- #36
yuiop
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DevilsAvocado said:... or do I need the salvation of higher powers to make it work ...?
This "salvation of higher powers" sounds like it might come in handy. Where can I download that? I think I might need it.
DevilsAvocado said:... or do I need the salvation of higher powers to make it work ...?
DevilsAvocado said:Sure, if you just give me a link to that silly little time machine of yours, I'll install it right away.
yuiop said:This "salvation of higher powers" sounds like it might come in handy. Where can I download that? I think I might need it.
A. Neumaier said:I can't do this for license reasons; I only have a confidential alpha version (and, understandably, it is still full of bugs).
I suggest you simply wait...
yuiop said:If each time Bob tosses a coin the universe splits into two universes, one where Bob got a head and one where he got a tail, then after 100 coin tosses there will be 2^(100) = 1.267E30 new universes. MWI is not very economical on resources. :smile.
Bell's proof demonstrated mathematically that it is impossible for any theory with properties that correspond to what physicists mean by "local realist" to replicate the predictions of QM (the properties are defined more precisely in the proof, but basically any theory where your description of the world can be broken down into a set of local facts, and the local facts at any given point in spacetime depend only on other facts in the past light cone of that point).thenewmans said:At a philosophical level, I understand that QM must break some classic principal we hold dear. But why must local realism be the most common victim? I get the feeling it's a popular whipping boy simply out of some lack of knowledge. It seems to me like an unnecessary assumption.
Similarly, if the universe is infinite in spatial extent, then for any given experiment there are going to be an infinite number of planets where that experiment is performed (including an infinite number where its performed by people who at the moment the experiment started were exact physical duplicates of the experimenter over here), and the law of large numbers says that some small fraction will get anomalous results like 100 tails in a row. Do you think this is a proof that the universe must be finite, and if not, do you think this forces us to "rewrite all laws on probability"?DevilsAvocado said:You should also ask K^2 this question: In MWI, when there’s a 50/50 outcome both always gets 'materialized' in different branches (worlds). Now, if you toss a coin a 100 times you expect to get approx 50 heads & tails, right?
But in one of these MWI branches some poor bastard will always get 100 tails, every time he performs this 'experiment'!
What is K^2’s advice to this guy? Just forget about it?? Or rewrite all laws on probability?? Or just show the "MWI-sign" if anybody ask 'difficult' questions??
JesseM said:Bell's proof demonstrated mathematically that it is impossible for any theory with properties that correspond to what physicists mean by "local realist" to replicate the predictions of QM (the properties are defined more precisely in the proof, but basically any theory where your description of the world can be broken down into a set of local facts, and the local facts at any given point in spacetime depend only on other facts in the past light cone of that point).
yuiop said:MWI is not very economical on resources.
yuiop said:If the experiment is repeated there is a 1/2(100) chance that the Bob that got 100 tails the first time around will get 100 tails the second time around which is (very) far from saying that the same Bob will get 100 tails every time the experiment is carried out.
JesseM said:Similarly, if the universe is infinite in spatial extent, then for any given experiment there are going to be an infinite number of planets where that experiment is performed (including an infinite number where its performed by people who at the moment the experiment started were exact physical duplicates of the experimenter over here), and the law of large numbers says that some small fraction will get anomalous results like 100 tails in a row. Do you think this is a proof that the universe must be finite, and if not, do you think this forces us to "rewrite all laws on probability"?
yuiop said:Well in the context of the OP with both entangled particles, there is a similar problem if both particles are detected *exactly* at the same time. Which particle "gives way"?
yuiop said:Lets say, that one of a pair of entangled particles has some sort of "priority" so that there is a sort of master and slave arrangement
yuiop said:This is not a formal discussion, but since this thread seems to have stalled somewhat, I thought I would put some ideas out there to revitalise discussion.
Please note that I am not in any way suggesting that the "communications" between entangled particles can in any way be used to send information or matter super-luminally and forwards or backwards in time at the macro or human level. That is demonstrably not the case.
[PLAIN said:http://en.wikipedia.org/wiki/No-communication_theorem]No-communication[/PLAIN] [Broken] theorem
In quantum information theory, a no-communication theorem is a result which gives conditions under which instantaneous transfer of information between two observers is impossible. These results can be applied to understand the so-called paradoxes in quantum mechanics such as the EPR paradox or violations of local realism obtained in tests of Bell's theorem. In these experiments, the no-communication theorem shows that failure of local realism does not lead to what could be referred to as "spooky communication at a distance" (in analogy with Einstein's labeling of quantum entanglement as "spooky action at a distance").
I don't really understand the question--what does the spatial extent of the universe have to do with the time of splitting? And I think "splitting" is only an approximate notion, though the question of what it means to talk of different "worlds" in the MWI is one I don't fully understand.DevilsAvocado said:First ('exasperating') question:
How do you split (branch) an infinite universe in finite time?
I dunno, isn't that kind of like asking "why is it always someone else, not me, who wins tens of millions of dollars in lottery jackpots"? Obviously it could be you, but the fact that tens of millions of people play and only one or two win these huge jackpots seems to make it "natural" to expect you're probably not going to be the winner. Perhaps you could think of it in terms of the self-sampling assumption, a type of anthropic reasoning which says if there are a large number of observers in some class you also belong to, you should reason as if your place had been "randomly selected" from the set of all observers--for example, if I am part of an experiment where I know 100 subjects were given a certain medication while 50 subjects were given a placebo, but I don't know which group I'm in, I should assume there is double the chance that I was given the medication than the chance I was given the placebo. For more on the logic of the self-sampling assumption, see the website of philosopher Nick Bostrom, anthropic-principle.com.DevilsAvocado said:Second question:
I get that in an infinite universe "strange things" ought to happen "all the time" – like http://en.wikipedia.org/wiki/Boltzmann_brain" [Broken]. I also get that the probability for Bob tossing 100 tails in a row in our "local universe", is extremely small.
Now, there is always gazillions of "tossing" going on in our "local universe" – why do we never see any sign of this weirdness "here"!? I mean, of all the probabilities that’s out there – everyone seems to cluster around the mean value in the probability distribution. Why are the no Boltzmann brains, or Bob-100-tails in our "local universe", or anything else that’s totally nuts? Not one thing??
I don't know that I "believe" it although from what I understand of the different interpretations it seems most elegant and plausible to me. And I don't know if I'd say I "struggle" with EPR-Bell, although I find it interesting...I would say that although the MWI gives me a general idea of how one could explain EPR in a "local" way, I don't understand the issue of the derivation of probabilities and the "splitting" of different "worlds" well enough to say that the MWI in its current form gives a definitive solution.DevilsAvocado said:Third question:
If you 'believe' in MWI – why do you struggle with EPR-Bell? Doesn’t MWI remove all 'questions' regarding EPR-Bell?
Yes, I agree that it seems preferable to have a local explanation...I don't know if the assumption that there is only one result for each experimenter counts as "realism", so that the many-worlds interpretation is non-"realist", or if the MWI must be seen as a separate loophole, but I think at least in principle some variant of the MWI could explain the results in a purely local way, see the simple "toy model" I wrote up in [post=1557143]this post[/post].thenewmans said:Yeah, I realize now that I mean just localism. Not both. I guess what I mean is that when the wave collapses (or when the worlds divide), if you say something happens instantly over a distance, it sounds to me like you're giving up on SR and localism instead of some other principle like realism or counterfactual definiteness.
thenewmans said:DevilsAvocado, thank you for helping me with this. Where would we all be without DrChinese? I hope he feels the appreciation.
You have said a key phrase for me here. Sometimes I hear myself saying something similar and I feel as if I'm painting myself into a corner. And this is the essence of my original post. It seems to me that your statement implies things like a direction, simultaneity and a preferred inertial frame of reference. From an SR point of view, describing events usually requires selecting an inertial frame of reference. But changing that frame does not change what actually happened. In other words, if someone travels past Alice at 95% C just as Alice measures the photon, does that “something” (wave collapse?) travel FTL from his point of view as well? As I follow this line of reasoning, it only gets worse.
At a philosophical level, I understand that QM must break some classic principal we hold dear. But why must local realism be the most common victim? I get the feeling it's a popular whipping boy simply out of some lack of knowledge. It seems to me like an unnecessary assumption.
recurveman said:Now this may be derived from my mis guided interpretation of QM and will probably label me the nut-case of the forum, however i also think that there must be something happening that is faster then light. But i don't think that its a signal or anything else that is traveling in a straight line connecting the two entangled parts. We have observed that electrons have the ability to (in layman's terms) blink in and out and "disappear". We see the world as three dimensions but what if there really was a 4th (or 11 if you buy into that theory as well) and the electrons were disappearing out of our 3 dimensional sight and bypassing space time to make the change. I always think of it like seeing two particles on a piece of paper. One on the top of the paper and the other on the bottom. The fastest way to connect the two particles is not to make a straight line between them but to fold the paper in half so that they are touching. ( does this make me crazy??)
recurveman said:So basically what i am getting out of this is that I AM in fact crazy like everyone else who buys into this QM stuff but am only one of the few that are just crazy enough to actually write down our preposterous ideas?
Special relativity is a theory proposed by Albert Einstein in 1905 that explains the relationship between space and time. It states that the laws of physics are the same for all observers in uniform motion, and the speed of light is constant in all inertial frames of reference.
Special relativity is the foundation of quantum mechanics, which is the theory that describes the behavior of particles at the subatomic level. Entanglement is a phenomenon in quantum mechanics where two particles become connected in such a way that the state of one particle affects the state of the other, regardless of the distance between them. Special relativity helps explain how this instantaneous connection between particles is possible.
Entanglement is a phenomenon in quantum mechanics where two particles become connected in such a way that the state of one particle affects the state of the other, regardless of the distance between them. This means that measuring the state of one particle instantly determines the state of the other particle, even if they are separated by vast distances.
Entanglement has potential applications in quantum computing, cryptography, and communication. In quantum computing, entanglement allows for multiple calculations to be performed simultaneously, making it much faster than classical computing. In cryptography, entanglement can be used for secure communication as any attempt to eavesdrop on the communication would be immediately detected. And in communication, entanglement can be used to transmit information instantly over long distances.
Yes, entanglement is a real phenomenon that has been observed and tested in numerous experiments. It is a fundamental aspect of quantum mechanics and has been confirmed by various experiments, including the famous Bell's Theorem. While it may seem strange and counterintuitive, entanglement is a well-established concept in physics.