What is containing the Universe?

[Mister T]

But how are they not contained?

In the same way that you can travel on those surfaces for years, going as far as you like, never reversing direction, yet never getting any further away from your starting point than you did on the first day.

 

[Spin2win]

There is a limit to how far you get from your starting point because you are coming back to it since there is no edges?

 

[A.T.]

There is a limit to how far you get from your starting point because you are coming back to it since there is no edges?

Yes, that's what it means to finite but not bounded. But we actually don't know if the universe is finite or not.

 

[russ_watters]

If you pull on a rubberband you need space to expand so rather you make your raisins shrink and you get free space and without having to expand into anything.

Huh? Maybe we need to pause for a while so you can put some more thought into this and reread the thread, because that makes no sense...

But then you told me that the analogy had its limits and that i had to picture just the surface of the balloon rahter than the whole balloon but isn't the surface of the balloon acting like the whole balloon?

That isn't what I said. You have to follow the exact construction of the analogy. If you break the analogy, you aren't finding a flaw in the universe, only a flaw in your understanding of it.

I said you consider the surface only. Not the space inside. Not the space outside. They aren't part of the balloon. The balloon - the piece of rubber that is the balloon - is only the surface.

How does it have no boundries if its finite?

Again: if you get in a plane and fly in one direction along the surface of the earth, do you ever run into a boundary?

Your house has walls. They are the boundaries that contain its area. But what if your house covered the entire surface of the Earth? Would it still need walls?

This is hard, if not impossible to picture in your head, so that makes it tough to accept. So at some point, you just need to accept that the same rules that apply in 1d and 2d also apply in 3d.

 

[pinball1970]

Ok So the universe can create as much space as he wants without "expanding" since its infinite?

Wasnt it a first form of life and from there it evolved into everything we know? , isn't the thing that made the first brain kinda intelligent? I was picturing Frankenstein^^ its dead and after the lightning strikes.. its alive. Or is the matter already alive but we don't notice it because it doesn't move or evolve?

The first replicating molecule can only be guessed at but there is real work in this area called Abiogenesis. Google "first life Deep first life deep sea vents" and "RNA world." The first cells were round around 3.5-4 billion years ago and that is the way life on Earth stayed for a few billion years. Too much information tom post in one go you will have to some reading on your own.

Urey and Miller used "lightening" of sorts to make amino acids from basic compounds but that is far as your Frankenstein idea goes.

https://www.windows2universe.org/earth/Life/miller_urey.html

 

[Dale]

How is something finite not contained by something else?

What does being finite have to do with being contained?

Isnt an infinite thing not contained and a finite contained by obligation?

No. Look at the definition of infinite and finite. Is there anything in the definition about containment?

 

[pinball1970]

Or is the matter already alive but we don't notice it because it doesn't move or evolve?

Just one more decent link on life, definitions, first life deep sea vents, RNA world and Urey and Miller.

https://en.wikipedia.org/wiki/Life

 

[Spin2win]

Ok but let's say you live on the rubber, if it is infinite, the only thing that could "contain" it would be for example, the infinite capacity computer containing the infinite game? But in the universe of the game there isn't anything like the game containing it since its infinite, but if the game was finite you could imagine that when you press escape and go back to the menu you are entering something that contain it ? So in a finite universe i imagine that there is a direct connexion betwin it and a container that share the same reality, and in a infinite universe it would be something like an other infinite universe not containing it but being parallel to it. Like, the universe of the game is nothing but numbers and electricity, there is no actual connexion betwin it and our world since it doesn't exist. So the game is an infinite universe parallel to our infinite world, It could also be finite being everything there is because it doesn't exist. Like a finite video game could be everything there is but isn't really a universe because its just data in the real one. So if its real and finite something has to contain it no?

 

[jbriggs444]

Ok but let's say you live on the rubber, if it is infinite, the only thing that could "contain" it would be for example, the infinite capacity computer containing the infinite game? But in the universe of the game there isn't anything like the game containing it since its infinite, but if the game was finite you could imagine that when you press escape and go back to the menu you are entering something that contain it ? So in a finite universe i imagine that there is a direct connexion betwin it and a container that share the same reality, and in a infinite universe it would be something like an other infinite universe not containing it but being parallel to it. Like, the universe of the game is nothing but numbers and electricity, there is no actual connexion betwin it and our world since it doesn't exist. So the game is an infinite universe parallel to our infinite world, It could also be finite being everything there is because it doesn't exist. Like a finite video game could be everything there is but isn't really a universe because its just data in the real one. So if its real and finite something has to contain it no?

It is difficult to follow the "reasoning" here.

The rubber might have a topology so that no matter how large a distance you choose, there are always points on the rubber more than that far apart. No container is needed in such a case.

The rubber might have a topology so that there is some distance such that all points are closer to each other than that distance. No container is needed in such a case.

In neither situation do we need to imagine the rubber as being a virtual entity in some computer simulation.

 

[Spin2win]

Its just that from your perspective the only thing that exist is the rubber but how does it make it the only thing there is? I could imagine it if you didnt run in circle.you would just go on forever and tell yourself that's probably the only thing there is unless i am being "contained" in another universe that could create a virtual infinite universe

 

[jbriggs444]

Its just that from your perspective the only thing that exist is the rubber but how does it make it the only thing there is? I could imagine it if you didnt run in circle.you would just go on forever and tell yourself that's probably the only thing there is unless i am being "contained" in another universe that could create a virtual infinite universe

If a thing can never be sensed, measured or detected in any way then its existence is a matter of philosophy, not science. For the person living on the surface of the rubber, nothing other than that surface is relevant. No container is required.

These forums are for discussion of science. If we divert into philosophy, I predict a quick thread close. We are perilously close already.

 

[Spin2win]

Is what you guys mean is that the rubber is stretching forever without cracking? How does it creates space without expanding into something or making the points shrink to infinity without having infinite ways to compress them

 

[jbriggs444]

Is what you guys mean is that the rubber is stretching forever without cracking? How does it creates space without expanding into something or making the points shrink to infinity without having infinite ways to compress them

Space is not a physical substance or fabric that needs to be created. All that is happening is that the distance between objects is increasing over time. [Any cracking of rubber is an implementation detail, irrelevant to the analogy]

You can Google "metric expansion" for some details on what is meant by this.

You could choose to describe the same phenomenon as all of the measurement devices getting smaller and all of the movement speeds decreasing. All of the same experiments would produce all the same results using either description.

 

[Spin2win]

Maybe space isn't a thing but the process of stretching is something no? Dont you need an infinite amount of energy to make things shrink to infinity?

 

[jbriggs444]

Maybe space isn't a thing but the process of stretching is something no? Dont you need an infinite amount of energy to make things shrink to infinity?

No and no.

In any case, Noether's theorem does not assure us of energy conservation in an expanding (or shrinking) universe. So any argument based on energy conservation needs to be more carefully made.

 

[Spin2win]

How can you go toward any infinity if you are not infinite yourself?

 

[jbriggs444]

How can you go toward any infinity if you are not infinite yourself?

Start walking.

 

[Mister T]

Its just that from your perspective the only thing that exist is the rubber but how does it make it the only thing there is?

It's a model created in your mind, so you can make it be anything you want. It's only utility is that it can be used to describe the way Nature behaves.

I could imagine it if you didnt run in circle.you would just go on forever and tell yourself that's probably the only thing there is unless i am being "contained" in another universe that could create a virtual infinite universe

You can construct a model that contains all your fantasies, but if it doesn't describe Nature's behavior it's not physics.

 

[Spin2win]

Isnt running in circles in the "universe" supposed to make you understand that its not all there is? the only way to not be contained without being infinite would be to be a simulation but you d be contained by the real world.
And if you are not running in circles because points shrink to infinity how can the universe be infinite if its not infinite?

 

[weirdoguy]

The only way to not be contained without being infinite is to be a simulation

That's ridiculous. Learn some proper maths and everything will be clear. There is no need for any containment, you can define manifolds abstractly. Read about it.

 

[Spin2win]

Then it has to be infinite right?

 

[weirdoguy]

No, as been said over and over again.

 

[Spin2win]

But how something not infinite be everything there is?

 

[weirdoguy]

Simply it can because there is no scientific (mathematical nor physical) reason it can't. It being hard for you to imagine means nothing. Read about manifolds and how can they be defined without them being contained in anything else.

 

[fresh_42]

But how something not infinite be everything there is?

That's ridiculous. Learn some proper maths and everything will be clear. There is no need for any containment, you can define manifolds abstractly. Read about it.

The surface of the Earth is finite and everything there is for us. Please do a little research on your questions. Wikipedia is a good source to answer those fundamental questions. Look up: dimension, manifold, universe, and the links you find therein.

 

[Spin2win]

Its not because its everything there is FOR us that its everyrhing there is no? Are maths going to help me transcand the logic that something finite can't be everything there is? How do you picture it yourself?

 

[jbriggs444]

Are maths going to help me transcand the logic that something finite can't be everything there is?

There is no such logic. You are making it up out of whole cloth to fit your preconceived notions of how things must be.

 

[fresh_42]

Its not because its everything there is FOR us that its everyrhing there is no? Are maths going to help me transcand the logic that something finite can't be everything there is? How do you picture it yourself?

The example of Earth's surface was a 2D example of what spatially is 3D in the universe: You can have a closed three dimensional, finite surface of a four dimensional manifold. Can I imagine it? No. Does math help to imagine it? Maybe, but at least it allows me to calculate with it, and this doesn't require imagination. I do not claim the universe to be the three dimensional surface of a four dimensional sphere, but it cannot be ruled out from the start. Cosmologists try to figure it out, but that's not an easy task, since manifolds aren't "embedded" in something. They are all there is: no outside!

 

[jedishrfu]

Without further ado, I think the thread has run its course and that's its now time to close it. Thank you all for contributing here.

For @Spin2win please research the notions of infinity in math and physics and see if what you have learned in this thread helps you come to grips with what you now know.

Often in math and science, we must go back to the math to understand something and that's usually because it doesn't follow our commonsense or that we simply can't picture it in our minds. However, the math of a theory coupled with experiment is the ultimate arbiter of what is what in the universe as we understand it today.

Here's an article circa 2015 in Universe Today that attempts to describe our understanding of the vastness of the universe.

https://www.universetoday.com/119553/is-the-universe-finite-or-infinite/

Jedi