the reality of gravity

[Mitch ATWUNFORTRUATZEM]

Correct me if I'm wrong, but the common conception of the reality of gravity is that all objects that have mass/density generate an attraction. Objects of higher density/mass will have more attraction than objects of smaller density/mass but every object of density/mass does exert attraction.

 

There are considered three other forces attributed to the cause of motion. The strong force (the reason for atomic particle motion), weak force (the reason for radiation) and electro-magnetism.

 

Gluons, Bosons and Photons are said to be the particles that carry the force that explain the strong,weak and electro-magnetic forces.

 

I understand there is a thought that it will most likely be discovered that gravity also has a particle that carries the force to explain how gravity works.

 

My question considering the reality of gravity is as follows: if we consider that particles carry a force that makes gravity function, must we not also ask ourselves how specifically does this force do what we give it credit for doing?

 

Is it possible that there is no reality to gravity? That the activity in the universe that we are attributing to gravity as it is presently defined, which is, and I will quote the start of this post "that all objects that have mass/density generate an attraction".

 

Should we be on the look out for another reason for why things move as they do without utilizing the theory of gravity? I understand that this is not the area for people to speculate on new theories. This is not what I am seeking. Rather I am hoping someone can give me an understanding as to what gravity is and how it works.

Edited May 21, 2014 by Mitch ATWUNFORTRUATZEM

[Mordred]

Do define gravity as a force, the boson it would need is the graviton. So far we haven not detected the boson. However that does not mean it doesn't exist. We just recently detected the Higg's particles (we may have not found all the predicted Higg's particles yet). The problem is the extreme energies required. The graviton is considered to be one of the hardest to detect and it would take higher energy levels than we can currently achieve.

 

Our understanding of gravity is far from complete in all its workings, we still do not know how to apply gravity to obtain Unification of the forces. Its hoped that quantum gravity, QFT or string theory will be able to one day integrate GR completely into the quantum.

However keep in mind GR is a well tested model of gravity, much of what it says it does has yet to be disproved.

 

a line from Introduction to particle Physics by David Griffith describes it well.

 

"In general the heavier the particle you want to produce, the higher the energy of the collision must be" In general the lighter particles are discovered first with the heavier particles coming later..

[mathematic]

Current theory of gravity is explained by general relativity.

 

The existence of gravitons has been inferred from the behavior of binary stars. However their existence is still subject to question.

[Mitch ATWUNFORTRUATZEM]

 

Edited May 21, 2014 by Mitch ATWUNFORTRUATZEM

[Mordred]

GR is general relativity

Current theory of gravity is explained by general relativity.

 

The existence of gravitons has been inferred from the behavior of binary stars. However their existence is still subject to question.

Do you perchance have the paper on that study, I would be interested in studying it

[swansont]

 

The existence of gravitons has been inferred from the behavior of binary stars. However their existence is still subject to question.

 

No, AFAIK that's not right. Gravitational radiation can be inferred, but that's a classical prediction coming from GR, not a quantum one.

[Mordred]

ah kk,

[MigL]

I liked the explanation given by a member who hasn't been here for a while ( elfmotat where have you gone ? ).

 

Consider two planes that take off at the equator and fly straight north on a parallel course. As they fly they notice their separation is decreasing and they keep getting closer together. Finally as they reach the north pole they crash into each other. They assume, since they weren't moving towards each other, that a force must have drawn them together. They call this force gravity.

 

This is how GR explains gravity. As a frame ( curved ) dependant geometric effect.

 

All other frame dependant forces that I know of are termed fictitious forces, because while they are manifest in one frame, they are not in others.

 

If gravity is a fictitious force, however, I've never been able to figure out which would be the other frames where it is NOT manifested.

[Fred Champion]

Some pictures of black holes show a discharge from both poles. Not sure, but I think the nature of the discharge is not determined. A cursory consideration leads me to the idea that there may be an outward flow proportional to an inward flow; a high velocity outward flow in a narrow beam corresponding to a wider slower inward flow. Somewhat similar action can be seen by some swimming pool vacuum cleaners. If we could relate this action to individual atoms it might provide an explanation for gravity. Of course we would have to come up with an explanation for what is flowing and what makes it flow. Spinning things may act as pumps and then there's the gyroscope.

[Strange]

Some pictures of black holes show a discharge from both poles.

 

Polar jets? These are created outside the black hole from matter falling in (the accretion disk).

http://www.scientificamerican.com/article/milky-way-black-hole-jet/

[Fred Champion]

I am quite surprised that we can tell how the polar jets are formed. Interesting that a jet seems to be visible only when it encounters visible material. Is it intuitive that jets would be ejected at both poles by magnetic forces?

[metacogitans]

Do define gravity as a force, the boson it would need is the graviton. So far we haven not detected the boson. However that does not mean it doesn't exist. We just recently detected the Higg's particles (we may have not found all the predicted Higg's particles yet). The problem is the extreme energies required. The graviton is considered to be one of the hardest to detect and it would take higher energy levels than we can currently achieve.

 

Our understanding of gravity is far from complete in all its workings, we still do not know how to apply gravity to obtain Unification of the forces. Its hoped that quantum gravity, QFT or string theory will be able to one day integrate GR completely into the quantum.

However keep in mind GR is a well tested model of gravity, much of what it says it does has yet to be disproved.

 

a line from Introduction to particle Physics by David Griffith describes it well.

 

"In general the heavier the particle you want to produce, the higher the energy of the collision must be" In general the lighter particles are discovered first with the heavier particles coming later..

Not true. Gravity needs no boson to explain it; it's geodesics of curved space-time. An object travels faster and farther in the direction of mass because there is literally "more space" in the direction of mass due to the presence of mass dilating spacetime.

And besides all that, gravity being mediated by a force carrier would completely fail to explain how gravity bends light. If it were mediated by a boson, it should not interact with other bosons, and would not curve the path of photons.

You could of course start making exceptions for your hypothetical boson, but before you know it what you're going to be describing is nothing more than the curvature of space-time already described in general relativity.

Edited July 11, 2014 by swansont
fix quote tag

[Mordred]

Correct me if I'm wrong, but the common conception of the reality of gravity is that all objects that have mass/density generate an attraction. Objects of higher density/mass will have more attraction than objects of smaller density/mass but every object of density/mass does exert attraction.

 

There are considered three other forces attributed to the cause of motion. The strong force (the reason for atomic particle motion), weak force (the reason for radiation) and electro-magnetism.

 

Gluons, Bosons and Photons are said to be the particles that carry the force that explain the strong,weak and electro-magnetic forces.

 

I understand there is a thought that it will most likely be discovered that gravity also has a particle that carries the force to explain how gravity works.

 

My question considering the reality of gravity is as follows: if we consider that particles carry a force that makes gravity function, must we not also ask ourselves how specifically does this force do what we give it credit for doing?

 

Is it possible that there is no reality to gravity? That the activity in the universe that we are attributing to gravity as it is presently defined, which is, and I will quote the start of this post "that all objects that have mass/density generate an attraction".

 

Should we be on the look out for another reason for why things move as they do without utilizing the theory of gravity? I understand that this is not the area for people to speculate on new theories. This is not what I am seeking. Rather I am hoping someone can give me an understanding as to what gravity is and how it works.

 

 

I answered in terms of the OP for this thread

I've already pointed out your mistake in assuming mass means volume in the other thread you posted. The stress energy tenser is the density of mass energy not the volume or space it occupies.

 

http://www.scienceforums.net/topic/52948-why-does-mass-curve-space-time/?p=813626

 

please read the entire thread before posting

 

 

.

Edited June 29, 2014 by Mordred

[aaa16797]

What about the fact that celestial objects bend space time, causing gravity?? I saw this in another forum.

[swansont]

What about the fact that celestial objects bend space time, causing gravity?? I saw this in another forum.

 

What about it? That's the basic description of General Relativity.

Not true. Gravity needs no boson to explain it; it's geodesics of curved space-time. An object travels faster and farther in the direction of mass because there is literally "more space" in the direction of mass due to the presence of mass dilating spacetime.

And besides all that, gravity being mediated by a force carrier would completely fail to explain how gravity bends light. If it were mediated by a boson, it should not interact with other bosons, and would not curve the path of photons.

You could of course start making exceptions for your hypothetical boson, but before you know it what you're going to be describing is nothing more than the curvature of space-time already described in general relativity.

 

 

GR is incomplete, so there has to be a model that works at quantum scales where gravity is important.

 

It seems to me that one can't really criticize the shortcomings of a nonexistent model; whatever properties a QM description will have, it must include mechanisms to account for phenomena we already observe. If it doesn't, it won't get very far.