Debate goes on as to whether or not our cosmos will some day undergo the
opposite end of the Big Bang - i.e., the "Big Crunch". Well, assume for the
sake of this question that another commonly-discussed possibility - that of
eternal expansion and eventual heat death - is definitively the case.

Here's
the question:

If at some point a technological civilization within the cosmos were to
become advanced and powerful enough to be capable of manipulating the
trajectories of entire galaxies, would they be physically capable of
deliberately reversing the expansion of the cosmos and inducing a "Big Crunch"?

Debate goes on as to whether or not our cosmos will some day undergo the
opposite end of the Big Bang - i.e., the "Big Crunch". Well, assume for the
sake of this question that another commonly-discussed possibility - that of
eternal expansion and eventual heat death - is definitively the case. Here's
the question:

If at some point a technological civilization within the cosmos were to
become advanced and powerful enough to be capable of manipulating the
trajectories of entire galaxies, would they be physically capable of
deliberately reversing the expansion of the cosmos and inducing a "Big Crunch"?

If there isn't enough information to answer the question, what variables
would need to be known which aren't already? :-?

I suspect there may be some kind of checks-and-balances aspect to the
calculations necessary to determine the answer to this which - assuming the
universe was presently and conclusively headed towards eternal expansion and
eventual heat death - will make it so that such a reversal would in fact be
impossible. The notion I have when trying to explain why I suspect this is an
image of someone trying to touch their own elbow with the pointer finger of the
hand on the same arm _as_ the elbow - the finger can move towards the elbow to
an extent, but at some point, moving the finger further towards the elbow causes
the elbow to move as well, and thus the two can never actually meet.

Just curious.... :-)

Debate goes on as to whether or not our cosmos will some day undergo the
opposite end of the Big Bang - i.e., the "Big Crunch". Well, assume for the
sake of this question that another commonly-discussed possibility - that of
eternal expansion and eventual heat death - is definitively the case. Here's
the question:

If at some point a technological civilization within the cosmos were to
become advanced and powerful enough to be capable of manipulating the
trajectories of entire galaxies, would they be physically capable of
deliberately reversing the expansion of the cosmos and inducing a "Big Crunch"?