Is energy conserved for light?

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Discussion Overview

The discussion revolves around the conservation of energy in the context of light and interference patterns, specifically addressing whether energy is lost at points of destructive interference in light waves.

Discussion Character

  • Debate/contested

Main Points Raised

  • Some participants question whether energy is lost at points of destructive interference in interference fringes.
  • Others argue that energy is not lost but rather redistributed, with constructive interference points compensating for the energy at destructive interference points.
  • One participant notes that for every destructive interference fringe resulting in zero energy, there is a corresponding constructive interference fringe that provides double the energy.
  • Another participant emphasizes that the mean energy value, which is used for conservation laws, remains independent of time despite fluctuations.

Areas of Agreement / Disagreement

Participants express differing views on whether energy is lost during destructive interference, with some asserting it is redistributed while others question the implications for conservation of energy.

Contextual Notes

The discussion includes assumptions about the nature of energy fluctuations and the definitions of energy conservation in the context of interference patterns, which remain unresolved.

The_Thinker
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In interferance fringes, at the points where the destructive interferance takes place isn't energy lost...?

So therefore isn't the law of conservation of energy at stake?
 
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No because the energy fluctuates with time and the energy-value that is used for conservation laws is the mean energy-value which can be calculated out of the given fluctuating energy and it is independent of time

marlon
 
For every destructive interference fringe giving 0, there is a constructive interference fringe giving 2E.
 
The_Thinker said:
In interferance fringes, at the points where the destructive interferance takes place isn't energy lost...?

No, it's just redistributed to the points where constructive interference occurs. The maxima of the interference pattern are brighter than the light would be at those points if there were no interference.
 
Ahhhh, right.. thanks guyz...
 

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