Force between two atoms

[HydrogenBond]

If the hydrogen proton and electron combine to make a neutron, than gravity would be the only force; an attractive one at that. But separate, the EM force will dominate gravity.

 

When electrons are moving in space, they not only give off electro-static forces but also magnetic forces, i.e., moving charge. If one uses the right hand rule, the direction of the electron current and the perpendicular magntic field direction will create another force perpendicular to these two force vectors, if another similar system is present, i.e., second hydrogen atom. In the case of the two hydrogen atoms, if the spins of the electrons happen to be opposite and/or their circulations are opposite, the two hydrogen atoms will attract, due to the third or right hand rule force. The result could be a collision that forms a hydrogen molecule.

[Qfwfq]

Isn't this one of the primary areas of focus of individuals searching for a GUT / TOE? I'm not sure it's been "proven" one way or the other (there is or is not a link between gravity and EM)...

True but, further, I had replied to:

 

the possibility of gravity being due to EM

the negation of which has a slightly different meaning than:

there is no relationship between gravity and EM

Many physicists are working on the idea of there being a relationship between gravity and EM (as well as strong and weak nuclear) forces but this would not quite mean one being due to the other. It simply means a framework which describes them all. Now there is something about gravity in common with the standard model. Does your calculus book include group theory and gauge symmetry? But there are also many differences.

 

Regarding gravity being a net effect of EM forces, and forgetting a sec about GR and it being a geometric effect, many have tried giving it a thought but it runs into difficulties. How do we explain there being a net effect between two electrically neutral bodies? A strongly charged one can attract dust or other tiny bodies by induction, that are overall neutral, this is due to the opposite charges getting displaced, they can move a bit differently from each other so the attractive force prevails. It also depends on the field having a gradient, so it's dependence on distance is not the inverse square law. Neutral bodies may also have a magnetic moment, but neither does this give the inverse square law and it also depends on orientation. It would be even harder to derive an effect that depends so strictly on mass when this can change without the positive and negative charges changing.

[Little Bang]

Hydro, the proton and electron can't form a neutron on their own. This only happens in the fusion process.

 

Q, the atoms A and B are electrically neutral but the force of attraction that proton A has for electron B extends to infinity.

[Qfwfq]

...and so does the repulsion between proton and proton and between electron and electron.

[Little Bang]

Here is another little item I found at wiki.

 

, which describes the interaction of electric charges:

 

mathbf{F} = frac{1}{4 pi epsilon_0}frac{Qq}{r^2}mathbf{hat r} = qmathbf{E}

 

is similar to the Newtonian gravitation law:

 

mathbf{F} = Gfrac{Mm}{r^2}mathbf{hat r} = mmathbf{g}

 

This suggests similarities between the electric field E and the gravitational field g, so sometimes mass is called "gravitational charge".

 

Similarities between electrostatic and gravitational forces:

 

1. Both act in a vacuum.

2. Both are central and conservative.

3. Both obey an inverse-square law (both are inversely proprotional to square of r).

4. Both propagate with finite speed c.

 

Differences between electrostatic and gravitational forces:

 

1. Electrostatic forces are much greater than gravitational forces (by about 1036 times).

2. Gravitational forces are always attractive in nature, whereas electrostatic forces may be either attractive or repulsive.

3. Gravitational forces are independent of the medium whereas electrostatic forces depend on the medium. This is due to the fact that a medium contains charges; the fast motion of these charges, in response to an external electromagnetic field, produces a large secondary electromagnetic field which should be accounted for. While slow motion of ordinary masses in response to changing gravitational field produces extremely weak secondary "gravimagnetic field" which may be neglected in most cases (except, of course, when mass moves with relativistic speeds).

[Little Bang]

Is there a location in an electrons energy level where the probability of find it is higher than in other positions?

[Jay-qu]

In a closed system with no other forces from the outside, no. Once you add other charges though, it will become skewed and more likely to show up at certain places rather than others.

[Little Bang]

Jay, how would it be in my hypothetical universe?

[Jay-qu]

Good question.. I tried to think of where they would be, first I thought that they would stay where they are, but now I am unsure. Ill look into it, anyone else know?

[HIENVN]

Hi all,

This is an interesting supposition that I mean quantum theory and relativity theory can not solve this supposition.

The right solution is belonging to an improvement of Newton’s first law (principle of inertia). An improvement of Newton’s first law will explain the existence of these atoms in the language of quantum and relativity theory.

[Little Bang]

A new thought has occurred to me, if there were a slight difference in the magnitude of charge between the proton and electron ( say the proton was 10^-36 weaker than the electron ) that difference would show up as gravity.

 

That is wrong, it would have to be the electron that is weaker by 10^-36

[Qfwfq]

How would it be attractive?

[Little Bang]

Upon further thought we don’t need any difference in the magnitude of the EM force. Lets go back to my original premise of a universe with two hydrogen atoms separated by some distance. I want to pick a point in time where the electron of atom A is at it’s closest point to atom B. Now I’m going to wave my magic wand, freeze atom A in this position and make the electron of atom B disappear from my hypothetical universe. I think proton B would find the location where it’s force of attraction for electron A was exactly equal to it’s force of repulsion for proton A. Your response to this would be, “Well, yes but this situation doesn’t exist in the real universe.” and you are right but something similar does exist. When the electron B is farther from proton A in the same scenario as above. The math to show this connection with gravity may or may not be straight forward but the larger atoms would be extremely complicated.

[Rade]

I'm not sure if this question has been answered but it is a question that results from another forum on the same topic--any help with answer is appreciated--what understanding of EM force do I lack ?:

 

...Suppose the hypothetical universe is a circle with diameter of 2 lightyears. Now, place the two hydrogen atoms at each end of the circle opposite each other, 2 lightyears apart. Does not theory predict no EM attraction between the two atoms for 2 years (730 days) since it is photons that mediate the EM force and they cannot travel faster than c ? Next, what is the origin of the photons that will result in the EM attraction when it does occur after 730 days, is it from the two atoms, or from the space-time between the two atoms, or both, or neither ?

[Little Bang]

First Rade, I personally dont believe that particles mediate any forces. I think that even the strong and weak nuclear force is some type of logrithmic jump in the charge of the proton and electron which probably has something to do with the formation of the neutron. But you are right, it would take two years before the two forces of each atom reached the other and started them moving towards each other.

[Rade]

First Rade, I personally don't believe that particles mediate any forces. I think that even the strong and weak nuclear force is some type of logarithmic jump in the charge of the proton and electron which probably has something to do with the formation of the neutron. But you are right, it would take two years before the two forces of each atom reached the other and started them moving to wards each other.

Thank you, but the "photon" is not a particle. If I am correct, and I think this gets to your OP question, after the two years of time, you seem to imply that the photons would come from the two atoms--correct ? But how, what is the mechanism that lets each atom come to a state where ?...OK, time now to send photons on a 2 year journey to attract that other atom...

Finally, on the journey, would the photons meet at the center, perhaps form collisions (experiments with photon-photon collisions are well known)--thus how can we predict the journey is ever completed, that 100% of photons do not collide. I know, all very abstract, but then the OP is a hypothetical study.

[niin]

Suppose we had a universe that contained only two atoms of hydrogen, separated by a few meters. Would there be a force between them that would cause them to come together and form diatomic hydrogen?

 

I think, that in a universe containing only two atoms, there would not be anything to separate the two atoms.

So the two atoms could never be separated to begin with.

I think, gravity would likely still be active, but it would not be observable.