Is The Universe a Closed System.

[peter]

I'm sure we assume it is; generally speaking we take for granted that we can't access information about or indeed influence anything beyond the boarders of our own Universe [if it has any; I'm still not clear on this] or I suppose vica-versa.But what do the maths say. What does the experimental data say. Have we actually applied any of our scientific/logistical 'tools' to this question, or is our assumption well, just that - an assumption.

I saw the film The Theory of Everything last night, in which the Hawking charachter was asked what he believed in and answered "There is no place for belief in physics", so what do the math, the experiments tell us about the openess/closedness of our Universe.

A little rider question; how well does mathematics model 'the real world'. I mean, if the maths says "it can be done", then is it the case that IT CAN BE DONE! So if the math allows for open Universes to exist, then we have to accept the possibility that ours is one untill the reverse is proven to be true with significant probability.

[Can/does the 'multiverse' idea co-exist with the idea of a Universe without boarders; I'm guessing that this would be a case where cosmologists would fall back on the idea of 'different types of infinity' [see Deutsch] so I believe [sorry Stephen] the answer would in likelyhood be yes.]

[Avatar]

Mathematical possibility does not equal technical proficiency?

--A

[peter]

Yes, but on this Av, the existance of black holes is a case in point; when they were first demonstrated as a theoretical possibility [in the Gen Theory of Relaitvity I think] even Einstein was not concerned with the singularities they contained, because he never believed they existed anyway - they were just a mathematical possibility that he thought the Universe would never actualise. Only experimental data gathered over many years actually demonstrated their existence, and now it appears these singularities are to be encountered everywhere.

[I - by the way - have developed a new 'creation myth' where I see the singularity that Hawking demonstrated at the center of the 'big bang' at the dawn of.....well everything..... as the point at which our 'extra-Universal [white-coated scientist] Creators' initiated their observational experiment in Universe creation, and the miriads of evenly distributed black-hole singularities as the 'ports' via which they extract the data about how their albeit 'hermetically sealed' study is progressing. Am I becoming paranoid? ]

[Hashi Lebwohl]

The Universe (capital letter) is most definitely a closed system. Anything which exists outside The Universe doesn't exist at all as far as the laws of physics are concerned and thus cannot have any effect on us inside The Universe.

The observable universe (lower-case letter) is not a closed system--some evidence suggests that the membranes which collided to form the observable universe are still colliding and that this is stretching that which we call "space". The fact that what we can see is still expanding or inflating means that something must exist outside/beyond what we see but is still having an effect on us, therefore we are not in a closed system.

Mathematics models the real world very precisely most of the time. Suppose we find a new star tomorrow. Based on observations from hundreds of thousands of other stars we will be able to calculate its distance, the rate at which it is moving towards or away from us, its temperature, its mass, its rotation, its chemical composition, etc. and the numbers we find will be pretty accurate to describe that star as we see it (which means how it existed at some point in the past).
Caveat: just because mathematics says that something can be done doesn't mean that it can be done--we may not have the technology to do whatever it is we are trying to do. Is it possible to update and enhance the jetpacks and jet-powered parawings we currently have so that a human could put on a suit, strap on a souped-up jet pack, and fly into orbit? Yes, it is possible....but it isn't likely to happen any time soon. Account for the extra weight of the equipment, the enhanced engines, etc. but also account for the fact that as the altitude increases the need for output decreases but don't forget that after a while the air is too thin for aerodynamics to be of any use....

[peter]

Yes, but Hashi - the observable universe is observable for a very 'prosaic' reason, namely that the finite speed of light puts a maximum distance on what can be seen before you reach a point where it has taken longer for the light to travel from than the universe has existed for; that this is so is no more suprising than say not being able to see round corners because light travels in straight lines [well - at the level of corners in your house anyway]. The Universe is composed of the observable bit plus the unobservable bit [of which as yet we seem to have a pretty fragile grasp].

If many of our current theories [the multiverse etc] do involve forays into, or beyond I should say the limits of the Universe [ie observable plus unobservable] what is to differentiate them from any other Creation Myth, but just mathematically dressed up in the 'emporers new clothes'? [Incidentally Deutsch, I believe said that just about anything you could concieve of as being possible for 'the multiverse' could just as easily be true for the non-observable universe, possibly [IIRC] negating the purpose of hypothesising the existance of a multiverse at all. {I may be wrong here} In such a scenario the knowledge of whether mathematical possibility equates to existensial probability is going to be crucial].

[Hashi Lebwohl]

The parts of the universe we cannot see yet are going to be subject to the same laws of physics as the parts of the universe we can see. Just because we can't see 20 billion light-years away doesn't mean that things are different there.

Our mathematics cannot describe anything outside our 4-dimensional (or 11-dimensional, if you subscribe to M-Theory like I do) so there really isn't any point in worrying about what may be "outside" at all--it would all be nothing but guesswork with no basis in fact. From that point of view, yes, anything which pretends to describe what might be outside or beyond the universe we can see is no different than a creation myth because all those ideas fall into the realm of the non-falsifiable.

The idea of creation myths, themselves, fundamentally apply onto to the directly-observable universe in any event. "Creation" implies a beginning and a temporal sequence of events which follow and that means "time". Time, as we experience it, does not exist even at the quantum level--we already know that some particles can move backwards through what we call time and that once a photon gets emitted it retains its energy level and direction forever. The existence of entanglement also proves that time, and by extension distance, have no meaning at that level. It seems reasonable that time wouldn't necessarily exist outside or beyond our universe, either...but that is only a guess and can be neither proven nor disproven.

At the risk of moving towards the Close allow me to make a few more parallels. What are the typical characteristics of the afterlife? It is a place where time has no meaning and conditions there do not change--either we are singing praises at the foot of the Throne of God or we are in a state of perpetual torture in Hell, or we have attained Oneness with the Buddha, or any of hundreds of other states of non-changing nature. Things don't change at the quantum level, either--things just exist as they are and they exist without time. Yes, some changes may occur but those changes may also easily reverse themselves and there is no set sequential order to how those events may occur: an electron which emits a photon to turn into a positron might run into a photon--the same one it emitted--and turn back into an electron again, only to emit a photon, become a positron, etc. The physical world we experience is an aberration, a temporary deviation, from that state--things exist, they have mass, there is a sequential order of events, etc. In other words, the temporal world is as it is and the afterlife, by whatever name or belief you wish to consider it, can be equated to the quantum realm. That is completely weird but then sometimes things are just weird.

[wayfriend]

Doesn't the definition of the word "universe" (as the word "everything"does as well) preclude the notion of there being anything outside of it's scope?

[Wosbald]

+JMJ+

The Empirical Universe of science (i.e. the "Physical Universe") is, indeed, a closed system. But this Physical Universe is merely an abstraction that, at best, participates in the Real Universe but does not replace it. Instead, it is only a narrative of the Real Universe.

However, the Real Universe is an open-system, and it is most precisely so in us — in Man — in our anthropological constitution which both transcends and transpierces cosmic reality — in our self-reflection and our radical openness to the Other.

Granted, this discussion is "at the risk of moving towards the Close", as Hashi noted, though there is inevitably a point of crossover whenever one, in the final instance, brings such discussions back into relation with the Real.

[peter]

But aren't some of these other theories 'bleeding' into the cosmology of our own Universe, say when they are used as an attempt to answer the 'fine-tuning' problem; don't they thus 'infect' even the best of our 'falsifiable' theories to at least some degree.

Thats a really interesting observation that at the quantum level particles can travell bacwards in time Hashi - I thought the 'arrow of time' was a 'one-way' ticket - end off! That has to open up all kinds of possibilities doesn't it?

That's a really interesting little set of posts, not least because it was in reference to a theological point that I was prompted to ask the question at all. {I think a theologian was asking [rhetorically] if the Universe was closed or not as pertaining to God's ability to act within it from out-side, and I realised that even just from a hard-headed physical point of view I could not answer the question, which seemed ridiculous.}

{nb. If the thread is better served in the Close than here then by all means shift it Hashi - I'm interested in all the facets of this question, existential or otherwise.}

Just one other point; The Universe of science - that Empirical one that Wosbald refers to - surely even much of that that is ....[whats the word].....speculative [?]. I mean we are entierly in the realm of mathematics for any consideration of the non-observable portion of even our own 'closed' universe; what we can and can't know about it will ever be defined by the 'Laws of Mathematics' - and these like any other laws seem only to opperate within a strictly defined set of parameters [don't they?]. Even 'Laws' change don't they - and with them surely the Universe as well?

[Hashi Lebwohl]

Thats a really interesting observation that at the quantum level particles can travell bacwards in time Hashi - I thought the 'arrow of time' was a 'one-way' ticket - end off! That has to open up all kinds of possibilities doesn't it?

Above the quantum/not-quantum threshold time occurs in one direction only. Below that threshold things are a little different. A positron moving forward in time--something we can see in spark chamber diagrams--is mathematically equivalent to an electron moving backwards in time. At the quantum level the phrase "mathematically equivalent" may be substituted for "is the same thing in reality as"--even if the positrons really aren't electrons going backwards we can think of them that way and our models and predictions would still hold true.

[peter]

Would I be right in seeing this as a particularly 'instrumentalist' take on things Hashi [hope I've got the correct term - the one for those who see scientific hypotheses/theories as 'models' in the sense of predictive tools, rather than as a reflection of how the world really is]. Maybe below the quantum threshold instrumentalism is as close as we'll ever get.

By the way, here's another question that's been bugging me; is the 'static model' of the Universe actually 'dead in the water' now [ie beyond ressurection] or are there 'hardcore' believers out in the physicist community who still see it as an [albeit out on a limb] possibility? [Say as dead as 'phlogiston' or 'aether'].

[Hashi Lebwohl]

Yes, instrumentalism is the way to go. Physical constants such as permittivity of a vacuum don't change because the numbers reflect reality; rather, they don't change (well, don't change much) because multiple scientists measured it and they all got the same result. When such things do change it is only because better, more accurate measurements are taken to refine the number. A theory which correctly described reality isn't a secret of the universe which gets revealed after searching for it; rather, a long series of failed or not-quite-good-enough theories were tested, failed to reflect reality, and were discarded. This sort of theory isn't a perfectly accurate descriptor of the universe, either--all theories contain a little error even if decades of testing have fine-tuned that inherent error down to only 0.001%. At some point, though, we start to touch on the Simulacra and Simulation map (a map the same size as the area it describes which is accurate down to the smallest detail, even including you, and which updates itself as the area changes. Is the map shown on itself?). How accurate can our predictive models be?

The universe doesn't care about laws or theories; it just works. We want to know how and why it works and so we have come up with ways to predict and model behavior and some of those models--theories--are pretty darned accurate.

I don't know if "static universe" is as dead as "phlogiston" but I am pretty certain that adherents of "static universe" are few and far between.

[Orlion]

Yes, instrumentalism is the way to go. Physical constants such as permittivity of a vacuum don't change because the numbers reflect reality; rather, they don't change (well, don't change much) because multiple scientists measured it and they all got the same result. When such things do change it is only because better, more accurate measurements are taken to refine the number. A theory which correctly described reality isn't a secret of the universe which gets revealed after searching for it; rather, a long series of failed or not-quite-good-enough theories were tested, failed to reflect reality, and were discarded. This sort of theory isn't a perfectly accurate descriptor of the universe, either--all theories contain a little error even if decades of testing have fine-tuned that inherent error down to only 0.001%. At some point, though, we start to touch on the Simulacra and Simulation map (a map the same size as the area it describes which is accurate down to the smallest detail, even including you, and which updates itself as the area changes. Is the map shown on itself?). How accurate can our predictive models be?

The universe doesn't care about laws or theories; it just works. We want to know how and why it works and so we have come up with ways to predict and model behavior and some of those models--theories--are pretty darned accurate.

I don't know if "static universe" is as dead as "phlogiston" but I am pretty certain that adherents of "static universe" are few and far between.

Sounds right. Essentially, "usefulness" is the name of the game. A constant is "useful" in so far as it helps make predictions. Or test our instruments!

If a new theory is more useful, or if the application of that theory does not work in certain situations, it is discarded (sometimes partially, say like Newtonian physics, or wholesale like phlogiston).

So, we assume, for example, that all the "rules" we observe here locally apply everywhere (we do not actually know that, having not been everywhere). This may not be the case, but "what-ifs" have little to no purpose in scientific applications.

[Vraith]

So, we assume, for example, that all the "rules" we observe here locally apply everywhere (we do not actually know that, having not been everywhere).

This may not be the case, but "what-ifs" have little to no purpose in scientific applications.

On the first...that's still kinda yes-and-know. [heh...that was a typo, but I left it cuz it is fun, implies some things.]
We can see a long way now, and they seem to work everywhere. But there are at least two known limits...we can't see into territory that we know exists, so maybe things change "there," and the rules DON't work for some things we're damn close to certain do exist within our purview [black holes being one.]

On mathematics...sorry, Hashi, you are incorrect. It can describe a plethora of things that are impossible, beyond question, in our universe.
In fact, I'd say the things it can describe that are not possible in our universe, no matter how many dimensions you give it, vastly outnumber the things it describes that are possible.
It MAY also be true that there are things that are possible/do exist that it cannot describe. [for instance, Pi isn't really so special, and is actually false except in particular spacial circumstances]
It is overrated by many who really understand it---they have a Platonic bent, with all its advantages and shortcomings.
OTOH, it is even more seriously underrated by almost everyone else.

More topical---yea, Av, a problem of terms exists. What we call "multi-verse" will be part of the Universe eventually, if it is real and we figure out how it works. Like the place peters ancestors called 'the world' turned out to be just some damp-but-fairly-pleasant islands in THE WORLD.

Orl---I think [though maybe I'm misreading your implications/meaning---because you did say "applications"] that "what if" plays a, and maybe THE central role in science. The only difference [though it is the one that matters] is that a scientist takes that "what if,", makes a sword, and tests it in battle with reality.

[peter]

OK, so what about the 'heliocentric' model of the solar-system? We know it's correct. It's not going to be improved upon; It's not going to be jettisoned in favour of an upgraded model - ever. [Ok the math of the revolutions etc may be tweaked but the heliocentricity will remain]. The model is not an intrument; it doesn't serve as a predictive tool [only]. It's the way it is. It's the way the world is. Is it thus no longer science - but truth? [No science is ever truth is it - if it were it would not be falsifiable.]

[Hashi Lebwohl]

On mathematics...sorry, Hashi, you are incorrect. It can describe a plethora of things that are impossible, beyond question, in our universe.
In fact, I'd say the things it can describe that are not possible in our universe, no matter how many dimensions you give it, vastly outnumber the things it describes that are possible.
It MAY also be true that there are things that are possible/do exist that it cannot describe. [for instance, Pi isn't really so special, and is actually false except in particular spacial circumstances]
It is overrated by many who really understand it---they have a Platonic bent, with all its advantages and shortcomings.
OTOH, it is even more seriously underrated by almost everyone else.

Of course math can describe things which are impossible, that is half the fun of it. Gabriel's Trumpet, for example--finite volume but infinite surface area.

I gladly overrate the value of math, even though the value of math cannot really be overrated. Sagan was definitely correct about one thing--math will be the initial language we use when starting to communicate with any non-Terrestrial species whom we might encounter. The symbols used might be different but the concepts will be the same.

[Vraith]

[No science is ever truth is it - if it were it would not be falsifiable.]

No, no. Things have to be falsifiable in principle---there has to be some method/path of evidence/test/what have you that will CHECK it, and show it is false if it is, in fact, false. But if a thing is true, it will simply continue to pass all the tests that would prove it false if it failed to pass them.
Which is one reason why no form of "Creation Science" that includes a creator as an assumption is even remotely science.
[[heliocentric is, in fact, false, BTW. even locally, the Earth doesn't orbit the Sun...Sun and Earth both move around a point between them. The Sun just so massive by comparison that assuming it as the center is close enough to the real point as to make no difference for most calculations...and even that point is a little shaky cuz all the other bodies around make things shimmy and shake in a chaotic little dance.]]

Edited to add---I wasn't speaking, Hashi, so much of it's value in a pragmatic/practical way, which is pretty damn well established, and probably is our best starting point for communications with aliens.
I was speaking of its totalizing/defining position in many peoples world-view, and the impression that it relates/connects/describes the material precisely, and within one single system/field. Both are false.

[Hashi Lebwohl]

Edited to add---I wasn't speaking, Hashi, so much of it's value in a pragmatic/practical way, which is pretty damn well established, and probably is our best starting point for communications with aliens.
I was speaking of its totalizing/defining position in many peoples world-view, and the impression that it relates/connects/describes the material precisely, and within one single system/field. Both are false.

Oh, that. There is always a margin of error because nothing is ideal and no measurement is perfect. If you give 10 students some paper, a pencil, and a ruler then tell them "draw a line segment that is exactly 7 cm in length" then you will get 10 lines, none of which are actually 7 cm long. Differences in the pencil leads and the quality of the rulers will assure this. If you look at a ruler you will see a mark to indicate 7cm but if you look closer you will see that this mark, itself, has width--which part of this mark denotes precisely 7 cm? The near edge? The far edge? Exactly in the middle?

You are correct, though, in that some people think that a model which describes some behavior or pattern is somehow related to or intrinsically linked to the behavior it is modeling. Nothing could be farther from the truth--mathematical models are reflectors or predictors of reality, not reality itself.

[peter]

But V. - I get the fact that for a statement to be 'scientific' and not 'metaphysical' it has to just be falsifiable but not necessarily actually falsified, but that's not my point. My point is that a statement can be made here - be it 'the Sun and Earth revolve around the point of gravitational equilibrium that lies on the straight line between their two centers of gravity' or whatever - that is true. Science is not going to refute it for a better model ever. Thus it's not a model, not an instrument, it's a true description of reality [or as damn close as we can ever get]. And the moment we accept science as capable of making a statement about reality in one place, surely we have to accept that it can do so in all places - including the quantum world. Which takes us back to Hashi's backward moving electron and the idea that we can view this 'mathematical equivalence' as an instrument because not to do so assaults our preconceptions of 'what is right and what is not' so badly.

Remember that weird thread we had where we discussed the thing about nothing being able to be said that was gramatically correct that did not have meaning - well this is the same, but with maths; surely with Universes the difficult is done at once, the impossible just takes a little longer .

[Hashi Lebwohl]

And the moment we accept science as capable of making a statement about reality in one place, surely we have to accept that it can do so in all places - including the quantum world.

Within reason, yes. Statements or observations which we know to be true at the macro level--objects in motion tend to stay in motion, for example--are going to be true at any point in the macro universe. If that were not true, then something fundamental about that point out there and our point here has to be different and that would cause our entire understanding to fail. The laws of physics apply only locally (by "local" I mean "a few light-years") and are different elsewhere? Wouldn't there be noticeable boundaries where one set of laws gave way to another set of laws? *shudder* No, reality may be weird but it isn't that weird.

True statements about the macro level do not necessarily apply at the quantum level and vice versa.