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General Science => General Science => Topic started by: RTCPhysics on 29/06/2015 15:20:32

Title: Variable speeds of visible light and relativity.
Post by: RTCPhysics on 29/06/2015 15:20:32
When a photon is slowed down in its passage through a translucent material, does it experience 'time'?
Title: Re: Variable speeds of visible light and relativity.
Post by: David Cooper on 29/06/2015 16:21:01
No - if it's used as part of the mechanism of a light clock, that light clock will simply slow down and ultimately stop ticking if you stop the light completely.
Title: Re: Variable speeds of visible light and relativity.
Post by: PmbPhy on 29/06/2015 18:18:36
Quote from: RTCPhysics
When a photon is slowed down in its passage through a translucent material, does it experience 'time'?
No.
Title: Re: Variable speeds of visible light and relativity.
Post by: RTCPhysics on 10/08/2015 19:19:35
Quote from: RTCPhysics
When a photon is slowed down in its passage through a translucent material, does it experience 'time'?
No.

With the brevity of your answer, I must guess at your reasons!

I posted this question to see if anyone else thought that Einstein’s ‘relativity theory’ could explain the change in the velocity of light on its passage from one transparent medium to another. If the photon experiences 'time dilation' and 'time contraction' as it passes from one medium to another of differing refractive indices, then the change in velocity is explained. On the other hand, if the 'time intervals' experienced by the photon in both media are the same, then another explanation is required.

A second option is that the change in the photon’s velocity is either a reduction in its wavelength with an unchanged frequency or alternatively, a reduction in its frequency with an unchanged wavelength. The change of its wavelength would be the favoured, as a constant frequency maintains the energy level of the photon throughout the transition process. But the concept of the wavelength and frequency being completely separate characteristics of a photon is a departure from Maxwell’s perception of the photon as an alternating, inter-dependent, electric and magnetic sinusoidal wave. If the wavelength changes but the frequency does not, then the shape of the photon’s electric and magnetic vectors must change to having an 'increased amplitude' in order to repeat the cycle within the shorter wavelength.

The third option is that the photon simply takes more time to cross the medium than its entry velocity and distance travelled would warrant. This is where a variation in the photon’s amplitude can explain the increase in time taken, but does not contradict Maxwell’s sinusoidal construct of the photon by maintaining both its frequency and its wavelength. For if the photon is a repeating cycle of electric and magnetic energy as it radiates through two media of differing refractive indices, then an increase in the amplitude of the radiating energy wave would cause it to take more time for each cycle to be executed and thus is slowed down on its journey through the medium. On exiting the medium, the amplitude would return to the level that it was at, prior to entering the higher refractive medium and the velocity would revert to its original value. This ability of the photon to change its velocity into amplitude and back again in differing refractive media, also enables the photon to conform to the fundamental 'conservation of energy' law.