: Hello,

: if a black hole exists inside a quasar, then the : gravitational effects must cause red shift on : photons. Why is it that the red shift of : quasars are attributed to dopplar effects? : I have never read any book (not technical journals : because I won't understand) which accounts for : gravitational red shifts. How can they be so : sure that such large red shifts present in : quasars are due to receding velocity?

I had thought slong the same lines. If a star can exhibit magnetism and magnetic permitivity directly affects the velocity of electromagnetic waves, then couldn't this 'tampering with velocity' create the same affect as the recession velocity of the quasar would?