speed of light variations

[hoola]

I recently read that the speed of light through glass slows down slightly due to a small effective increase in mass of the photons due to frequency dependent interactions with the medium. I also read that the speed of light might be higher than through a vacuum if virtual particles could somehow be removed from a pathway in space conducting a beam of light. Does this mean that photons have a small mass due to the interactions with virtual particles, and the speed of light in a vacuum is not truly a fundamental value, and "C" must be revised upward to a theoretical maximum within a VP free enviornment ?

Edited December 11, 2014 by hoola

[Mordred]

Can you provide a reference. This sounds like a questionable source. The speed of light in a vacuum has a strong well tested following.

 

Though there have been articles etc that question c nothing has been conclusive enough to reset the speed limit.

[hoola]

I am not contesting the speed of light in a vacuum, only that if virtual particle interaction in space might lend some mass to the photons, and affect speed....

[Strange]

Are you thinking of something like this: http://www.space.com/19202-einstein-space-time-smooth.html

[MigL]

I assume these scientists are much more competent than I am, Strange, but even gamma ray wavelengths would be HUGE in relation to Planck scale. I don't see how a ship the size of the Titanic would be slowed down by <1mm foam bubbles on the water's surface ( have I got the scale approx. right ? )

[swansont]

I recently read that the speed of light through glass slows down slightly due to a small effective increase in mass of the photons due to frequency dependent interactions with the medium. I also read that the speed of light might be higher than through a vacuum if virtual particles could somehow be removed from a pathway in space conducting a beam of light. Does this mean that photons have a small mass due to the interactions with virtual particles, and the speed of light in a vacuum is not truly a fundamental value, and "C" must be revised upward to a theoretical maximum within a VP free enviornment ?

 

 

I suppose you could try and model the effect as an increase in mass, but AFAIK in standard theory photons travel at c and remain massless, and the slowing is caused by interactions with virtual states.

 

The idea that you could increase c by excluding some vacuum modes is known as the Scharnhorst effect. It has not been experimentally confirmed.

http://en.wikipedia.org/wiki/Scharnhorst_effect

[Peace]

Does this help?

 

About the speed

http://www.askamathematician.com/2011/08/q-if-light-slows-down-in-different-materials-then-how-can-it-be-a-universal-speed/

 

or, alternatively,

[http://www.physlink.com/Education/AskExperts/ae509.cfm

 

About the mass

http://www.desy.de/user/projects/Physics/Relativity/SR/light_mass.html

[hoola]

thanks, peace on the light mass link....it stated that light can exhibit gravitational effects on matter, that makes me wonder if two parallel light beams closely aligned would attract each other, and would that attraction necessarily cause the beams to drift towards each other ?