I think I misundertsand your post. Are you saying two objects speeding away from eachother don't change their apparent size?

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Problem with this question is motion in space is relativistic there could be 2 bodies of mass not have a motion regarding to each other. There is no object with mass doesnt move relatively to some other object. If your question is if there is a object that doesn't move relatively to space it self ,that is another can of worms because space it self is in motion (expansion)

apparently, no. Everything in the universe is expanding in all directions.

> And if there is, wouldn't this galaxy in a way be more the center of the universe than ours?

I think this is kind of at the heart of the first tier of theoretical multiverses. as the universe expands clumps of galaxies will spread so far from one another that they each will exist within their own observable universe bubble.

It's a little bit like asking what is the probability that one water molecule remains immobile inside a pot of boiling water. Which is certainly null.

The universe is extremely dynamic, even if superstructures can look immuable during our very short lives.

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I guess another way to frame my question is: are there galaxies that experience no redshift of the CMBR at all? (Motion of the individual stars not taken into account)

I'm not talking about size. I'm talking about the motion of galaxies relative to the CMBR.

Space-Time itself is inflating at an extreme rate so everything embedded in Space-Time is in motion just from that alone. Whether the bubble of Space-Time is also in motion within some super framework of other Universes is unknown and will probably forever remain unknown. What we observe is that the majority of observable Galaxies are all heading away from our Milky Way Galaxy, and as Edwin Hubble discovered the further away and farther back in time the observed Galaxy is the faster it is heading away from every other Galaxy. There are local groups of Galaxies orbiting around the Milky Way and the Andromeda Galaxy among others is heading directly towards a collision with the Milky Way Galaxy. So to answer the basic question everything is in motion. The Earth and Solar System are orbiting the Milky Way in excess of 600,000 miles per hour. The Earth orbits the Sun at about 60,000 miles per hour. The Milky Way Galaxy is traveling towards the Andromeda Galaxy at about 1 Million miles per hour. The local group of Galaxies is traveling within the Virgo Super Cluster of 100,000 Galaxies at about 50 million miles per hour. Note these are all just rough numbers and should be researched further but this is what I remember from an Astronomy lecturer at Kitt Peak Observatory, Arizona. Standing on the Earth which is 24,000 miles in circumference rotating once every 24 hours means that everything on the Earth's surface at the Equator is traveling at about 1,000 miles every hour. So calculate how many miles you are away from where the Earth and Solar system, Milky Way, Local Group was when you were born. Now imagine a time traveler that forgot that time is not entrained with the Earth and they successfully blip out of Time for 1 hour. Where will they reappear in 1 hour? Better have a Starship handy if they wish to return to the Earth.

There is a possibility of that if space itself was not expanding and something could be relatively expanding at the same rate as our galaxy. Then you would never see a red shift from our galaxy.

But when we say universe is expanding, it's also the space between galaxies that is expanding. So, everything is moving away from each other. I highly doubt if we will ever find anything not moving relative to us because even the space between earth and anything else in the galaxy is expanding constantly.

The issue is that there is NO 'centre of the universe' to measure against. Because of expansion and inflation and that (as far as we know) the universe started from a Singularity, every point is 'the centre of the universe'. No matter were we are looking from, every other point is moving away from us.

But our galaxy (and we) are moving 550km/s through space, relative to the CMBR. I understand the centre is everywhere, but our centre is moving with the same speed relative to the CMBR. Are there places that don't move relative to the CMBR?

yes, any object you want you could say is stationary, with the rest of the universe moving relative to it, but you'd be making your physics very difficult.

slightly easier to just say everything is moving.

Not in motion… in comparison to what?

I know it can seem like a silly question, but bear with me. Most people who haven’t thought a lot about relativity are going to be confused by the question. Because every time they’ve thought about motion the earth has served as a frame of reference. Things have always been “at rest” or “in motion” in relation to the earth. It’s natural to extend this to the universe at large and ask, what is the reference frame for the universe. And what, if anything is at rest in relation to it.

Minor problem. There is no universal reference frame. This is what the Michealson-Morley (sp?) experiment, that “proved” Einstein’s theory of relativity failed to show. They were trying to measure earths motion against the reference frame and… there was no there, there. Science is pretty cool.

There are about 100 galaxies (including dwarf galaxies) that are blueshifted, meaning they are getting closer rather than receding, the most famous example being Andromeda.

Stands to reason that a galaxy with zero redshift could exist, but not sure if any actually do.

It’s even more meaningless because the fundamental principle of the theory of relativity is that there is no preferred reference frame that could be used to determine an objective ‘center’: any reference frame in uniform motion is as valid as any other.

I would look for a galaxy about 7.86 Mpc from us, in the direction opposite our motion through the CMBR. Since the average distance between galaxies is about 25 Mpc, there might not be any galaxies there.

550 / 70 = 7.86

There is no preferred rest reference frame. Any object can be thought of as being at rest and everything else in motion relative to it.

Hello u/ProphetMoham, your submission "Are there objects in the universe that are not in motion at all?" has been removed from r/space because:

• Such questions should be asked in the "All space questions" thread stickied at the top of the sub.

Please read the rules in the sidebar and check r/space for duplicate submissions before posting. If you have any questions about this removal please message the r/space moderators. Thank you.

This is what I was looking for, thank you.