Vaster Spaces

In Poul Anderson's History of Technic Civilization, all that commercial, industrial and imperialist activity takes place at the end of one spiral arm of one galaxy. Do similar events occur elsewhere in the spiral arm and in the galaxy and in other galaxies? Could we be given an overview of the history of a vaster volume of space? In Anderson's After Doomsday, this galaxy is full of civilization-clusters with little regular contact (see here) but no one can see the full picture.

In James Blish's main future history:

"'...we saw very little of [the Andromeda] galaxy, which is as vast as our home; we think that it is not inhabited by any widespread, space-cruising race such as yours and mine, but in the brief sampling of its stars that we were able to take we might well simply have missed hitting upon an inhabited or colonized system.'"
-James Blish, The Triumph Of Time IN Blish, Cities In Flight (London, 1981), pp. 467-596 AT p. 504.

Mayor Amalfi suggests seeking civilization in the next galaxy, NGC 6822, a million light years away, but instead the dirigible planet He flies to the Metagalactic Centre and what the author accepted in conversation was "an unacceptable coincidence." See James Blish: Okies.

Although it is now known that there are many extra-solar planets, some of us remain skeptical as to whether there is a great deal of intelligence, let alone industrial civilization, out there.