3 ms·
> We have no idea of the physics behind red shift "caused by the metric expansion of space". What do you mean we have no idea? Redshift is one of the few simpl
by Maro 8y ago
> We have no idea of the physics behind red shift "caused by the metric expansion of space".
What do you mean we have no idea? Redshift is one of the few simple concepts in Astrophysics, whether it's doppler, cosmological or gravitational.
- Zamicol 8y agoI could have better said, "We don't understand the physical causes for the metric expansion of space". It's the physical reasons for the expansion we don't understand.
- pdonis 8y ago> It's the physical reasons for the expansion we don't understand. Sure we do; it's the Einstein Field Equation and the initial conditions at the Big Bang. What we don't fully understand is how the initial conditions at the Big Bang came about. The current front-runner hypothesis is some form of inflationary model (in which the Big Bang is really the end of inflation), but the question is still open.