What is Gravity?

[floersh]

You know I have heard so many explanatios of gravity but most are meerly descriptions of its effects. I've heard people talk about space time and how it is warped by massive objects. But no one can explain how or why massive (aka matter) warps space time or what space time is if it can be warped.

 

Given how much science has explained and how much we know it seems a bit rediculous that we know so little about what actually causes gravity.

 

Gravity is relative to mass. Great how? Why do more massive objects exert more gravitational force? Because it bends space time more? Ok How does it bend space time more? What is space time if it can be bent and what does mass have to do with it?

[ajb]

Go read a book on general relativity. You will have to do some work and not rely on others to just explain it all.

[floersh]

Go read a book on general relativity. You will have to do some work and not rely on others to just explain it all.

 

I've read general relativity and special relativity and I can say without question that man kind has no idea what causes gravity.. And neither of those theories even touch on what causes it. Beyond making some blanket statement about how mass bends space time and creates gravity wells.

 

Like I said before. Great. How does it bend space time and what is space time if it can bend. General relativity doesn't eloborate on that.

 

Now I have read a number of proposed theories that seem to suggest that gravity and inertia are both a product of Zero Point Energy. Of course general and special relativity don't touch on this. And as far as I know none of these ZPE theories have any real experimental evidence to support them.. I could be wrong on that..

[ajb]

General relativity tells you exactly how space-time is curved via the Einstein field equations. Energy-momentum couples to curvature.

 

If you mean "why" then I cannot answer that.

[floersh]

General relativity tells you exactly how space-time is curved via the Einstein field equations. Energy-momentum couples to curvature.

 

If you mean "why" then I cannot answer that.

 

Exactly. General relativity does not explain why. Not in the sense that other theories explain eletromagnatism as an example..

 

I have found this and am unsure how connected it really is to mainstream science. But I found it interesting..

 

http://www.arxiv.org/PS_cache/gr-qc/pdf/0504/0504061v3.pdf

 

Whether or not it is real science it does give you an idea of what I mean when I say how/why..

[ajb]

Do Maxwell' s equation explain "why" electrons are charged and that they interact electromagnetically?

 

It is an observed fact. Maxwell's equations tell you how in the sense that you can calculate observable effects.

 

You will have to explain more by your meaning of "why".

 

I will have a look at the paper you suggest.

[floersh]

Well I found a link from this research to the DOE.. Not that it means it is accepted theory but at least its not totally fringe..

 

http://www.osti.gov/energycitations/product.biblio.jsp?osti_id=5200267

 

Here is another article that I assume is the predecessor to the above article

 

http://arxiv.org/PS_cache/physics/pdf/9807/9807023v2.pdf

 

It comes from the same site but details the connection between ZPF and Inertia..

[Severian]

Science can never answer the question 'why'. It just answers 'how'. We can only ever contruct theories that describe how the universe works, but to say 'why' it is like that is philosophy, not science.

 

Classical gravity is very well understood in terms of General Relativity. If you don't agree with that then you are not understanding GR. Quantum gravity on the other hand, is not understood (yet).

[floersh]

Actually I was thinking more along the lines of things that cannot yet be experimentally verified. Like does gravity interact at the speed of light as Einstien suggests?

 

People have tried to verify that. In fact there was an article just a few days stating that someone had verified it. Then came the calls that the data was misinterpreted. And around in circles we go.

 

Bottom line. There is a great deal about gravity that science has not experimentally verified and it takes for granted due to Einstiens mostly accurate predictions. (Aka he was right these 20 times so its likely he is right on all accounts)..

 

Heck show me a scientist that will say without a smile on his/her face that he/she knows gravitons exist.. Another example of what I mean.. We know what the effects of gravity are. We THINK we know what causes gravity (Aka space time curviture) but we don't even know what space time is or how it can be curved or what matter's real interaction is with space time..

 

Another one for ya: Does anti-matter create normal graivty or anti-gravity. I know scientists believe it creates normal gravity. But the point is it is just a beliefe and no one really knows..

[someguy]

space-time is a 4 dimensional thing that is energy. all forms of energy. everything is the same thing. when you have strong concentrations of it clumped together it "weighs down" the lighter concentrations of energy that are in and around it and those things fall in towards it. if you put a bowling ball in a trampoline it makes a dent in it. it is the weight making the dent, curving material. in order for other materials to act like they are in orbit around the bowling ball you need that trampoline there. the bowling ball needs to use the gravity of the earth pulling it into the trampoline in order to fake this 2d version of gravity. but if the mass of the bowling ball were great enough then it wouldn't need a trampoline. all matter would be the trampoline at the same time as they are the things rolling on the trampoline. so what is bending is energy, and what is traveling in the bent "space" is energy. it's all energy. there is no nothingness in existence by existing it would be something and thus not nothing. the universe is a solid "block" of energy. that's how i think of it anyways.

[floersh]

space-time is a 4 dimensional thing that is energy. all forms of energy. everything is the same thing.

 

Got it matter and energy are the same

 

when you have strong concentrations of it clumped together it "weighs down" the lighter concentrations of energy that are in and around it and those things fall in towards it.

 

One issue here. Weight is a property of gravity. Weight can not and does not create gravity rather it is gravity that gives matter weight.

 

 

if you put a bowling ball in a trampoline it makes a dent in it. it is the weight making the dent, curving material.

 

Right. It makes an indention based on weight that is the result of gravity. You've heard of the chicken and the egg right?

 

Its a good analogy except it doesn't really answer the question. I realize the GR dictates a curvature/bending/warping of space time due to mass. And that creates gravity which is really not gravity at all but angular momentum.

 

The question is how does mass warp/bend/curve space time? I realize that matter and energy are essentially interchangable with the exception that one has mass and the other does not (in some cases anyway)..

 

So what is it about a photon that makes it different from say a muon. Why does one have mass while the other doesn't? Is it due to the way it interacts with the background Zero Point Energy? Is the background zero point energy the medium we call space time? Is it the same interaction whatever that might be that gives one particle mass while another remains massless that also gives rise to gravity? Or Inertia?

 

To use your own analogy. Gravity is what causes the bowling ball to create the indention on an elastic material such as the trampoline. So what is the trampoline made of???? And what is it that creates the indention if not gravity's effect on the mass of the bowling ball?

[Klaynos]

floersh, are you familiar with the higgs field? If not I suggest you spend some time reading around this area.

[floersh]

I am somwhat familiar with the higgs field and the Higgs boson. However, I am also familiar with the fact that it is the only Standard Model particle not yet observed.

 

Anyway it is a piece of the puzzle..

[someguy]

Got it matter and energy are the same

 

 

 

One issue here. Weight is a property of gravity. Weight can not and does not create gravity rather it is gravity that gives matter weight.

 

 

 

 

Right. It makes an indention based on weight that is the result of gravity. You've heard of the chicken and the egg right?

 

Its a good analogy except it doesn't really answer the question. I realize the GR dictates a curvature/bending/warping of space time due to mass. And that creates gravity which is really not gravity at all but angular momentum.

 

The question is how does mass warp/bend/curve space time? I realize that matter and energy are essentially interchangable with the exception that one has mass and the other does not (in some cases anyway)..

 

So what is it about a photon that makes it different from say a muon. Why does one have mass while the other doesn't? Is it due to the way it interacts with the background Zero Point Energy? Is the background zero point energy the medium we call space time? Is it the same interaction whatever that might be that gives one particle mass while another remains massless that also gives rise to gravity? Or Inertia?

 

To use your own analogy. Gravity is what causes the bowling ball to create the indention on an elastic material such as the trampoline. So what is the trampoline made of???? And what is it that creates the indention if not gravity's effect on the mass of the bowling ball?

 

the trampoline is made of energy. it is made of whatever is there. if there were a million little balls around a mass it would be made of those million little balls. somehow, and this i think is what you would like to know and me too, energy likes to clump together the more it does the more it likes to clump together with other stuff. why does it like to be clumped? i don't know, the way it clumps, space-time gets warped. i don't think naybody really knows the answer you're looking for. just like if someone asks why do negastive charges like positive charges but not themselves? i don't think anybody really knows. so far we just know that it happens. is there an answer to find? maybe, maybe not. maybe the answer is just that's the way it is, like if you wondered why is there a universe, i don't know, there just is one. I like to think that there is an answer that we have not yet discovered though.

 

as for photons why they are different, i'm not sure, but since they are massless it is puzzling what they could be, i was thinking maybe they are similar to gravity in substance or lack thereof, yet are waves through space-time rather than just the bending of it.

 

all energy has mass except for light, as far as i know anyways. motion of an object increases the object's mass, most energy is in fact motion if you think about it. even matter if you break it up it is smaller objects in motion, and then smaller objects in motion, definitely a large part of matter is motion of stuff.

[floersh]

floersh, are you familiar with the higgs field? If not I suggest you spend some time reading around this area.

 

Sorry my previous response was rushed.. Your response is exactly the kind of stuff I was looking for..

 

A real scientific theory for what gravity is.. Although this touches more on inertia. We do know that in some way shape and form gravity and inertia are linked..

 

I was looking into it more and apparently they are building a new tool at CERN that is specifically designed to try and find this higgs boson. Could be quite exceiting if they are to find it. It could mean a total revolution in our understanding of a great number of things.. Although if they fail to find it it could mean doom to the standard model and decades of research..

 

A lot is riding on those experiements.. Lets keep our fingers crossed.

 

all energy has mass except for light, as far as i know anyways. motion of an object increases the object's mass, most energy is in fact motion if you think about it. even matter if you break it up it is smaller objects in motion, and then smaller objects in motion, definitely a large part of matter is motion of stuff.

 

Exactly. From what I can tell it seems that there are two major theories. The first is some sort of quantum interaction between various particles and zero point fields (aka the either is a zero point field) and associated drag forces that interaction creates which leads to mass, gravity and inertia in some way.

 

The second is a very similar approach where there is a higgs field of higgs bosons that make up the ether per sey which also create a drag force on various particles which leads to mass and thus to inertia and gravity..

 

Can't say which is right and which is wrong or if maybe the two are interconnected. But it seems to me that the bulk of science today is leaning toward this concept of certain particles interacting with something and resulting in drag forces that are responsible for what we measure as mass but probably more descriptive of the concept of inertia.

 

And your right. It would appear from these theories that motion is very much a part of the puzzle.. Whether that motion be macroscopic or quantum..

 

So in essance the trampoline (according to modern theory anyway) is either a higgs field or zero point fields or both. And the warping/bending/curving of that material/energy is due to equal and opposite reactions of particles moving through it and resulting in essentially friction/drag..

 

If we can (And I have every confidence that man will one day achieve this) understand how the interaction works then it opens up the possibilities of manipulating it much as we manipulate electromagnetic fields today.. Assuming we can find a means to manipulate it we could build technology that very few could even conceive of today.. Think of it. What might you be able to do if you could eliminate or minimize that drag and thus an objects apparent mass or inertia? What might you be able to do if you could say increase the drag of any object?