Is our universe expanding?

[Ignat]

According to Hubble's law, galaxies are moving away from Earth at a speed proportional to their distance. In other words, the further away they are, the faster they move away from the Earth. The speed of galaxies is determined by their redshift.

Based on this law, some scientists have come to the conclusion that the universe is expanding with acceleration. However, there are galaxies that are not moving away, but approaching the Earth, for example Andromeda. Now this approaching is explained by the proximity of the Milky Way and Andromeda and their attraction. But there is, for example, the Large Magellanic Cloud galaxy, which is also close to Earth, but moving away from the Milky Way.

Thus, obviously, it is not the expansion of the Universe that is taking place, but the movement of parts of matter, possibly in the form of a vortex. Since this process is very slow for an observer on Earth, we only see an instant of this process. Perhaps, over time, new galaxies will appear, which will not be moving away, but approaching the Earth.

 

[Catastrophe]

The definition of Universe is incorrect. Who is to decide what "all there is" means?

The map is not the territory. There are only observable universes.

Of course, you can imagine "the sum of all the observable universes", but this is metaphysics, not science.

Who is to decide what is "observable" - what is observable by whom or by what?

And what if something cannot be observed in any way by any thing?
Because there is no "observing entity" within observing range.
Does it exist.? This, again, is metaphysics, not science.

As "our" observable universe ages, most of what we now observe will no longer be observable (according to model of observable universe employed) due to expansion and finite speed of light.
Will "all there is" shrink? This is the worst "metaphysics" - just playing around with semantics.

Cat

See also:

Page 3 - Goodbye infinity and all that infinite singularity and infinite density descriptions

Page 3 - Seeking answers about space? Join the Space community: the premier source of space exploration, innovation, and astronomy news, chronicling (and celebrating) humanity's ongoing expansion across the final frontier.

forums.space.com

 

[Ignat]

The definition of Universe is incorrect. Who is to decide what "all there is"

The map is not the territory. There are only observable universes.

Of course, you can imagine "the sum of all the observable universes", but this is metaphysics, not science.

Who is to decide what is "observable" - what is observable by whom or by what?

And what if something cannot be observed in any way by any thing?
Because there is no "observing entity" within observing range.
Does it exist.? This, again, is metaphysics, not science.

As "our" observable universe ages, most of what we now observe will no longer be observable (according to model of observable universe employed) due to expansion and finite speed of light.
Will "all there is" shrink? This is the worst "metaphysics" - just playing around with semantics.

Cat

See also:

I didn't quite understand your answer. How does it fit in with what I was asking?

 

[Catastrophe]

Ignat, welcome to the Forum.

Hubble's "law" is overruled at 'small' distance, being subservient to gravity, and a few galaxies, like Andromeda, approach, rather than move away.
This means that the "straight line" ceases to apply near the origin.

Perhaps, over time, new galaxies will appear, which will not be moving away, but approaching the Earth.

Thus, for this to happen, new galaxies would have to form nearby.

Local Group - Wikipedia

en.wikipedia.org

So, would your question be, is there new material nearby to form new galaxies?
Would new stars forming from this new material form new galaxies, or would they be more influenced by local galaxies already existing?

One idea is that galaxies could pass through local concentrations of matter.

rotating galaxies new matter - Google Suche

The rotation of galaxies and the existence of dark matter are both complex topics that are still being studied. Some recent research suggests that the existence of dark matter may not be necessary to explain the rotation of galaxies

I hope this helps.

Cat