Multiple Universes

Gegerty

Parallel means they never meet. So the decisions we make do not cause us to cross over into other universes/branches.

Pompey Magnus

pH wrote:

All these universes and I end up stuck in this one, where I haven't won the lotto .

Ah but you won the biggest lottery of them all, you won the sperm race 9 months before you were born beating hundreds of millions of other competitors.

Asiaprod

pH wrote:

Arrg .. you're stuck in this one too?

Yes, and I'm the Buddhist:(

Son Goku

Scofflaw wrote:

That, too, is a particular interpretive position - that one should not look for physical realities behind the models behind the maths.

Perhaps I wasn't clear. I'm not saying you shouldn't look for the physical reality behind the maths. What would be the point in physics as an intellectual interest otherwise?

What I am saying is that since all interpretations are interpretations, they should be proposed as such. What Deutsch, Cramer and Bohm claim is that there is some particular advantage to each of their interpretations which regular "Hilbert Space" or Vanilla QM doesn't offer. Since the different interpretations can't, by definition, give different predictions, what people usually claim is that they make Quantum Mechanical results easier to intuit. However outside very specific simplified circumstances unique to each interpretation, they are usually (and even their proponents will admit this) to hard to follow.

For instance Bohm's interpretation is good for particle's in a potential, but the hydrogen atom or multiple particle scattering can't be understood as the formalism becomes to cumbersome.

Similarly the many-worlds interpretation is good for simple Quantum Computers and light emission/absorption, but massively cumbersome in other situations.

Regular QM has always been the easiest to follow.

Scofflaw wrote:

The question of whether it is the correct interpretation is a separate question - but if no other model fits the maths, that can be seen as falsifiable evidence.

All the interpretations are just transformations of QM into another framework. All other forms of QM fit the evidence, since there is only one QM, simply transposed into different frameworks.

Scofflaw

Son Goku wrote:

Perhaps I wasn't clear. I'm not saying you shouldn't look for the physical reality behind the maths. what would be the point in physics as an intellectual interest otherwise?

Phew! Still, given we're talking about a crossover between quantum mechanics and theology, the chances of us achieving less than perfect clarity are pretty high.

Son Goku wrote:

What I am saying is that since all interpretations are interpretations, they should be proposed as such. What Deutsch, Cramer and Bohm claim is that there is some particular advantage to each of their interpretations which regular "Hilbert Space" or Vanilla QM doesn't offer. Since the different interpretations can't, by definition, give different predictions, what people usually claim is that they make Quantum Mechanical results easier to intuit. However outside very specific simplified circumstances unique to each interpretation, they are usually (and even their proponents will admit this) to hard to follow.

For instance Bohm's interpretation is good for particle's in a potential, but the hydrogen atom or multiple particle scattering can't be understood as the formalism becomes to cumbersome.

Similarly the many-worlds interpretation is good for simple Quantum Computers and light emission/absorption, but massively cumbersome in other situations.

Regular QM has always been the easiest to follow.

All the interpretations are just transformations of QM into another framework. All other forms of QM fit the evidence, since there is only one QM, simply transposed into different frameworks.

Yes, I can see what you're saying. Your initial comment seemed much more dismissive of possible physical reality. While each of the frameworks offers, as you say, advantages only under certain circumstances, we are still left with the possibility that one of them represents actual reality (and we are also left, of course, with the possibility that reality depends on how you look at it).

cordially,
Scofflaw

Son Goku

Scofflaw wrote:

Phew! Still, given we're talking about a crossover between quantum mechanics and theology, the chances of us achieving less than perfect clarity are pretty high.



Yes, I can see what you're saying. Your initial comment seemed much more dismissive of possible physical reality. While each of the frameworks offers, as you say, advantages only under certain circumstances, we are still left with the possibility that one of them represents actual reality (and we are also left, of course, with the possibility that reality depends on how you look at it).

cordially,
Scofflaw

I should also point out a few other things, since people might find them of interest.

First ,the strengths of the Many-Worlds interpretation. It and the Copenhagen interpretation are still the only interpretations that can function equally well as interpretations of Quantum Mechanics and Quantum Field Theory (which is Quantum Mechanics + Special Relativity). Most other interpretations can't make any sense of Quantum Field Theory. It is also probably one of the easiest to grasp.

Second, it is immensely useful in Quantum Computing. Deutsch most important work, the first interesting quantum algorithm, only came about because of his work on Many Worlds. Which shows that these extra ways of looking at and appreciating QM have practical benefits.

Third and this is very important, all the interpretations centre around one issue. That is the measurement problem, which concerns the fifth of QM‘s five axioms. On other issues QM is easy to interpret once you get the hang of it and what the maths means is directly transparent. Something that is often not explained is that maths in theoretical physics doesn't function like maths in other areas. It isn't there to only calculate quantities, it is also descriptive. For instance Maxwell's equations don't just provide models which match experiment and can be solved on a computer. If that's all they did, I can tell you, far less people would do physics. The point of Maxwell's equations is that the actually tell you something about what kind of object an electromagnetic field is. There is more mathematical properties than just numbers and values. That's why there is no questions about what the maths really means, because the maths is a descriptive language.
What makes QM different to all other physical theories is that one section of its mathematical structure (its fifth axiom), has no native descriptive content. The interpretations are basically attempts to give this axiom descriptive content consistent with the other four axioms.
However questions about the fifth axiom only come up when you work in Quantum Computation (the power of Quantum Computers comes from the fifth axiom) and what is called Foundational QM, which is literally the study of the fifth axiom(So you can imagine the fifth axiom comes up quite a bit). In other areas of physics, such as particle physics, you don't really need it in such detail so this kind of stuff rarely comes up.

Fourth, since I've introduced the necessary concepts I can explain the point behind this $1,000,000 maths problem: Yang-Mills problem.
As I've already said QM has five axioms. However QM doesn't work with special relativity. In order to make it work with special relativity you have to add six extra axioms, bringing the total to eleven. QM with these extra six axioms is called Quantum Field Theory. The problem is nobody has ever proven that these six extra axioms don't contradict each other, although it has been proven they don't contradict the original five. As such Quantum Field Theory remains shaky logically, even though it matches experiment. If you can prove they don't contradict each other you win a million.

Absolutely nothing to do with atheism or agnosticism or theism, but there you go.

stevejazzx

Isn't anyone going to quote, emm I think it's Feynman,

if you think you know anything about quantum mechanics then you don't know anything about quantum mechanics

Yeah well QM is extremely interesting, I've just seen a documentary with a bit about branes and gravity or 'gravitons' leaking from branes into higher dimensional space explaining why gravity is such a weak force...and qunatum computing is absolutely fascinating calcuting a far greater density of algortihm...the problem with it is that it is still in its infancy and so using it as an argument against religon is a bit premature...it does however appear to hint at things to come...

aidan24326

Depeche_Mode wrote:

Also I have always been baffled at the near impossibility that I have come into existance at all. An exact chain of events over ten billion years since the Big Bang was necessary for me to be born, and had even the slightest variation occured over that time frame I most certainly would never have been born. This vast improbably is explained away by the theory as any possible event is inevitable, such being the nature of infinity

Yes but while you and I are here there is a very very large set of possible humans that aren't and never will be. So I guess somebody had to be, that it is you and I who 'got lucky' is really of significance only in our own minds.

humanji

If there are an infinite number of universes with infinite possibilities, does that mean there's a universe where they've proven that the multiverse idea is wrong and that only one universe exists? And if so, does one cancel out the other?

I'm dizzy and need to sit down

Sir Digby Chicken Caesar

if it is true, then yeah there probably is.. but all that means is that they got their calculations wrong

Myksyk

Quick question ... is it proposed that the infinity of other worlds includes all 'imaginable' worlds? Or do those universes have to obey the laws of physics (I understand these may differ from universe to universe)? I guess I'm asking does infinity have to include everything imaginable or can it still be circumscribed in someway ... i.e. infinite in one or more directions but not ALL directions?!!

This would mean, perhaps, that within certain infinities, there is still no room for a world, for example, where oompa loompas walk upside down on chocolate clouds while vermicious Knids paint the sky polka dot blue with the innards of willy wonka?

Dades

Myksyk wrote:

This would mean, perhaps, that within certain infinities, there is still no room for a world, for example, where oompa loompas walk upside down on chocolate clouds while vermicious Knids paint the sky polka dot blue with the innards of willy wonka?

Only marginally more preposterous than some of the stuff we're told happened in this universe, I would think.

Fallen Seraph

As is my understanding: the answer is no.

This theory only proposes that any time that anything could go one way or another on a quantum level that it goes both ways. Which means that the fundamental laws of phyics are still the same.

If the laws of physics permit oompa loompas too walk upside down on chocolate clouds while vermicious Knids paint the sky polka dot blue with the innards of willy wonka, then this would happen. But it wouldn't if it couldn't. Simply.

The same with humanji's proposed paradox. If it can't be proven in this universe it can't be proven in any other.

But I'm not convinced that this means quite what everyone is touting it as. Is anyone in a position to elaborate on what effect the collapsing of a quantum state has on your average decision making process? I'd be surprised if anyone knew. And if I were to have a guess at it I'd say that our cognitive processes behave classically, which leaves me rather unconvinced that even if the theory is true that I'm both sitting here discussing quantum physics in this universe and actually working, like I should be, in another.

Zillah

Depeche_Mode wrote:

Similarly with Schrodinger's Cat paradox, whereby two universes will exist in parallel, in one of which the cat is dead and in the other it is alive.

Not quite. The Schrodinger's Cat experiment is a demonstration of an uncollapsed quantum state. Once it collapses we get two universes from it, one with a dead cat, one with a not dead cat. But that happens at the end and is not the purpose of the experiment.

Scofflaw

Zillah wrote:

Not quite. The Schrodinger's Cat experiment is a demonstration of an uncollapsed quantum state. Once it collapses we get two universes from it, one with a dead cat, one with a not dead cat. But that happens at the end and is not the purpose of the experiment.

The idea that new universes might be an accidental byproduct of physics experiments is not one that would sit well with Creationists.

cordially,
Scofflaw

pH

Myksyk wrote:

This would mean, perhaps, that within certain infinities, there is still no room for a world, for example, where oompa loompas walk upside down on chocolate clouds while vermicious Knids paint the sky polka dot blue with the innards of willy wonka?

Now that's exactly the kind of universe I'd like to live in ...

Zillah wrote:

Not quite. The Schrodinger's Cat experiment is a demonstration of an uncollapsed quantum state. Once it collapses we get two universes from it, one with a dead cat, one with a not dead cat.

... but with my luck I know I'd end up in the universe with the dead cat.

Dades

pH wrote:

... but with my luck I know I'd end up in the universe with the dead cat.

And better off for it, I say.

Zillah

pH wrote:

... but with my luck I know I'd end up in the universe with the dead cat.

You could eat it. Right now there is a pH somewhere starving to death in a post apocalyptic earth just wishing he could have even a dead cat to eat.

Oh, and somewhere, somehow, there's a pH who's monitor explodes in his face the instant he stops reading this post.

I love this game. BAM!