The expanding universe

[geordief]

Fueled  by word choices such as the "Big Bang" it was always a temptation to think  of an initial event where the Early Universe  started from a well defined point and grew into an existing Space.

But this, we are told is not what happened and  it is said that everywhere is the centre of the Universe .

Trying to make sense of this (I suspect  it may not be too hard or counterintuitive,moreso  that I may be "making a meal of it") can I view the situation as the Universe "expanding into itself"?

And,if so  is the "space" it is expanding into created by itself and equivalent to the distances between its constituent parts?

Edited March 18, 2021 by geordief

[Bufofrog]

5 hours ago, geordief said:

can I view the situation as the Universe "expanding into itself"?

I don't think that would be correct.  The universe is not expanding into anything, it is just expanding.

[beecee]

6 hours ago, geordief said:

Fueled  by word choices such as the "Big Bang" it was always a temptation to think  of an initial event where the Early Universe  started from a well defined point and grew into an existing Space.

But this, we are told is not what happened and  it is said that everywhere is the centre of the Universe .

Trying to make sense of this (I suspect  it may not be too hard or counterintuitive,moreso  that I may be "making a meal of it") can I view the situation as the Universe "expanding into itself"?

And,if so  is the "space" it is expanding into created by itself and equivalent to the distances between its constituent parts?

It is and was (according to the BB theory) space and time itself that is expanding, or all there ever was, so everywhere (all of spacetime at least as we know them) was packed to withing that incredibly small volume, remembering that our laws and theories are non applicable at the quantum/Planck level. In that scenario we cannot talk about any before, or any "expanding into"  There was no before (as we know it) and nothing (as we know it) to expand into.

Hope all that makes some sense!

This of course gets back to previous debates about what is nothing. I like Professor Lawrence Krauss' speculative scenario, that the quantum foam is the true definition of nothing.

Edited March 18, 2021 by beecee

[Bufofrog]

46 minutes ago, beecee said:

space and time itself that is expanding

Space is expanding, however, I don't believe time is expanding.

[beecee]

2 minutes ago, Bufofrog said:

Space is expanding, however, I don't believe time is expanding.

Agreed, thanks....I should have said that space is expanding and is inexorably linked, and inseparable from time. The expansion of space occurs over time. One cannot exist without the other. 

[geordief]

 

1 hour ago, Bufofrog said:

I don't think that would be correct.  The universe is not expanding into anything, it is just expanding.

Is the idea that this expansion was initiated at  some point and that it is continuing wherever we look "under its own steam"  or inertia as it were ? (aside from Dark Energy which seems like some godawful joker in the pack)

 

But to come back to my "expanding into itself" notion can we posit a moment in the evolution

of the universe where there was no distance  ** between objects so that the space that there came to be subsequently between the constituent parts of this earlier unified object came out of that object (so that the later distinct  objects and the space between them could be seen as  the two fundamental elements of the earlier unified object)

 

If there was a time when all the matter in the universe was gathered in one object can we see this object as having  evolved into (1) the later distinct objects and (2) the space between them?

 

Or is "space" just another word for "distance"......?

 

** does that notion imply an impossibly perfect symmetry?

[MigL]

We have a fairly good idea of the separation between objects in our observable universe, and we also know that separation between them is increasing ( expansion ).

With this information, we can 'wind back' the clock, such that 4 Billion years ago those same objects were separated by half the present amount. Assuming a cnstant rate of expansion, 4 Billion years before that, they were separated by half the amount again. And the separation was reduced by half the previous 4 Billion years. A scaling factor that sounds a lot like Zeno's paradox.
However, we know that expansion seems to be currently accelerating, and the universe may have undergone an exponential 'growth spurt' shortly after its 'origin'.

This scaling factor is happening throughout the observable universe, such that there is no 'outside' that the expansion is moving into, and, the effect looks the same from every vantage point ( ie. there is no center ).