wj writes:
The relative motions of the galaxies near the Milky Way which form the local group have been known for some time. The motions are determined by red shifts.
This site provides information on the local group. And
this figure shows the results of
simulations by Rami Rikola at a Finnish observatory.
This is interesting! The simulations extend the motions of galaxies in the local group
back in time, and amongst other things attempt to infer an approximate age for the universe, based on the time when all the galaxies were together. The ages obtained are around 17 to 18 billion years. This is substantially larger than most currently accepted estimates (13.7 billion years) but it is in the ball park given the problems with this kind of modeling.
The time step of the simulations is 80 million years; this gives an idea of the time scales on which galactic interactions occur. I don't think there is anything useful to be gained by plotting motions all the way back 17 billion years, because by that stage you need to worry about a lot more than the local group; and also the formation of galaxies themselves, which is a mostly unsolved problem (as I understand the matter).
But it is very interesting all the same. Thanks.
Cheers -- Sylas