Infinitely old universe

[Tranquility]

I first read about this concept in one of Carl Sagan's books. The argument goes something like this:
An infinitely old universe would disprove the existence of God, since an infinitely old universe would never have had to be created.

Now I dont want to discuss the implications of the argument itself, i quite understand what the author is getting at.

I am, however, having a hard time understanding the concept of an infinitely old universe.

When we studied infinite series a couple months ago, there was always a starting point, at say n=0, 1, 2, 3... or any real number, but it was a well defined starting point and went on into infinity.

I dont understand how a universe of infinite age could have come into existence in the first place. Even an oscillating universe must have had a beginning, some trigger to this oscillation, even if the oscillation pattern repeats for indefinite (or infinite) amount of time.

So can someone please explain to me the concept of an infinitely old universe? I really have a hard time grasping the concept of something that did not have a starting point.

Disclaimer: I'm not trying to start a religious debate. I'm just trying to understand the concept of an infinitely old universe. Please dont feel obliged to argue from a religious point of view because I want to know the basis of the concept from a scientific perspective (and I dont want the thread to get locked).

[Slamoid]

Man, you're brave.

It's hard to discuss this without religon coming into question, but I'll try my best. (myself being of very strong religous conviction)

The true question here is do atoms die? Do they have a lifespan? Do the electrons' orbit degrade? Or would, given the chance (barring any 'big crunch' theories) the atoms of the universe live on forever? Would new ones be 'Born', as is possible by Einstein's theory of relativity? (slowing down energy to make matter) And if so, would this process be infinately repeatable?

So if the universe could 'live' forever, could always be in existance (again, barring a 'big crunch' or other quantum disaster), why couldn't it have always been in existance? (this thread is not about how the universe/multiverse came to be, so I'm stopping here. )

[Normandy6644]

Pretty much everything you're talking about is a good way to get a headache. I think the concept of "infinitely old" is just as difficult to understand as the universe having a beginning. We can always ask more questions. Like, if the universe is infinitely old, how do we have a concept of time, or how did it "begin"? At the same time, if the universe had a beginning, what was before that and what caused it? These are the most important questions to ask; however I'm not sure if they can ever be answered. It doesn't stop people (myself included) from trying. It's actually questions like these that have made me choose cosmology as my lifestyle. To better understand the important questions helps us understand ourselves, as well as the universe.

As far as the infinitely old universe goes, it basically goes hand in hand with steady state theory, saying that the universe always has and always will exist. I don't think it has much credit anymore, so you probably don't have to worry about it. :wink:

[iFire]

As it seemed taht he was gettign at ^^, infinatly old is just really really hard to understand, we are so used to marking things at a start time and an end time... It really just make you feel weird to think about....

[harlequin]

I first read about this concept in one of Carl Sagan's books. The argument goes something like this:
An infinitely old universe would disprove the existence of God, since an infinitely old universe would never have had to be created.

An infinitely old universe does not disprove the existence of God: both God and the universe could be infinitely old.

I dont understand how a universe of infinite age could have come into existence in the first place. Even an oscillating universe must have had a beginning, some trigger to this oscillation, even if the oscillation pattern repeats for indefinite (or infinite) amount of time.

An infinitely old universe or an infinitely old God would have NEVER come to existence in the first place by definition of infinitely old. Something with infinite age never started but has always been.

So can someone please explain to me the concept of an infinitely old universe? I really have a hard time grasping the concept of something that did not have a starting point.

In math lots of things don't have a starting point. Consider the set of real numbers. There is no first number. The first number exactly corresponds with your "starting point". So conception of this is no problem.

Of course just because we can conceive of an infinitely aged "universe" or "God" does not mean that either really is.

[Quartermain]

An infinitely old universe, by definition, will already have been subject to an infinite number of consequences. It stands to reason that an infinitely old universe, having been ravaged by an infinite number of consequences, should be very homogenous in nature. Consider the following examples...

a) An infinitely old universe that isn't expanding might be one giant black hole as all of the matter will have coalesced into one body. The extreme nature of such a universe would be indescribable.

b) An infinitely old universe that is expanding would already have expanded beyond all recognizable proportions. No stars would be visible. The universe would not appear to exist to the casual observer.

c) An infinitely old universe subject to proton decay (the spontaneous break down of the most fundamental subatomic particles) all matter would already be broken down saturating the universe with gamma radiation. This would be a universe of energy.

It is difficult for me to consider an infinitely old universe that is both subject to the efefcts of causality and also stable. It is even more difficult for me to consider how life could survive in an infinitely old universe. If God did create life in an infinitely old universe then he did so knowing we would die within microseconds of our creation. But since we're here talking about it that obviously isn't the case. In conclusion; God can be infinitely old (heck he's GOD right?) but the universe cannot.

[Tranquility]

Pretty much everything you're talking about is a good way to get a headache.

Indeed .

An infinitely old universe does not disprove the existence of God: both God and the universe could be infinitely old.

Sure the argument itself may have logical fallacies, but I was not trying to discuss the argument itself, i just used it as an introduction to what I was trying to ask - it started the train of thought for me.

An infinitely old universe or an infinitely old God would have NEVER come to existence in the first place by definition of infinitely old. Something with infinite age never started but has always been.

Thats where the problem lies, I cannot relate this argument. I just dont understand the concept of a universe that was "always there".

In math lots of things don't have a starting point. Consider the set of real numbers. There is no first number. The first number exactly corresponds with your "starting point". So conception of this is no problem.

That is fine, but I dont think it explains it away. I think this mathematical concept does not explain away how a universe can be infinitely old. Its giving me a headache already trying to relate them.

--

Thanks a lot Quartermain for your explanation of what an infinitely old universe might be like.
But, what about an infinitely old oscillating universe. The way I see it, the matter is recycled. Cycles of Big Bangs and Big Crunches allow all the matter to be converted into energy and vice versa in an infinite succession of repetitions. Would that also be impossible to live in? (while not elevating the previous argument of how this whole cycle managed to start in the first place)

EDIT to fix typos

[brithlor]

An infinitely old universe does not in any way prove the non-existance of God.

Something of infinite existance is impossible to comprehend to a finite mind.

[snowflakeuniverse]

Hi Tranquility

For me, physics should not only correspond to a mathematical or geometric structure, it must make philosophical sense.

For me, the only logical conclusion one can reach about the age of the universe is that it is finite, it is not infinitely aged. Everything observed in the universe has a beginning and an end. Every seed will yield a plant that will rot. Every man born will decay. Every star in the universe has a beginning and will have a cold end. If everything in the universe has this fate, then the same fate will befall our universe.

This now creates another problem, for something to exist, there must be some source or cause for the existence. This then requires something that has an eternal nature from which our universe is created.

Snowflake

[paulie jay]

I had once read that an infinitely old Universe would by now be flooded by the light and radiation of every star from the past that has ever existed. Made sense to me

[AGN Fuel]

I had once read that an infinitely old Universe would by now be flooded by the light and radiation of every star from the past that has ever existed. Made sense to me

Olbers' paradox.

[Normandy6644]

This now creates another problem, for something to exist, there must be some source or cause for the existence. This then requires something that has an eternal nature from which our universe is created.

Not that I disagree with you, but by this logic we would just have an infinite regression. That is, there would be no end to the "creators" since everything that has been created must have some source, and in turn the source must have a source, ad infinitum. I'm not sure of a way around it yet, but it does pose an interesting problem.

[TravisM]

The static universe died when Hubble made his famous observations. The idea of things 'holding still' for us isn't observationally correct. Following what the red-shift data tells us, earlier in the history of the universe all galaxies were closer together, there's only a few 'realistic' scenarios that could have given us the universe we see today.
Barring discussions on what happened before the big bang we can talk about the creation of this universe in great detail, and its finite limits. The only thing we have to go on is prevailing theory and observational evidence supporting that theory. This is the coolest part of science, I think, where cosmology meets physics. I'm a backyard astrophysicist most of the time...

[Pi Man]

For me, the only logical conclusion one can reach about the age of the universe is that it is finite, it is not infinitely aged. Everything observed in the universe has a beginning and an end. Every seed will yield a plant that will rot. Every man born will decay. Every star in the universe has a beginning and will have a cold end. If everything in the universe has this fate, then the same fate will befall our universe.

This now creates another problem, for something to exist, there must be some source or cause for the existence. This then requires something that has an eternal nature from which our universe is created.

I have one more thing to add to this. There's no reason to think that any of the laws which apply inside our universe (such as causality, time, qhysics of any sort, thermodynamics) apply outside the universe. Many of these laws do seem to hold for the universe as a whole (for instance, the universe does seem to have a beginning) but this is not so just because "every star in the universe has a beginning."

[George]

I have one more thing to add to this. There's no reason to think that any of the laws which apply inside our universe (such as causality, time, qhysics of any sort, thermodynamics) apply outside the universe. Many of these laws do seem to hold for the universe as a whole (for instance, the universe does seem to have a beginning) but this is not so just because "every star in the universe has a beginning."

Since you mentioned thermo....entropy (2nd law) has a lot to say about the idea of a finite universe. If universe is "winding down" constantly, it would need a "winder-upper" to keep it ticking. No such mechanism has been found. If you find one, call me first. :wink:

[cyrek1]

cyrek1 reply

Tranquility
The SSU would be an infinitely old Universe.

I came to this conclusion because of the Conservation Laws in physics.
My imterpretation of these laws is that matter cannot be created or destroyed but only transformed. Therefore, matter always existed which implies that there is no beginning or end.

Maybe Carl Sagan had thought likewise before me although I did not read Sagans book.

[SciFi Chick]

How about thinking of it like a circle? There is no beginning and no end to the circle.

[Russ]

snip
When we studied infinite series a couple months ago, there was always a starting point, at say n=0, 1, 2, 3... or any real number, but it was a well defined starting point and went on into infinity.

I dont understand how a universe of infinite age could have come into existence in the first place. Even an oscillating universe must have had a beginning, some trigger to this oscillation, even if the oscillation pattern repeats for indefinite (or infinite) amount of time.
Snip

I read through the responses and did not see a concept for infinity that I was taught in junior high. It was pretty easy to grasp and made sense to me.

You seem to grasp the consept of an "onset ray'", a number line that begins at zero, 1, 2, etc. and goes on without end. The next step is to deem that line to be seconds of time. Every tick of the clock is a step in the + direction. By taking that step you creat a time point on the line that is -1 from where you live your life at time zero. To take it the other direction, you consider yourself at the zero point looking back in time from zero to -1, -2, -3, etc. on into infinity. You now have an onset ray that goes in the + direction and another that goes in the - direction.

The perception of time is just a characteristic of the human nervous system. It has little significance in physics, except as our own perception. If you look at time mathematically, all points are valid and and there is no such thing as future or history.

This is strictly my opinion: The reason humans apply such significance to the creation and end of the Earth and the cosmos, is because we ourselves have a begining and end. Being highly egocentric creatures, we just assume the univers is the same. And we all know what happens when you ASSUME. :wink:

[soupdragon2]

How about thinking of it like a circle? There is no beginning and no end to the circle.

i Or a figure of Eight. Isn't this the general (Mystical) symbol for infinity?

ii If the universe is a finite age, then something had to create it. But what created the primary creative force? This argument is self-defeating, or is it? Has The creative force always been? If so the the universe could also be infinitely old, alleged expansive and accelerative features notwithstanding, as these could be localised and cyclical, blah, blah.

All such arguments tend to invoke circular reasoning, however, when they should be double looped as per i? :roll:

[mutineer]

I hope Tranquility will forgive me for giving a twist to this thread, but I want to make a point about beginningness in relation to endness.

It is as difficult to get ones mind round the problems of an infinitely old universe as it is to imagine a beginning point in time BUT I have a strong intellectual prejudice in favor of the following principle:
IF the universe did not have a beginning it will not have an end
IF the universe had a beginning it will have an end.

I am deeply uncomfortable with any theory that proposes a universe that has a beginning but lasts for all eternity.
I wonder if this feeling is shared?
(I am trying to look at this as a philosophical proposition abstracted from any consideration of the BBT etc.)

[soupdragon2]

IF the universe did not have a beginning it will not have an end
IF the universe had a beginning it will have an end.

This is logical, and I like it. But logic never guaranteed the truthfulness of any propostion, let alone when the premises are complex and subjective.

The two letters in the middle of Life spell IF...

[Gullible Jones]

Soupdragon, a warning to you: don't go where I think you're going. The argument of the first cause has been debunked. Plus, we really do not need another religious thread, and the accompanying flame wars.

[cyrek1]

cyrek1 reply

Gullible
I think Mutineer and soupdragon are using logic.
I do not see where this has anything to do with religion.

[soupdragon2]

Soupdragon, a warning to you: don't go where I think you're going.

Eh? Where do you think I'm going? I have no interest whatsoever in religious arguments. In terms of a philosophical angle, I favour some form of intelligent design behind the universe/s, but I really can't be bothered to get into all that on this particular board which quite rightly focuses on scientific issues.

The argument of the first cause has been debunked.

This is a philosophical argument which is still going strong, like it or not. Theology has a habit of taking philosophical ideas and bending them to suit its own needs, but science has been known to do the same.

Plus, we really do not need another religious thread, and the accompanying flame wars.

Couldn't agree more!

cyrek1 reply

Gullible
I think Mutineer and soupdragon are using logic.
I do not see where this has anything to do with religion.

Agreed, for the most part. Mutineer's logic is sound, but I'm offering my opinion that logic has it's limitations.

[Kesh]

A Moebius loop is what soupdragon is describing. And really, there's only the barest difference between a Moebius and a circle.

If you make a circular loop from a strip of paper, you can trace a pen along its outside and end up meeting the beginning of your pen-stroke. You can do the same to the inside of the loop. However, the outside pen-mark and the inside one never meet.

With a Moebius loop, when you start your pen-mark and follow the surface of the paper, you'll eventually meet the beginning of your pen-stroke and will have marked both sides of the paper in the single stroke.

In practical terms, however, they just mean the same thing: from whatever point you start at, you eventually return to.

What that has to do with the universe, I have no idea. :-s

[beskeptical]

My three cents:

The thread seems to be conceptualizing no beginning (and maybe no end). The proof of god or not seems to be a red herring and not relevant to the topic. Perhaps it should have been left out for clarity.

Mutineer stated his position of either beginning and end or no beginning and no end as a "strong intellectual prejudice" and not a 'logic' argument. That gets him off the hook, but I don't think the logic follows.

I'm inclined toward the direction of PiMan,

There's no reason to think that any of the laws which apply inside our universe (such as causality, time, physics of any sort, thermodynamics) apply outside the universe. Many of these laws do seem to hold for the universe as a whole (for instance, the universe does seem to have a beginning) but this is not so just because "every star in the universe has a beginning."

This is where I begin from. We cannot yet and maybe never will know what occurred before the Universe. The Universe is everything so far as we know and there seems to be no edge, but that doesn't necessarily preclude other universes outside of ours, which implies there may be an 'outside' of the Universe.

So, I stop short of reaching the concept of no beginning because I don't have the data to fill in the answer.

In other words, I can't imagine how it would work to have no beginning, but I'm not bothered by that because I also know I don't have all the facts yet. I presume I could conceptualize no beginning if I knew more about before the Big Bang and more about things 'outside' of our Universe, if there are any things outside.

One example I have thought of would be 'time' as the edge of the Universe. Perhaps we perceive no 'edges' because we are expecting 3 dimensional edges and perhaps the edges are not in 3D.

As hard as it is to conceptualize no beginning, it is equally hard to conceptualize 'nothing' and then a beginning. So either way, we just have to keep contemplating the 'ol Universe and little by little a better concept might emerge.....in a few million years or so :roll: .

[beskeptical]

An infinitely old universe, by definition, will already have been subject to an infinite number of consequences. It stands to reason that an infinitely old universe, having been ravaged by an infinite number of consequences, should be very homogenous in nature. Consider the following examples...

a) An infinitely old universe that isn't expanding might be one giant black hole as all of the matter will have coalesced into one body. The extreme nature of such a universe would be indescribable.

b) An infinitely old universe that is expanding would already have expanded beyond all recognizable proportions. No stars would be visible. The universe would not appear to exist to the casual observer.

c) An infinitely old universe subject to proton decay (the spontaneous break down of the most fundamental subatomic particles) all matter would already be broken down saturating the universe with gamma radiation. This would be a universe of energy.

It is difficult for me to consider an infinitely old universe that is both subject to the efefcts of causality and also stable. It is even more difficult for me to consider how life could survive in an infinitely old universe. If God did create life in an infinitely old universe then he did so knowing we would die within microseconds of our creation. But since we're here talking about it that obviously isn't the case. In conclusion; God can be infinitely old (heck he's GOD right?) but the universe cannot.

I think the issue isn't the Universe as we see it today, but rather what existed before the Big Bang. If you take the premise that something was there to Bang, you don't have a beginning at the point we currently consider counting from. If you had nothing to Bang, well....then what happened to get something?

[beskeptical]

Man, you're brave.

It's hard to discuss this without religon coming into question, ...

No it isn't.

[beskeptical]

.....Something of infinite existance is impossible to comprehend to a finite mind.

Well, start stretching those nerve fibers, then. :wink: Personnaly, I think that old premise is a crock. [-(

[beskeptical]

BTW Mutineer, I sooo agree with your sig about skeptics having a very broad minded approach. I keep trying to point out to folks that skepticism isn't a negative word.