Originally Posted By: Bill S.
I found the following statement: "Since the relation [between observed redshifts] is the same in all directions it cannot be attributed to normal movement with respect to a background which would show an assortment of redshifts and blueshifts."

Why could not "normal movement" produce the observed redshifts?

Presumably because normal movement would generate an assortment (roughly an equal amount) of redshifts and blueshifts not an overwhelming preponderance of redshifts as observed.