towards them, simply by occupying space". I should have elaborated. What I mean isn't that different from GR's description for space-time curvatures around larger objects (planets and stars). It just attempts to describe the constituent interactions at the Planck scale that give rise to what gravity is at our scale. In this description gravitation exists only above a certain scale as a result of an accumulation of particles that occupy a volume of space. Below that scale theories like quantum gravity would be a more suitable tool for describing the interactions of objects (particles).

 

[DaveC426913]

Despite it being no better at answering the question (particles pinch/warp space: true. How do they do this?), you are essentially correct in that gravity is caused by the mass of individual particles.

Every atom warps spacetime minutely. Accumulate 10^50 atoms and you get an Earth-scale warp in spacetime.

 

[DaveC426913]

In this description gravitation exists only above a certain scale as a result of an accumulation of particles that occupy a volume of space. Below that scale theories like quantum gravity would be a more suitable tool for describing the interactions of objects (particles).

No. gravity works at any scale. Electrons create gravity. Just not a lot.

The gravity of a large body is nothing more than the cumulative gravity of its component particles.

 

[ZapperZ]

In the original post I wrote "pinching space towards them, simply by occupying space". I should have elaborated. What I mean isn't that different from GR's description for space-time curvatures around larger objects (planets and stars). It just attempts to describe the constituent interactions at the Planck scale that give rise to what gravity is at our scale. In this description gravitation exists only above a certain scale as a result of an accumulation of particles that occupy a volume of space. Below that scale theories like quantum gravity would be a more suitable tool for describing the interactions of objects (particles).

Aren't you making a rather wild speculation here? Where are the quantitative aspect of your "theory"? Can you show how you could derive the same macroscopic scale results that we know and love using your scenario?

Please note, before you go any further, of the https://www.physicsforums.com/showthread.php?t=414380" and our policy on speculative posts.

Zz.

 

[TCorp]

Despite it being no better at answering the question (particles pinch/warp space: true. How do they do this?), you are essentially correct in that gravity is caused by the mass of individual particles.

Every atom warps spacetime minutely. Accumulate 10^50 atoms and you get an Earth-scale warp in spacetime.

Uhuh...

@ZapperZ, I just read that non-mainstream posts will be deleted. Feynman would be swiftly banned.

Anyway, the question as to why matter warps space remains open and I guess won't be resolved here.

 

[DaveC426913]

Aren't you making a rather wild speculation here? Where are the quantitative aspect of your "theory"? Can you show how you could derive the same macroscopic scale results that we know and love using your scenario?

Frankly, I don't see how his ideas are not very much mirroring how it actually works.

Earth's dent in spacetime is the sum total of the dents caused by Earth's inidividual particles.
Correct.

Please note, before you go any further, of the https://www.physicsforums.com/showthread.php?t=414380" and our policy on speculative posts.

Zz.

I figure as long as he's open to corrections, he's not really making a theory so much as he is getting his head around how gravity works. He's got a model in his head of how it works; we're helping him make corrections to it till it's right. Me, I'd allow it until he starts forming convictions that are patently false.

 

[DaveC426913]

Uhuh...

@ZapperZ, I just read that non-mainstream posts will be deleted. Feynman would be swiftly banned.

Yeah yeah. You're the next Feynman/Einstein/Newton... :uhh:

Anyway, the question as to why matter warps space remains open and I guess won't be resolved here.

It is one of the big questions in physics.

The key is to build our understanding based on what we know already, not based on throwing away what we know and starting again.

Start with what we know.

 

[ZapperZ]

Uhuh...

@ZapperZ, I just read that non-mainstream posts will be deleted. Feynman would be swiftly banned.

Please don't start that! It is a very tired argument that we've debunked so many times already (read the Feedback forum). It is a common argument that crackpot uses, so don't fall into it.

Anyway, the question as to why matter warps space remains open and I guess won't be resolved here.

True, but why is your scenario any better? That's my question. Spacetime warping (not just space, thankyouverymuch!) is well-known. I don't see the advantage of your "pinching", because you don't offer an explanation on why such pinching would occur as well.

Zz.

 

[Ryan_m_b]

As far as I can see you are simply taking the artistic impressions of how mass warps spacetime and replacing the word "curve" with "pinch". I fail to see the advantage.

Current scientific understanding posits that mass warps spacetime, each individual component (atoms, subatomic particles etc) all warp spacetime a little with the cumulative effect of generating larger gravity wells. Though as I understand it even massless particles such as light also warp spacetime.

I don't think you have presented anything new here or any way to better understand, you have simply used a different word to explain an artistic representation.

 

[WannabeNewton]

I agree 169% with ryan_m_b; in the end it doesn't matter what your wording for space - time curvature is because you are going to quantify it with the Riemann curvature tensor anyways which depends only on the metric - a quantitative representation of how mass 'warps' space - time. Your description of 'pinching' concludes with some 'warping' as you yourself stated.

 

[Born2bwire]

Uhuh...

@ZapperZ, I just read that non-mainstream posts will be deleted. Feynman would be swiftly banned.

Anyway, the question as to why matter warps space remains open and I guess won't be resolved here.

How would Feynman be banned? Take his groundbreaking path integrals for example. Schroedinger quantum mechanics is based upon the Hamiltonian approach from classical mechanics. The path integral is just a logical extension of this by looking to produce quantum mechanics from the Lagrangian approach. Feynman's big break in his work on this was when Jehle alerted him to Dirac's earlier attempts at producing a quantum mechanical Lagrangian.

The point here being is you can't just come out with an idea. You have to build it off of a fundamental framework.

 

[TCorp]

I'll have to start by saying I don't know how matter bends/curves/pinches/dents space time. I have some ideas on how it might be doing it related to the effects of matter occupying space, but I couldn't find any materials online describing gravity in this way. That's why I posted here to begin with.

 

[Ryan_m_b]

I'll have to start by saying I don't know how matter bends/curves/pinches/dents space time. I have some ideas on how it might be doing it related to the effects of matter occupying space, but I couldn't find any materials online describing gravity in this way. That's why I posted here to begin with.

If you have some idea about the mechanism by which mass bends/warps/curves/pinches spacetime and you want to discuss it you should first do background research into what contemporary understanding is as well as looking for papers that support your hypothesis.

 

[TurtleMeister]

No. gravity works at any scale. Electrons create gravity. Just not a lot.

The gravity of a large body is nothing more than the cumulative gravity of its component particles.

Highlighting by me.

How do you know that Dave? Isn't that just a postulate? As far as I know, there is no experimental evidence to suggest that leptons contribute to the active gravitational mass of a macro object.

 

[Drakkith]

Highlighting by me.

How do you know that Dave? Isn't that just a postulate? As far as I know, there is no experimental evidence to suggest that leptons contribute to the active gravitational mass of a macro object.

Is there any for a proton or a neutron? Any measurements of the amount of gravity from individual atoms? I don't think so, someone correct me if I'm wrong. But because all 3 particles have mass it is acceptable to say that they do.

 

[TurtleMeister]

Highlighting by me.

How do you know that Dave? Isn't that just a postulate? As far as I know, there is no experimental evidence to suggest that leptons contribute to the active gravitational mass of a macro object.

Is there any for a proton or a neutron? Any measurements of the amount of gravity from individual atoms? I don't think so, someone correct me if I'm wrong. But because all 3 particles have mass it is acceptable to say that they do.

Since it is experimentally known that leptons and baryons have inertial mass, it is postulated by the equivalence principle that they also have active gravitational mass. But the experimental evidence for this is very weak.

Laboratory experiments envolving active gravitational mass are almost non existant. The most recent, and the only one that I know of, was the Kreuzer experiment of 1966. I've posted about this many times at PF. I would love to see more experiments in this area.

 

[ZapperZ]

Since it is experimentally known that leptons and baryons have inertial mass, it is postulated by the equivalence principle that they also have active gravitational mass. But the experimental evidence for this is very weak.

Laboratory experiments envolving active gravitational mass are almost non existant. The most recent, and the only one that I know of, was the Kreuzer experiment of 1966. I've posted about this many times at PF. I would love to see more experiments in this area.

You must have missed the neutron drop experiment where they detected the quantized effect of gravity. See this:

http://physicsworld.com/cws/article/news/3525

Zz.

 

[ZapperZ]

Is there any for a proton or a neutron? Any measurements of the amount of gravity from individual atoms? I don't think so, someone correct me if I'm wrong. But because all 3 particles have mass it is acceptable to say that they do.

http://physicsworld.com/cws/article/news/2981

Zz.

 

[Drakkith]

Zapper, do either of those deal with gravity acting FROM those particles and not ON them? I didn't see anything for that.

 

[Vanadium 50]

Zapper, do either of those deal with gravity acting FROM those particles and not ON them? I didn't see anything for that.

The conservation of momentum says that they are equal. We also know from Eotvos-type experiments that the gravity from aggregates of neutrons is the same as for aggregates of protons and electrons. If the question is where we have instruments sensitive enough to see the gravitational field from a single atom, the answer is "no".

 

[Drakkith]

I agree Vanadium, but I don't know if TurtleMeister will.

 

[TurtleMeister]

The conservation of momentum says that they are equal. We also know from Eotvos-type experiments that the gravity from aggregates of neutrons is the same as for aggregates of protons and electrons. If the question is where we have instruments sensitive enough to see the gravitational field from a single atom, the answer is "no".

I agree Vanadium, but I don't know if TurtleMeister will.

No, I do not agree. The Eotvos experiments, along with most all of the gravitational experiments from Newton's pendulum experiments to STEP, deal with passive gravitational mass. They deal with how different compositions of matter respond in a gravitational field generated by another source.

The experiments that I am interested in are the ones that test how different compositions of matter generate a gravitational field. In other words, I want the source to be the test mass. For example, take two objects of the same inertial mass but composed of different elements. Will they generate the same strength gravitational field? If you know of any experiments of this type, other than the Kreuzer experiment, I would be very interested to know about it. And please read the Kreuzer experiment before responding. Especially the section titled "II Theory". You can read it http://books.google.com/books?id=3U..."gravitational constant" composition&f=false".

 

[Drakkith]

So do you agree or disagree that electrons have active gravitational mass?

 

[TurtleMeister]

So do you agree or disagree that electrons have active gravitational mass?

Well, I don't know, and no one else knows. The experiment that I'm talking about could possibly help determine the answer to that question.

 

[Drakkith]

Alright.

 

[Antiphon]

I don't think the OP got a fair hearing. Pinch is maybe a bit too loose in terminology. Let's try to read his mind.

If I might speak for his notion, GR says that a stress-energy tensor is the source of gravity. Traditionally you'd lump in there all forms of energy including rest masses of particles, electric field stresses, etc. Yes, even the electron is a source of gravity in GR, with m0c^2 in the T00 term and it's electric field in the EM tensor, nonzero at least along the diagonal in a rest frame I think.

Now *if* you postulated that space-time had a certain energy density and *if* you assumed that the particle masses and EM energy densities had their origin in this same energy density (Higgs?) and *if* space-time were an elastic medium such that concentrating some of it ("pinching") meant straining it near the pinch in accord with the Einstein equation, *then* maybe the pinch model might be onto something. I think maybe one of these assumption has a case. Most are not going to hold any water.

At best it's a nice mental extension of the overused rubber sheet analogy. I like it but I don't think it works.

 

[TurtleMeister]

I hope my posts did not come off as disrespectful. I appreciate the link Zapper, and the input from you Vanadium. My communications skills are not the best. My girlfriend even thinks I'm mildly autistic. Anyway, if anyone reading this happens to come across anything related to what I posted in post #28, please feel free to send me a pm. Also, I did not mean to hijack the thread. I think what I brought up is very much related to the OP "Fundamental source of gravity", just not in the GR conceptualization.