Is the universe like a balloon?

Some physicists have told me that the universe is like the surface of a balloon. Does this mean that if it were possible to travel at an infinite speed, you'd come back to the same place if you travelled straight in one direction?

Also, is it true that all galaxies are at rest in space, while the universe (and therefore the relative distances between the galaxies) expands? Doesn't this mean that the universe is filled with a kind of expanding ether (space)?

Also, is it true that all galaxies are at rest in space, while the universe (and therefore the relative distances between the galaxies) expands? Doesn't this mean that the universe is filled with a kind of expanding ether (space)?

Also, is it true that all galaxies are at rest in space, while the universe (and therefore the relative distances between the galaxies) expands? Doesn't this mean that the universe is filled with a kind of expanding ether (space)?

The galaxies are moving wrt each other, and as well, the space is expanding. There is no aether.

I have a question relating to this...
I saw that balloon analogy of the expanding universe. But there was something I was confused about. In the balloon analogy there were dots on the balloon and as the balloon was blown up and increased in size, the space between the galaxies increased. And that was the analogy of the expansion of the universe; The galaxies are moving away from each other because space is expanding.
I realize that the balloon analogy is a simplified model but here is where my confusion lies. On the balloon if it were blown up the dots (representing galaxies) would increase in size, and thus the relative distances apart would stay the same.
So if space is expanding shouldn't the galaxies also be expanding, and if that is true would the distance apart not remain the same?

I have a question relating to this...
I saw that balloon analogy of the expanding universe. But there was something I was confused about. In the balloon analogy there were dots on the balloon and as the balloon was blown up and increased in size, the space between the galaxies increased. And that was the analogy of the expansion of the universe; The galaxies are moving away from each other because space is expanding.
I realize that the balloon analogy is a simplified model but here is where my confusion lies. On the balloon if it were blown up the dots (representing galaxies) would increase in size, and thus the relative distances apart would stay the same.
So if space is expanding shouldn't the galaxies also be expanding, and if that is true would the distance apart not remain the same?

If I've got it right, the galaxies (dots) don't expand, even if dots on a balloon would expand. Only space itself expands. It is said to expand into nothing. I don't understand how that is possible.

In fact the 4th dimension is the time dimension as thought by Einstein & his General theory of relativity.

Indeed.

mubashirmansoor said:

But you don't really have to look for some beings living in the 4th dimension because I think there are already many of them in the cosmos!!!

I think what you mean here is that one does not need to look very far for a being living in the fourth dimension as per Einstein; that is, you are talking about the fourth dimension being temporal, as opposed to spatial. This may have caused some confusion in the thread.

I have a question relating to this... I saw that balloon analogy of the expanding universe. But there was something I was confused about. In the balloon analogy there were dots on the balloon and as the balloon was blown up and increased in size, the space between the galaxies increased. And that was the analogy of the expansion of the universe; The galaxies are moving away from each other because space is expanding. I realize that the balloon analogy is a simplified model but here is where my confusion lies. On the balloon if it were blown up the dots (representing galaxies) would increase in size, and thus the relative distances apart would stay the same. So if space is expanding shouldn't the galaxies also be expanding, and if that is true would the distance apart not remain the same?

If I've got it right, the galaxies (dots) don't expand, even if dots on a balloon would expand. Only space itself expands.

kasse has got it right here: the dots in this analogy do not expand. It is perhaps a better analogy to think of sticking pieces of paper, or pennies onto the balloon to represent gravitationally bound systems.

kasse said:

It is said to expand into nothing. I don't understand how that is possible.

There is no need for there to be anything for the universe to expand into. The analogy starts to break down when you think about what the balloon is expanding into.

I have a question relating to this...
I saw that balloon analogy of the expanding universe. But there was something I was confused about. In the balloon analogy there were dots on the balloon and as the balloon was blown up and increased in size, the space between the galaxies increased. And that was the analogy of the expansion of the universe; The galaxies are moving away from each other because space is expanding.
I realize that the balloon analogy is a simplified model but here is where my confusion lies. On the balloon if it were blown up the dots (representing galaxies) would increase in size, and thus the relative distances apart would stay the same.
So if space is expanding shouldn't the galaxies also be expanding, and if that is true would the distance apart not remain the same?

A better model for the analogy is, instead of drawing dots on the balloon, to glue pennies into it. As the balloon expands, the pennies do not. The solidity of the penny's metasl easily overwhelms the weak force of the balloon expanding. Likewise, the gravity of a galaxy easily overwhelms the weak force of space expanding.

I think what you mean here is that one does not need to look very far for a being living in the fourth dimension as per Einstein; that is, you are talking about the fourth dimension being temporal, as opposed to spatial. This may have caused some confusion in the thread.

I apologize for not completing my statement... I meant something totally different...

I was trying to say no need to search for beings living in the 4th dimension since we have enough living organisms in our surroundings!!! just joking don't take it serious :)

Some physicists have told me that the universe is like the surface of a balloon. Does this mean that if it were possible to travel at an infinite speed, you'd come back to the same place if you travelled straight in one direction?