What exactly causes gravity?
- Thread starter samj_13
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We haven't discovered what gravity is yet, there are just theories iirc from my physic lessons.
- 7,666
I think Famine is right. The gravitron has a lot to do with gravity. Mass also has a lot to do with Gravity. If the gravitron is a part of the atom, more atoms means more gravitrons, which means more attraction.
If you see Hyperspace it will give you an explanation. Spacetime is like a fabric, like a flat mattress. When you put a massive object down, it creates a divot, which would be gravity. An object trapped in that divot would move toward the middle, or if it had enough speed it would go in a circle a constant distance from the object. My guess would be that a gravitron would cause this dent in the fabric of spacetime.
Make sense?
If you see Hyperspace it will give you an explanation. Spacetime is like a fabric, like a flat mattress. When you put a massive object down, it creates a divot, which would be gravity. An object trapped in that divot would move toward the middle, or if it had enough speed it would go in a circle a constant distance from the object. My guess would be that a gravitron would cause this dent in the fabric of spacetime.
Make sense?
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Okay... Simply put, danoff is right.
Gravity is a function of the mass of two objects and the distance between them.
Quite how this comes about is a bit of a mystery, but the proposed model is that a particle called a "graviton" is emitted by matter (including dark matter and anti-matter) - the more matter, the more gravitons, the more gravity and, handily, as distance doubles, graviton concentration quarters - like gravity...
Gravity is a function of the mass of two objects and the distance between them.
Quite how this comes about is a bit of a mystery, but the proposed model is that a particle called a "graviton" is emitted by matter (including dark matter and anti-matter) - the more matter, the more gravitons, the more gravity and, handily, as distance doubles, graviton concentration quarters - like gravity...
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- skip0110
Gravitons are exchanged between particles with mass.
When a graviton is exchanged, gravity results.
Well thats what the physicists say.
Really there does not need to be a "cause" for gravity. We observed it, and developed a theory to predict how it will behave. In order to refer to it, we named it gravity. Asking what causes gravity is a stupid question, because there is absolutely no practical applications of this knowledge. We know how to model gravity very accurately, and that is all there is to it.
Asking what causes gravity is like asking "what causes F=ma". It is just a model for something we obeserve.
When a graviton is exchanged, gravity results.
Well thats what the physicists say.
Really there does not need to be a "cause" for gravity. We observed it, and developed a theory to predict how it will behave. In order to refer to it, we named it gravity. Asking what causes gravity is a stupid question, because there is absolutely no practical applications of this knowledge. We know how to model gravity very accurately, and that is all there is to it.
Asking what causes gravity is like asking "what causes F=ma". It is just a model for something we obeserve.
- 1,069
- gtjezard
- sj11393
Okay, it's starting to make more sense. I guess I should have asked it as "What exactly is gravity?", but then I would have gotten a bunch of people saying the attraction between everything in the universe, which I already know.
But gravitrons, dark matter, and anti-matter are a bit much to take in for me right now...there was something on the Science Channel last night about dark and anti-matter, too bad I was half asleep.
But there's just one thing about gravitrons. If all matter emits them, but they have no suggested mass, would they just be another form of energy?
But then how is that energy produced?
Is it the moving of atoms in matter that causes vibrations?
But then what would happen if something hypothetically reached absolute zero?
So many questions...
But gravitrons, dark matter, and anti-matter are a bit much to take in for me right now...there was something on the Science Channel last night about dark and anti-matter, too bad I was half asleep.
But there's just one thing about gravitrons. If all matter emits them, but they have no suggested mass, would they just be another form of energy?
But then how is that energy produced?
Is it the moving of atoms in matter that causes vibrations?
But then what would happen if something hypothetically reached absolute zero?
So many questions...
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Another thing about gravity. It has no time of propogation. There is no "speed of gravity."
As for magnetism, that's another force entirely. But any magnet can be broken into a smaller magnet, and no matter how small you break it, it still has a north pole and a south pole, albeit weaker than the big one you started with. So far there is no "monopole."
As for magnetism, that's another force entirely. But any magnet can be broken into a smaller magnet, and no matter how small you break it, it still has a north pole and a south pole, albeit weaker than the big one you started with. So far there is no "monopole."
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- bramturismo
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If you had two protons in a vacuum a large distance apart, which would be stronger, The attraction of gravity between the masses or that the protons are both positively charged and repel each other?
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...strong nuclear force, actually. But the sappy Hallmark-ish-ness of your answer made me laugh either way.
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- landseaair
Does the fact that a black hole has enough gravitational pull to absorb light make any difference in gravitons theoretically traveling the speed of light??
This conversation is very interesting 👍 👍
This conversation is very interesting 👍 👍
- 7,666
As I mentioned earlier, check out Hyperspace. A lot of questions here can be answered there, or by Famine.
The speed of gravity is instantaneous. if the sun suddenly disappeared, we wouldn't know for eight minutes because of the distance from here to the sun and the spped of light. We wouldn't continue to orbit around nothing, would we?
does not involve time.
This also leads me to believe that gravitrons are not transferred between molecules to cause gravity. I would say that they are a more permanent feature of the atom. That would mean that their proximity to each other woudl cause gravity.
The speed of gravity is instantaneous. if the sun suddenly disappeared, we wouldn't know for eight minutes because of the distance from here to the sun and the spped of light. We wouldn't continue to orbit around nothing, would we?
does not involve time.
This also leads me to believe that gravitrons are not transferred between molecules to cause gravity. I would say that they are a more permanent feature of the atom. That would mean that their proximity to each other woudl cause gravity.
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That's a Newtonian equation, and Newton assumed gravity to be instantaneous. Naturally, his equation would reflect that.
It works well enough for bodies in close proximity (and by close, I mean in the way that we're close to the sun, or something), but I think it falls apart in the face of general relativity because it means information is being passed from one body to another at a speed well exceeding the speed of light.
I don't exactly remember the Einsteinian explanation or equations for how gravity works in general relativity theory, probably because it has never been of any use to me in simple kinematics or dynamics I've done. But I'm sure if you need to know you can google it. ...there was a second derivative and something about weak field gravity potential... or something along those lines. It's been awhile since I took Physics II, a lot of that knowledge about general relativity is lost.
It works well enough for bodies in close proximity (and by close, I mean in the way that we're close to the sun, or something), but I think it falls apart in the face of general relativity because it means information is being passed from one body to another at a speed well exceeding the speed of light.
I don't exactly remember the Einsteinian explanation or equations for how gravity works in general relativity theory, probably because it has never been of any use to me in simple kinematics or dynamics I've done. But I'm sure if you need to know you can google it. ...there was a second derivative and something about weak field gravity potential... or something along those lines. It's been awhile since I took Physics II, a lot of that knowledge about general relativity is lost.
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- skip0110
👍 👍
Thats exactly right. Einstein defined equal times in spacetime through the synchronization of clocks at different locations via a pulse of light. The fact that you can't pass information any faster than the speed of light is an interesting side effect. Since equal times are defined around the time it takes a light pulse to go from one location to another, by sending information faster than the speed of light, you would be send it back in time (effectively time travel), which is impossible.
To use the sun example, if we did not continue rotating around the sun for 8 minutes, we would know the sun was gone before the light reaching us from it disappeared.
When considering this law in the context of quantum mechanics, things can get interesting. For example, the phenomenon of quantum entanglement is often misunderstood. It says that you can have two particles whose states will always be the same. Quantum mechanics says this will be true even if the particles are separated by a great distance (a phenomenon often called rather inappropriately quantum teleportation in popular magazines). Does this mean that I can move information faster than the speed of light, because if I change the state of a particle here, then an entangled one far away will reflect that change immediately? Nope. Heisenberg says that when I go to look at that entangled particle, it's state will simultaneously decompose with such probabilities that I didn't learn any information at all.
Cool stuff.
Personally, I'm satisfied with this explanation, because it's sufficient to model anything we want to. Physicists, though, have too much time on their hands...they are asking the question, how does one particle "know" that it is close to another particle and it is attracted to it? Which is a stupid question IMO.
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- Gai-Gun
I remember reading an old Michael Crichton book (maybe 'Sphere') where there was a theory about space not being empty and bodies (mass) making dents in(displacing) it, and this could be what we consider gravity.
But then again, I read that book long ago, and I can't remember the specifics. An interesting idea at the time.
But then again, I read that book long ago, and I can't remember the specifics. An interesting idea at the time.
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This is a really interesting topic but one which my high school understanding of physics only partially understands, while i have read up on stuff like this before only bits of this makes sense to me. Hopefully once i join collage and even university i will have a greater understanding of this topic
