Chapter 16, Problem 50A

To determine

To Explain:Observed wavelength on earth shift toward red light or blue light.

Explanation of Solution

Introduction:

The Doppler effect (or the Doppler shift) is the frequency change of a wave in response to an object moving with respect to the source of the wave. This is named after Christian Doppler, the Austrian physicist who introduced the phenomenon in 1842.

If a distance galaxy emits a spectral line in the green region of the light spectrum, then the observed wavelength on the earth will be shifted towards the red light.This is because the frequency of the wave moving towards an observer is more than of the frequency of the waves moving away from the observer.

According to Doppler Shift, the galaxy moving away from the Earth will be having longer wavelength. Thus, the galaxy will be red-shifted.

Conclusion:

Hence, due to the Doppler Shift, the galaxy moving away from the Earth will be having longer wavelength. Thus, the galaxy will be red-shifted.