An observation of the red shift of galaxies suggests that the universe is

a. expanding b. contracting c. reversing d. stagnant

A. expanding because the wavelength is increasing and I learned that blue shift would mean the universe if contracting so you could assume red is expanding.

Mysteriously, all of the distant galaxies show a red shift in their light,

and the farther a galaxy is from us, the greater its red shift is.

The only explanation we have now for a red shift is that the source

of the light is moving away from us.

So the observations of the red shifts of distant galaxies suggest that

the universe is expanding.

If somebody discovers something else tomorrow that can shift the

observed wavelength of light toward the red, then the whole idea of

the big bang and the expanding universe will be out the window.