- #1
AspiringEEngineer
- 10
- 1
- TL;DR Summary
- I am trying to wrap my head around the explanation for the results discovered by the pith ball experiments. In particular, the fact that when a body is rubbed with another body, touches a pith ball, then is repelled by the pith ball it just touched; I do not think the transfer of electrons can satisfy the phenomenon.
As a preliminary note, most people flex about how dumb questions and then continue to school and scold curious minds. Instead of taking a demeaning approach I just ask for respectful insight to quench curiosity.
I will 1) explain the experiment as I know it to be, 2) explain what I have been taught as to what is happening, and 3) my reasoning as to why I do not see how what I've been taught makes sense to what is actually happening.
I understand that it is most likely a mere misunderstanding in 2) or 3) or both, but that is why I am here: To clear up my confusion.
1)
A pith ball can be suspended on a silk thread and then two separate bodies (glass rod and silk cloth) can interact to cause electrostatic actions. Before the two bodies interact, there appears to be no effects on the pith ball-- namely, there does not appear to be any attraction or repulsion with either the glass or the silk cloth. Only when the two bodies are rubbed against each other do interesting things occur. The pithball is attracted to both the bodies. Additionally when-- let's say-- the glass rod touches the pith ball and then removed from the pith ball, it will instead repel the glass rod whilst still being attracted to the silk cloth.
2)
When the two bodies undergo no interaction, they are in net neutral charged state and have no electrostatic forces acting on the pith ball. It is as if the pith ball does not even know the two bodies are there across space. When the two bodies interact by means of friction, they transfer charge through conduction. The electrons on the silk cloth rub off onto the glass rod. once this interaction takes place, a net negative and positive charge exists on the glass rod and silk cloth respectively. Once exposed near the pith ball, the pith act as if it now knows the bodies exist and even though the pith ball is net neutral, it will polarize the particles inside it due to induction (the negative charges will repel against the presence of the glass rod creating the pith ball as net positive on its side closest to the glass rod). Once the glass rod touches the pith ball, it will send electrons to the pith ball in the form of conduction. Only when the glass rod is pulled away from the pith ball does it start to now repel the glass rod as both are net negative. On the other hand, the pith ball is still attracted to the silk cloth because it is net positive. Thus, the discovery of "opposite charges attract and like charges repel" was deduced.
3)
Problem #1: Somehow it seems as if the assumption that the inner particles (of the pith ball and glass rod) polarize and become only interested in another body (which is also polarized) across space. This means the electron particles inside the pith ball feel more force from the glass rod across space than it does from its own protons trying to attract it. Does this mean the negative repulsion of the distant glass rod is stronger than the protons pull nearby? Further, the silk cloth's protons would have to pull the electrons of the pith ball better than the pith balls own protons are pulling them.
Problem #2: Once bodies touch, the particles are somehow apt to transfer to the other body which would 1) make the receiving body net negative now and 2) the releasing body is now net positive and immediately should want its electrons back; since the pith ball would be net negative, it should gladly give the electrons back making the transfer process pointless to begin with. But, somehow they are prevented from going back.
Problem #3: Even if #2 was explained by the releasing body having excess charge, giving pith ball some of that charge, and still having excess charge (which means it wouldn't want those electrons back); The releasing body was somehow forced by the silk cloth as way of friction to accept electrons it never wanted to begin with.
Problem #4: Since the silk cloth and glass rod are net neutral at the start, touching them alone would not cause a net charge. Somehow friction is needed which is like touching each other over and over again very quickly, which should not do anything since they are neutral. Furthermore, even if the friction activated some type of potential causing the transfer of charge, once the silk cloth gives an electron to the glass rod (making the cloth net positive and rod net negative), why doesn't it immediately want its electron back? And once they are net opposite charges, why don't they neutralize those charges once they are touched again after the friction is said and done?
Problem #5: When the glass rod touches the pith ball, why does it stay stuck to the rod until it is pulled away? If after the rod transfers charges and the pith ball becomes net negative, shouldn't it repel itself immediately away from the rod once the transfer takes place? Instead, it is just adhesive to the rod until forcefully removed.
I will 1) explain the experiment as I know it to be, 2) explain what I have been taught as to what is happening, and 3) my reasoning as to why I do not see how what I've been taught makes sense to what is actually happening.
I understand that it is most likely a mere misunderstanding in 2) or 3) or both, but that is why I am here: To clear up my confusion.
1)
A pith ball can be suspended on a silk thread and then two separate bodies (glass rod and silk cloth) can interact to cause electrostatic actions. Before the two bodies interact, there appears to be no effects on the pith ball-- namely, there does not appear to be any attraction or repulsion with either the glass or the silk cloth. Only when the two bodies are rubbed against each other do interesting things occur. The pithball is attracted to both the bodies. Additionally when-- let's say-- the glass rod touches the pith ball and then removed from the pith ball, it will instead repel the glass rod whilst still being attracted to the silk cloth.
2)
When the two bodies undergo no interaction, they are in net neutral charged state and have no electrostatic forces acting on the pith ball. It is as if the pith ball does not even know the two bodies are there across space. When the two bodies interact by means of friction, they transfer charge through conduction. The electrons on the silk cloth rub off onto the glass rod. once this interaction takes place, a net negative and positive charge exists on the glass rod and silk cloth respectively. Once exposed near the pith ball, the pith act as if it now knows the bodies exist and even though the pith ball is net neutral, it will polarize the particles inside it due to induction (the negative charges will repel against the presence of the glass rod creating the pith ball as net positive on its side closest to the glass rod). Once the glass rod touches the pith ball, it will send electrons to the pith ball in the form of conduction. Only when the glass rod is pulled away from the pith ball does it start to now repel the glass rod as both are net negative. On the other hand, the pith ball is still attracted to the silk cloth because it is net positive. Thus, the discovery of "opposite charges attract and like charges repel" was deduced.
3)
Problem #1: Somehow it seems as if the assumption that the inner particles (of the pith ball and glass rod) polarize and become only interested in another body (which is also polarized) across space. This means the electron particles inside the pith ball feel more force from the glass rod across space than it does from its own protons trying to attract it. Does this mean the negative repulsion of the distant glass rod is stronger than the protons pull nearby? Further, the silk cloth's protons would have to pull the electrons of the pith ball better than the pith balls own protons are pulling them.
Problem #2: Once bodies touch, the particles are somehow apt to transfer to the other body which would 1) make the receiving body net negative now and 2) the releasing body is now net positive and immediately should want its electrons back; since the pith ball would be net negative, it should gladly give the electrons back making the transfer process pointless to begin with. But, somehow they are prevented from going back.
Problem #3: Even if #2 was explained by the releasing body having excess charge, giving pith ball some of that charge, and still having excess charge (which means it wouldn't want those electrons back); The releasing body was somehow forced by the silk cloth as way of friction to accept electrons it never wanted to begin with.
Problem #4: Since the silk cloth and glass rod are net neutral at the start, touching them alone would not cause a net charge. Somehow friction is needed which is like touching each other over and over again very quickly, which should not do anything since they are neutral. Furthermore, even if the friction activated some type of potential causing the transfer of charge, once the silk cloth gives an electron to the glass rod (making the cloth net positive and rod net negative), why doesn't it immediately want its electron back? And once they are net opposite charges, why don't they neutralize those charges once they are touched again after the friction is said and done?
Problem #5: When the glass rod touches the pith ball, why does it stay stuck to the rod until it is pulled away? If after the rod transfers charges and the pith ball becomes net negative, shouldn't it repel itself immediately away from the rod once the transfer takes place? Instead, it is just adhesive to the rod until forcefully removed.