Whats in the space between any 2 galaxies?

In summary, the conversation discusses the concept of gravitational potential between two galaxies and how it is affected by the presence of dark matter and the vacuum of space. It is mentioned that in Newtonian mechanics, the gravitational potential can be anything, while in general relativity, it cannot be defined for cosmological spacetimes. The existence of galaxy clusters is seen as evidence of gravitational attraction between galaxies, and the vacuum between galaxies is described as extremely good. There is a question about whether the vacuum can be differentiated from spacetime, but it is unclear in what context.
  • #1
aditya23456
114
0
like is there any gravitational potential in the space between 2 galaxies due to galaxies mass.?how large is this gravitational potential is it significant..If possible please provide me a link where i can learn more about it..thanks in advance
 
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  • #2
In Newtonian mechanics, the gravitational potential can be anything you want it to be, since it's arbitrary up to an additive constant. It isn't a physical substance that exists in the space between two galaxies. If you want to estimate it relative to its value within a galaxy, just plug into the usual equation, approximating the galaxy as a sphere.

In general relativity, there is not any way of defining a gravitational potential that applies to cosmological spacetimes. That means that if you try to generalize this to discuss things happening on cosmological scales, it won't work. The Newtonian approximation only works for your original question because you were describing something within a cluster of galaxies, which is much smaller than the Hubble scale.
 
  • #3
bcrowell said:
In Newtonian mechanics, the gravitational potential can be anything you want it to be, since it's arbitrary up to an additive constant. It isn't a physical substance that exists in the space between two galaxies. If you want to estimate it relative to its value within a galaxy, just plug into the usual equation, approximating the galaxy as a sphere.

In general relativity, there is not any way of defining a gravitational potential that applies to cosmological spacetimes. That means that if you try to generalize this to discuss things happening on cosmological scales, it won't work. The Newtonian approximation only works for your original question because you were describing something within a cluster of galaxies, which is much smaller than the Hubble scale.

I think this is a simple way to put the question in..Has anyone observed a gravitational effect of 1 galaxy on the other(if yes,this proves that force of gravity had been passed in the medium between)If no,it means force of gravity doesn't exist..Isn't it a simpler way of presenting question.?
 
  • #5
The existence of galaxy clusters itself is evidence that galaxies attract each other - otherwise, we would expect a nearly uniform distribution of galaxies everywhere. Galaxies (or parts of them) moving around other galaxies can be seen, too.

(if yes,this proves that force of gravity had been passed in the medium between)
That "medium" is an extremely good vacuum, even better than the vacuum inside the galaxies.
 
  • #6
mfb said:
The existence of galaxy clusters itself is evidence that galaxies attract each other - otherwise, we would expect a nearly uniform distribution of galaxies everywhere. Galaxies (or parts of them) moving around other galaxies can be seen, too.

Since clusters of galaxies exist,ie gravitational attraction between any 2 galaxies have been recorded,are the velocities of both galaxies in match with there mutual gravitational pull without need of any dark matter concept?

As mentioned the medium between galaxies is perfect vacuum,Can we distinguish this vacuum with space,ie Is this vacuum(similar to spacetime) capable of being wrapped due to presence of Gravitational field flowing through it?
 
  • #7
aditya23456 said:
are the velocities of both galaxies in match with there mutual gravitational pull without need of any dark matter concept?
No.

As mentioned the medium between galaxies is perfect vacuum
Not perfect, but extremely good.

Can we distinguish this vacuum with space,ie Is this vacuum(similar to spacetime) capable of being wrapped due to presence of Gravitational field flowing through it?
Vacuum is space with no matter at that place. I don't understand the question.
 

1. What is the space between any two galaxies made of?

The space between any two galaxies is mostly made up of a vacuum, meaning it is mostly empty space. However, there are also various forms of matter, including gas, dust, and dark matter, that make up a small percentage of this space.

2. Are there any objects or structures in the space between galaxies?

Yes, there are various objects and structures in the space between galaxies. These include stars, planets, asteroids, and comets that may have been ejected from their original galaxies. There may also be clusters of galaxies, galaxy filaments, and voids within this space.

3. How far apart are galaxies in the space between them?

The distance between galaxies can vary greatly, but it is typically measured in millions of light-years. For example, the Milky Way galaxy is about 100,000 light-years across and is approximately 2.5 million light-years away from the Andromeda galaxy.

4. Is there anything that can travel through the space between galaxies?

Yes, various forms of energy can travel through the space between galaxies, including light, cosmic rays, and gravitational waves. However, due to the vast distances and emptiness of this space, it is highly unlikely that any physical objects or matter can travel through it.

5. How does the space between galaxies affect the movement of galaxies?

The space between galaxies plays a crucial role in the movement and interactions of galaxies. The gravity of dark matter and other forms of matter present in this space can affect the movement and trajectories of galaxies. Additionally, the expansion of the universe and the distribution of matter also influence the movement of galaxies in the vast space between them.

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