The spectra of most galaxies show redshifts. This means that their spectral lines
A. have wavelengths that are longer than normal.
B. always are in the red part of the visible spectrum.
C. have wavelengths that are shorter than normal.
D. have a higher intensity in the red part of the spectrum.
Answer:A
The spectra of most galaxies show redshifts. This means that their spectral lines
A. have wavelengths that are longer than normal. B. always are in the red part of the visible spectrum. C. have wavelengths that are shorter than normal. D. have a higher intensity in the red part of the spectrum.