Does Light Travel Forever or Eventually Fade Away?

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    Light Travel
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Discussion Overview

The discussion revolves around whether photons from electromagnetic sources, such as light and radio waves, travel indefinitely or eventually fade away. Participants explore concepts related to the behavior of light and electromagnetic radiation over time, including absorption and energy loss due to cosmic expansion.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification

Main Points Raised

  • Some participants propose that photons will travel indefinitely until they are absorbed by matter.
  • Others mention that photons can lose energy over extremely long periods due to the expansion of the universe, leading to longer wavelengths.
  • A participant clarifies that the discussion pertains to electromagnetic radiation, specifically light and radio waves.
  • It is noted that the energy loss and wavelength change occur over billions of years.

Areas of Agreement / Disagreement

Participants generally agree that photons can travel indefinitely until absorbed, but there is uncertainty regarding the implications of energy loss and the effects of cosmic expansion on their behavior.

Contextual Notes

The discussion does not resolve the implications of energy loss or the exact nature of how photons behave over cosmological timescales, leaving some assumptions and definitions open to interpretation.

jsa0100
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So from an electromagnetic source, will the photons travel "forever" or will some of them "collapse" after a while ?
 
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Are you talking about an electric/magnetic field (ie a magnet) or light (ie a flashlight)?
 
I'm going to assume you mean a flashlight.
In that case the photons will travel forever until they get absorbed.

They will also lose energy over extremely long periods of time due to the expansion of the universe, but will never 'dissapear'.
 
Sorry i ment Electromagnetic radiation (Radio and Light). By loosing energy do you mean that the wavelength will be longer?
 
jsa0100 said:
Sorry i ment Electromagnetic radiation (Radio and Light). By loosing energy do you mean that the wavelength will be longer?

Yes

(adding text because my post was too short)
 
But remember that takes billions of years :)
 

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