B Why Is Universal Attraction Used If Galaxies Accelerate Apart?

[Zerger]

If galaxies fly apart from each other with ACCELERATION, why is the term "universal attraction" used and not "universal repulsion"?

 

[kuruman]

Throw a rock staright up in the air. While it's moving up, is it attracted or repelled by the Earth? Is it accelerating? How many forces, do you think, are acting on the rock on its way up?

 

[Zerger]

The object of the question is the universe. Maybe the rock is pushing in.

 

[phinds]

If galaxies fly apart from each other with ACCELERATION, why is the term "universal attraction" used and not "universal repulsion"?

To expand on @kuruman's question, why do you think it is not possible for two things to attract each other even while one accelerates away from the other? How do rockets leaving Earth act?

 

[PeroK]

If galaxies fly apart from each other with ACCELERATION, why is the term "universal attraction" used and not "universal repulsion"?

The Milky Way and Andromeda galaxies are on a collision course, due to their mutual gravitational attraction. See, for example:

https://en.wikipedia.org/wiki/Andromeda–Milky_Way_collision

At the largest cosmological scales, so-called dark energy (energy of the vacuum) dominates gravitational attraction and results in an accelerating expansion of the universe.

 

[phinds]

The Milky Way and Andromeda galaxies are on a collision course, due to their mutual gravitational attraction. See, for example:

https://en.wikipedia.org/wiki/Andromeda–Milky_Way_collision

At the largest cosmological scales, so-called dark energy (energy of the vacuum) dominates gravitational attraction and results in an accelerating expansion of the universe.

And ... so much for the Socratic Method.

 

[Zerger]

To expand on @kuruman's question, why do you think it is not possible for two things to attract each other even while one accelerates away from the other? How do rockets leaving Earth act?

Why do you think that two objects cannot repel each other, even if one is accelerating toward the other?Which should be exemplified - all rocks or all galaxies?

 

[phinds]

Why do you think that two objects cannot repel each other, even if one is accelerating toward the other?Which should be exemplified - all rocks or all galaxies?

Answering my question with a strawman does not answer my question, even though you seem to think that it does.

To specifically answer your question, I do NOT think that two objects cannot repel each other even if one is accelerating toward the other, since they clearly can. Think magnets.

 

[PeroK]

Can we focus on cosmology?

 

[Zerger]

The Milky Way and Andromeda galaxies are on a collision course, due to their mutual gravitational attraction. See, for example:

https://en.wikipedia.org/wiki/Andromeda–Milky_Way_collision

At the largest cosmological scales, so-called dark energy (energy of the vacuum) dominates gravitational attraction and results in an accelerating expansion of the universe.

The force pushing the entire universe is the force of universal repulsion. Ok?

 

[Dale]

why is the term "universal attraction" used

Where is the term "universal attraction" used? Please provide some specific references that use that term. Two words taken out of context are not particularly meaningful.

My guess is that those specific references are describing the Newtonian law of gravity. This law does not apply at cosmological scales.

 

[PeroK]

The force pushing the entire universe is the force of universal repulsion. Ok?

Not OK!

 

[Zerger]

Not OK!

Ok.