Re: So . . . . .
@ John Mangan - Would it be correct to assume therefore that the older the waves, the longer the wavelength, due to the fact that space-time (the universe) continues to expand from origin and therefore stretches everything out - the oldest waves having been stretched the most?
@ Alan Brown - Thank you for that.
TIL: Space time is gigantically wibbly-wobbly, but sadly not raspberry flavoured (yet).