No; they ***define ***how everything that exists behaves. They don’t “describe”.
This analogy doesn’t quite work that way, since anti-matter, despite being originally conceived of as a means of solving the problem of negative energy solutions of the Dirac equation, isn’t actually analogous to ‘negative energy’ in any ‘positive plus negative equals nothing’-scheme. To see that, just consider mass – if you have an electron and a positron, you’ll have a total invariant mass equal to two electron masses, which is clearly something, and even if the two annihilate, you’ll still be left with a photon with an energy equivalent to that total mass.
On the face of it, the general idea has merit, though – if nothing ‘decayed’ into something, there ought to be a way to recombine that something into nothing. But this contains several implicit assumptions, most notably that there was nothing before there was something, and also that nothing can exist in the first place, which at least would need a careful look at what it means to exist. Also, it is a common assumption that nothing is a somehow more natural state of existence, seeing as how it is often claimed that creation happened ex nihilo, which implies that nothing is something that’s thought of as needing no further explanation, which I’m not sure is actually that obvious. No, I think it’s thoroughly possible that there always was, and always will be something (always here not necessarily meaning an infinite amount of time, but merely ‘since the beginning’ or ‘until the end of’ it, which possibly may include infinity; consider that there can be no ‘before the beginning’, and similarly no ‘after the end’ of time, so the question of what was before is inherently meaningless in this case. And that doesn’t mean it can’t be answered, it means it is answered in there being no such thing).
As for my own views, Leibniz famously stated that we live in the best of all possible worlds, and I tend to agree, though on somewhat different reasoning: An invaluable tool in physics is something known as the ‘variational principle’. In oversimplifying brevity, what it means is that you take a certain quantity, and try to optimize it by finding the spot where each change only leads to a less optimal situation (this is, in principle, similar to problems involving finding extrema of some function by requiring the derivative to vanish, for instance in order to find the minimal amount of fencing required to enclose a certain area and other such cheerfully ‘realistic’ problems high school students everywhere roll their eyes at). Many systems in nature show such an optimization – soap bubbles minimize their surface area, light always takes the shortest path, etc. Note that physical systems don’t really ‘feel out’ the alternatives to arrive at the optimal one, instead, the optimal one is the only one that has physical reality; this may seem curiously teleological at first – how is the system supposed to know which path best to take, if it hasn’t actually tried it --, but this actually makes somewhat more sense when you turn to quantum mechanics, where, depending on the interpretation, a particle in some sense takes all possible paths, to only upon measurement settle into some definite state with a certain probability, which ultimately lays the groundwork for our macroscopic, decoherent world (it says something about the human mindset that the classical, teleological formulation never really raised an eyebrow, as far as I can tell, whereas the quantum description causes so many heads to be shaken in disbelief that we could solve the energy crisis if we could tap into all that motion).
So, that’s more or less what I believe – the universe is simply an appropriately optimized state. On the face of it, that answers bugger all, of course. This may tell us why the universe is the way it is, but not why it is in the first place!, I hear the audience roar (yes, I have my own audience; I even have my own laugh track). Don’t you need something to optimize before you can optimize something? What, exactly, is supposed to be optimized in the first place?
Well!, I retort, somewhat ineffectually, in physics, the quantity that’s optimized generally is something called the action. Find the path (through spacetime, or rather, through the space of its possible configurations) for which the action is optimal (a better word would be stationary; however, in most cases, we can live with it being minimal), and you’ll get the path of the system’s evolution. But again, this apparently requires both a system and a spacetime to already exist, so how could it be used to explain their emergence? I don’'t think I can do much more than reason by analogy, here (and I hope this will not turn out to be a mere appeal to quantum magic) – consider the teleological nature of the action principle I’ve hinted at earlier: despite not having the opportunity to feel out which paths actually minimize the action, the system still knows which one to take; this apparent impossibility (for that’s what it is: in a universe with a strict causal order, where causes always precede effects, there is no way to get information about the optimal path ‘back’ to the system in its original configuration) is, as I again can only hint at, resolved within a quantum context. Similarly, it might be possible for a system that does not even exist to ‘spontaneously’ (gotta watch those time-related concepts) come into being, its existence just being one path in the space of its possible configurations.
And from there on, it just kinda goes all downhill, and here we are!
IMO as the universe exists it has always existed,as that means for ever,it means eternity.
Time and space are supposed to be different facets of the same thing so the multiverse must be indinite.
In an infinite universe all things are possible including the God of the Book,Zeus ,Odin whatever you like but not necessarily in our own local universe.
But what if the universe is an endless replication of the same thing?
It seems unlikely given the huge variety of things just on our own little planet,from sea dragons(A form of seahorse) to bacteria to whales,to lightening and rainbows and cuckoo clocks.
Theoretically anything can exist including contradictions.
Yes. At least, according to some levels of Kripke logic systems. In fact, when the condition on the accessibility relation is symmetric, then A -> <>A. In other words, if A actually exists, then it is necessary that it is possible that A exists. (In fact, the axiom just stated is called the Brouwer Axiom, and when added to the Modal Axiom itself forms B-logic, or Brouwer logic.) Indistinguishable can comment on this with greater clarity than I.
I disagree. Although it is true that we can construct logics where contradictions can exist in some possible world, contradictions cannot exist in the actual world. And lucky for us. Were it not so, science would be turned on its ear. Were observations to contradict a hypothesis, one could declare that his hypothesis is nonetheless correct. There would be no science at all. Only pseudoscience — like astrology and macroeconomics.
That it is possible for A to exist does not mean that it is impossible for A to not exist, though. (In fact, your axiom can be restated as ‘it is necessary that it is not necessary for A to not exist’.)
I’m sure that they’ll be no end of people who’ll “answer” your question, but the fact is, we don’t know. We cannot explain existence itself at this time.
If you want, you can consider that a gap in which to insert a god. However, the god hypothesis seems to just add to the problem.
No. Because we can certainly conceive of events that haven’t happened and entities that don’t exist.
The set of things that can happen appears to be limited by physical laws.
Certainly, no one would argue with that. In fact, the S5 Axiom assures us that: <>A -> <>A. In other words, “If it is possible that A exists, then it is necessarily possible that A exists.”
Well, to be clear, it is Luitzen Egbertus Jan Brouwer’s axiom, not mine. 
But it cannot be restated as you say. For one thing, it is an implication. Therefore, something must imply something. But it could be restated by a modal modus tolens, like this: ~(<>)A -> ~A (where “~” is negation). That would mean “If it is not necessarily possible that A exists, then A does not actually exist.”
So, the fact that the universe exists does not mean that it is impossible for it to not exist? 
Sorry, I only restated the right side, omitting the ‘if A exists’, without pointing that out, so that in full, it was supposed to read ‘if A exists, it is necessary that it is not necessary that A doesn’t exist’, something different from ‘if A exists, it is necessary that it is not possible that A doesn’t exist’, which appeared to be what you were proposing in answering cmyk’s question affirmatively. Or is not A -> <>A <-> A -> ~~A?
You may have a frame of reference issue. Infinity is a big place and it has been determined the Universe is not infinite. Thus there is a boundary, maybe not one we can traverse or learn anything about what exists beyond, but the very fact that the Universe is finite tells us something. Whatever is beyond the boundaries of our universe may well be “nothing” but we’re not in a position to observe it, and therefore understand it.
Scientific American had an interesting article a couple months ago about parallel universes. In one model there’s infinity with a bunch of universes spread across it each roughly the size of what we think of as our universe. Still there are gaps between these universes and within that frame of reference there would indeed be “nothing.”
Enjoy,
Steven
God, I really need to bone up on Modal logic. I’ve never taken a logic or philosophy course, but I remember encountering some when I was trying to trudge through the GEB. Nevertheless, I think I’m following you both, Half Man Half Wit and Liberal.
Of course we can’t know the true nature of existence, and whether or not our universe had some starting point (which science certainly seems to be eluding to with a huge vegas-style, arrow-shaped marquee), there could have always been another universe proceeding it. Whether that was because of branes intersecting each other in n-dimensional meta-reality or what, the point is, that something has always existed.
Like Der Trihs stated, there’s the idea that nothing is unstable. But even so, my thoughts are that it’s meaningless to even make such a claim.
Also, I’d rather not try to fill the gap with God or any such thing; as stated, it only seems to add to the problem. If nothing existed, than neither would God.
I see that you’ve parsed my thread title in the way I didn’t intend. My bad. But, you do bring up another argument that I’ve always had a beef with. Perhaps we could start a new thread about it? The thing is, I just don’t buy that given an infinite amount of time that anything at all will necessarily come into being, such as a purple planet full of slug-shaped clowns. Balderdash, I say!
So I think you real question is, given infinity, is it possible for every point within infinity to contain nothing? I don’t know if it’s provable, but given the probabilistic nature of most things, when you give them an infinity to play out over, they’re all going to occur. Given infinity, if something is possible, it will occur. That’s what’s interesting about the parallel universes concepts. It hurts the head, but it’s interesting.
Enjoy,
Steven
Even then, the presence of nothing (what a paradox), with islands of existence/universes spread across an eternal expanse of nothingness sounds like a different kind of nothing that I have in mind. Wouldn’t this scenario simply be another sort of meta-universe… where in it, exists existence? (ouch.)
Perhaps, like set theory, we need different classes of nothingness.
Could there have ever been a nothingness, where indeed, there was absolutely nothing?
Just like infinity, it’s all up, in and around our mathematics, but may not actually exist outside of an abstract concept. Unless that is, existence itself is infinite…
It is tough to make out exactly what the OP is driving at, but it seems the biggest confusion is treating existence as either a predicate or otherwise reified (as in “nothingness”).
“Nothing” is not a thing, it is a quantifier. To say “Something exists” just means that there is a thing which is a thing. This is not a tautology; if the universe of discourse is the null set (an empty universe), it is false.
Maybe this is the source of the bewilderment: An empty universe is a thing, one reasons, and therefore, even in an empty universe, some thing (an empty universe) must exist. I think this is an instance of confusing metalanguage with the object under investigation. The empty universe exists in our description of it, not in that universe itself.
I’ve heard this argument before. And my OP is very confusing. Even to me. I think it is only so, because it is counter-intuitive. We can’t conceive of absolute nothingness. When we try to, we sling terms around like empty-set universes and the like, but what I’m really driving at is existence itself.
The universe; matter, energy, and the laws that hold it all together are only an anomaly of existence. For this, our universe or any other, to exist, it means that the opposite of existence is impossible or meaningless.
No. If you have an infinite set of possibilities, you can choose an infinite set of actualities from that, without actualizing every possibility. Let’s say you have the infinite set of natural numbers, and from that choose only the even ones; both are equal in cardinality, yet, while ‘3’ is possible, it never ‘happens’.
Got locked out of edit – even if you have just a finite set of possibilities, say {a,b,c}, it’s not a given that in infinite time, all actually happen. For example, you could choose ‘a’ or ‘b’ infinitely often, or any combination thereof, so that ‘c’ never happens; in fact, there are infinitely many strings of choices that omit ‘c’, just consider the progression ababab…, aabaabaab…, aaabaaab… and so on.
3 is not possible in the second set, by definition. Yes they’re both infinite, but the definition of the second set precludes the inclusion of 3.
Enjoy,
Steven
I don’t think you meant to be abrupt in characterizing my talk about empty-set universes as “slinging around terms.” Nevertheless, permit me to observe that your second paragraph is meaningless horseshit.
There’s a difference between what’s possible, and what happens.
I think he’s saying in a set of all natural numbers, including both odd and even, you can choose only the even set for all eternity and never have to choose an odd number. So, that pokes a hole in the “In an infinite universe, all things that are possible, will happen.”
It could happen, but it won’t necessarily happen.