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If gravity is a force, like the other forces of nature, the rock falling should be exothermic and give off energy?

Nobody has ever measured/characterized the exothermic energy quanta from a loss of gravitational potential.

Another possible affect might be on distant mass

the expanding universe... Dark matter... Black holes

I have seen it stated that since the gravitational field has energy it can produce gravity just like mass does. Is this necessarily true?

Quote from: JeffreyI have seen it stated that since the gravitational field has energy it can produce gravity just like mass does. Is this necessarily true?My understanding is that GR says that gravity creates gravity. I've been looking for where I got this idea and can't find at the moment. It has come up in discussion on other forums, and seems to be accepted widely.An interesting point that arises from it must be: Why do we not observe run-away gravity? Why doesn't every massive body spontaneously collapse into a black hole?

Quote from: Bill S on 13/03/2016 20:22:29Quote from: JeffreyI have seen it stated that since the gravitational field has energy it can produce gravity just like mass does. Is this necessarily true?My understanding is that GR says that gravity creates gravity. I've been looking for where I got this idea and can't find at the moment. It has come up in discussion on other forums, and seems to be accepted widely.An interesting point that arises from it must be: Why do we not observe run-away gravity? Why doesn't every massive body spontaneously collapse into a black hole?You have hit the nail right on the head.

Quote from: jeffreyH on 13/03/2016 11:14:02I have seen it stated that since the gravitational field has energy it can produce gravity just like mass does. Is this necessarily true?According to GR, there isn't any gravitational field.Fixed. []--lightarrow

According to GR, there isn't any gravitational field.

Well Jeff, I'm following your logic... but, why does there 'have' to be a force carrier? Can't mass be the force instigator, and gravity be a form of energy that merely dissipates across space via the inverse square law? This renders space, or in fact 'distance' itself as being the energy, or force carrier. Then, as light dissipates via the inverse square law, it's energy can be explained via the energy of the gravitational field affecting the light... This being based on light, gravity and all forms of energy being massless. This is an entirely logical notion that negates the necessity for a graviton... that, at its largest, is vastly humungous (or so I recall Evan stating in a post elsewhere... I 'think' he did anyway, eek, sorry Evan if I have misquoted you here), which, as yet, we neglect to detect.

Gravity is the entirety of space, a gravity singularity, mass is denser than space, all denser mass is attracted to denser mass through the gravity singularity made of the same but a less dense mass of space.

Quote from: TheBoxGravity is the entirety of space, a gravity singularity, mass is denser than space, all denser mass is attracted to denser mass through the gravity singularity made of the same but a less dense mass of space. It's easy to bandy about words like "singularity", but what do you actually mean in this case?

One reason why the physics of general relativity is much more difficult than that of Newton's theory of gravity or the theory of electrodynamics is a property called non-linearity. In short, gravity can beget further gravity - where gravitational systems are concerned, the whole is not the sum of its parts.

…… they are being sloppy with their wording. All this website is saying is that gravity is ultimately non-linear, which is correct. It is not saying that gravity can be created out of nowhere…..

added sorry - ask yourself this - We have a box that is full of tightly packed dice, we can clearly observe that there is no space in the box.When we remove a single ''dice'' , does space fill where there was no space or was the space already there to begin with?

Quote from: TheBoxadded sorry - ask yourself this - We have a box that is full of tightly packed dice, we can clearly observe that there is no space in the box.When we remove a single ''dice'' , does space fill where there was no space or was the space already there to begin with?The space must already be there, or the dice would not be able to occupy it.

Jeffrey, going back to your link: ...sorry, you cannot view external links. To see them, please REGISTER or LOGIN and the statement that gravity begets gravity;Quote One reason why the physics of general relativity is much more difficult than that of Newton's theory of gravity or the theory of electrodynamics is a property called non-linearity. In short, gravity can beget further gravity - where gravitational systems are concerned, the whole is not the sum of its parts.Christopher Baird (email) says:Quote…… they are being sloppy with their wording. All this website is saying is that gravity is ultimately non-linear, which is correct. It is not saying that gravity can be created out of nowhere…..

For gravity to exist between things the important factor is that the something's must have Physical dimensions

The inverse square law from either observers perspective contracts relative to increased radius apart, eventually the line between observers becomes this ''singularity'', neither observer having any affect on each other any more.

Not so fast lightarrow... GR is a theory of gravity. We do in fact observe there to be gravitational fields,

and, to say so, how do you then explain the GR 'field equations'. What 'field' are they equating?

The Maxwell equations are a description of the electromagnetic fields and cannot be linked to gravity via GR.

What are you saying here? Are you stating that GR constitutes an incorrect description of gravity?

That by stating a phenomenon that we know exists as non existent, that GR just 'fixes' the fact of the existence of a gravitational field by simply ignoring it?

Quote from: lightarrowAccording to GR, there isn't any gravitational field.I am no expert (and I can't read German), but I heard that Einstein originally produced General Relativity as a gravitational field theory, inspired by Maxwell's electromagnetic field theory.The geometric interpretation and application of Riemann Geometry came soon after, when people realized that Einstein's equations were similar to those developed for quite different purposes - which opened up a new set of mathematical tools which could be applied to General Relativity.Perhaps the analytical advantages of the geometric interpretation have overshadowed the original field theory?

Quote from: timey on 14/03/2016 18:01:32Not so fast lightarrow... GR is a theory of gravity. We do in fact observe there to be gravitational fields,No. Where would you observe such "gravitational fields" if you use GR?Quote and, to say so, how do you then explain the GR 'field equations'. What 'field' are they equating?It's just a name. IIRC, Einstein initially called them "equations of the gravitational field" but then he realized it was wrong and so changed the name in "field equations of gravity" or something alike.QuoteThe Maxwell equations are a description of the electromagnetic fields and cannot be linked to gravity via GR.And what does it relate with what I wrote about GR?QuoteWhat are you saying here? Are you stating that GR constitutes an incorrect description of gravity? ?It's writing "gravitational field" which is wrong in GR because is to interprete GR in an incorrect way.QuoteThat by stating a phenomenon that we know exists as non existent, that GR just 'fixes' the fact of the existence of a gravitational field by simply ignoring it?You're wrong. The existence of a "gravitational field" is not a "fact", is just "a theory-dependent interpretation".According to newtonian theory, gravity is a field, according to GR is not.--lightarrow

Quote from: evan_au on 14/03/2016 19:31:48Quote from: lightarrowAccording to GR, there isn't any gravitational field.I am no expert (and I can't read German), but I heard that Einstein originally produced General Relativity as a gravitational field theory, inspired by Maxwell's electromagnetic field theory.The geometric interpretation and application of Riemann Geometry came soon after, when people realized that Einstein's equations were similar to those developed for quite different purposes - which opened up a new set of mathematical tools which could be applied to General Relativity.Perhaps the analytical advantages of the geometric interpretation have overshadowed the original field theory?I only know that Einstein tried a lot but at the end, only the geometrization of spacetime worked, all the other methods didn't.--lightarrow