An infinite universe?

[excreationist]

I used to suspect that space was on the surface of an expanding hypersphere.... like this balloon picture:


That way there is no edge or center.... yet it was finite....

But according to this:

https://www.discovermagazine.com/the-sciences/where-is-the-edge-of-the-universe

“The universe is flat like an [endless] sheet of paper,” says Mather. “According to this, you could continue infinitely far in any direction and the universe would be just the same, more or less.” You’d never come to an edge of this flat universe; you’d only find more and more galaxies.

......The problem is that, unlike a spherical universe, a flat one can be infinite — or not. And there’s no real way to tell the difference. “What could you look for to see whether there’s an infinite universe?” Trimble says. “Nobody quite knows.”


​

I think the edge of the "observable" universe is moving away from us faster than the speed of light so I think we can never interact with what's beyond that boundary....

So if this is a simulation then I think only the observable universe would need to simulated... after all it is impossible to simulate something that is literally infinite...

But even if this isn't a simulation I have a problem with a finite point expanding to a literally infinite size within a finite amount of time.... maybe it involves space expanding far, far faster than the speed of light....

It's a shame that the spherical universe doesn't seem to be the case....

 

[Bomb#20]

But even if this isn't a simulation I have a problem with a finite point expanding to a literally infinite size within a finite amount of time....

According to the infinite flat geometry version of the Big Bang model, the whole universe was always infinitely large. No finite part ever becomes infinite.

 

[untermensche]

You can't travel infinitely far. That makes no sense.

And nothing can be infinitely long.

That is absurd.

Who measured this infinity?

 

[excreationist]

According to the infinite flat geometry version of the Big Bang model, the whole universe was always infinitely large. No finite part ever becomes infinite.

I thought the point of the Big Bang is that you could extrapolate it back to a point of infinite density.... I thought this singularity was agreed upon in mainstream sceince. I think that link would imply that the Big Bang happened when talking about a possible infinite size for the universe....

 

[excreationist]

You can't travel infinitely far. That makes no sense.

And nothing can be infinitely long.

That is absurd.

Who measured this infinity?

Well it seems a lot of physicists think it is possible that space is infinite....

 

[untermensche]

You can't travel infinitely far. That makes no sense.

And nothing can be infinitely long.

That is absurd.

Who measured this infinity?

Well it seems a lot of physicists think it is possible that space is infinite....

I wonder how many have actually measured?

How does one finish measuring an infinite distance?

 

[Elixir]

I wonder how many have actually measured?

Precisely the same number that found and measured the end of the universe.
Do you believe that something must be measured to exist?

 

[skepticalbip]

According to the infinite flat geometry version of the Big Bang model, the whole universe was always infinitely large. No finite part ever becomes infinite.

I thought the point of the Big Bang is that you could extrapolate it back to a point of infinite density....

Not quite. The BB theory is a description of the expanding universe that we measure. The term, "Big Bang", was a derogatory term coined by Fred Hoyle ridiculing the idea that the universe was expanding. But cosmologists liked the term so adopted it. The extrapolation "back to a point of infinite density" isn't part of the BB theory but an extrapolation. The Inflation theory that was to make the extrapolation of that 'point of infinite density' fit what we measure is rather disputed by many cosmologists because it has some serious problems.

 

[excreationist]

Well it seems a lot of physicists think it is possible that space is infinite....

I wonder how many have actually measured?

How does one finish measuring an infinite distance?

The article said:
"a flat one can be infinite — or not. And there’s no real way to tell the difference"

i.e. it is possible to be infinite...

 

[untermensche]

I wonder how many have actually measured?

Precisely the same number that found and measured the end of the universe.
Do you believe that something must be measured to exist?

It must be measurable to be "real".

 

[untermensche]

Well it seems a lot of physicists think it is possible that space is infinite....

I wonder how many have actually measured?

How does one finish measuring an infinite distance?

The article said:
"a flat one can be infinite — or not. And there’s no real way to tell the difference"

i.e. it is possible to be infinite...

So if a model says an infinity could exist could reason tell us something else?

 

[Elixir]

Do you consent that space is ‘real’?
That it is measured to be expanding?

So if a model says an infinity could exist could reason tell us something else?

You need to READ what the article SAYS, not what you think you can refute. Their model posits that the observable (measurable) facts do not include a limit to the extent to which space can expand, not that "an infinity exists".

 

[untermensche]

Do you consent that space is ‘real’?
That it is measured to be expanding?

I believe expanding from a singularity.

 

[Elixir]

Do you consent that space is ‘real’?
That it is measured to be expanding?

I believe expanding from a singularity.*

Do you concede that this expansion continues (as measured) and is currently accelerating (also as measured)?
Do you believe that a limit to either the size or rate of expansion the eventual universe has ever been measured?

OR - Do you need to re-visit your thesis that "it must be measurable to be "real" ?

It must be measurable to be "real".

Uh... the whole point of the article was that it's NOT measurable. And a lot of shit that IS measurable, eventually WON'T be measurable due to accelerating expansion. Once something is going away from you at lightspeed, it is NOT measurable by you, but there is no reason to think it ceases to exist. It has no reason to care if you can measure it.

Of course, there are schools of thought that postulate that the universe is not "real", that measurements are figments of our own projection, that waveforms collapse when observations are made, etc.
But I suspect that's not what you meant.

* You believe in singularities??? INFINITELY small points of INFINITE density?

 

[excreationist]

I thought the point of the Big Bang is that you could extrapolate it back to a point of infinite density....

Not quite. The BB theory is a description of the expanding universe that we measure. The term, "Big Bang", was a derogatory term coined by Fred Hoyle ridiculing the idea that the universe was expanding. But cosmologists liked the term so adopted it. The extrapolation "back to a point of infinite density" isn't part of the BB theory but an extrapolation. The Inflation theory that was to make the extrapolation of that 'point of infinite density' fit what we measure is rather disputed by many cosmologists.

https://en.wikipedia.org/wiki/Big_Bang
says:

"These theories were based on the hypothesis that all the matter in the universe was created in one big bang at a particular time in the remote past"

​

​Hoyle seems to be talking about very dense beginning rather than merely inflation......

I was under the impression that some physicists believe in both a singularity and then an infinite universe....

 

[skepticalbip]

I thought the point of the Big Bang is that you could extrapolate it back to a point of infinite density....

Not quite. The BB theory is a description of the expanding universe that we measure. The term, "Big Bang", was a derogatory term coined by Fred Hoyle ridiculing the idea that the universe was expanding. But cosmologists liked the term so adopted it. The extrapolation "back to a point of infinite density" isn't part of the BB theory but an extrapolation. The Inflation theory that was to make the extrapolation of that 'point of infinite density' fit what we measure is rather disputed by many cosmologists.

https://en.wikipedia.org/wiki/Big_Bang
says:

"These theories were based on the hypothesis that all the matter in the universe was created in one big bang at a particular time in the remote past"
​

There are several cosmological models. There are expanding models, BB being one. There are oscillating models, Penrose's CCC is the latest but not only. There are modified steady state models.

​Hoyle seems to be talking about very dense beginning rather than merely inflation......

Not sure how you got that but Hoyle was a fanatical believer in a steady state universe that always was and always will be just as we see it now.

I was under the impression that some physicists believe in both a singularity and then an infinite universe....

Indeed so and some that don't.​

 

[untermensche]

Do you concede that this expansion continues (as measured) and is currently accelerating (also as measured)?
Do you believe that a limit to either the size or rate of expansion the eventual universe has ever been measured?

OR - Do you need to re-visit your thesis that "it must be measurable to be "real" ?

It must be measurable to be "real".

Uh... the whole point of the article was that it's NOT measurable. And a lot of shit that IS measurable, eventually WON'T be measurable due to accelerating expansion. Once something is going away from you at lightspeed, it is NOT measurable by you, but there is no reason to think it ceases to exist. It has no reason to care if you can measure it.

Of course, there are schools of thought that postulate that the universe is not "real", that measurements are figments of our own projection, that waveforms collapse when observations are made, etc.
But I suspect that's not what you meant.

* You believe in singularities??? INFINITELY small points of INFINITE density?

Must be measurable in theory to be real.

It could be measured if there was something that could measure it.

 

[Elixir]

Do you concede that this expansion continues (as measured) and is currently accelerating (also as measured)?
Do you believe that a limit to either the size or rate of expansion the eventual universe has ever been measured?

OR - Do you need to re-visit your thesis that "it must be measurable to be "real" ?

It must be measurable to be "real".

Uh... the whole point of the article was that it's NOT measurable. And a lot of shit that IS measurable, eventually WON'T be measurable due to accelerating expansion. Once something is going away from you at lightspeed, it is NOT measurable by you, but there is no reason to think it ceases to exist. It has no reason to care if you can measure it.

Of course, there are schools of thought that postulate that the universe is not "real", that measurements are figments of our own projection, that waveforms collapse when observations are made, etc.
But I suspect that's not what you meant.

* You believe in singularities??? INFINITELY small points of INFINITE density?

Must be measurable in theory to be real.

It could be measured if there was something that could measure it.

Where's your limit theory? Beliefs aren't theories.
Infinity could be measured if there was something that could measure it.

* You believe in singularities???

There are oscillating models

I think you need to get busy on this one, Unter. You might be able to prove the limit you seem to crave so desperately. (Plus it's what I thought in sixth grade, when I first read about "Big Bang" stuff.)

 

[untermensche]

Must be measurable in theory to be real.

It could be measured if there was something that could measure it.

Where's your limit theory? Beliefs aren't theories.
Infinity could be measured if there was something that could measure it.

An infinite length could be measured?

How long would it take?

And combining limits with infinities is a way to deal with infinities in mathematics. Not in the real world.

 

[Shadowy Man]

I thought the point of the Big Bang is that you could extrapolate it back to a point of infinite density....

Not quite. The BB theory is a description of the expanding universe that we measure. The term, "Big Bang", was a derogatory term coined by Fred Hoyle ridiculing the idea that the universe was expanding. But cosmologists liked the term so adopted it. The extrapolation "back to a point of infinite density" isn't part of the BB theory but an extrapolation. The Inflation theory that was to make the extrapolation of that 'point of infinite density' fit what we measure is rather disputed by many cosmologists.

https://en.wikipedia.org/wiki/Big_Bang
says:

"These theories were based on the hypothesis that all the matter in the universe was created in one big bang at a particular time in the remote past"

​

​Hoyle seems to be talking about very dense beginning rather than merely inflation......

I was under the impression that some physicists believe in both a singularity and then an infinite universe....

The singularity that the universal expansion extrapolates down to is one of density. Mathematical singularities are typically indications of the limitations of a physical theory (e.g., the ultraviolet catastrophe that gave birth to quantum physics) and not necessarily a limitation of the universe itself. One day we may be able to explore what happened near that singularity but for now our physics are incomplete.