Spacetime is Infinite

infinity can't be reached of course. the universe doesn't expand into infinity, it is already infinite. at least the space must be, but the matter is probably infinite too because matter is created from space.

 

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Why? What if inflation hadn't occurred and the universe recollapsed? What about the BB would have been infinite? Space-time would have remained finite for the entire length of it's existence.

 

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If the universe had recollapsed, then it's not very infinite at all. But i did say, that with the accelerated expansion now observed, is is accepted that spacetime is certainly infinite, and must have been from word go.

 

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Why? The simplest space-time topology with negative curvature is AdS but is that the only one? Are there no compact topologies which have negative curvature?

What if dark energy is a growing phenomena and didn't exist until a certain point in the history of the universe, then the universe could have transitioned from finite to infinite. Can you cite some evidence for your claims? Perhaps just a differential geometry publication which proves there's no compact shape which has curvature less than 0 everywhere. Heck, if you're doing curvature in your class, could you do a proof yourself perhaps?

 

That would be why, then, definite sizes have been given to the extent of the universe at differing periods throughout its history - measuring the expansion...

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Incorrect, completely incorrect, as evidenced by the links I gave.

 

These measurements are not exact, and they are only predictions of an imaginary size. The universe can never have a volume that can be meaured, because it is always one more than now. Why can't you understand this?

''Incorrect, completely incorrect, as evidenced by the links I gave.''

What links did you read? They sound scientifically incorrect.

 

This link, explains the universe is accelerating in its expansion, and therefore leads to the only logical solution that the universe is Open. This means that the universe has always been Open, and therefore always been infinitely expanding. This means there is an infinite amount of space and time, and even an infinite amount of matter and energy.

Lecture 41: The Accelerating UniverseSo, how do astronomers go about determining whether the expansion of the universe is speeding up or slowing down? The current rate of expansion is given by ...
www.astronomy.ohio-state.edu/~ryden/ast162_10/notes41.html - 11k - Cached - Similar pages

And this next explains how a universe that is Open, has no physical barriers:

Extended Definitions: Open UniverseThe term open universe refers to a universe which has no physical or practical barriers to it's continued expansion. If the universe is indeed open, ...
www.geocities.com/recycling_universe/ed_openuniverse.htm - 11k - Cached - Similar pages

 

In math, any number that approaches a limit is considered to be able to reach that limit by definition. Do you want to argue that point with this guy?

I'm almost infinitely sure someone will, but 0.999~...n is the equivalent of 1 in math. It needs to be that way because the tiny discrepancy that creeps into higher math without this rule would cause meaningful errors. Anyone disagree?

So the debate about can we reach an infinity of can we really perform an infinite number of iterations, or any such debate is already resolved in math. Approaching a limit mathematically implies by definition that the limit can be reached.

Or you can google 0.999~=1 and get this guy.

So with that agreed, then to say that we can or cannot comprehend infinity is a matter of how our individual brains deal with the term "infinity". If you say we cannot perform anything to reach infinity you are correct. If you say that we cannot work with infinity as a concept and by definition reach infinity for mathematical purposes, you are wrong.

 

Not exact?
So you've changed specialties now?
You're an astronomer/ astrophysicist?

Because I always fail to understand wilful ignorance.

Ah, so you personally are the final arbiter of scientific correctness?
Okay try this:
From the links YOU gave

Notice the word IF there?
and

which sort of negates your comment that

Your own "research" invalidates your argument.

 

The word ''if'', Oli, became powerfully weaker with the accelerated expansion of the universe.

And i don't plan to be a physicist in the long run. I plan to be an astrophysicist. It's always been something i have enjoyed. But if i say something isn't correct, it's just like someone correcting someone else, if the say the electron has a positive charge. That's all. Stop making it into more than what it is.

 

So as you hopefully see, you are wrong.

 

The word "if" is a conditional.
It were actually known that the universe IS infinite then if wouldn't come into it.

Yup, and in this case you appear to be correcting all the astrophysicists and astronomers that have done the observations.
Astounding, what equipment do you use to get your figures?
What basis do you have for claiming they are incorrect, other than your own prejudices?
Your beliefs outweigh their work?

 

If is conditional, in the sense, that acceleration is not what we think it is.

And for no other reason. We can actually pretty much say that about any astrological theory.

''Yup, and in this case you appear to be correcting all the astrophysicists and astronomers that have done the observations.''

Oli, any physicist and astrophysicist will agree, you cannot make an absolute calculation on the volume of the universe, as i have explained, it is continuously expanding, and now is expanding faster than the smallest unit of time.

 

No, not the acceleration: read the damn sentence -
if the universe is infinitely big
Universe, not acceleration.

Reiku, you seem to be completely ignoring the FACT that a figure has been found for the current size of the universe.
"Absolute " doesn't come into it, it's a round figure, and it's not "calculated" it's observed and measured.

 

Oli, stop trolling. Everything on how we determine the infinite expansion depends on the nature of acceleration.

''Reiku, you seem to be completely ignoring the FACT that a figure has been found for the current size of the universe.
"Absolute " doesn't come into it, it's a round figure, and it's not "calculated" it's observed and measured.''

Oli, are you trying to be stupid? Are you telling me the radius of the universe is bona fide, even though that radius is continuously getting larger, faster than the speed of light?

 

Hypocrite.
You have so far failed to provide any evidence to support your assertion other than your own beliefs.
You consistently ignore posted links and counter arguments and continue with "according to me I'm right".

Except for the fact that a figure has been measured...

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Yes, and once I've achieved total stupidity I'm calling myself Reiku, it seems to be the mandatory.

Which part of "it has been measured" did you not understand?

 

''You have so far failed to provide any evidence to support your assertion other than your own beliefs.''

What part of the conversation are you reading? Try again.

Lecture 41: The Accelerating UniverseSo, how do astronomers go about determining whether the expansion of the universe is speeding up or slowing down? The current rate of expansion is given by ...
http://www.astronomy.ohio-state.edu/...0/notes41.html - 11k - Cached - Similar pages

And this next explains how a universe that is Open, has no physical barriers:

Extended Definitions: Open UniverseThe term open universe refers to a universe which has no physical or practical barriers to it's continued expansion. If the universe is indeed open, ...
http://www.geocities.com/recycling_u...enuniverse.htm - 11k - Cached - Similar pages

Universe - WikipediaCurrently the evidence seems to point to an open universe. ... Retrieved from "http://nostalgia.wikipedia.org/wiki/Universe" ...
nostalgia.wikipedia.org/wiki/Universe - 17k - Cached - Similar pages

Cosmological constant - Wikipedia, the free encyclopediaFrom Wikipedia, the free encyclopedia. Jump to: navigation, search ... the associated negative pressure will drive an accelerated expansion of empty space. ...
en.wikipedia.org/wiki/Cosmological_constant - 56k - Cached - Similar pages
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''Which part of "it has been measured" did you not understand?''

And what part of expansion do you not understand...? If you have a calculation which determines the volume of the universe, and a radius, does the universe stop expanding just for you?

You might believe that, but you'd be wrong.

 

As long as we remember that infinity in mathematical purposes has no bearing on the real world that's fine. An infinity can't describe anything in the real world, because it's an abstract concept.

You say "any number that approaches a limit", but infinity literally means "no limit". A number approaching infinity doesn't approach a limit. A number approaching 1, like 0.9999..., is a totally different concept.

 

Dark energy far outweighs the normal matter we see everyday, so i would assume your conclusion is flawed.