Thread: Contact/noncontact forces

How do non contact forces differ from contact forces? I mean, why do contact forces need to touch something and not at a distance?

Please define what you mean by a contact force.

I guess there is going to be no further contact on this one.

I guess the question is what forces really act for example when somebody push or beat a wall, which are the forces acting between the wall and the hand or may be more precisely between the wall's atoms and the hand's atoms.

I believe that the first idea is to consider that the protons inside the nucleus of an atom repeals the protons of other atom.

The question is not so easy when we consider high energy collisions between subatomic particles. For example beams of electrons can be accelerated to collid with the nucleus of some atoms, in this case what prevent the electrons to "fussionate" with the protons or neutrons!
A very strong force must exist to prevent the elementary particles be destroyed in high energy collisions!

In my new theory about the elementary particles and forces of nature I propose that the elementary "particles" actually are "sources of fields of force. They are the source of four fields: the electric, the magnetic, the gravitational and the ultimate force. Inversely to the gravitational force, the "Ultimate Force" is a repulsion force between any two kind of "particles" and is stronger than the atomic "strong force" that mantains protons and neutrons together inside the nucleus.

Please take a look at www.geocities.com/anewlightinphysics

At the end all forces are originated by fields of forces that act at a distance!

Originally Posted by martillo

I believe that the first idea is to consider that the protons inside the nucleus of an atom repeals the protons of other atom.
!

It has nothing to do with this. They are isolated from each other by the electorn cloud around the nucleus. It is the ineraction of these that leads to the the so called contact forces.

Ophiolite,

May be you are right, may be the electrical repulsion of many electrons are strong enough.

Question: Do you consider that the electrons orbit around the nucleus?

Originally Posted by martillo

Question: Do you consider that the electrons orbit around the nucleus?

No. I consider they form a probability cloud around the nucleus. This cloud has restricted forms and dimensions that relate to the orbitals the electrons are probably in. Only the s1 orbital, if I recall correctly, has a spherical shape.

Ophiolite,

I believe the orbiting model, where an equilibrium between electrical atraction and centriphetal force is present, is too weak to handle the "contact forces". It seems to me the electrons would easily change orbits and be taken away of the atoms when for example a hammer beats on a table.
I can agree that the repulsion between electrons can handle the "contact forces" but not with the electrons orbiting around the nucleus but with a strong link between each electron and a correspondent proton in the nucleus.

Originally Posted by martillo

Ophiolite, I believe the orbiting model, where an equilibrium between electrical atraction and centriphetal force is present, is too weak to handle the "contact forces".

The orbiting model has nothing to do with a balance between electrical attaction and centripetal force. What makes you think that it does?

Ophiolite,

The orbiting model has nothing to do with a balance between electrical attaction and centripetal force. What makes you think that it does?

That balance is present in the Rutherford-Bohr model of the atom. The protons atract the electrons and the centriphetal force mantain them apart in the same way planets orbits around the Sun. This is the basic behavior of the orbiting model. It's in basics Physics' texts.
How do you think the orbits are mantained?

Quantum level ring any bells?

I don't understand your point.