[graham.d]

Democritus, is is true that the redshift is due to cosmological expansion of a theoretical hyperspherically symmetric universe based on the FLRW model rather than a simpler Minkowski, flat model. The redshift is primarily due to this and the Doppler effect just modifies the results because of local variations.

It is, perhaps, easier for people not familiar with the idea of 4D spacetime to think of redshift due to Doppler effect from distant galaxies receding at a speed in proportion to their distance though.

[Murchie85]

Andrew I know you say that energy is lost and not conserved, but at the risk of sounding dumb, how can this be. I thought that in all cases of physics energy is conserved except in the virtual particle circumstance.