Gravity verses electromagnetic attraction

[malawi_glenn]

What is over simplified? The General Theory of gravity? Have you studied it at university?

 

[W3pcq]

What is over simplified? The General Theory of gravity? Have you studied it at university?

That gravity is caused by the curved space time. Do you actually understand what that means or how that works?

Also, I have never heard of "The general theory of gravity", what is that?

 

[W3pcq]

I tohugh you could use your logic, since I have two times stated that all mass generates gravity and since the neutrons have mass, they generate gravity. Many people thinks that the role of the neutron in atoms are to generate gravity, that is a very big missconception! (does not the hydrogen atom generate gravity??).

Another missconception is that people tends to separate gravity from space-time curvaturing. Gravity IS curvature in space, generated by mass.

Sorry, you should have said it different, you must not know the english language very well. You should have said it like this: All mass generates gravity, NOT just the neutron.

 

[W3pcq]

It is just boring to thoughtlessly recite lines that you have memorized and not even understand what you are saying.

 

[cristo]

That gravity is caused by the curved space time. Do you actually understand what that means or how that works?

I'm not sure that this is the place for teaching you General Relativity. In short, and as malawi_glenn has mentioned, gravity is the curvature of spacetime-- it is not cause by the curvature of spacetime.

In some cases gravity can be repulsive instead of attractive. But in every day circumstances you're right.

Elaborate. I am mystified.

I guess Nerfmonkey is talking about exotic scenarios in which the pressure of the "matter" is negative, like in the case of "dark energy" (whatever that may be). This will give rise to a repulsive gravity term.

 

[W3pcq]

One theory about the accelerating universe is that gravity becomes repulsive in some conditions.

 

[cristo]

One theory about the accelerating universe is that gravity becomes repulsive in some conditions.

You mean like the condition I just mentioned?

 

[malawi_glenn]

i. Yes a know a bit how Einsteins field equations work, but I will not be able to study its derivations and so on until I get into grad-school, I am still undergraduate and we have still only got the forumulas and learn how to use them, not to derive them.

ii. The general theory of gravity is called many things, like Einsteins general theory of relativity and so forth.

If you don't have any idea what this is, then I am stunned how you still want to argue with me about what gravity is and how it works. The language of physics is math, therefore one can not understand physics correct by using every day life thinking and non-mathematical reasoning.

iii. I ve seen many people who have the missconception that the neutron is the only source of gravity in atoms.

iv. I have quite good knowledge about the English language, if I say "All mass generates gravity" then I of course mean that neutrons, which has mass, is generating gravity. Then one can use his/hers logic to draw the conclusion that massive objects which are not neutrons also generates gravity.

v. I think its boring that people who aren't students of physics, or working physicists, can judge wheater a person have understand something or not. As cristo said, this is not the appropiate place where to study general theory of gravity (I can give you a study plan and book references if you want to learn it, or recommend a college/university), but we (who are physicists) can answer questions about gravity in a short and quite understandable way (that is of course something subjective).

The main question was "what is the difference between gravity and electro magnetic force"? Then some missconceptions where brougth up (the ones I mentioned earlier), and those I gave short comments on.

 

[W3pcq]

I would like to know more about the link between time and gravity. When an object approaches a gravitational field, it's clock slows right. Why is this? Does this have anything to do with sub atomic spin?

 

[W3pcq]

You mean like the condition I just mentioned?

You added that part in after I posted.

 

[W3pcq]

i. Yes a know a bit how Einsteins field equations work, but I will not be able to study its derivations and so on until I get into grad-school, I am still undergraduate and we have still only got the forumulas and learn how to use them, not to derive them.

ii. The general theory of gravity is called many things, like Einsteins general theory of relativity and so forth.

If you don't have any idea what this is, then I am stunned how you still want to argue with me about what gravity is and how it works. The language of physics is math, therefore one can not understand physics correct by using every day life thinking and non-mathematical reasoning.

iii. I ve seen many people who have the missconception that the neutron is the only source of gravity in atoms.

iv. I have quite good knowledge about the English language, if I say "All mass generates gravity" then I of course mean that neutrons, which has mass, is generating gravity. Then one can use his/hers logic to draw the conclusion that massive objects which are not neutrons also generates gravity.

v. I think its boring that people who aren't students of physics, or working physicists, can judge wheater a person have understand something or not. As cristo said, this is not the appropiate place where to study general theory of gravity (I can give you a study plan and book references if you want to learn it, or recommend a college/university), but we (who are physicists) can answer questions about gravity in a short and quite understandable way (that is of course something subjective).

The main question was "what is the difference between gravity and electro magnetic force"? Then some missconceptions where brougth up (the ones I mentioned earlier), and those I gave short comments on.

I didn't ever mean to get into an argument with you. You kept wording a sentence wrong making it mean something that you didn't intend.

 

[W3pcq]

Look, I'm sorry I used a metaphor that isn't in a physics book to try and look at things from a new angle. Why are you guys so upset about it?

 

[malawi_glenn]

I would like to know more about the link between time and gravity. When an object approaches a gravitational field, it's clock slows right. Why is this? Does this have anything to do with sub atomic spin?

Remember that the general theory of gravity is not a quantum theory.

You may want to start a new thread or search for old or just google, there is plenty much written about this topic.

 

[malawi_glenn]

I didn't ever mean to get into an argument with you. You kept wording a sentence wrong making it mean something that you didn't intend.

So what is wrong with "All mass generates gravity" ?

 

[W3pcq]

Remember that the general theory of gravity is not a quantum theory.

You may want to start a new thread or search for old or just google, there is plenty much written about this topic.

This is an Astrophysics forum not a GR forum. If we can only talk about GR, then maybe it should be moved there?

 

[W3pcq]

So what is wrong with "All mass generates gravity" ?

You kept saying : "All mass generates gravity, just not the neutron." This statement implies that a neutron doesn't generate any gravity. You should have put the NOT before the JUST, and then it would have been correct.

 

[malawi_glenn]

This is an Astrophysics forum not a GR forum. If we can only talk about GR, then maybe it should be moved there?

This thread has lost focus from the original question, therefor you may want to start a new thread. GR is a part of astrophysics, and cosmology, so try the cosmology forum.

 

[malawi_glenn]

You kept saying : "All mass generates gravity, just not the neutron." This statement implies that a neutron doesn't generate any gravity. You should have put the NOT before the JUST, and then it would have been correct.

ah then I see! Thanx! :-)

 

[W3pcq]

I like the topic though, only put differently. The only problem is that if science had resolved this question, then we could talk about it, but since science has not, then there is only speculation, and that isn't allowed. The next best thing to do is try and more clearly understand what gravity is, and what EM is. If all we can do is say curved spacetime and go no further as to what that means, then we are all just wasting time.

 

[cristo]

W3pcq: Do you actually have a question, or are you just trying to stir someone up the wrong way? You seem to be asking random questions, and flitting from one to another. IF you have a well-posed question, that you have actually thought about and are confused by, then feel free to ask it in the relevant forum. But, you need to stop the sort of posting style you have adopted in this thread, now!

I should also point you to the Pf Guidelines which disallow any overly speculative posts. I encourage all users to report such posts and, if you feel you are being personally attacked, like you said here, to report the offending post so that the matter can be looked into, rather than responding.

Thank you.

 

[malawi_glenn]

What question? What the difference between gravity and EM is?

I think contemporary science has a very good explanation for that, which I and others here have argued for. Also science has good explanation what EM and gravity is.

Maybe it is just you who don't know what curvature in space-time is? That is a physical concept, and here lies a big difference - physicists thinks and reason in a different way that a non-physicists does, therefore it is hard for a layman to understand things in the same way as a physicists does.

 

[dude222]

There is an interesting way to calculate the electromagnetic force without using the magnetic field. An example is given at johnwilliams22dothi5dotcom. This same technique can be applied to Newton's theory, except it needs to be slightly modified to account for the fact that the force on the influenced particle is proportional to its energy. Does anyone have a good reference for this?

 

[Khursed]

Although many if not most hold onto the hope that some time (most likely long from now) all of the fundamental forces will somehow be unified... according to our understanding, gravity and E&M are very different.
For instance, E&M forces don't act on things without charge (i.e. neutral sums of charged particles or neutrinos(?) ).
Similarly, gravity doesn't effect massless particles (i.e. photons).
The details of the differences aren't too important, but another one of the main things, is that gravity is about a billion times weaker than the E&M forces.

Gravity is more like 41 order of magnitude smaller then electromagnetism. Which makes a billion look small.

 

[russ_watters]

I just happened to wade into this, but I'm struck by the possibility that much of the issue here might be due to a grammar error:

All mass generates gravuty, just not the neutron. [emphasis added]

Did you reverse those two words? Did you mean 'All mass generates gravity, including the neutron and all other massive particles'?

 

[Redbelly98]

Russ, I think that statement got cleared up eventually:

Sorry, you should have said it different, you must not know the english language very well. You should have said it like this: All mass generates gravity, NOT just the neutron.

 

[Laidback]

Also, gravity is strictly an attractive force, whereas electromagnetism can work to attract or repel.

Hi there Nabeshin,

Could you do me a favour and explain to me how attraction is actioned or possible?

As I was under the impression all forces are Repulsive..

Cheers,

Peter J schoen..