5 positivly charged particles on sphere, min energy configuration, rel

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Discussion Overview

The discussion revolves around the configuration of five positively charged particles constrained to the surface of a sphere, specifically focusing on the conditions that minimize electrostatic potential energy. Participants explore the existence of stable configurations that may not represent the minimum energy state and consider methods for identifying these configurations.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant inquires whether stable configurations exist that are not the minimum energy configuration for five charged particles on a sphere.
  • Another participant identifies the problem as the "Thomson Problem" and provides a link for further reading.
  • A different participant suggests that a triangular dipyramid configuration is symmetric and may be relevant, noting that the problem becomes more complex with larger numbers of particles.
  • There is mention of a Java app that allows users to visualize the arrangement of charges and their energy minimization, with a question about whether stable relative minima exist.

Areas of Agreement / Disagreement

Participants generally agree on the identification of the problem as the Thomson Problem, but there is no consensus on the existence of stable configurations that are not minimum energy configurations, leaving the discussion unresolved.

Contextual Notes

Participants express uncertainty regarding the methods for finding minimum energy configurations and the potential for stable relative minima, indicating a need for further exploration of the topic.

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Assume 5 charged particles (charge 1) constrained to live on the surface of a sphere are in a configuration that minimizes electrostatic potential energy. Are there configurations that are stable but that are not the minimum energy configuration?

A simple computer program could quickly(?) examine many random configurations and slowly map out the potential energy surface E(θ_1,phi_1,θ_2,phi_2,θ_3,phi_3,θ_4,phi_4,θ_5,phi_5)?

There must be more elegant(less computer time) ways to find the minimum energy configuration?

Has this problem been solved?

Edit, E above is a function of only 8 variables, we can always let one particle be at the north pole?Thanks for any help!
 
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Simon Bridge said:
It's called "the Thomson Problem".
http://en.wikipedia.org/wiki/Thomson_problem

Triangular dipyramid :rolleyes: Nice and symmetric, I should have seen that. Things probably get more interesting with larger numbers. From the link above check out a fun Java app at,

http://thomson.phy.syr.edu/thomsonapplet.php

Check out the screen shot and add a charged particle and watch the charges rearrange to I assume the lowest energy configuration. Still would like to know if there are stable relative minimum.

Edit, I think you have to hit the Auto button on the app to get the configuration to minimize energy?

Thanks for your help!
 

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Nice find!
 

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