Welcome to the BAUT forum.

Maybe that's a way to think about the smaller visible Universe, that part we can see and that can affect us. Wrap your mind around a more common expectation of the entirety: there is no edge, no boundary, yet space is expanding.

You might enjoy the Cosmology Primer and FAQ.

And where the big bang happened is right here, where the tip of your nose is, and mine, and all other points. Everything is the result, space and energy and matter, so it happened, and continues, everywhere.

Way weird. And weirder.

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Perhaps the problem in grasping the notion of there not being an outside of the universe is that we are trying to relate it to space, rather than time. The universe is not only an expansion of the physical space, but of time, which is only defined by the relationship between 1 object and everything else.

If you can agree that you cannot step out of time, then the concept becomes quite clear. If you could somehow find an (esoteric) "outer edge" to the universe, you could go no further, because one step or million steps or a billion miles to nowhere is the same distance. You cannot step out of time.

Hi, just wanted to ask something.

Is 15BLY the limit of our technology?

Fifteen billion years is a limit on the age of the Universe, closer to around 13.7 billion years.

Having better tools now wouldn't make the Universe any older.

(Having better tools in 100 years will make the Universe 100 years older.)

Fifteen billion lightyears is a current limit on the distance light can travel since the beginning of the Universe.

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In my mind the universe is infinite. To me there is no good reason thus far to show the universe needs to have an end to it. Let the simplest answer be the correct one, the 'verse goes on forever in all directions. The stars you base the age of the universe on are in fact only the stars we know of, therefor better tools could in fact show an older universe.

-- Additional Thoughts:

Just as in our solor system with comets and planets going every wich direction at any given time, so too could the galaxys we know about be revolving around something much bigger much further away than we know of.

Many say the universe we know does not revolve around anything. I think this is relative to where we think the center should be. Rather, just because the center does not factually appear to be in the middle of our known galaxys does not mean a center does not exist some where.

Speed of our galaxys vs. a universe with a finite end to it.
How fast would you say the milky way galaxy is travelling through space?
5 miles per second? 100 million miles per second? Totally relitive to what point in space your basing this on right? All of the galaxy's we can see could in fact be moving in direction (a) at 300 times the speed of light, and at the same time be moving in other directions and speeds relative to us.

Because of this possiblity it helps me imagine a never ending universe otherwize at some point in time our galaxy itself would collide with the end. It hasnt that we know of for roughly 15billion years at who knows what speed, and the end of the universe still isnt in sight.

I made a perrrrty picture (1A) to help explain my dimentia. Have a look and give me your thoughts. Thoughts on the concept not the art.

http://www.w2r.com/ep/

By the way i just noticed your user name 0110 1001 did you think about the 2 binary numbers you made, or just happen to come up with a 6 and a 9

Thanks sirChuck I think you answered my question (sorry may have been a poorly worded question).

"The stars you base the age of the universe on are in fact only the stars we know of, therefor better tools could in fact show an older universe".

Thank you.

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I can't believe it! We've got no food, we've got no jobs, our pets heads are falling off!

No, 01101001 is right-- the issue is not how big the universe is (infinite is fine), the issue is how old it is. We don't "base" the age of the universe on any particular stars, we base it on many things, and it all comes out 13.7 billion years old. That's just as true for an infinite universe as a finite one-- your reference to Occam's razor is the basis for this. Even an infinite universe would have no stars older than 13.7 billion years, if one goes on the simplest interpretation of what we see.
Of course that's true, but what is the point of asking a question that we cannot know the answer to? Philosophically, perhaps, but it's not of scientific interest.

Now there's a question that does have an answer, if it should be forthcoming!

Initially I was trying to stay on topic of what comes after the universe, but got sidetracked in to the age of the universe sorry for the confusion.

However, I just assumed we based the estimated age of the universe on what we do know. In particular, the stars we know and the charted data of the movements of these stars. Perhaps you could give me some referance to other methods used to determine the age of the universe other than the stars we observe.

Maybe we are talking about two differnet things when we say universe so let me clarify, perhaps I am using the wrong word. To me the universe is everything in our three dimentional space. I dont think you can put an age on the beginning of the universe the way I see it because then you could always ask what was in the universe before it was born?

I think when you say universe your talking about the known universe in wich case you are probably right. 15billion years ago or so perhaps our known universe was born.

In my opinion asking questions is the fundamental epicenter science. Ever since you asked your mom why the sky is blue. At some point it was a question without a way to determine the answer. To switch to philosophy how does this grab you, Who is to say what cannot be known, or what we cannot know the answer too?

Thank you for your input, and I realize I am probably way wrong I am a computer programmer not a scientest.

cheers

So, 'we' know for certain that there aren't any other stars or objects at say 10Trillion Light Years from us, because all of the evidence points to the fact that the universe is 13.7 BYO?

So, if the universe is infinite, how can it have an age? Kind of goes back to sirChucks last post.

My apologies if this is covering old ground, I have read through numerous posts on this thread and I probably should have picked this up somwhere in all the incredibly amazing answers.

Anyway, just more for me to ponder on, no real need for anyone to post a reply.
Thanks,
Take it easy.

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I can't believe it! We've got no food, we've got no jobs, our pets heads are falling off!

Olbers Paradox would indicate that the Universe is of finite age and finite extent.

The CMB radiation would indicate that the Universe was once hot and dense. Very hot and very dense. We call this the "Big Bang". The ratio of hydrogen to helium observed in our Universe is consistent with what we know of the physics of this event.

The redshifted spectra of galaxies, and the apparent magnitude of Type 1A supernova gives a Hubble constant which indicates a age of 13.7 billion years for the Universe.

When we look into the deep Universe, the galaxies look like what we would expect young galaxies to look like at a much earlier age in the Universe's history, consistent with us looking back in time.

The ages of stars in globular clusters, as derived from our understanding of physics, are consistent with this.

Space-time appears to be largely flat with insufficent matter in the Universe to constrain continued expansion. This is consistent with the picture above.

As this sounds somewhat like a homework question, you are invited to look these up yourself. Be prepared for lots of reading.





So when you talk about the universe what you really mean is the unknown universe not the known universe.

I don't think that there is much evidence for this unknown universe.

So whatever you want to make up, that's fine.

Over the last few years, our understanding of the physics of the Big Bang has improved up to the first few milliseconds after this event, with some indications of what happened before. I am optimistic that the future will allow us to push back our understandings of the Universe even further.




Philosophy seems happiest when it is answering questions to which no-one knows the answer.

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The Heavens Declare the Glory of Mathematics

We know from Einstein that space has 4 dimensions - length, height, width and time. Time is the critical dimension, and the question you are really asking is "what is before space-time". The answer is that there can be nothing before time began at that critical moment 13.7 billion years ago. I know that this is counter-intuitive, but much of modern physics is. Irrespective of this, it appears to describe reality quite well.

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The Heavens Declare the Glory of Mathematics

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Everyone is entitled to his own opinion, but not his own facts.

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Hi Chuck, You got it right. The simple answer is the best. Infinity,
The universe is infinitly old and infinitly large. This may disturb some people.
Rock and roll disturbs some people. Never the less, it is there.
In brief: You can't put the universe in a can.
Hey...I said that ! You can quote me if you like.
Best regards, Dan

Hi all,

Yes I see your point with the age of chemical elements, age of oldest star clusters, and age of oldest white dwarf stars helping to determine the age of the universe scientifically. Note: I am not saying we will find an older star somewhere in the universe than is possible, simply that a star may have existed and died in the universe before our stars came to be therefor adding time to the age of the universe itself.

You are correct without anything to observe in the unknown universe I could make up anything I wanted to support my model.

Perhaps the basic question comes down to this:
Did the big bang create the universe, or did the big bang happen inside the already existing universe.

1) If it created the universe by expanding outward in all directions then yes the universe should be finite and have quantifiable age.

2) If it was simply an event that happend inside the universe then we can not give an age to the universe with the information we have access to.

If we could determine the age of the universe though, and the rate of expansion, shouldnt we then also be able to tell aproximately on a three dimentional grid where the edge of the universe is at any given time? If so then it seems we could prove or disprove the finite universe theory some day with better tools. (maybe not until the universe starts collapsing but still)

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Because it can still be either way we are both making arguments with many unknowns. I just do not see a problem with having the universe be so large it could support multipul big bangs 'gazillions' of light years apart at different times. I think the theory of the big bang is along the lines of all the matter in the universe coming together, but in my mind it could just as easily be all the matter in a section of the universe.

My thinking is misguided and I wont waste more of your time on this subject beyond this post, but I thank you for your scientific input. Very entertaining stuff Please post on my 'Speed of Light' topic in the question and answers section.

General Relativity describes space-time using the model of a four-dimensional manifold.

In a one-dimensional manifold (or 1-manifold) every point has a neighbourhood that looks like a line. An example of a 1-manifold could be a circle. Wherever you are on that circle, all you can see is a line.

In a 2-manifold, every point has a neighbourhood that looks like a disk. An example of a 2-manifold could be the surface of a sphere. Wherever you are on the surface of that object, all you can see around you is a disk.

The good old balloon model is an example of an expanding 2-manifold. Someone living on the surface of that balloon can only see across the surface, they cannot look up (out of the balloon) or down (into the balloon). They see all points of their universe moving away from them as it expands, but their is no centre of expansion within their universe (the surface of that balloon).

An example of a 3-manifold is a 3-sphere, an object that lives in 4-dimensional euclidean space where every point has a neighbourhood that looks like a sphere. I won't pretend to understand what this object looks like!

If space-time can be modelled as a 4-manifold, I think concepts like the edge of the universe become null and void. Einstein considered that the universe might be finite, but boundless. To me, boundless doesn't mean it goes on forever, it means it has no edge or no bound as space curves back on itself dimensionally. The whole thing expands within itself!

I like the idea of the "Fred & Barney" syndrome.

They drive and drive and all they do is pass the same tree, mailbox, house and tree again...over and over.

If you tried to leave Earth on a ship in a straight line toward anwhere (this way, or that way, or over there...), you would theoretically arrive back where you started. You can't look to the "outer edge" of the Universe because there isn't one.

Check this out for proof. Astronomers don't have to choose a direction when trying to look back in time (very far in space)... it is everywhere. No matter which side of the sun we are on, we can look "up" into space and back into time....whether they are in Australia, or in Alaska. Up-Down-Sideways....every direction only points toward the beginning... never the other way.

You can have only history...not future. Not even present.

That doesn't prove the universe is spatially closed. We will most likely never know, as it seems to be extremely close to the boundary between open and closed, so I suspect humanity will never know if the universe is spatially finite or infinite. That such a fundamental issue might be completely unknowable is a stark reminder of our own limitations.