Example for Poynting's Theorem

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Discussion Overview

The discussion revolves around finding examples to apply Poynting's Theorem, which relates to the conservation of energy in electromagnetic fields. Participants explore various applications and seek clarification on the components involved in the theorem.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification

Main Points Raised

  • One participant, Martin, asks for examples of Poynting's Theorem and its application in energy conservation in electromagnetic fields.
  • Another participant suggests laser tweezers as a potential example.
  • There is a repeated inquiry about the workings of laser tweezers and which parts of the equation are relevant, specifically mentioning the integral of the Poynting vector.
  • A different participant proposes the example of absorbed sunlight heating a surface as another application of Poynting's Theorem.
  • A further elaboration on laser tweezers describes how they maintain a trapped object through light scattering and the transfer of momentum from light to the particle, as well as the creation of a potential well.
  • One participant expresses uncertainty about whether the initial inquiry was seeking an interesting problem to solve or something else.

Areas of Agreement / Disagreement

Participants present multiple competing views on examples of Poynting's Theorem, including laser tweezers and sunlight absorption, indicating that the discussion remains unresolved with no consensus on a single example.

Contextual Notes

Some assumptions about the familiarity with the Poynting vector and its integral are present, but these are not fully articulated. The discussion lacks detailed mathematical steps or definitions that may be necessary for a complete understanding.

shynee
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Hi,

Anyone knows a good example to aply Poynting's Theorem?

The one thas defines the conversation of energy in the electromagnetic field?

Regards Martin
 
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Laser tweezer?

I don't have a clue, how they work.

Which parts of the Equaction are involved?

The integral of the Poyntig Vektors, and which more?
 
Absorbed sunlight, heating a surface.
 
shynee said:
Laser tweezer?

I don't have a clue, how they work.

Which parts of the Equaction are involved?

The integral of the Poyntig Vektors, and which more?

A laser tweezer maintains a trapped object by light scattering. Momentum from the light is transferred to the trapped particle. Alternatively, the focused beam of light creates a potential well for the particle.

There's lots of material out there- my understanding was that you were looking for an interesting problem to solve. Is that wrong?
 

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