Dipole moment at the sub atomic level

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Discussion Overview

The discussion revolves around the concept of dipole moments at the subatomic level, particularly focusing on whether a moving neutral object composed of atoms can generate an electric field due to a small dipole moment. Participants explore the implications of atomic movement, the nature of dipole moments, and related forces such as Van der Waals interactions.

Discussion Character

  • Exploratory
  • Debate/contested
  • Technical explanation

Main Points Raised

  • One participant proposes that a moving neutral object generates an electric field due to a small dipole moment caused by shifts in electron clouds relative to atomic nuclei, estimating a dipole moment of 10-5 Debay.
  • Another participant mentions that this phenomenon is related to Van der Waals forces, which can occur for neutral molecules and are measurable.
  • A later reply clarifies that Van der Waals interactions are independent of molecular velocity, suggesting that the initial proposal may not align with established understanding.
  • One participant argues that a dipole field would exert a force on a charge in the field, but in the rest frame of a neutral atom with a moving charge, no force would be present, implying no dipole moment exists in that frame.
  • A participant provides a link to a paper discussing the velocity dependence of Van der Waals forces, indicating that there may be some literature on the topic.
  • Another participant asserts that the proposed shift in electron clouds does not occur and suggests that the forum is not suitable for personal theory development.

Areas of Agreement / Disagreement

Participants express differing views on the relationship between atomic movement and dipole moments, with some supporting the idea of a velocity-dependent dipole moment while others challenge its validity. The discussion remains unresolved, with no consensus reached on the initial proposal.

Contextual Notes

Participants reference established concepts such as Van der Waals forces and dipole moments, but there are uncertainties regarding the implications of atomic velocity on these phenomena. The discussion highlights the complexity of the topic and the need for further exploration.

Dilema
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The following mechanism leads me to wander that a moving neutral object (compose from atoms) in vacuum may generates electric filed due to very small dipole moment.
I propose that when atoms force to move in a certain direction the force propagates within the atom. A retardation in movements will happen depending on response time and the time it takes the force (Field) to travel within the atom (probably the speed of light). This leads to a very small shift (depending on the atom velocity) in electron clouds relative to the position of the nuclei (very similar to portability but without external electric field).
My first simple estimation (classical approach) is that for 1m/sec the atom clouds shits in 10-18m.
This would generates dipole moment of 10-5Debay (just for comparison H2O has 1.85Debay).
1. Did someone consider such mechanism? (I need link or paper).
2. Is it possible to measure such low dipole moment?
3. Consider lattice of mole atoms then I expect this dipole moment to sum up to much more significant, isn't it?
 
Physics news on Phys.org
1. Yes. Otherwise known as the Van der Waals force. It can occur for neutral molecules/atoms alike. I'm sure you can look up papers or read the Wikipedia page.
2. Yes, these measurements are often done. http://phys.org/news/2016-05-physicists-van-der-waals-individual.html
3. As the above article states, that's why geckos can stick to surfaces so well. The van der waals forces sum up enough to enable that.
 
Thank you Modestyking for your repay. I'm well aware of the Van der Waals forces. Please note that I was referring to a phenomenon that should increases with the velocity of the subject. As far as I know Van der Waals interactions are independent on molecule velocity. Namely you can have interactions even the molecules are standing still.
 
A dipole field would lead to a force on a charge in this field.

Consider the same situation in the rest frame of the neutral atom, with a moving charge somewhere: no force. Therefore, no dipole moment.
 
A simple Google search seemed to yield a few papers, one of which is here: https://www.researchgate.net/publication/231076123_Velocity_dependence_of_the_van_der_Waals_force_between_molecules
 
Last edited by a moderator:
Dilema said:
a very small shift (depending on the atom velocity) in electron clouds relative to the position of the nuclei (
This does not happen, and PF is not the place for personal theory development.

Thread closed.
 

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