Doppler effect and how it affects the light spectrum

[roineust]

Looking for a beginners explanation to the following question:

How is Doppler effect separated from the original spectrum of light emanating from a moving body (in astronomy or other physics branches)?

If the question does not make sense, here is the reasoning to ask it:

If a certain color is emanating from a moving body, then it is shifted to red or to blue, according to the speed and relative direction of that body. Does this mean that the observed color is a 'scrambled' signal of both its original color and its shifted color? How are these 2 original causes separated back into their original values?

I assume that i did not take into account in my question the difference between wave frequency and wave length and that is perhaps important in considering the answer?

 

[anorlunda]

Good question. Spectra have recognizable features. They have emission lines and absorbsion lines with frequencies determined by atomic physics. We know that no matter where we are in the universe, the atomic elements there (such as hydrogen) are the same as here. So, like in the picture below, it becomes intuitively obvious that the spectrum has been shifted.

Does that answer your question?

 

[roineust]

Got it, the change in relative position or pattern of spectral lines of different elements, thanks!

 

[ZapperZ]

Got it, the change in relative position or pattern of spectral lines of different elements, thanks!

Another question:
How are different elements spectral lines naturally 'scrambled' and then differentiated by observation into each and every element contained in a 'single' light beam emanating from a light source?

This is the type of question that I ask my students in their homework and/or quizzes. Are you sure we are not doing your assignment for you?

Second question: have you ever played with a prism before?

Zz.