Edwin hubble famously discovered that distant galaxies are increasingly redshifted the further they are from the earth. although hubble himself was vocal in his belief that the universe was not expanding and insisted his results only displayed apparent recession of distant objects, we now know that the universe is indeed expanding and the apparent recession discovered by hubble is a physical recession due to an overall expansion of the universe as predicted by einstein’s theory of general relativity. the recession velocity is proportional to the position according to hubble’s law
\vec{v_i}=h_0\vec{r_i}
where h_0 is hubble’s constant, and \vec{r_i} are measured with earth at the origin of the spherically symmetric coordinate system. show that in choosing a different location for the origin, hubble’s law still applies, which implies that we are not the center of the universe (as much as we like to think we are).