# Lightspeed wave lenghts

1. Mar 28, 2009

### Questioner...

Hello there, I am new to the sight and am curious to know if light has a standard wave length? And that maybe different spectrum's of light could possibly have different wave length- thus creating multiple speeds of light?

Last edited: Mar 28, 2009
2. Mar 28, 2009

### Staff: Mentor

The speed of light in a vacuum is independent of wavelength.

3. Mar 28, 2009

### Questioner...

How would one make a model of that?

4. Mar 28, 2009

### Staff: Mentor

What do you mean?

5. Mar 28, 2009

### Questioner...

How can one go about proving that?

6. Mar 28, 2009

### Questioner...

My theory could proven wrong with a simple test, the sun- a standard would be my base unit of speed. I would focus a beam sunlight through a simple hole in a piece of paper and see where the shadow has cast. I would then proceed to cover the whole in the paper and use some sort of timer to depict the speed in which it takes the light to travel from the hole in the paper to the ground.

Now using this same model we can find out how fast a beam of Sunlight travels from point A: This piece of paper casting the shadow, to point B: the shadow on the ground.
I believe also we could find are exact angle to the sun? I am not sure though,

Please forgive me if you think it is a radical or stupid Idea, I am new to the subject of physics but I carry an open mind.

7. Mar 28, 2009

### Staff: Mentor

See the FAQ on the experimental basis of special relativity, in particular section 3.4, "Measurements of the Speed of Light, and Other Limits on it," which has a subsection "Limits on Velocity Variations with Frequency."

8. Mar 28, 2009

### Staff: Mentor

It can be derived from Maxwell's equations and properties of free space (which do not depend on wavelength). But the real "proof" is experimental, as jtbell indicated.

9. Mar 28, 2009

### Bob S

Wavelengths vary over many orders of magnitude; AM radio is about 300 meter wavelength, FM about 3 m, 1 GHz about 30 cm, infrared about 1 to 100 microns, red light about 600 nanometers, blue light about 400 nanometers, etc.