What is gravity? I'll tell you what it is.

[chembuff1982]

Here's my hypothesis on what gravity is. You can leave all the criticism you want, because it's an open mind that is doubted that has the possibility of coming true. <br /> So we have gravity and spacetime. What causes gravity? Matter and energy in collective units spread out through the universe bend spacetime. If spacetime did not counteract this force, the universe would fold in and never exist. Think of a rubberband, what happens when you pull the rubberband out (here's the old rubberband example), the rubberband which is elastic, bends back. Spacetime to will create a counter force which is equal to the force created by matter and energy. This force is known as gravity. If you are wondering why gravity has pretty much no effect out side of a collective mass or energy, this is so because spacetime is not bending back there creating a counter force (gravity), thus you are weightless until you come close enough to the object. It makes so much sense, think about it, you don't have to be Einstein to realize that. <div class="Discussion_UserSignature"> You may be a genius, but google knows more than you! </div>

 

[enigma10]

So why does matter bend space-time? <div class="Discussion_UserSignature"> <em>"<font color="#333399">An organism at war with itself is a doomed organism." - Carl Sagan</font></em> </div>

 

[why06]

You just posted the thery of relativity. Maybe a hundred years ago that would have been a profound statement, but someone already invented that concept and his name was Einstein....<br /><br />Ps: I had thought bonzelite started this thread before I read the name <img src="/images/icons/laugh.gif" /> <div class="Discussion_UserSignature"> <div>________________________________________ <br /></div><div><ul><li><font color="#008000"><em>your move...</em></font></li></ul></div> </div>

 

[chembuff1982]

To be honest, I don't read much of science books, I really do derive my own thoughts. Remember when I wrote a hypothesis and this site said Stephen Hawking already had it? Well I never even to this day have read his work. Anyways, if this is so, has he come up with a proportional constant for gravity due to spacetime? It wouldn't be that hard to take a collective mass and energy and determine the ratio from gravity with several samples in our galaxy? This would definitely prove that this is what causes gravity? Or did they prove this already. I'm confused, everyone on this site has been saying they aren't sure what creates gravity. Someone fill me in. You people change your mind by the post. <div class="Discussion_UserSignature"> You may be a genius, but google knows more than you! </div>

 

[weeman]

Gravity has never been proved. Even if Einstein's and Hawking's theories are widely accepted, it still doesn't mean we have found the answer.<br /><br />Einstein believed that any object with mass, meaning something as small as an atom (or smaller), bends spacetime around it. Gravity is simply how we perceive the bending of spacetime.<br /><br />However, just like Enigma asked; why does matter bend space-time?<br /><br />Visualize this, we observe a planet revolving around the Sun in a circular pattern. This is because the planet is held in orbit by the Sun's gravity. However, in all reality, the planet isn't necessarily traveling in a circle, the planet is traveling as straight as it can go. But due to the bending of spacetime from the Sun's mass, the planet appears to travel in a circle. <br /><br />This is the basic idea of Einstein's theory. <div class="Discussion_UserSignature"> <p> </p><p><strong><font color="#ff0000">Techies: We do it in the dark. </font></strong></p><p><font color="#0000ff"><strong>"Put your hand on a stove for a minute and it seems like an hour. Sit with that special girl for an hour and it seems like a minute. That's relativity.</strong><strong>" -Albert Einstein </strong></font></p> </div>

 

[chembuff1982]

I said matter/energy bends spacetime. It all goes back to the earth example of standing by a train, large objects that move by or move by at high speeds create a pull, on the other object which ineffect would be bending or pulling spacetime, and space time bends back just like the rubberband example. <div class="Discussion_UserSignature"> You may be a genius, but google knows more than you! </div>

 

[enigma10]

That didn't answer my question. Think harder.<img src="/images/icons/wink.gif" /> <div class="Discussion_UserSignature"> <em>"<font color="#333399">An organism at war with itself is a doomed organism." - Carl Sagan</font></em> </div>

 

[sad_freak]

it just does!!!<br /><br />for instance: the sun bends the space around it. all the plaents go round the sun, BUT the planets are accually going in a stright line throught the curved space created by the sun. <br /><br />like was said originally gravity is the result of space bending and curving. <br /><br />every object has a gravotiational field. the pattern of bening it creates around itself.

 

[why06]

Gravity is an observation. We know it exists because we can see it, but what causes gravity.<br />Mass?<br /><br />We know gravity is a result of mass, now how does mass cause gravity?<br /><br />Bending of spacetime? that a good one<br /><br />Perhaps something else?<br /><br /><br />Enigma 10:<br />Why does mass bend spac-time?<br /><br />Answer: "Does matter bend spacetime"<br />If so: "How would it?"<br />"What is the signifigance of this?" <div class="Discussion_UserSignature"> <div>________________________________________ <br /></div><div><ul><li><font color="#008000"><em>your move...</em></font></li></ul></div> </div>

 

[weeman]

I think I am completely unable to answer your original question Enigma <img src="/images/icons/tongue.gif" /><br /><br />Have you researched this at all? Do scientists know exactly why a mass creates this bend in 4-D Spacetime? <div class="Discussion_UserSignature"> <p> </p><p><strong><font color="#ff0000">Techies: We do it in the dark. </font></strong></p><p><font color="#0000ff"><strong>"Put your hand on a stove for a minute and it seems like an hour. Sit with that special girl for an hour and it seems like a minute. That's relativity.</strong><strong>" -Albert Einstein </strong></font></p> </div>

 

[sad_freak]

<blockquote><font class="small">In reply to:</font><hr /><p>...Einstein proposed that spacetime is curved by the presence of matter, and that free-falling objects are following the geodesics of the spacetime. More specifically, Einstein discovered the field equations of general relativity, which relate the presence of matter and the curvature of spacetime and are named after him. The Einstein field equations are a set of 10 simultaneous, non-linear, differential equations whose solutions give the components of the metric tensor of spacetime. A metric tensor describes a geometry of spacetime. The geodesic paths for objects in inertial motion in a spacetime are calculated from the metric tensor of that spacetime<p><hr /></p></p></blockquote><br /><br />the fisrt post says the whole theroy pretty accuratley i think.<br />

 

[SpeedFreek]

Yes the original poster made a pretty good but simple description of the space-time model as proposed in Einsteins relativity. He also, later in the thread mentions that he came up with the same solution as Hawking in another thread, and claims "I don't read much of science books, I really do derive my own thoughts."<br /><br />So I would suggest he did read a few science books, so as to not repeat others work and waste his time. <img src="/images/icons/wink.gif" /><br /><br />But he does ask if we are sure yet what creates gravity, and the answer is, we are not sure. The concept that mass can bend space-time and cause the effect we attribute to gravity seems to work when compared to our obervations, but to understand what <i> causes </i> this, we have to, as others have said, understand <b>why</b> mass bends space-time, by what <i> mechanism. </i><br /><br />We haven't found the mechanism yet. <div class="Discussion_UserSignature"> <p><font color="#ff0000">_______________________________________________<br /></font><font size="2"><em>SpeedFreek</em></font> </p> </div>

 

[nevyn]

Please explain how you know that mass causes gravity. I am unaware that it has been proved or even has any evidence.<br /><br />You might also want to explain what mass is, as well. I've never found a good explaination of what it is or why it occurs or why it causes gravity. Until I have these things I will not accept that it even exists.<br /><br />As for spacetime: there can be no such thing. In physics, a dimension is what can be measured by a ruler. Mathematics uses the term dimension to mean any number of variables in an equation. Modern physics misuses the mathematical term in the physical context. Once you realise that time can not be a dimension, then you have to let Relativity go, and most of physics for the last 100 years.

 

[weeman]

<font color="yellow"> I've never found a good explaination of what it is or why it occurs or why it causes gravity. </font><br /><br />Well, first of all, for the definition of mass, this might help answer your question, or at least get you close to it!<br /><br />http://en.wikipedia.org/wiki/Mass<br /><br />As for why it occurs or why it causes the fabric of Spacetime to bend, no one really has a clue. To ask why it occurs, in some ways, is no different than asking one of the original questions: Why is the Universe here? <br /><br />We don't know why it occurs. Why did matter come to be? Why did everything come to be? In a sense, when you're asking why matter occurs, you're using your own words to ask the age old philosophical question of everything <img src="/images/icons/smile.gif" /> <div class="Discussion_UserSignature"> <p> </p><p><strong><font color="#ff0000">Techies: We do it in the dark. </font></strong></p><p><font color="#0000ff"><strong>"Put your hand on a stove for a minute and it seems like an hour. Sit with that special girl for an hour and it seems like a minute. That's relativity.</strong><strong>" -Albert Einstein </strong></font></p> </div>

 

[why06]

I don't knoow if the word "cause" was a good choice. Perhaps a better one would have been have. Gravity is a property of mass. I 've never seen mass withought gravity and I probalbly never will. We don't know what causes it. What we do know is it only originates from mass and there are no other candidates in which present this kind of effect. actually there is only ONE candidate... energy, and gravity seems to have no effect on it.<br /><br />E=mc^2<br />This equation means that the equivalent amount of energy to on unit of mass would be that mass multiplied times the speed of light SQUARED! That is an enourmous amt of energy. In theory one would believe Mass is super-condensed energy. This may clarify things, but I don't understand how you think mass doesn't exist... Have you stepped on a scale lately?<br /><br />As for space-time:<br />How do you know time cannot be a dimension? Thats what everyone thought before Einstein. And this was probalbly one of the first questons his theory had to face. Time has been shown to slow down and speed up with speed. Differences of time at in a plane vs. at home have been mesured with atomic clocks. Weve seen evidence. You don't know enough about time to say that. No one does. You live in one dimension of time. That like existing as an infinitey small point on a one-dimensional line. How can you possibly understand 3-dimensions as a point? <div class="Discussion_UserSignature"> <div>________________________________________ <br /></div><div><ul><li><font color="#008000"><em>your move...</em></font></li></ul></div> </div>

 

[ajna]

Another thing associated with gravity wells is slowed time compared with an observer higher in the well. Following on from what Brian Greene says about strings, characteristics in the curled-up dimensions control such things as mass etc. (For small dimensions, the size of a quantum must be small, making it highly energetic, meaning greater mass. These are not seen because they are too energetic for the macro dimensions, yet probably account for some dark matter). It seems to me that as the dimensionality changes so do the properties of matter/energy contained in that <i>and vice versa</i>. I don't know anything about tensors but they become shorter or longer reflecting the curvature. This seems awfully like a spaceship becoming shorter as it approaches the speed of light. Here i suspect is a dimensional change as well. We must look to the dimensional properties to see why gravity is. My question is what would need to change in the 11 dimensions (M-theory model) to cause tensors becoming shorter?

 

[nevyn]

Gravity is a property of mass? Never proven. And I don't see how a dynamic force like gravity can come from a static property. And if it is a property, then how is it that the gravity of the earth varies? I'm pretty sure that the mass is not varying. There are also known regions of the moon that exhibit gravity anomalies so much that NASA must be careful of them.<br /><br />You say "What we do know is it only originates from mass" but what you are actually saying is that it is only found where we find matter. Matter is not mass.<br /><br />Stepping on a scale does not prove mass. It proves gravity and weight. Basic principle of physics is that mass and wieght are not the same thing because weight is affected by gravity. I will not weigh the same on the moon, but I will still have the same mass.<br /><br />How do I know time can not be a dimension? Simple: I can't measure it with a ruler. That is the definition of a dimension in physics. In mathematics, that's a different story because a dimension is something different. Einstein created a purely mathematical model. Nothing more, nothing less. This does not mean it has anything to do with physics because physics is about concepts, not values. Relativity provides no concepts for the real world. It provides a way to calculate some things which closely correspond to some things we measure in reality, but that doesn't make it reality.<br /><br />We knew that gravity measured out to an inverse square law before Newton wrote the Principia. Therefore the theory must come to this value/equation otherwise the creator would keep working on it until it does (probably why Newton took years to show his theory of it after he said that he already had it).<br /><br />The reason I don't believe in mass is because it was a fudge used when Newton's theory didn't work. His theory was that everything was made up of a single particle, uniformely distributed throughout a body so he could use volume to calculate orbits.<br /><br />Now we've proven that

 

[SpeedFreek]

<i> 'Gravity is a property of mass? Never proven.' </i><br /><br />Gravity is <i> proportional </i> to mass. Two planets, one has a mass double the other. For the planet with double the mass, gravity is doubled. If they are the same size, <i> surface </i> gravity is doubled.<br /><br />Because of this, we think there might be a connection between mass and gravity. Mass has gravity, gravity has mass. They are both part of the same thing. We see the mass but we don't see the gravity, we only see it's various effects on <i> other </i> masses.<br /><br />Weight is the force imparted by the gravitational attraction between a smaller mass by a larger mass, at a certain distance from the centre of gravity of the larger mass. As gravity diminishes over distance, you weigh less the further you are from the centre of gravity of the larger mass.<br /><br />Does this mean that mass might <i> cause </i> gravity? It might. But is it just as likely that gravity might cause mass? All we know for sure is that gravity is proportional to mass.<br /><br />As for time, well there are two views, the scientific and the philosophical.<br /><br />Newton thought that time is part of the fundamental structure of the universe, a dimension in which events occur in sequence, and time itself is something that can be measured.<br /><br />Einstein showed that time and space are mathematically linked to each other in a way that also links energy, momentum, mass and force.<br /><br />Then there is the philosophical view of Leibniz that time is part of our mental measuring scheme.<br /><br />But back to the point, <i> modern </i> physics views the curvature of spacetime around an object as much a <i> feature </i> of that object as are its mass and volume. <div class="Discussion_UserSignature"> <p><font color="#ff0000">_______________________________________________<br /></font><font size="2"><em>SpeedFreek</em></font> </p> </div>

 

[vandivx]

<font color="yellow">Gravity is a property of mass? Never proven. And I don't see how a dynamic force like gravity can come from a static property.</font><br /><br />mass is not a static property! mass is a measure of inertia which is a dynamic measurement<br /><br /><font color="yellow">And if it is a property, then how is it that the gravity of the earth varies? [...] Now we've proven that atleast the earth is not a uniform density.</font><br /><br />doesn't the latter answer the former in the above quote? and why would it need proving? one doesn't have to measure anything to know beforehand that the gravity of Earth won't be uniform, I mean its not molten body 100% mixed and not free from influences, so what's the problem there<br /><br />vanDivX <div class="Discussion_UserSignature"> </div>

 

[ajna]

nevyn i love your answers you raise good points. i agree that time doesn't flow and so how could i have said that time 'speeds up' or slows down? each now of time has its own reference frame that varies from place to place (and from time to time). just like tensors in a grav well, to themselves they are exactly as they have been all eternity, but from somewhere else the appear shorter or longer depending on gravity, speed etc.<br /><br />From what has been written I have a hypothesis that mass is caused by the inertia of energy of quanta. It also explains the effect of gravity (but not the curvature of spacetime - yet).<br /><br />Imagine that the tensors are shorter deeper in a grav well. Compared to higher up, time will have to be slower so that each (shorter) tensor is traversed by a photon (say) in the same amount of <i>subjective</i> time as any other tensor. That explains the time effects of gravity. <br /><br />The effect of gravity (weight) becomes apparent when we try to move or hold something against it. Why would quanta want to move down the well? Because time is slower there and so it will have a lower <i>relative</i> energy because it is vibrating more slowly, but its subjective energy/vibration will remain the same. If you try to raise something up, you are working against the tendancy of the matter to fall to a slower time-frame. You need to do work to lift the matter to a faster vibratory rate in the faster time that exists higher up the well.<br /><br />This is just an idea. What I don't see yet is why/how tensors become relatively shorter because of the presence of matter. mmmm

 

[vandivx]

<font color="yellow">Newton thought that time is part of the fundamental structure of the universe, a dimension in which events occur in sequence, and time itself is something that can be measured. </font><br /><br />time measures the rate at which things change and that can certainly be measured, typically we pick some stably changing 'standard of change' like periodicaly oscillating spring as in a watch (or better oscillating atom) and compare other changes to this standard - we measure change by a change same as we measure length by a length (by length standard)<br /><br /><font color="yellow">Does this mean that mass might cause gravity? It might. But is it just as likely that gravity might cause mass? All we know for sure is that gravity is proportional to mass.</font><br /><br />egg causes chicken and chicken causes egg, both are right and so mass causes gravity and gravity causes mass are also both right<br /><br />vanDivX <div class="Discussion_UserSignature"> </div>

 

[skippystars]

Good stuff all,<br /><br />Nevyn, if I can quickly butt in and ask you. Based on your final paragraph beginning with; "Time has not been shown to speed up and slow down. Clocks have been shown to speed up and slow down...", based on such a statement would you say that the classical presumption that traveling near or at the speed of light would not make the loved one's you left behind not age faster than you? <br /><br />I have no position in this as I think everyones argument has validity. I'd just like to know more about your thought process if possible. Thanks.<br /><br />SK

 

[ajna]

vanDivX you said that mass is a property of inertia, a dynamic energy. I tie that with what Brian Greene has said about super-massive particles too heavy to be in this dimension. His premise was that because the curled up dimensions are so small, the energy of a quantum must be high (therefore less spread-out) to fit in, giving it immense inertia and hence enormous mass by particle standards. Because the dimension is so small we don't detect it directly in 4D.<br /><br />I made a mistake in my prev post: "Why would quanta want to move down the well? Because time is slower there and so it will have a lower relative energy because it is vibrating more slowly, but its subjective energy/vibration will remain the same." I was wrong because it is precisely <i>because</i> of the slower time-frame that the particle maintains its relative energy, even though to itself its energy is increasing. Why does it increase? Because of entropy. The more energetic a particle is, the more virtual activity there will be around it, increasing entropy. And so I think quanta of any kind have a natural tendency to be as close as possible to slower time-frames so that their entropy can increase via this effect. This explains the <i>nature</i> of gravity but not its substance.<br /><br />vanDivX you also brought in the chicken and the egg, stroke of genius. You may be pointing to a symmetry here between 'inertia' (tied up energy) and gravity/speed (time frames). Both of these appear at once do they not? Are they mutually interdependent?<br /><br />Cheers, Ajna<br /><br />

 

[vandivx]

Ajna, I wouldn't put it quite that way - that mass is the property of inertia - but rather that it is a measure of inertia<br /><br />and yes, 'mass' is not some static property (attribute) of matter, it is a measure of the gravitational and inertial properties of matter<br /><br />I don't do that kind of physics that BG does, I wouldn't understand anything about those dimensions he talks about<br /><br /><font color="yellow">You may be pointing to a symmetry here between 'inertia' (tied up energy) and gravity/speed (time frames). Both of these appear at once do they not? Are they mutually interdependent?</font><br /><br />well, Einstein told us that we can't tell one from the other (his famous lift thought experiment when you couldn't tell if the lift was being accelerated on a rope in free space or if it was just hanging suspended in a gravitational field above a planet)<br /><br />but that doesn't tell us what makes it the same, just that it is<br /><br />keep going <img src="/images/icons/smile.gif" /><br /><br />vanDivX <div class="Discussion_UserSignature"> </div>

 

[neolistic]

Gravity is created by a mass in space. It is the force of space pushing down on the mass, exp: earths gravity is based on its size. The smaller a object in space, the less gravity it has. If there were no planets, or suns in space gravity would not exist. <br /><br />Exp: you take earth out of space, and drop earth, and yourself standing on earth down in jupitors atmosphere. Both you, and earth will fall at the same time. Earth no longer has its own gravity to support you, so you fall with earth.