If the Universe is infinite does anything we imagine exist?

Here is one to wrap your minds around. If the universe is infinite and life exists on this planet it stands to reason that there is a chance that it exists elsewhere. Taking that chance what ever it happens to be (let's say 1 in 100,000,000,000) and applying it across an infinite universe; life therefore HAS to exist elsewhere. Now if I imagine a planet populated by super intelligent sheep knowing that sheep exist here and there is that chance that they exist elsewhere...(you can see where this is going don't you. Well to finish it off: If the universe is infinite does anything I imagine therefore exist no matter how absurd?

If the universe were infinite (which I do not believe it is), it would still be subject to its own laws.

Certainly you can imagine things that are impossible (say a brain of a certain size is required for intelligence: an intelligent worm might be impossible; I don't know about a sheep).

Regarding those things you believe that are actually possible, it is still not an open and shut case. The universe could be infinite but without much variety. This is sort of like the question about whether any arbitrary pattern of digits can be found in the decimal expansion of Pi: we just don't know.

Now we're getting somewhere. Yes, anything and everything that has ever been thought has definitely existed IF you agree that thought itself is a realm of reality. But, that doesn't necessarily mean that the smart sheep planet exists in the physical world. I believe that reality is indeed subjective. So if I see Elvis in a flying saucer and really believe that(my emotions will reinforce the belief with physiological responses), then for ME it was real. But no amount of ranting on my part will make it true for your reality(or the physical world).
I assume that when I die, the hallucination dies with me. Unless we carry our delusions into the next plane of existence....

> Well to finish it off: If the universe is infinite does anything I imagine therefore exist no matter how absurd?

First, the universe isn't infinite, it's just really big. Second, even if it was infinite, that doens't imply that anything you can imagine must exist.

k0myers

This reminds me of the old fallacy that a thousand monkeys at a thousand typewriters will eventually hammer out Hamlet. Even given an infinite number of monkeys, I don't think it would ever happen. This is because (and I'm quite sure I'll be corrected if I'm wrong) of entropy, or chaos theory. Simply put, the universe does not tend toward any kind of pattern or organization, it tends towards chaos and homogenization. Not only that, but even if the universe were infinite (which I don't think it is), I don't think there would be any guarantee that any and all possibilities of all things exist somewhere, somehow. Rather than trying to think of why it wouldn't be, I can't think of any reason that it would.

Oh well, my two cents anyway.

Eclipsee writes,

"Even given an infinite number of monkeys, I don't think it would ever happen. This is because (and I'm quite sure I'll be corrected if I'm wrong) of entropy, or chaos theory."

Ok, consider yourself corrected :-). Neither entropy nor chaos theory have anything to do with it. The premise was that the monkies type randomly, in which case an infinite number of monkies for a finite time, or a finite number of monkies for an infinite time, will eventually produce hamlet. Nobody is saying you can actually obtain an infinite number of monkies, just that if you could, and they typed randomly, you'd get hamlet out of them.

k0myers

Now I don't believe that being able to download Hamlet off the Internet proves the monkey thing.

I'll not monkey with the Hamlet question, but is the chaos theory generally accepted?
If so, how would an organism come to be?

TennHippie writes, "I'll not monkey with the Hamlet question..."

Har har :-)

And carries on, somewhat less pun-ishingly: "but is the chaos theory generally accepted? If so, how would an organism come to be?"

Yes, chaos theory is generally accepted; there are examples of such systems, so think of it as an existence proof. The theory basically says that for some types of systems, small variations in the initial conditions can bring about large variations in the future conditions, in a manner that is difficult to predict. But the way you phrase the question leads me to think that you see this as rendering life less probable? On what basis? I don't see the connection. If anything, I would think the opposite, that a chaotic system would be far more likely to have life arise in it, due to the potential for wide variation in conditions. A static or near-static system isn't too interesting when the goal is to randomly stumble upon something that can reproduce itself.

Many people also try to use entropy to prove that life "can't arise from nothing", but this betrays a total misunderstanding of what that theory says, which is that entropy in a closed system increases or remains the same. Nowhere does the theory prevent local (such as on a planet), decreases of entropy. Planets are not closed systems; they tend to have rather large energy inputs. The universe is teeming with examples of local decreases in entropy.

k0myers

If the Universe is infinite, does anything we imagine exist?

Hmmm...that all depends.

If the wave function of the Universe collapses, then no, this "reality as we know it" is pretty much all that there is. Every possibility that didn't become reality will be as if it never existed.

If the waveform of the Universe does not collapse, then yes, anything at all is indeed possible. Possibilities will all be reality in some world (ever watch Sliders?)

Consider the words of Jorge Luis Borges:
" ... a picture, incomplete yet not false... an infinite series of times, in a dizzily growing, every spreading network of diverging, converging and parallel times.

This web of time - the strands of which approach one another, bifurcate, intersect or ignore each other through the centuries - embraces...every possibility.

We do not exist in most of them.

In some you exist and not I, while in others I do, and you do not, and in yet others both of us exist.

In this one, in which chance has favored me, you have come to my gate.

In another, you, crossing the garden, have found me dead.

In yet another, I say these very same words, but am an error, a phantom."
--The Garden of Forking Paths

No, remember that infinite size does not mean infinite variation. For instance, we might have infinite space, but limited matter.


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>>while contemplating the navel of the universe, I wondered, is it an innie or outie?<<

---The dragon observes

To repeat what k0myers has already stated: first, the universe is not infinite; second, even if it were infinite, this would not make everything imaginable exist.

The simple counterargument is the point jens brings up, which is that certain things we can imagine are impossible. For instance, I can imagine a species identical to humans, which live on the surface of a sun. The properties of the universe make this completely impossible, which means the probability of its occurrence is zero; it will never ever happen, even given infinite opportunity.

If you change the question, and ask whether everything possible must eventually exist in an infinite universe, the answer is less clear. I think this must be a "yes", if only because of the mathematics. (Small probability * infinity = 100% probability)

Jens writes, "say a brain of a certain size is required for intelligence..."

It may be required, but as the existence of Pauly Shore demonstrates, it by no means guarantees that result :-)

k0myers

Slightly off-topic:

In the Hitchhiker's Guide to the Galaxy, it was surmized that since the universe was infinitely large but that the number of life forms was necessarily finite, the average population of the universe is zero. 8-)

OK I am somewhat befuddled on a couple of points here... First: IF the universe is infinite how can there be a finite amount of matter is one not dependent on the other?? And second How can any one prove the size of the universe? I realize we are dealing in abstracts here but how can one sat for sue that the universe is finite (and if it is what the heck does it look like? (Is it the doughnut shape that we all know and love?)) My point is in the original phrasing of the question IF being the key word but I suppose is I had wings growing out of my butt I could learn to fly too

OK I am somewhat befuddled on a couple of points here... First: IF the universe is infinite how can there be a finite amount of matter is one not dependent on the other?? And second How can any one prove the size of the universe? I realize we are dealing in abstracts here but how can one say for sue that the universe is finite (and if it is what the heck does it look like? (Is it the doughnut shape that we all know and love?)) My point is in the original phrasing of the question IF being the key word, but I suppose is IF had wings growing out of my butt I could learn to fly too

Has anyone else read Heinlein's "Number of the Beast"? I'm not much on higher mathematics or multi-dimensional space, but Heinlein came up with the charming notion that there are three time axes as well as three spacial axes, and that because of this, there was an indenumerable number of possible universes.

The heroes ended up exploring Rice-Burroughs' Mars, Baum's Oz, Carroll's Wonderland and a few other universes made possible by a not-quite-infinte variety of universes. Heinlein uses the theme in his multiverse several different times.

Of course, it's fiction, but a delightful idea nonetheless.

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"Knowing others is wisdom. Knowing yourself is enlightenment." - Lao-tzu, Chinese philosopher

Does anything we imagine exist?

I imagine a being who has the capacity to imagine something that does not exist.

Either the being that I imagine does not exist, or else the being I imagine does exist, but can imagine something that does not exist.

Conclusion: Not everything we can imagine exists.

Easy.

>If the wave function of the Universe >collapses, then no, this "reality as we >know it" is pretty much all that there is. >Every possibility that didn't become >reality will be as if it never existed.

Ah, but the wave function won't colapse until it state is tested by an external observer? So anything (and everything) goes up until the point God peeks in the box. Then he will know what existed and what didnt.



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[Insert Clever Quote Here]

Ahhh...but who will peek into the box to see a fully informed God?

Thanks,all. I find these posts infinitely delightful, if not universally understood.

Cast one more vote for the "because something can be imagined, it does not mean it can exist" side of this discussion. We could get into the the whole "possible" vs. "probable" with this as well.

Patricinus Scriblerus writes, "First: IF the universe is infinite how can there be a finite amount of matter is one not dependent on the other??"

Well, it seems that no Real Astronomer(tm) has popped up to answer this, so I might as well take a swing at it. Disclaimer: I'm not an astronomer. I might be wrong here.

To your first question, I suppose that as long as one limit's one's self to talking about hypothetical universes, one can envision a universe with an infinite spacial extent but a finite amount of matter in it. But the more interesting question, IMHO, is your second one, where you ask, "And second How can any one prove the size of the universe?"

This is where I stand to be corrected by Real Astronomers(tm). But AFAIK, we there are two related questions: the univere's age, and it's size. We can estimate the universe's age by noting that it's expanding, and that this expansion obeys certain physical laws. We can extrapolate this backwards to t=0 and arrive at an estimate in the ballpark of 12 to 16 billion years old (which is even older than US Senator Strom Thurman!) So this puts a maximum upper bound on how big the universe could possibly be. The value of the Hubble Constant (the rate of expansion of the universe) is something scientists are trying to get a good handle on, because it affects the answers to all these other related questions.

To get an idea of how big the universe is, we need to be able to estimate distances to distant objects. For distances to nearby objects, we can use the earth's orbit as a baseline and use simple trigonomotry to calculate the distance rather directly, but this method breaks down over longer distances since the earth's orbit is so tiny. For more distant objects, other, less direct techniques are used. For example, we know about how bright certain classes of objects are by observing nearby ones, and if we see one of those objects in a distant galaxy, we can measure how bright it looks to us from here, and thus estimate how far away it is. Think of it like this: if you see an automobile headlight pointed right at you from 10 feet away, it looks very bright indeed. But that same auto headlight pointed at you from 2 miles away won't appear very bright at all. If you know it's pointed right at you in both cases, you can estimate its distance based on how bright it looks. (There are limitations and problems with this technique of course, such as interstellar dust absorption). Another technique is to observe that for a given class of galaxy, the distance between its stars similar to other galaxies of the same class. So by looking at how "grainy" a galaxy looks to us from earth, we can estimate the angular separation of it's stars, and because we know the actual separation of the stars in that type of galaxy, we can estimate the distance to the galaxy. There are many other techniques, all with various limitations and sources of error, but combined, they give us at least a rough picture of how far away things are.

So (consider this subject to correction by anyone who knows more about this than I do): AFAIK, the process goes like this. We estimate the distances to some not-too-distant galaxies at various distances from us as accurately as we can. We can measure their rate of recession quite accurately by looking at the redshift of their spectra. Doing this allows us to estimate the Hubble constant. Knowing the hubble constant, we can estimate how old the universe is, and when we know _that_, we can estimate how far away the very oldest objects are.

Ok, so there's a fair amount of handwaving in there, but until you get a better answer from a Real Astronomer(tm), maybe this will suffice :-)

k0myers

k0myers brings up an interesting idea, if we map out the most distant objects in each segment of the sky, they should describe the edges of the known universe, and should tell us the geometry. Has anyone ever bothered to do this?

Falcon2,

As far as I understand it (and again, I'm not an astronomer, so take this for what it's worth!), is that the universe is basically closed. It doesn't have an "edge" per se.

The usual example used is a balloon, the surface of which is a 2D surface, but there's no "edge" to this surface because it's curved throughout one higher dimension. As far as I understand it, our universe is thought to be the same way, just one higher dimension up. We can't see all the way around it; as we look farther back in time (and thus farther away in distance), our ability to see things becomes progressively more limited since the universe was denser/hotter/etc back then.

But I don't understand the intricacies of the theory here, so I'm probably not the best one to answer this question. Maybe there's somebody with a real astronomy background lurking?

k0myers

Oh, the other thing I forgot to add is that there i a lot of research going on into large scale (100+ LY) structures in the universe. I don't pretend to understand the significance of this, but large groups of galaxies are grouped into larger structures, sometimes hundreds of lightyears across. I think they're measuring the location of as many galaxies as possible to get the best map they can. Measuring the angular position of a galaxy is trivial, but measuring its distance is difficult, so there's only so much they can do.

k0myers

To back up k0myers's remarks of 07-05-99 11:10 PM, let me point out that Nobelist Ilya Prigogine demonstrated some 20-odd years ago that systems that are sufficiently far from equilibrium can exhibit local "reversals" of entropy, or what he called "order through fluctuations".

Prigogine's findings repudiate the view that entropy and the laws of thermodynamics make the "spontaneous" (i.e., non-Created) development of life impossible.


On another point, I think there is some confusion about the idea of an "infinite" universe. As others have already pointed out, the universe is not infinite in terms of space; astronomers and cosmologists call the universe "finite, but unbounded". But it would certainly appear to be infinite in terms of future time.


As for Wayne McDougall, I agree with your conclusion but not with the way you reached it. The existence of something in someone's imagination has no bearing on its existence in reality.


SoulFrost: I second your succinct answer to falcon2's Quantum Berkeleyism.


Finally, AuraSeer's post intrigues me (in line with SBW's remarks). I agree with everything up to the last sentence of Aura's last paragraph:(Small probability * infinity = 100% probability) "Possibility" probably shouldn't be confused with "probability" -- I don't think that's the way either one of them works. In order to estimate the probability of an event, doesn't the occurrence of the class of event in question have to be in some sense known and predictable? For example, even though the time at which a particular atom will decay is unpredictable, the probability of this kind of event is based on quantum theory (and perhaps measuring large numbers of decay events and plotting a distribution); i.e., it's based on the fact that decay is known to exist.

Saying that something is possible doesn't say anything more than that its existence wouldn't violate known natural laws -- it doesn't say anything about the probability of that state occurring, nor does it say anything about the frequency with which the event might occur. In other words, I can't imagine why there could not be "possible" events whose probability is zero. I'm not convinced that "possible" and "probability > 0" are synonymous...

... but it's a damn interesting, if highly confusing, question for debate!