[RightWhale]

Suppose the sun were to be flung out of the Milky Way by such a collision, say by an interaction with M31, would the change in the sun's neighborhood change conditions in the sun itself and on earth besides having far fewer visible stars afterwards and more stars during?

During the collision would planets fare less well than stars due to the passage of gravitational fields and a galaxy full of debris through the vicinity of the sun?

The heliopause is quite a distance out, but nowhere near halfway to the next star. Would the heliopause move farther out than its present radius of about 100 AU?

[glock rocks]

excellent question. thanks.

in that instance, would not time (and the fabric of local space-time
due to the severe gravity fluctuations) change as well?

now, would we notice this change? (i don't think so.)
what other changes would we not notice, even though
to an outside observer major changes would be evident?

put yourself into einstein's inertial reference frame elevator
and ponder whole galaxies colliding. lotsa variables.

in the relative mean time, i think i'll go ponder
a cold miller and change my truck battery.