Why frequency of light doesn't change?Explain.?

Answer 1

Light is emitted from objects(whether it be the sun, a tree, yourself, or whatever), with a specific frequency, speed, and wavelength. The frequency and wavelength determine what type (color, visible/UV/Infrared, etc) of lightwave it is. When the light wave enters a new medium, like a piece of glass, the speed immediately decreases and the wavelength increases. These are the only properties that change because the frequency of the light wave is constant. The frequency is basically the rate at which the light waves were produced at. Since this rate is determined by the inital emission of the waves, it cant be changed.
The best example I can think of right now is...
if you are underwater in a pool and your friend claps his hands 2 times per second. Im sure you know that the clap will sound differently to you when you are underwater, but... you will still here the claps happening at 2 times per second. That is because the frequency the claps are produced does not change.
You gotta know that the frequency of light is constant though. But once a light wave is produced, it is unchanged.

Wow, I could have definitely explained that in fewer words. Oops.
Hope it helps.

Answer 2

Frequency of light does not change if you are stationary relative to the light source. If you move toward or away from the light, you will cause a frequency shift. movement toward the light will cause a frequency shift toward the blue end of the spectrum. Movement away will cause a frequency shift toward the red end of the spectrum.

You earlier asked about refraction? Refraction changes the speed and wavelength of the light, causing the "bending". It does not change thefrequency because there is no consideration for moving toward or away from the light source.

You need to keep these things separate.

Answer 3

Light or electromagnetic wave is produced because of the fast change of acceleration of charges in a matter.

The frequency of oscillations of electric and magnetic fields (or light) depends upon the frequency of oscillations of charges.

Once emitted from the source the light travels with a fixed speed of 3x 10^8 m/s in vacuum or air.

The velocity of light, entering into any medium, decreases. This is due to the interaction of light with the dipoles present in the medium.

How frequently it interacts is determined only be the frequency of the light and it cannot be determined by the medium.

Frequency being constant, the wave length and speed change accordingly.

Answer 4

It seems everyone has missed the point of your question - I think I have got it.

The speed of light changes in different media depending on their dielectric properties. This means that the relationship between wavelength and frequency is changed - and it is the frequency that stays the same between media. Here's why.

Imaging being on the wavefront at the boundary between two media. On the one side the (say) electric field vector of the light is oscillating at a particular frequency. This induces an oscillation in the electric field vector on the other side of the boundary (this is how light propagates). This induced oscillation is clearly at the same frequency as the one inducing it - it simply cannot be otherwise.

Answer 5

It does change. Light from distant galaxies is shifted toward the red ("red shift") because our galaxies are moving apart. The speed of light in the vacuum is constant, but the wavelength increases, and identically the frequency decreases. This is the same as Doppler effect with sound.

Answer 6

Frequency of light does change. It depends on the wavelength and the speed. Wavelength changes depending on the color, and speed changes depending on the medium through which the light is traveling. So the frequency changes.

Answer 7

Frequency of visible light changes and they form what our eyes see as colors. If you can tell me how many colors we have, then I can tell you how many frequencies of light we have. My phone display says 65500 colors. Some plasma TVs claim millions/ billions of colors.
What does not change is the speed of light in Space / Vacuum. It changes in different media, like ti is slower in water, and even slower in refractive glass, which forms the basis of spectacles and corrective glasses.