Does Light Travel Forever or Eventually Fade Away?

[jsa0100]

So from an electromagnetic source, will the photons travel "forever" or will some of them "collapse" after a while ?

 

[James Leighe]

Are you talking about an electric/magnetic field (ie a magnet) or light (ie a flashlight)?

 

[James Leighe]

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'.

 

[jsa0100]

Sorry i ment Electromagnetic radiation (Radio and Light). By loosing energy do you mean that the wavelength will be longer?

 

[James Leighe]

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)

 

[James Leighe]

But remember that takes billions of years :)