The Death of Cosmology

Not in any humans life time!

Actually, considering how un-neighborly a lot of people can be, I should think we're already alone now.

Wouldn't each of two receding galaxies only have to be moving in opposite directions at half the speed of light each? What about the many cases where galaxies are approaching each other, i.e., Andromeda and the Milky Way? Galactic clusters where a number of galaxies orbit a common CG? I don't think we'll have to worry about this for a few more years.

Wouldn't each of two receding galaxies only have to be moving in opposite directions at half the speed of light each?

-No, because light from those galaxies still travels at the speed of light.

What about the many cases where galaxies are approaching each other, i.e., Andromeda and the Milky Way? Galactic clusters where a number of galaxies orbit a common CG?

-- Yes, our local galaxy group will stay intact.

I don't think we'll have to worry about this for a few more years.

-- I'm worrying about it now!!

I thought no two things can move faster than the speed of light with respect to each other. The speed of light is constant while time varies.

Hence the epithet "weird".

Thats somewhat true, but since the space underneath them is moving, they technically aren't accelerating past the speed of light. Also, they can't see each other, because they're past each other's horizons, just as we can't see the entire universe because much of it has expanded past our horizon. So we're not causally connected and blah blah blah..

a galaxy could never reach the speed of light, but in answer to your question, we are already alone and fast approaching (in cosmological time references) our end.