What is gravity, really?

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iwonder

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Just some basic questions about gravity. What is gravity, really? What causes it, just the existence of mass alone? <br /><br />What are the knowns vs. unknowns about gravity, and how it works?<br /><br />I have also seen some theories about the "space-time continuum" on astronomy shows, and about how gravity creates something similar to a "depression" in it. How much is really known about this elusive "membrane" of existence?
 
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kmarinas86

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No matter what the composition of a planet, star, etc, it will be made of up countless charges. Electrons, protons, and/or neutrons.<br /><br />All matter is surrounded by electric and magnetic fields. These fields interact with light in a way as to influence their direction. See how light bends in a prism. The group refractive index of the material determines the group velocity, or propogation rate of light. When the refractive index changes along the light's path, the light changes in angle. The same thing happens with light in a gravitational field. Light goes under a blue shift when it travels towards dense regions of space, and it bends. Dense regions of space have magnetic fields that can be measured in gauss units. Neutron stars, quark stars, and magnetars have especially high gauss ratings. They are also the objects in the universe with the highest energy density, besides black holes. It is no wonder why their escape velocity can reach half the speed of light or more! They also have gravitational time dilation, but could it really be the case that it's really just the residual electric and magnetic fields that are causing the time dilation?<br /><br />If so, for light:<br /><br />group refractive index = gravitational time dilation<br /><br />That would mean matter under goes gravitational time dilation that which is equal to the group refractive index.<br /><br />This would imply the unification of gravitational potential energy with electric potential energy. But we don't see any positive gravitational potential energy perhaps except with the expanding universe that is interpreted from the telescopes.<br /><br />Also, G would have to variable with range. Mutiply by 10^41 to get the value of G at the small, since the electric field densities are so much higher at the small. The difference in G is not noticed at our level since we have stayed pretty much from our level of fractal, that is, the range and domain of human beings. The exception is the van de
 
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CalliArcale

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<blockquote><font class="small">In reply to:</font><hr /><p>I have also seen some theories about the "space-time continuum" on astronomy shows, and about how gravity creates something similar to a "depression" in it. How much is really known about this elusive "membrane" of existence?<p><hr /></p></p></blockquote><br /><br />Don't let it mislead you -- the rubber sheet analogy (for which Einstein is famous) is just that: an analogy. There isn't really a membrane in that sense. But it helps to think of it <i>as if</i> the 3-D universe were actually just a 2-D rubber sheet; this does a surprisingly good job of predicting the motion of objects (and, significantly, light) in a very intuitive way. But the "membrane" is meant to represent the entire 3-D universe, not just some part of it. Everything that is is part of the membrane, so if you want to get a look at it, just look around. <img src="/images/icons/wink.gif" /> <div class="Discussion_UserSignature"> <p> </p><p><font color="#666699"><em>"People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff."</em>  -- The Tenth Doctor, "Blink"</font></p> </div>
 
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iwonder

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Is gravity in any way related to electromagnetism?<br />If so, how?
 
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drwayne

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Those are very good, very deep questions.<br /><br />There has been, for decades the field of investigation what is sometimes been referred to as unified field theory that examines the very questions that you ask, how do the 4 "fundamental" forces relate and tie into the reality we observe.<br /><br />Wayne <div class="Discussion_UserSignature"> <p>"1) Give no quarter; 2) Take no prisoners; 3) Sink everything."  Admiral Jackie Fisher</p> </div>
 
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CalliArcale

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<blockquote><font class="small">In reply to:</font><hr /><p>Is gravity in any way related to electromagnetism?<br />If so, how?<p><hr /></p></p></blockquote><br /><br />It has some things in common with it, most notably that it follows the inverse square law (intensity decreases proportionally to the inverse square of the distance), but it does not seem to be fundamentally related. For one thing, electromagnetic fields only affect certain things (mainly ferromagnetic materials like iron and things which are conductive), but gravity's affect is universal and appears to be a fundmental property of all matter. <div class="Discussion_UserSignature"> <p> </p><p><font color="#666699"><em>"People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff."</em>  -- The Tenth Doctor, "Blink"</font></p> </div>
 
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Leovinus

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Actually electromagnetic fields affect all charged matter. Send an electron through a magnetic field and watch what happens. <div class="Discussion_UserSignature"> </div>
 
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kmarinas86

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The fundamental electromagnetic force is also responsible for van der waals forces, covalent bonds, and ionic bonds. Electromagnetic forces coexist with the electromagnetic field. They cannot be seperated, that is, the existence of a electromagnetic field implies an electromagnetic force. The force extends to infinity, therefore an electromagnetic field cannot be isolated.
 
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kmarinas86

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<font color="yellow">Just a note: <br />The inverse square law does not hold good when the bodies involved are very heavy. Above a certain level of mass involved gravity itself starts to produce more gravity. This is why the theory of general relativity is called a "nonlinear theory".</font><br /><br />The inverse square law does not work very well with quarks either.
 
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jatslo

Guest
Gravity is a effect that requires electrodynamics to exist.
 
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norisk

Guest
Hi, I'm new. Nice to meet you. It is nice to know that this forum exists for those mind boggling questions that pop up from time to time!<br /><br />As I understand things, Einstein proved that Gravity does not exist. Newton theorized that Gravity was a FORCE and that it exerted influence in relation to MASS. <br /><br />But Einstein reasoned that Gravity was not a force but rather a curvature of the time-space continuum. He postulated that if he was correct then even though light had no mass, it would be affected by gravity. Sure enough, this has been confirmed.<br />Light wants to travel in a straight line. Although mass bends the space-time continuum, from the point of view of the beam of light, its path of travel is straight ahead. From a perspective outside of the path, it appears curved.<br />So to answer your question, if my understanding of all of this is correct, then gravity was an erroneous explanation by Newton of the curvature of the space-time continuum caused by mass wherein he conceived of a force exerted by mass upon mass.
 
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harmonicaman

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Hi <b>Norisk</b>; usually I find myself having to tell new people that they are spewing pseudoscientific Bozo flux and other forms of psycho-babble, but I have to agree with member <b>Ranur</b> - I think you nailed it!<br /><br />Nice job & welcome to the forums!
 
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paintwoik

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<blockquote><font class="small">In reply to:</font><hr /><p>Although mass bends the space-time continuum<p><hr /></p></p></blockquote>How does mass do this? If space has properties - What are those properties? None of this bending can happen witout some form of interaction. GR is blind to this yet it is accepted with out question. How can warped space be correct without any explanation of how it works?
 
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paintwoik

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This notion of warped space has been a dead end heading towards a century. Other than the idea of it .....nothing has been done. This is tantamount to having good cause for it's rejection. All the experiments that are done only serve to buttress the effect and not the cause.
 
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newtonian

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Iwonder - We do not fully appreciate the gravity of the matter!<br /><br />In one sense gravity is nothing, i.e. no thing:<br /><br />(Job 26:7) . . .He is stretching out the north over the empty place, Hanging the earth upon nothing;<br /><br />Newton, in effect (literally), discovered what that nothing is - as in his laws of motion. Einstein refined and added to Newton's discoveries. We are still learning, of course.<br /><br />As for the shape of the universe that you, and Einstein, alluded to:<br /><br />(Isaiah 40:22) . . .There is One who is dwelling above the circle of the earth, the dwellers in which are as grasshoppers, the One who is stretching out the heavens just as a fine gauze,. . .<br /><br />It would be helpful to imagine our universe as a stretching fine gauze, with expanding threads and filaments.<br /><br />This is what is actually observed - we do not observe curved space-time. We observe effects that Einstein explained with that model. <br /><br />However, we also observe the stretching out stated in Isaiah 40:22 - with varying models notably including dark energy which may or may not be related to gravity in some way - directly or indirectly.<br /><br />A stretching fine gauze would have filaments and threads which could simply stretch or could break and rebound - both would occur in normal stretchable gauze material.<br /><br />Concerning whether bonds among stars would hold fast or break loose:<br /><br />(Job 38:31-33) 31 Can you tie fast the bonds of the Ki´mah constellation, Or can you loosen the very cords of the Ke´sil constellation? 32 Can you bring forth the Maz´za·roth constellation in its appointed time? And as for the Ash constellation alongside its sons, can you conduct them? 33 Have you come to know the statutes of the heavens, Or could you put its authority in the earth?<br /><br />Thankfully, most of the laws, or statutes, of our universe (and perhaps others) do have authority on earth - and this allows scientists to discover and learn about these
 
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newtonian

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SVMsmiles - And where was the Bible when philosophers and astronomers taught the earth was flat in contrast with the round earth of Isaiah 40:22?<br /><br />It was clearly and simply stated but ignored while so-called intelligent men pursued wild goose chases so to speak.<br /><br />And where was the Bible when prevailing theories had earth on some support, such as Atlas for example, when Job 26:7, written c. 1513 BCE, clearly stated earth is hung ujpon nothing?<br /><br />Compare the many errors of Aristotle adopted by 'the Church.'<br /><br />And where was the Bible when scientists pursued the steady state theory or philospher's eternal universe theories when Genesis 1:1 clearly stated that heaven and earth had a beginning?<br /><br />And where was the Bible when scientists mused our universe might collapse on itself rather than being stretched out as clearly stated in Isaiah 40:22?<br /><br />Isaac Newton believed in the Bible and science - but rejected popular teachings of religions and scientists in a search for truth.<br /><br />This is one reason for my user name - I see no conflict between the Bible and Science - rather I find many clues to scientific truths - some of which have only recently been discovered.<br /><br />Like the actual appearance of the universe as a spreading gauze with its expanding threads and filaments.<br /><br />If you trust in science alone you will be disappointed - because what is scientific truth in one century will be quite different from what is considered sceintific truth in the next century.<br /><br />Meanwhile the clear, slimple Biblical statements remain truth eternally.<br /><br />Another case of where the Bible helped advance science is the rejection of the false scientific teaching of junk DNA vs. the clear purpose of God's book stated in Psalms 139:16.<br /><br />You did ask, btw.<br /><br />Did you know Newton wrote more on the Bible than on science? <br /><br />Here is one of the Biblical hints concerning gravity - and which remains to be discove
 
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newtonian

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ranur - That's fine, though I really want to know if some black holes may have achieved escape velocity from our universe's gravity and light - i.e being outside the universe's light cone.<br /><br />This would mean some black holes expanded faster than gravity - hence relates to the speed of gravity.<br /><br />Also, wouldn't black holes be more likely at early stages of universal expansion, perhaps involved in FTL inflation beyond gravity?<br /><br />On your post - perhaps a graviton is simply nothing in not being matter. Or perhaps no graviton actually exists.<br /><br />I ask, does the propagation of gravity involve e=mc^2?<br /><br />Such that its propagation reduces some other form of matter or energy?<br /><br />Or is it related to dark energy propagation by some other ratio besides e=mc^2?<br /><br />Or is dark energy totally independent, perhaps being supplied by God or by some natural means from beyond our visibility horizon?<br /><br />And you have me curious.<br /><br />What is the new LHC? <br /><br />Launch Higgs Confirmation?
 
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newtonian

Guest
ranur - Jude 13 might be describing black holes that were inside the universe but are now outside - hence interesting to me.<br /><br />lightcone: If the universe expanded FTL at inflation, then the universe would have exclusive lightcones - such as those beyone our visibility horizon.<br /><br />However, if some black holes were accelerated to FTL faster than universal expansion, then they would be beyond all universal light cones.<br /><br />And perhaps beyond the universe's gravity - more on thread theme.<br /><br />Remember, inflation models do assert FTL expansion - but gravity is considered to be limited to light speed.<br /><br />On E=mc^2 - this is a ration such that energy is larger than mass in the equation by the equations math - though I don't know how one derives the values of the necessary units to cause this ratio.<br /><br />If gravity is energy or is related to energy by e=mc^2, then as units of gravity increased, units of either energy or matter would decrease.<br /><br />Interestingly - the strength of gravitation is fine tuned in relation to the other 3 forces of physics such that stars and life are possible.<br /><br />If you do not believe in God, then how did gravity have such a precisely fine tuned value?
 
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Saiph

Guest
a few caveats:<br /><br />warping of space-time is <i> not</i> accepted without question. There are many experiments that evaluate the viability of GR and the warped space-time paradigm.<br /><br />Orbit of mercury, behavioral models for black holes accretion disks and jets, gravitational lensing.<br /><br />Now, as for you're last question, how can it be correct without any explaination of why it works...lets just call it a work in progress.<br /><br />For example...we really don't know why <i>any</i> field of force works.<br /><br />We do know our descriptions produce accurate answers.<br /><br />Wether those theories are what's "really" happening, or merely mathematical tools...is an issue for philosophy, assuming the theories are sufficiently accurate. <div class="Discussion_UserSignature"> <p align="center"><font color="#c0c0c0"><br /></font></p><p align="center"><font color="#999999"><em><font size="1">--------</font></em></font><font color="#999999"><em><font size="1">--------</font></em></font><font color="#999999"><em><font size="1">----</font></em></font><font color="#666699">SaiphMOD@gmail.com </font><font color="#999999"><em><font size="1">-------------------</font></em></font></p><p><font color="#999999"><em><font size="1">"This is my Timey Wimey Detector.  Goes "bing" when there's stuff.  It also fries eggs at 30 paces, wether you want it to or not actually.  I've learned to stay away from hens: It's not pretty when they blow" -- </font></em></font><font size="1" color="#999999">The Tenth Doctor, "Blink"</font></p> </div>
 
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doc_harra

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Gravity<br /><br /><br />Thought it was effect of matter in motion ? In an area that has no gravity or not enough to effect objects of this size or distance, Thus causing/allowing some objects to spin so rapidly it causes other objects to be attracted to a point, But due a very fast spin also keeping it at a distance creating the attracted object to be in orbit, this too creates a spin on the orbiting object allowing it to attract as well, Also creating more attractions for other objects in the area, Maybe the central object spins so fast it combusts ? I dont know is the sun spinning ? Is it spinning faster than it's surrounding planets ? If it was to slow down a bit would some objects get sucked into it, Until it had enough mass to speed up again ? Would it create a magnetic attraction sucking in large amounts of local conductive materiel during formation ?
 
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newtonian

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ranur - The fundemental theory of everything, which does not exist btw, would simply show a common origin for all the 4 forces of phsyics.<br /><br />It would not show why the ratios of the strengths of these forces are what they are.<br /><br />If you disagree, please explain why.
 
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