What Happens to Photon Energy When Light is Turned Off?

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Discussion Overview

The discussion revolves around the fate of photon energy when light is turned off, exploring concepts related to energy conservation, absorption, and re-emission of energy. Participants examine the implications of light cessation on photon energy and its interactions with surfaces.

Discussion Character

  • Exploratory, Technical explanation, Debate/contested

Main Points Raised

  • Some participants assert that when lights are switched off, the energy of the photons is absorbed by surrounding surfaces, such as walls, which then may re-emit energy as infrared radiation.
  • Others emphasize that according to the law of conservation of energy, energy cannot be destroyed, leading to questions about the fate of photon energy in darkness.
  • One participant notes that once photons are absorbed, they no longer exist, and their energy is completely transferred to the absorbing material.
  • There is a suggestion that the absorbed energy may still be present in the form of thermal energy in the walls.

Areas of Agreement / Disagreement

Participants generally agree that the energy of absorbed photons is transferred to the walls, but there is some contention regarding the implications of this absorption and whether the energy is re-emitted or simply converted to thermal energy.

Contextual Notes

The discussion does not resolve the specifics of how energy is re-emitted or the exact mechanisms involved in photon absorption and energy transfer.

gokhul
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Light consists of photon
Photon is carrier of energy
When lights are switched off where had the energy of photon gone
According to law of conservation of energy
Energy can't be destroyed
In darkness, are they any radiation due to conversion of energy??
 
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The visible light is absorbed by the walls, heating them up. Often the energy is re-emitted in the infra-red.
 
gokhul said:
When lights are switched off where had the energy of photon gone

As Dave said, the energy of the photons already created and in flight when the light is switched off are absorbed by the walls and anything else in line-of-sight of the bulb. After that, well, no more photons are being generated from the light source.
 
Drakkith said:
As Dave said, the energy of the photons already created and in flight when the light is switched off are absorbed by the walls and anything else in line-of-sight of the bulb. After that, well, no more photons are being generated from the light source.
Photon contains energy ,an energy can't be destroyed or if they are absorbed by walls do they posses any energy or reemit as infra red radiation
 
gokhul said:
Photon contains energy ,an energy can't be destroyed or if they are absorbed by walls do they posses any energy or reemit as infra red radiation

The photon no longer exists after absorption. The energy it contained is completely transferred to the wall, so no energy is lost.
 

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