While examining the spectrum of a galaxy, you find all the hydrogen lines are shifted tolonger wavelengths. This galaxy is:
A)moving away from us.
B)moving towards us.
C)expanding explosively.
D)blueshifted.
E)not forming new stars.

Question

Quizplus · Accepted Answer

The hydrogen lines being shifted to longer wavelengths indicate a redshift, which means the galaxy is moving away from us. This is due to the Doppler effect, where the wavelength of light is stretched as the source moves away from the observer. The shift of the hydrogen lines to longer wavelengths indicates a redshift, which implies that the galaxy is moving away from us. This is consistent with the idea of the universe expanding, and galaxies moving away from each other.

While Examining the Spectrum of a Galaxy, You Find All