# The criteria of light

My question is regarding if the "speed of light" 299,792,458 m/s should only apply to certain frequencies of light/colors/amplitude and most the medium in which it travels at 299,792,458 m/s . Shouldn't light be broken down into more systems and criterias.

These are just examples and need no further explaining.

Would the extremely energized purple light in a UV frequency travel at the same speed as a light with the lowest frequency of pure orange in a vacuum?

another example if I held a laser device with the capabilities to reach the earth's moon that would be (the lasers Z axis), then I moved the laser's beam to the opposite region of the night's sky (the lasers Y axis) and it only took 1 second I manually broke the speed of light by speeds far beyond the "speed of the light" the fastest speed achievable in physics.

what would this experiment of manually moving lights Z axis to a Y axis at speeds faster than "speed of the light" be classified under and should the speed of light be stated as the fastest speed capable?

Question - Should the "Speed of Light" be the model to explain the highest capable speed achieved by all "LIGHT" or is "The Speed of Light" significant and will only apply not to forget observable if all of these rules are in place that a light will capture the speed of 299,792,458 m/s?

1-The lights trajectory must be an act of nature and not governed or controlled by man.

2-The light must be in a specific medium.

3-The light must be of a certain frequency.

4-This speed of 299,792,458 m/s is the highest speed that physics has observed by light traveling in the X axis only/forward motion.

5-"The Speed of Light" does not apply to all colors.

6-"The Speed of Light is as constant as its potential. All Light derives from a source of energy and infinite energy is incapable. So Light is constant yet limited by time.

• This would basically boil down to an energy dependent index of refraction of the physical vacuum. Despite all our efforts on many energy scales, such a dependence has not been found. It is very important research, though, just not in the optical, where it would be undetectably small. It's a different story though at the energy of gamma rays and, even more so, of high energy cosmic rays. That's where it could and, if it exists, should be detectable. At the low energy end it could also become the question if the em field has rest mass... but if it does, it's extremely small. – CuriousOne Jun 8 '16 at 0:03
• sciencedirect.com/science/article/pii/0168900294011176 – user83548 Jun 8 '16 at 0:09
• All photons travel at the same speed no matter what their frequency is. – Bill Alsept Jun 8 '16 at 0:46
• @BillAlsept- This is the first time I have been told photons work in this manner, can you please place a link to this information so I can learn more on this theory? – user5434678 Jun 8 '16 at 1:32
• @user543678: singleedgecertainty.wordpress.com – Bill Alsept Jun 8 '16 at 6:29

In a vacuum all frequencies and amplitudes of light travel at the same speed of c = 299 792 458 m/s. Frequency is equivalent to colour. Amplitude relates to intensity.

When light travels in material mediums (air, water, glass, etc) it travels at a slower speed v < c which depends on frequency. The ratio of c/v is what we measure as the refractive index n of the material. The relation between v and frequency is called the dispersion relation for that material in the particular conditions (temperature, pressure, etc) which apply.

Intense light (such as that emitted by a laser) can also alter the properties of the material, causing the refractive index to change, and along with it the speed of light in the material.

• very intense light can alter the refractive index of the material so that the light gets even more focused and intense in a runaway process, thereby destroying your entire laser system, cf. 'catastrophic self-focusing'. – Emilio Pisanty Jun 8 '16 at 0:52
• @EmilioPisanty- I had no intentions on performing my laser experiment in real time by the way. Everything can be simulated in my imagination...safely. Try it sometime. – user5434678 Jun 8 '16 at 4:42

Not surprisingly, physicists have looked for variations in the speed of light as a function of frequency in vacuum. The state of the art in 1972 can be found in Z. Bay and J. A. White, 'Frequency Dependence of the Speed of Light in Space', Phys. Rev. D 5(4) 796-799 (1972). Using data from pulsar emissions (radio, visible, x-ray) and other sources (see paper), they arrive at a conclusion that limits "the dispersion in the microwave, infrared, visible, and ultraviolet regions of the spectrum to less than one part in $10^{20}$."

In other words, the speed of light is the speed of light.

• I am not against the speed of light I am just implying what frequency and amplitude of light can travel this fast or do they all in a vacuum? I Just think the statement does not apply to all frequency of light and should be more specified. – user5434678 Jun 8 '16 at 14:48