Question

In the Doppler Effect Measurement activity, is the shift (redshift) the amount of milimeters that shifted to the right compared to the line in model a? Or is the redshift the new measurement between each line (after being shifted a certain amount of milimeters to the right)?

Model a is a hydrogen emission spectrum with wavelengths from the right to the left are 656.3nm(red), 486.1nm(blue-green), 434 nm (violet), and 410.1 nm (violet). I measured the distance between each line by using millimeters. After finding the distance, I divided nanometers by millimeters (nm/mm) in order to find the scale. The next part of the question says for me to compare the lines between the two spectra. The second model shows each line moved to the right compared to the first model. Then I figured how how many millimeters the line has shifted to the right. For example, how many millimeters has the 656.3-nanometers line shifted to the right?

I found out how many millimeters each line shifted to the right compared model a, but then they want me to translate this shift (redshift) into nanometers by using the scale I found out from model a. I am just not very sure on what exactly the redshift is. Is the red shift the amount of millimeters that it shifted to the right compared to model a, or is the redshift the new distance between each line after the lines have shifted to the right?

Answer 1