Are all galaxies moving away from the Milky Way?

In summary: Pbody101 you might find it informative to read the one-page discussion provided by the link in my signatureIn summary, the conversation discusses various theories about the beginning of time and space, specifically regarding the movement of galaxies. It is explained that space everywhere is expanding, causing distant objects to move further away from each other. This means that all distant galaxies appear to be receding from any point in the universe, with no specific galaxy at the center. However, local clusters of galaxies are gravitationally attracted to each other and will eventually collide and merge. The conversation also explores the concept of the observable universe and how it appears the same for any galaxy. It is also mentioned that in the future, all galaxies outside our local group will disappear
  • #1
Pbody101
11
1
Once again I am reading and trying to understand more about the different theories of the beginning of time/space. I don't know why I never thought about this, but they say that galaxies are moving further and further away. One day we will not be able to see them because they moved so far. My main question is how is everything moving away from us? In retrospect wouldn't some galaxies be getting closer, or does that make us the center of the universe, or is it an optical illusion?

Thank you for your time to reply.

P
 
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  • #2
Pbody101 said:
Once again I am reading and trying to understand more about the different theories of the beginning of time/space. I don't know why I never thought about this, but they say that galaxies are moving further and further away. One day we will not be able to see them because they moved so far. My main question is how is everything moving away from us? In retrospect wouldn't some galaxies be getting closer, or does that make us the center of the universe, or is it an optical illusion?

Thank you for your time to reply.

P
Regarding galaxies there are two factors. Space everywhere is expanding. This means that distant objects get further and further away from each other. We see all distant galaxies receding from us, but so would someone in another galaxy. To them, our Milky Way would be receding.

No galaxy, therefore, is at the centre of the universe. It has no centre.

But, galaxies that are not so far away are attracted gravitationally to each other and move towards each other faster than space is expanding between them. These local clusters of galaxies will eventually collide and merge. For example, the Milky Way will eventually collide and merge will the Andromeda galaxy.
 
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  • #3
PeroK said:
Regarding galaxies there are two factors. Space everywhere is expanding. This means that distant objects get further and further away from each other. We see all distant galaxies receding from us, but so would someone in another galaxy. To them, our Milky Way would be receding.

No galaxy, therefore, is at the centre of the universe. It has no centre.

But, galaxies that are not so far away are attracted gravitationally to each other and move towards each other faster than space is expanding between them. These local clusters of galaxies will eventually collide and merge. For example, the Milky Way will eventually collide and merge will the Andromeda galaxy.

Just in theory,what if we were on a planet looking at the sky but we were on the most distant galaxy the one that is approximately 14 billion years old would everything look like it was still moving away, or coming towards us? As I am doing my research I have noticed a relentless amount of information about other theories outside of the big bang, and the information just keeps expanding like the universe seems to. Other than mathematics where to start seems crazy, just the definitions and explanations in all of this leave me with more questions than answers. I love it, where should I put down all of my questions so I don't flood out the forum board? Any ideas?

Thanks

P
 
  • #4
If we consider one of the most distant galaxies that we can see - that is at the limit of our observable universe. We will be at the limit of the observable universe for someone in that galaxy, but their observable universe will extend as far again in all directions, including galaxies outside our observable universe.

Each galaxy therefore is at the centre of its observable universe and, in this respect, no galaxy is special.
 
  • #5
Pbody101 said:
Just in theory,what if we were on a planet looking at the sky but we were on the most distant galaxy the one that is approximately 14 billion years old... would everything look like it was still moving away, or coming towards us?
The overall picture should look the same for any galaxy anywhere in the Universe.
The most distant galaxies from them will seen to be receding increasingly fast, less distant ones not so fast, and closeby ones hardly receding at all, some of them actually getting closer, like Andromeda is to the Milky way.
 
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  • #6
Well. once I've heard that Andromeda is coming to colide with us.
 
  • #7
Leonardo Machado said:
Well. once I've heard that Andromeda is coming to colide with us.

yeah ... post #2 of this thread
 
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  • #8
Consider a balloon, fill some air and mark two dots. Draw a line joining the two dots. Now enter more air into the balloon. As the balloon expands, the dots separate more and the line between them extends. This is happening with the galaxies. As the universe itself is expanding like the balloon, we see other galaxies in every direction moving away from us.
 
  • #9
@Pbody101 you might find it informative to read the one-page discussion provided by the link in my signature
 
  • #10
500 galactic years from now, all galaxies outside of the Milky Way local group will disappear behind the cosmic horizon.
 
  • #11
JackFrost16 said:
Consider a balloon, fill some air and mark two dots. Draw a line joining the two dots. Now enter more air into the balloon. As the balloon expands, the dots separate more and the line between them extends. This is happening with the galaxies. As the universe itself is expanding like the balloon, we see other galaxies in every direction moving away from us.

Thank you Jack, for your reply. That is a very simple and easy to understand way of looking at it.

phinds said:
@Pbody101 you might find it informative to read the one-page discussion provided by the link in my signature

I will definitely read it! Awesome, thank you.

lifeonmercury said:
500 galactic years from now, all galaxies outside of the Milky Way local group will disappear behind the cosmic horizon.

Crazy when you think about it, it makes me wonder if our galaxy is expanding as well.
 
  • #12
Pbody101 said:
Crazy when you think about it, it makes me wonder if our galaxy is expanding as well.

My understanding is that the gravitational force in our galaxy and galaxy cluster and supercluster is sufficient to nullify the expansion of space within it/them.
 
  • #13
Pbody101 said:
Crazy when you think about it, it makes me wonder if our galaxy is expanding as well.
No, it is not. This is explained in the link I gave you.

lifeonmercury said:
My understanding is that the gravitational force in our galaxy and galaxy cluster and supercluster is sufficient to nullify the expansion of space within it/them.
Correct.
 
  • #14
Cool, I am sorry I haven't been here with stupid questions I have been on a journey from the begging in Mesopotamia. It all began with what we understand now, and strangely led me to the past. Ironically the ancient past, perhaps it is because I can understand it clearer @phinds I read the article and it was wonderfully written. It explains a lot that didn't make sense to me.

although it is still hard for me to grasp the fact that the universe is expanding pulling against things at a rate that is crazy, and it would have no effects on galaxies. That is why I am an idiot, and I ask questions.

I will re-read the article.

sorry if I sound crazy tonight I had a little to drink
 
  • #15
We've established that the cosmic light horizon exists due to space between galaxies expanding at a speed that is faster than light. Does this horizon apply to gravity as well since gravity propagates at the speed of light? If so, this should mean that the particle horizon is also the point after which the gravity of matter can no longer have any effect whatsoever on Earth. Is this correct?
 
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  • #16
How do we know that our Big Bang was not just a local big Bang of an infinite number of other far off Big Bangs?
 
  • #17
Zachary Smith said:
How do we know that our Big Bang was not just a local big Bang of an infinite number of other far off Big Bangs?
We don't and there are a number of theories which conclude that there could be a 'multiverse'.
However there is no evidence of that being a fact, and unlikely there will be since these other universes are not causally connected with the one we are in.
That means there is no way of obtaining any information about them (if they do indeed exist)
What *might* happen in the future is that we find a way to peer further back than the CMB radiation.
That could rule out multiverse proposals, or maybe it could strengthen the case, but at present the idea is only a hypothesis based on mathematical speculations.
 

Related to Are all galaxies moving away from the Milky Way?

Are all galaxies moving away from the Milky Way?

Yes, according to the current evidence, it appears that all galaxies are moving away from the Milky Way.

What is the evidence for galaxies moving away from the Milky Way?

The main evidence for this is the observation of redshift in the light coming from other galaxies. This indicates that they are moving away from us and the further away a galaxy is, the faster it is moving.

Is there any exceptions to this phenomenon?

There are a few exceptions, such as the Andromeda Galaxy, which is actually moving towards the Milky Way due to the gravitational pull between the two galaxies. However, this is a rare occurrence and does not change the overall trend of galaxies moving away from each other.

What is the significance of galaxies moving away from the Milky Way?

This phenomenon is evidence of the expansion of the universe, as predicted by the Big Bang theory. It also helps scientists understand the structure and evolution of the universe.

Could galaxies eventually collide due to their movement?

It is possible for galaxies to collide in the future, but the likelihood of a collision is very low due to the vast distances between galaxies. Additionally, the expansion of the universe is causing galaxies to move away from each other at an increasing rate, making collisions even less likely.

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