Question

In 1929 Hubble used light spectra as evidence to indicate the motion of distant galaxies. In the image below show the differences of light spectra of different galaxies compared to a laboratory reference to uses as comparison, or control group. Describe the differences between nearby stars and galaxies compared to distant stars and galaxies by using the spectral lines.

Answer 1

Answer:

i dont know the answer but i hope this help you figure it out

Explanation:

During his work studying galaxies, Hubble used Cepheid variable stars to measure the distances to a sample of galaxies. Even before the Shapley/Curtis debate and the discovery that spiral nebulae are external galaxies, observations had shown that the vast majority of galaxies had spectral lines redshifted from the laboratory values. If you recall from our work on the Doppler effect, a redshift in a spectral line indicates that the object is moving away from us. In a publication by Hubble in 1929, he showed that if you plot the distance to a galaxy (measured from Cepheid variables) and the velocity of the galaxy (measured by the shift in the spectral lines), the two quantities are directly correlated! See the reproduction of his plot below.