How does the universes expand?

Originally posted by RJHinds
I believe you guys don't understand the two main types of space. One type of space consists of nothing and the other type of space is an invisible substance than can expand into the nothingness of space.

Please take your nothingness and expand over to the spirituality forum and leave the science forum to those of us actually interested in science.

Originally posted by RJHinds
I will let you so-called scientists do the speculating.

Yes please do.

Originally posted by FabianFnas
Time is not a spacial dimension.

Or do you mean that the universe expands out in the time dimension? That the universe is surrounded by time and not space? Isn't that to complicate things...?

No I mean that space-time is a four dimensional thing. There is a unit vector that points in a purely time-like dimension.

Originally posted by humy
He explained it well enough I think and you are clearly still totally confused and I don't understand why. Do you at least understand "..Space isn't expanding into space. It IS space. ..." so space can expand WITHOUT moving into some other kind of space (which doesn't exist -space is just space ) ? -because this somehow seems to me to be part of your confusion. ...[text shortened]... anding, because it is SPACE ITSELF, doesn't imply it is something expanding INTO something else.

I believe you are correct, I don't get it.
If the universe were nothing but 24 cubic feet and now its 48 cubic feet,
then something beyond the area of the original 24 cubic feet was moved
into. If there were nothing to move into, it couldn't, if there were than it
moved into it.
Kelly

Originally posted by KellyJay
I read about the rulers being laying end to end, and didn't think it
addressed the question at all. If there were 12 rulers and you moved each
one whatever it takes to equal a 12 inches of space between them, you may
as well just stick another ruler on one end and not move them. It is still
having the rulers slide apart into new space. There has to be s ...[text shortened]... upies more cubic inches of space has
that balloon moving into space it wasn't in before.
Kelly

That post was designed to answer vivify's question about not breaking the rule about not going faster than light. It was not intended to explain how a thing can expand when there is "nothing" to expand into.

Distance is a physical quantity. If you really want imagine the universe staying the same size and everything in it shrinking. It's basically the same thing, provided you alter the speed of light and so forth as I predict googlefudge will point out in his next but one post.

Originally posted by KellyJay
Now I think we are speaking about two different things.
If space is the same then the only thing we are talking about are all the
things that fill it. Those would be moving into areas where only space was
before.
Kelly

Hmmmm. I think I have just thought of a better analogy.. possibly.

Imagine the entire universe is a 24 inch computer screen.

The 'size' of the screen is constant at 24 inches. [~246 square inches]

But the resolution [number of pixels per square inch {dp2i}] keeps increasing.

So the screen starts out with a resolution of 800x600 [1950 dp2i]...
then increases to 1024x768 [3195 dp2i]... then 1152x864 [4044 dp2i]....

Now for an object in this universe travelling from one side to the other
will require traversing an ever increasing number of pixels, which if travel
takes a given time per pixel will mean that journey times will increase an
'distances' between points on the screen/universe will increase...

Without the screen ever ceasing to be 24 inches across.

The amount of 'space' [number of pixels] between points will be constantly
increasing, and will look to an observer inside this universe as if the universe
is expanding, but the 'external size' of this universe is constant.

Originally posted by DeepThought
That post was designed to answer vivify's question about not breaking the rule about not going faster than light. It was not intended to explain how a thing can expand when there is "nothing" to expand into.

Distance is a physical quantity. If you really want imagine the universe staying the same size and everything in it shrinking. It's basically the same thing.

Not quite the same thing.

The effect you were thinking of would be my example of the universe getting
higher resolution, which superficially looks like 'everything shrinking'.

But 'everything shrinking' doesn't give you the increased travel time that
increasing resolution gives you.

If your ruler is 10 pixels long, then in an increasing resolution universe of fixed
'external' dimensions it will indeed shrink.

But unless you have a mechanism by which velocity [as measured according to
an external reference] reduces as well, you wont get galactic red-shift effects,
or an event horizon form.


EDIT: hah. Just spotted your edit 😉

Good prediction.

Originally posted by googlefudge
Hmmmm. I think I have just thought of a better analogy.. possibly.

Imagine the entire universe is a 24 inch computer screen.

The 'size' of the screen is constant at 24 inches. [~246 square inches]

But the resolution [number of pixels per square inch {dp2i}] keeps increasing.

So the screen starts out with a resolution of 800x600 [1950 dp2i]... ...[text shortened]... niverse as if the universe
is expanding, but the 'external size' of this universe is constant.

That is a better analogy that I get, thank you!
Kelly

Originally posted by KellyJay
That is a better analogy that I get, thank you!
Kelly

You're welcome.

Originally posted by DeepThought
No I mean that space-time is a four dimensional thing. There is a unit vector that points in a purely time-like dimension.

I know, but now we're talking about the universe 3-dim space and how it doesn't need any 4th to expand into anything else. Any temporal dimensions are irrelevant here.

My question was - In which direction is the 4th dimension into where universer is expanding into? The lack of answer answers that no 4th one is needed.

Originally posted by KellyJay
I believe you are correct, I don't get it.
If the universe were nothing but 24 cubic feet and now its 48 cubic feet,
then something beyond the area of the original 24 cubic feet was moved
into. If there were nothing to move into, it couldn't, if there were than it
moved into it.
Kelly

If the universe were nothing but 24 cubic feet and now its 48 cubic feet,
then something beyond the area of the original 24 cubic feet was moved
into.

NO NO NO, that is NOT how we are saying it is because how it is is impossible to correctly visualize because there are no boundaries to it and it isn't within a larger universe. If you are visualizing that hypothetical/imaginary universe with boundaries and within our actual universe, yes, it would be expanding into our larger universe. BUT, although this is impossible to visualize, what if that hypothetical/imaginary universe HAS no boundaries AND is NOT within some larger universe?
The fact that you cannot visualize this should not be confused with it not making sense or being impossible, which is what I suspect is the main part of your confusion i.e. you are equating you personal (and our ) inability to visualize something with that something not making any possible sense or being impossible (and the only best alternative we got to visualizing how it actually is is to use inevitably imperfect and confusing analogies such as an expanding balloon etc which isn't how it actually is at all! ) . If you believe that not visualizing something equates with it being impossible (Do you? ) , just think of this: you and I cannot truly visualize the number of particles in the universe. So does that mean that number of them doesn't exist? You really must stop believing that just because you cannot make a sensible visualization of something, that means it makes no sense or it doesn't exist. I cannot either visualize nor make sense of many kinds of quantum events -and yet it is proven that they exist.

Do you believe that not being able to visualizing something equates with it being impossible?
If no, then noting that should end your confusion.
If yes, then why? -and do you accept the possibility that something can exist that you cannot visualize nor understand?

If there were nothing to move into,

There is no “IF” in this context; there IS nothing to move into!

it couldn't,

correct!; it couldn't move into something if there is nothing to move into and therefore it is NOT “moving into” -THAT is the point! Space itself expanding is a none-standard type of expansion with no “moving into” because all other types of expansion (which I will call "standard" types here ) do involve "moving into" but this one is the EXCEPTION to this rule.


What you must understand is that all the analogies we use and give you are, in a sense, completely wrong! We only give them because there is no alternative to these analogies in this case because visualizing be analogy, although inevitably deeply flawed, is the ONLY way we got to visualize so we got no choice! I think your confusion is to take these analogies, along with the deeply flawed pictures they paint, as meant to be correct and represent what we are actually saying -but they are not quite that because they are merely tools for visualizing something that can NOT give the correct visualization of what is actually going on and what we are saying is going on.

Originally posted by humy

If the universe were nothing but 24 cubic feet and now its 48 cubic feet,
then something beyond the area of the original 24 cubic feet was moved
into.

NO NO NO, that is NOT how we are saying it is because how it is is impossible to correctly visualize because there are no boundaries to it and it isn't within a larger universe. If you ...[text shortened]... give the correct visualization of what is actually going on and what we are saying is going on.

You realize I get it now right, I told googlefudge after he explained it a better
way that I understood the point?
Kelly

Originally posted by KellyJay
You realize I get it now right, I told googlefudge after he explained it a better
way that I understood the point?
Kelly

Ah yes, the old mistake of posting before reading the previous few posts to make sure it's still relevant. I think we've all done that...

Originally posted by DeepThought
Ah yes, the old mistake of posting before reading the previous few posts to make sure it's still relevant. I think we've all done that...

Yes, I agree, we all have or about to. 🙂
Kelly

Originally posted by googlefudge
Hmmmm. I think I have just thought of a better analogy.. possibly.

Imagine the entire universe is a 24 inch computer screen.

The 'size' of the screen is constant at 24 inches. [~246 square inches]

But the resolution [number of pixels per square inch {dp2i}] keeps increasing.

So the screen starts out with a resolution of 800x600 [1950 dp2i]... ...[text shortened]... niverse as if the universe
is expanding, but the 'external size' of this universe is constant.

No, that is not what is happening. The stars are moving further apart as the space expands into nothing.