# The mechanics of gravity.

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The mechanics of gravity.

Most of us have wonder about the magnificent workings of gravity and have at some point or the other asked the question, how does gravity work? Through countless people, and have only ended up with the age old mathematical answer, in this age of information where information is abundant, even the most innate theory of the mechanics of gravity is impossible to find. Which leads to the conclusion that either the Symantec search is invalid or that no such theory of gravity even excites.

Gravity

The FORCE that attracts two objects to each other in space. (Which force and why is it present?)

Most will agree that they must be something in space that is causing the pull that can be measured without the aid of a third object. How would one determine the mass or the velocity of those two objects if they were blinded to the two objects and were confined to determine the mass and velocity of those two objects by only examining the space near by? Well I guess the answer to that is they cant and neither can I.

(1) Either the result of gravity, causes no external energy or force,

(2) Or the energy that it is causing cant be measured by man since we lack the natural or artificial sensory equipment to measure it (much like how our eyes can't detect infrared light).

OR both (1) and (2) are at work.........

The empty nothingness of space, where gravity seem to excite could also be a product of space itself.

Lets presuppose that space is everything but empty, the fabric of space allows for the existents of matter. It could infact even be the force that we call gravity, the fabric of which being cubical (as seen in 3d programming) or like the honeybee hive sharp etc. The size of which being suspect but most problely in the macroscopic level, creating phenomena's like atoms being in two places at once when cooled. A fabric without which matter cannot exist or without which matter is converted in that very fabric when without it. Having a relationship that resists each other (possible but not relevant to gravity in this context) and hence creating drag, the result of which being gravity or space drag.

The about couple of statement cant be stated as true but can neither be stated as false, below I shall state the countless processes that fall in tile which supports the process,

Apparently the universe started off with a big bang, if the big bang was a purely chemical bang, than most problely the bang itself has already consumed up 99.9 percent of the total energy of the universe, not to mention that it seems highly improbable that anything could destroy a single object that had all the mass of the universe, even light cannot escape from black holes, imagine the energy that was required that could split that single object. What I am trying to say is that it might have been space that overcame matter causing the big bang, mass in motion that creates gravity losses motion in the absences of space (offcouse this model of gravity boldly imply that space is not infer net) and the fact that there was a massive inflation period right after (which was also created by space) supports this model greatly. In short, slow inflation followed by the faster more rapid inflation (that we all read about) and than again slow inflation.

Apparently all the planets in our solar system also rotate in the same direction, which could also be due to space drag since the above model of the bang only left particles in its after math, through which the star came into being later, the first few partials that fussed together determined the clock wise direction (as from point up) of the entire solar system, which could also be an explanation of the world pools that spin in a clock wise direction on earth.

The moon illusion. If the inwards movement of space into the earth is at an angle than it could be the curved space that gives the illusion that the moon is at a greater distances when its at 12 o'clock in the sky and given the illusion of being near when at the horizon. Offcouse the perception theory does exist but it is still to explain why the same illusion occurs even when viewed thought a lens.

Another abbreviation that again falls in line with the above is anomalies that occur in computer hard drives, if one powers up a hard disk out side the case of a computer and holds it in their hand, than rotate it a bit or by changing its angle, it gives out a slight force (must like magnates but independent in nature), at first I suspected the head of the hard drive moving from one end to another which was creating this resistance, but than I opened up the hard drive, removed the head and arm and the same happened again (40 GBs of storage are gone for ever) and by the way, I was using a hard drive that rotated at 7200 rpm. ( if gravity is not doing that, could someone please tell me, what is)

Finally if gravity due to acceleration or due to mass cant be told apart, than they must be the same thing, the only way to test it and put the final nail in the coffin is by spinning an x amount of mass with an x amount of speed and observing wither any gravitational field forms around it. If it works well and good, if it does not kindly delete the above

And there is one more thing, in order for this model of gravity to be true, there would also have to be something like "space hijacking" to exist, meaning the amount of space pulled into a massive object would have to be greater than the amount that escapes, but this hijacked space does not add up to the mass of the object and “hijacked space” near other pockets of “hijacked space” are going form equilibrium.

This is my email address brian_dean2002@yahoo.com, kindly contact me if u have a better reason why hard drives do that.

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Another abbreviation that again falls in line with the above is anomalies that occur in computer hard drives, if one powers up a hard disk out side the case of a computer and holds it in their hand, than rotate it a bit or by changing its angle, it gives out a slight force (must like magnates but independent in nature), at first I suspected the head of the hard drive moving from one end to another which was creating this resistance, but than I opened up the hard drive, removed the head and arm and the same happened again (40 GBs of storage are gone for ever) and by the way, I was using a hard drive that rotated at 7200 rpm. ( if gravity is not doing that, could someone please tell me, what is)

that is conservation of angular momentum, not gravity. too tired to comment on the rest, suffering from a bout of insomnia just now.

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It's hard to understand either of these two posts. Newtonian theory does not give any hypotheses as to how gravity "works" but the general theory of relativity certainly does.

As for the "hard drive"- it wasn't necessary to disassemble it, exactly the same effect can be seen with a bicycle wheel. In fact it's a standard example in high school physics classes- one student stands on a small platform that is free to rotate, holding a bicycle wheel by an extended axis. Get the bicycle wheel rotating at high speed. When the student tries to tilt the wheel to one side or the other, the entire platform rotates. That's because the "torque" vector of the wheel is at right angle to the wheel itself. It's the basis of the "gyroscope" effect. I don't see why you would think it had anything to do with gravity.

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Apparently all the planets in our solar system also rotate in the same direction

Except for Venus, Uranus and Pluto (whose rotation did not change even when it was demoted from planet status)

The moon illusion. If the inwards movement of space into the earth is at an angle than it could be the curved space that gives the illusion that the moon is at a greater distances when its at 12 o'clock in the sky and given the illusion of being near when at the horizon. Offcouse the perception theory does exist but it is still to explain why the same illusion occurs even when viewed thought a lens.

Sometime an illusion is just an illusion.

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The big bang wasn't chemical.... There was no chemicals...

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hey, yea me again

i guess i have typed that long inquiry in yet another wrong fastion, i could have just typed in " whats gravity" but chances are that again most of youll would have just said "force times this times that" is gravity... but what i was hoping for was that someone would have pointed out a link or a better suggestion as to how gravity works. lets try another example,, i just hope my numbers are not wrong this time... planet mercury has a mass of 3.302*10(23) and a period of almost 59 days to complete one rotation, while mars has a mass of 6.4153*10(23) and it takes it 1.02 days to complete one rotation, now mars has a greater mass, almost twices that of mercury and a 1 to 59 day faster rotation period but gravity is almost the same, that is 0.377 gs for mercury and 0.376 for mar,,, question, if mass does not determine gravity, rotation does not, than what does.

ok now i am sure that they must be some scientific way of calculating planety mass and stuff, i am pritty sure that they formula would also be logical, but rather than stateing the formula of calculating planetry mass, can anyone explain what gravity really is, if i may put it in a different way, "what takes place in mass that creates gravity"

dont go rough on me, i know nothing about physices infact i just spent the last 3 years learning about economics.

about that moon illusion, last i heard they were about 50 different explanation for the illusion, some of them were illusion (i.e due to faults in human presurption) and some of the justifations did not fall into the category of illusions, i am pritty sure that i remember from a "Philosophy of Mind" lecture or "Ideas of Psychology" lecture that this was still an open question.

http://spaceplace.jpl.nasa.gov/en/kids/pluto/index.shtml

take a look at the third image of this page, all the plantes rotate in their orbit in the same direction, in this image its an counter-clock wise direction. Venus, Uranus and Pluto also rotate in the same direction.

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http://spaceplace.jpl.nasa.gov/en/ki...to/index.shtml

take a look at the third image of this page' date=' all the plantes rotate in their orbit in the same direction, in this image its an counter-clock wise direction. Venus, Uranus and Pluto also rotate in the same direction.

[/quote']

No, the link provided clearly shows that the rotation direction is opposite for Venus, Pluto, and Uranus. Look more carefully at the diagram:

BTW, what determines gravitational force of a planet is its mass, density, and radius of the body. The equation should help you with this. This determines the gravitational force felt by two bodies and, the larger the radius between the two bodies, the smaller the force of gravity. So even if the body is really small, it can still have a large gravitational force if the body is super-dense, such as in a Neutron Star, which has the mass of a large star packed into a 10 km diameter.

As for what gravity is, according to our current theories (i.e. General Relativity) it is the curvature of spacetime that is caused by mass. Mass distorts spacetime, and this is how we feel a gravitational force.

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No, the link provided clearly shows that the rotation direction is opposite for Venus, Pluto, and Uranus. Look more carefully at the diagram:

It's even worse, because Uranus and Pluto have rotation axes that are significantly tilted, as shown in the next drawing.

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No, the link provided clearly shows that the rotation direction is opposite for Venus, Pluto, and Uranus. Look more carefully at the diagram:

It seems to me that the OP meant that the planets all ORBIT THE SUN in the same direction

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well in that case its due to the collapsing accretion disk that formed along with the sun. this part of space just had extra angular momentum in this direction.

it is also the same thing that accounts for the rotation of the planets as the material closer to the sun was moving faster. the planets with abnormal rotations are either tidally locked, in the process of becoming tidally locked or have been ht by something big enough to change its rotation.

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planet mercury has a mass of 3.302*10(23) and a period of almost 59 days to complete one rotation, while mars has a mass of 6.4153*10(23) and it takes it 1.02 days to complete one rotation, now mars has a greater mass, almost twices that of mercury and a 1 to 59 day faster rotation period but gravity is almost the same, that is 0.377 gs for mercury and 0.376 for mar,,, question, if mass does not determine gravity, rotation does not, than what does.

Here, you are definitely talking about the planets rotation on its own axis. And it is easy to see why you think the situation is strange here... Mars does have about twice the mass that Mercury has... so why is the surface gravity so similar? The answer has nothing to do with rotation. The surface gravity is determined by the mass of the object, as well as your distance from the center of mass. Mars has more mass but it is less dense and quite a bit larger than Mercury, so you are farther from the center of mass. Mercury is compact and smaller than Mars, so you are much closer to the center of mass. If Mars's mass were compacted until both planets were the same size, then you would be much heavier on Mars than on Mercury (twice as heavy, I think)

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It seems to me that the OP meant that the planets all ORBIT THE SUN in the same direction

Ah, then we have a great lesson in the difference between rotate and revolve.

You rotate on an axis. It passes through the object.

You revolve around a point. It's not part of the object.

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The moon illusion. If the inwards movement of space into the earth is at an angle than it could be the curved space that gives the illusion that the moon is at a greater distances when its at 12 o'clock in the sky and given the illusion of being near when at the horizon. Offcouse the perception theory does exist but it is still to explain why the same illusion occurs even when viewed thought a lens.

It has nothing to do with 'curved space', this would imply that it is not an illusion at all. The truth is that when you take a picture of the moon in the sky and again (with the same camera on the same settings) on the horizon, and then measure the size of the moon in those pictures, they are identical in size. Even in the picture, the moon on the horizon might seem larger... but it is just your perception. If it were anything other than your perception, then the size difference would show up when you measure the diameter of the moons in the pictures. No size difference. So the explanation for the illusion lies with how your brain interprets the image. ie: perception!

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yea i did mean "revolve", hahahhahah just for the record, i did mention the word "arbit" a cupple of times so that should have tipped u off.

losfomot (Baryon), so than that is the conclusion,, mass( along with the state its density and velocity etc) determens gravity throught the medium of space. Am i understanding u right ?

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losfomot (Baryon), so than that is the conclusion,, mass( along with the state its density and velocity etc) determens gravity throught the medium of space. Am i understanding u right ?

I answer hesitantly, as I am no expert...

The mass of an object determines it's gravity (field). However, all we have right now is a description of how gravity acts. In other words, we have a set of equations that we can use to accurately calculate orbits and predict the existence of things like black holes.

The equations we have are built around the idea that space is generally flat, except around mass. Mass curves space just like a bowling ball curves the surface of a trampoline. This curvature then tells mass how to move (orbits and such). Just like a marble tossed alongside the bowling ball will circle the bowling ball because of the curved surface of the trampoline. The marble spirals closer and closer until it hits the bowling ball, but this is because friction is slowing the marble down, without friction, the marble would continue circling the bowling ball just like the Earth circles the Sun.

I was happy when I first heard this idea because I thought it was a solid mechanism for gravity, the curvature of space. I was a little disheartened to be made to understand later that the curvature of space is merely a convenient mental picture that we use to understand the effects of gravity. It is not necessarily what is actually happening. ie There is not a physical tangible thing called space or spacetime that actually curves in the presence of mass.

So, in conclusion, I can't really help you... my understanding is that we have 'laws' and equations that tell us, to a high degree of accuracy, how mass moves in the presence of other mass. And that's as far as I go.

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I was happy when I first heard this idea because I thought it was a solid mechanism for gravity, the curvature of space. I was a little disheartened to be made to understand later that the curvature of space is merely a convenient mental picture that we use to understand the effects of gravity. It is not necessarily what is actually happening. ie There is not a physical tangible thing called space or spacetime that actually curves in the presence of mass.

Well, no, according to General Relativity spacetime is actually being distorted and curved by the presence of a mass. It is physically happening, and spacetime is curved. The geometry of spacetime is distorted. The bowling ball on trampoline is just an analogy we use to help us visualize the concept. Note that I am using the term spacetime because you cannot have space without involving time as well.

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Well, no, according to General Relativity spacetime is actually being distorted and curved by the presence of a mass. It is physically happening, and spacetime is curved. The geometry of spacetime is distorted. The bowling ball on trampoline is just an analogy we use to help us visualize the concept. Note that I am using the term spacetime because you cannot have space without involving time as well.

I wish you were right.

Here is a thread I started a couple of years ago... unfortunately it was chopped up by the forum moderators because it was getting off-topic, they were cracking down on that sort of thing at that time. A lot of good stuff got trashed... (sigh)

This quote is also from a couple of years ago:

Actually we know that GR is wrong. That is, it does not correctly describe gravity at very small distances since it is a classical theory, not a quantum one. However, it is still a very good description of gravity at macroscopic distances so we should not throw it away.

We also know that our current theories of QG are wrong since they are either incomplete or have bad properties (like infinities cropping up all over the place).

So we don't really understand gravity very well yet. However, it is pretty certain that the correct theory of gravity will contain a graviton which mediates the force (so your case B). But this final theory has to look like GR at large distance scales: so if we screw up our eyes it should look like case C. The fact that it can look like both at once is a consequnce of particle-wave duality.

Here is the thread I took it from. Also a good read.

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This reminds me of the Warning: gravity is "only a theory" page, and it's mostly for humor rather than anything factual. As for something with actual meat, try the Thiemann lectures on loop quantum gravity (2002). There's also the paper on the empirical foundations of relativistic gravity (2005).

Gravity as an effective field theory

Brief review of quantum gravity phenomenology

Hope this helps,

- Bryan

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One post that really stuck out from the rest in "Warning: gravity is "only a theory" link was that little bit about negative gravity, at first glance it appeared to be something as werid as suggesting that, if a certain kind of flashlight can give out light than surely anyother kind of flashlight would be able to give negative light ( darkening effect!) but having throught that, i kinda also implyed earlier that "inflation" was some kind of gravititinal thing,

Would it be ok to sum things up by saying that gravity is just a law about knownreactions at present, the working of which is unknown? secondly, any explanation about the working of gravity might only come from quantum Physics and since quantum physics is not as advanced as classical physics it could take some time? third, would a philosophical explantion be more revealing at present? or is it way to premature for any form of an explanation.

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• 4 months later...

jr writes>

1) If we define gravity as the resistance we work against and quantify in terms of our inertial mass, then by definition it is an action generated by mass. It has been an 'a priori' notion for us for as long as the recorded history of thinking. The ideas of up and down, Heaven and Hell, a flat world, and even the Earth as the center of the universe. It is the basis for Newton's universe and Einstein's universe. The idea of "up and down" through the idea of "a curved space time" originates from the same 'a priori' notion. The subjective notion that what we feel is fundamental, augmented by the idea that our quantitative definition(s) of what we feel is causal.

2) The idea that equal and opposite action at a distance existed between orbiting pairs rested on Newton's third law. The third law in turn falls out of the behavior of impacting inertial mass objects. Where we, as inertial mass objects define gravitational force in terms of and proportional to the resistance we work against, inertial mass. The conjecture that this quantified but nonetheless subjective notion of force applies to non-impacting celestial objects or between inertial mass objects and celestial objects is not proved. As far as gravity goes all that is proved is that the effort we as inertial mass objects expend in lifting an inertal mass object is equal and opposite to the comparative measure of the product of the inertial object's mass and the accelerative planet action taken on the balance scale. Where we know that [g] is independent of mass and divides out on the balance scale.

3) Newton defined centripetal force in terms of his second and third law by setting his first law object on a circular trajectory at a uniform motion. Here the law of areas and its controlling time function, falls out as a joined artifact of the efficient area enclosing circle itself. Which eliminates the controlling time function in the real orbits, enabling mass to operate as the sole (non-time controlled) cause of the least action motion. He connected the efficient joined time artifact of the uniform circle motion to Kepler's efficient time controlled law of areas. Newton generalized the least action property of Kepler's law of areas to the entire universe as the mathematical carrier for his centripetal force. He assigned the resistance he worked against (inertial mass) and called "gravity" as the 'a priori' cause of his centripetal force.

If we define gravity as the resistance we work against and quantify in terms of our inertial mass, or the inertial mass of any object we, as inertial mass objects interact with quantitatively, by virtue of the equal and opposite behavior of interacting inertial mass objects, an equal and opposite quantitative, but nonetheless subjective notion of force ensues. This is proved gravity.

Have a good time.

johnreed

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actually if GR is completely correct than gravity could easily be describedas the curvature of spacetime, as that is exactly what GR says. To say that its wrong would be a bit unfair and to state that the new quantum theory will look nothing like it conceptually is not a good thing at all as currently there is alot of progress to nowhere in quantizing gravity and its quite likely that there will turn out to be something new in the future that still looks like GR just with some refinements, such as a quantized spacetime.

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Gravity

The FORCE that attracts two objects to each other in space. (Which force and why is it present?).

If you are referring to outer space, you got to know that objects (planets) are moving aways form each other, the universe is expanding so such attraction seems to be minute!!!

The empty nothingness of space, where gravity seem to excite could also be a product of space itself.

There is no nothingness , it's just dark, something that we still just don't know what it is.

The big bang wasn't chemical.... There was no chemicals...

yeah, you're right. Just the creation of everything from nothingness!

Apparently all the planets in our solar system also rotate in the same direction...

I'm sure, but I've heard somewhere (not sure where!!) that there is one planet in the solar systen, whose trajectory is normal (90 degrees) to other planets trajectories, and that somewhere round 2009 we'll be able to see that planet from our own!

thats a myth

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thats a myth

Le's hope we're alive till 2013 to discuss about it!

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• 3 months later...

No one really knows. Gravity is just some oddball. However, some scientists theorize that planets create "folds" or "dips" in the fabric of space, pulling objects near them. The more mass an object has, the large dip it can create, and the more gravity it will have.

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