I think you misunderstood Hawking. "Now" in the relativistic sense is not the same as our past light cone. Reference frames for simultaneity are defined by rela

I think you misunderstood Hawking. "Now" in the relativistic sense is not the same as our past light cone. Reference frames for simultaneity are defined by relative motion. Galaxies without too big a redshift are close enough to moving at the same speed we are, and thus being in our same reference frame, that simultaneity (and times relative to the present) are reasonable to talk about.