I'm reading the book "The theory of everything". In the second chapter it says the Universe is expanding, and we know this because the measurements made using the doppler efect to other galaxies gives redshift signals. My question is, There are no galaxies behing us in this expansion? I mean, If all the galaxies are everyday more and more far from us, this means that the center of the universe if empty? or the galaxies behind us are slower and then the redshift efect is less?

Sorry for my english and thanks in advance.

I'm reading the book "The theory of everything". In the second chapter it says the Universe is expanding, and we know this because the measurements made using the Doppler effect of other galaxies gives redshifted signals. My question is, There are no galaxies behind us in this expansion? I mean, if all the galaxies are moving farther away from us all the time, does this mean that the center of the universe is empty? or are the galaxies behind us slower so the redshift effect is smaller?