As you move away from a lightsource

[grantP]

As you move away from a lightsource...

Homework Statement

(from title)
...the wavelength of the light _______? (increase, stays the same, decrease, decrease in amplitude?)

Homework Equations

The Attempt at a Solution

 

[grantP]

my guess would be the wavelength would stay the same, but I am not certain at all, anyone know?

 

[Antineutron]

explain why you believe it would stay the same.

 

[grantP]

well because wavelength is the distance between two successive points on waves right? well as you move away, the length dosent change, just the amount or possibly the frequency?

 

[slakedlime]

This is just a theory. Technically neither the frequency or wavelength change. But for the observer, if you account for the Doppler effect, light sources/stars moving away from the Earth appear to have a 'red shift' while those moving towards Earth have a 'blue shift'. Red light has a longer wavelength than blue light. Frequency appears to decrease, but speed of light remains the same.