50 Years of the Multiverse Interpretation 198
chinmay7 writes "There is an excellent selection of articles (and quite a few related scientific papers) in a special edition of Nature magazine on interpretations of the multiverse theory. 'Fifty years ago this month Hugh Everett III published his paper proposing a "relative-state formulation of quantum mechanics" — the idea subsequently described as the 'many worlds' or 'multiverse' interpretation. Its impact on science and culture continues. In celebration, a science fiction special edition of Nature on 5 July 2007 explores the symbiosis of science and sf, as exemplified by Everett's hypothesis, its birth, evolution, champions and opponents, in biology, physics, literature and beyond.'
So in another universe of the multiverse... (Score:2, Funny)
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Who wants to loan me their account at Nature so I can log in?
Re:So in another universe of the multiverse... (Score:5, Funny)
Try one username/password combination at random. At least one of your instances will get in.
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Can I now borrow your username and password for that universe?
Re:So in another universe of the multiverse... (Score:5, Funny)
I am embarrassed to say.. (Score:2)
Nothing for you to see here. Please move along. (Score:3, Funny)
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SF (Score:3, Funny)
Wait, no, that's not why. It's because they're the same thing.
Oh, great! (Score:4, Insightful)
Just what we need; the knowledge that there are an infinite amount of dupe posts in the multi-verse.
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Funny thing is, in the almost-this other universe everyone who parties on a Friday night is a geek loser, and social people all post on Slashdot every day.
Now the only thing you gotta do, is devise a machine that lets you two swap the universes.
MWI is cool and all.... (Score:3, Interesting)
Quantum mechanics does weird stuff when you measure it (probability field of position/velocity).
When something is measured, it collapses it... What causes the collapse?
Perhaps consciousness?
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Greg Egan wrote a book [wikipedia.org] on that topic. Aliens were relying on non-collapsed wave functions as a part of their normal life. New instruments like the Hubble Telescope were causing mass genocide in the observable universe, which got some aliens pretty pissed off.
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The premise of encasing the solar system reminds me of a book I read where earth was encased for, IIRC, a similar reason. I just googled around until I found it. It's Spin [wikipedia.org] by Robert Charles Wilson.
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As a physicist, Gr
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There is no good reason to believe that such a thing exists.
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Re:MWI is cool and all.... (Score:4, Interesting)
Going beyond the semantic issue, the GP seemed to be implying that consciousness is something special, some unknown part of nature.
However, suppose that you ask a person if they are sane. Should you believe their answer? The only means you have to evaluate the experience of your own consciousness is your own consciousness itself. If your consciousness wasn't some supernatural thing but instead was a little program in your brain to fool you into protecting your existence above all else by creating the illusion of being something special and supernatural, you wouldn't be able to tell the difference.
Now consider everything that we know about reality. Does the universe work more like a precise machine or more like some transcendental mystical metaphysical drug hallucination? Consider everything we know about the mechanics of the brain. It is organized a lot like and its components are a lot like a computer. Is this a description of a ghost trap or of a computational device?
The Earth sure does look flat, though, doesn't it?
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Fry: You're a bender, right? We can get outta here if you just bend the bars!
Bender: Dream on, skin tube. I'm only programmed to bend for constructive purposes. What do I look like, a de-bender?
Fry: Who cares what you're programmed for! If someone programmed you to jump off a bridge, would you do it?
Bender: I'll have to check my program. (short pause) Yep.
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Well, good for you. Of course, your explanation above is the exact equivalent of someone telling me that they believe in God and thumping "the good book", or that they believe in magic. You may belie
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No, it isn't. Much of philosophy is every bit as rigorous as hard science (though, I will admit, some is not); they (we, actually) are just working with different axioms and different data sets. My personal work revolves around uniting the three perspectives (computation, physics, and metaphysics) through a zero-player game model, much like cellular automata systems. Folks like Wolfram, et. al. give us a bad name. Popper's three-worlds hypothesis or Whitehead's Process and Reality might give you a taste o
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Even if you do come up with a thoroughly rigorous and internally consistent philosophy of things beyond observable reality, what of it? There is no way to know if it's right, because it can't be tested. There are conceptually an infinite number of such philosophies, so the probability of any one of them being the correct descri
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I was using the term in an informal sense.
"Reality is that which, when you stop believing in it, doesn't go away."
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I can't be bothered typing out my bookself but I found you don't have to be god to proclaim "I am".
BTW: I liked your old sig better.
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However, even a computer has this thing called software, an immaterial product of mind. No matter how minutely you examine the physical hardware of a computer, you learn little or nothing about its software until you turn it on.
Jesus in particular and the Bible in general mentions the existence of another dimension, that of the spirit. It is in effect another universe, where different rules apply. He called that universe "
The bible (Score:2)
Biblical mysticism first requires that a person believes in the supernatural. This in itself is an unf
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I never did and the Bible doesn't either. Both science and the Bible give hints that there are other dimensions. You did not read the last sentence of what I wrote before. Of course you can believe or not, but that is all. Nothing can be proven.
(...Want to prove that Jesus rose from the dead?.....)
I do believe that he did, based on the testimony of multiple witnesses. We humans tend to declare that which we do not understand as "mystical" or "su
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With enough effort, you could determine patterns, but not necessarily the meaning or message of these. For centuries, scholars could discern the patterns engraved in the ancient stones of Egyptian monuments, but the meaning of these had been lost until the "Rosetta Stone" was found and used in 1822, somewhat like a cryptographic key to make sense of the ancient inscriptions. Because we know the ASCII code, we have
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That being said, I don't buy that consciousness is required for a collapse in
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However, you are a faulty witness to your own consciousness. Like Bender [slashdot.org], you may simply be unable to escape from your own programming.
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For that sentence to have any meaning whatsoever there has to be a "witness" in the first place, meaning consciousness. Whether it all actually comes down to programming or not is completely irrelevant. No matter how you slice it, that the tiny subset of nature that is us is able to comprehend nature itself is pretty remarkable.
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At this stage, we get bogged down in semantics.
Irrelevant or not, this is the subject at issue in the entire thread. Most people seem to believe that their consciousness demonstrates that they are special and have a supernatural soul that will have an afterlife. However, there's no good reason to believe t
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The only semantics involved is the definition of "consciousness." And if you're going to claim that a thing does not exist, it's kind of important to pin down what people mean by that thing in the first place. "Consciousness" is most commonly thought of as awareness, especially of one's own existence but also of one's surroundings. I don't think it's too big of a leap to consider this awareness to be equivalent to the self.
Most people seem to believe tha
Re:MWI is cool and all.... (Score:5, Informative)
Re:MWI is cool and all.... (Score:5, Funny)
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But I'd like to know what consists a measurement.
Generally at the quantum level, a measurement or observation is when you bounce a particle (usually a photon) off another particle.
It's similar to how you see things. Light bounces off of a thing, and that light bouncing into your eye is how to observe and measure things. Just lower the scale to a single photon of light (or even a smaller particle) and youre set.
The reason you can't measure all the details of a particle at this level is because when the photon you bounce off it actually hits the particle
Re:MWI is cool and all.... (Score:4, Informative)
The reason you can't measure all the details of a particle at the same time is NOT because photons bounce off of it and disturb it. The reason you can't measure all of the details of a particle at the same time is because that is JUST THE WAY IT IS. It has nothing to do with interference from other particles. There is no "reason" for it. No one knows why it works that way. It's called "complementarity", and it's the fundamental quantum mystery.
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The thing he didn't elaborate on was that until that physical interaction (and after it), the particle exists like a wave. It has everything to do with interference
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I'm not a physicist but at least from what I've read that's a rather common misconception.
It is the act of measurement itself, not the interaction of the particles that causes changes we see in the particles. The collapse of a wave function is different from anything that we have in the macroscopic universe, it simply does not happen in every day life to an extent that we can view it.
Quantum mechanics/physics/theory doesn't work like normal life.
Analogies don't work properly when you try to explain Q
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Rather, all the *possible* outcomes of a quantum measurement do happen: each one in a different universe.
When you measure one particular outcome, that means that you are in the particular universe where you measure that outcome: by definition.
A measurement consists in an event that translates "quantum information" into "classical information": quantum information is very complex
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Re:MWI is cool and all.... (Score:5, Informative)
No in the MWI the wavefunction does NOT collpse. This is the whole point of the MWI, in the Copenhagen interpretation the wave function collapses on a measurement to a single state. In the MWI a measurement splits the world into two different states there is no collpse of the wavefunction.
The Copenhagen interpretation abolishes physical reality and brings in the idealist concept of a conscious observer collapsing the wavefunction. The MWI restores physical reality in quantum mechanics.
Let's take the Schrodinger cat thought experiment: <cat alive|cat dead>
This gives rise to the density matrix:
cat alive ...................... cat alive + cat dead
cat alive - cat dead ..... cat dead
The CI supporters would say the MWI didn't explain why we don't see the off diagonal mixed states. But the modern approach to the measurement problems in MWI uses the concept of decoherence which is the interaction of the isolated quantum states with the macro environment. It has been shown that the mixed states are destroyed by interference when decoherence from interaction with the environment occurs. Thus in this experiment the world is split into two, one where the cat is alive and one where it is dead.
The decoherence approach in conjunction with the MWI abolishes the necessity of observers and restores the independent physical reality abolished the the CI. The proliferation of many worlds is the price we have to pay for physical reality and the unitary evolution of the wavefunction.
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The Copenhagen Interpretation puts a magical significance on "measurement" that boggles the mind. It' not just photons interacting with the system, it's those photons being perceived by a mind. What's special about minds? Sssshhhh, don't ask that question.
This insistence upon putting the mind (particularly the human mind) at the center of the quantum universe reminds me of the insistence of the Medieval Church upon putting the Earth at the center of the Universe. I'm p
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There is no such thing as "wavefunction collapse".
Apart from the second law of thermodynamics (which, it would be fair to say, we don't really understand), all of the laws of physics are time-symmetric. In quantum theory, causality works backwards in time just as well as it does forwards, and that includes interactions that leak quantum information.
consciousness?? (Score:2)
The collapse of the wavefunction is caused by interaction with other particles. After the interaction, the particle has a new modified wavefunction.
*Interpretation* (Score:3, Informative)
I like SF as much as probably most people here, but I can't see the scientific significance.
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The many-worlds hypothesis does have some serious problems, such as how a universe with probability p and one with probability -p cancel each other out. (The branching would have to happen "after" the cancellation.)
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So, being 'inside' the universe and taking its measurements from the inside only gets us so far. Beyond that, we have theories about the nature of the universe, but they can't be shown to be true or untrue. There are theories that are certainly untrue, but there are al
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No faster-than-light travel, causality, single-valued universe. Pick any two. That'll give you your preferred QM interpretation. (Hint: FTL = CI, backward causality = TI [wikipedia.org], more or less, and multi
Mirror, Mirror (Score:5, Funny)
Personal experience of the Multiverse (Score:3, Interesting)
I've observed many times that I "should have" died. It struck me that, perhaps, I did die in an alternate universe, but I (whatever I "is") continue on in at least one of the multiverses. In those multiverses in which "I" experience the death of a close friend or family member... well... that just is how it goes. But they, too, continue in an instance of the multiverse. Perhaps I do not.
Anyway... "They're coming to take me away, ha ah..."
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I had to look closely to see if you had used the letter J [wikipedia.org]
Re:Personal experience of the Multiverse (Score:5, Interesting)
Luckily he made it out alive. But he suffered severe PTSD for a few years afterwards. He would just be walking to the grocery store and be suddenly struck with the terrifying reality that he wasn't walking to the store at all -- this was the final hallucination of his mind moments before he perished in the apartment fire. Instead of his past flashing before his eyes, this was his mind's final, desperate attempt to comfort itself, by creating a reality where he lived out the rest of his life.
I try not to think about it because it's creepy. If I really start to think about it I get terrified.
Wanna hear something really disturbing? (Score:2)
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In fact, the ONLY lessons to be learned from your story are
1) Check your smoke detector batteries, dumbass!
2) Get a cat.
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1) Check your smoke detector batteries, dumbass!
2) Get a cat.
So... What if in universe B you didn't check the batteries because you flipped a coin that came up heads... Or got a dog instead of a cat because you killed the original cat in some sort of weird science experiment.
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Not really, but does consciousness require comprehension? Most likely not since an amoeba probably has some type of consciousness and the fore counts as an observer.
Heck... A video camera probably counts an observer unless of course until a conscious being looks at the tape and only then does the waveform collapse.
But the point I was trying to ma
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Re:Personal experience of the Multiverse (Score:4, Interesting)
Note that this is not a very exciting kind of immortality. Especially since a goodly number of worldlines coming from here will produce computronium [wikipedia.org]. At least some of which will simulate you, yes you personally for an unspeakable amount of subjective time (possibly infinite if even one non-zero probability path leads to that outcome), during which you will in some cases experience what can only be described as "as close to a literal heaven as you can get", and in other cases "as close to a literal hell as you can get", and the full range of things in between. If Quantum immortality is "true", there are things worse than death, and we will more or less all get to experience them on some worldline.
Note further that it is not meaningful to wish that "you" will end up in one of the good cases; if QI is true, all cases lie in your future equally. "You" will end up in the good and the bad and the inbetween, all at once. Perhaps some people consider this a form of escapism, but it is also fairly horrifying if you follow the implications out beyond "In some very real sense, I can not experience death."
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Life is suffering. If the mutliverse is true, then absolute hell really does exist in one instance of a Universe. If QI is true, is there ever really a way to escape 'reality'? Does everyone experience every form of existence for eternity? or instead do some of us go into loops of existence, and never escape the loop? Can we direct our path to a desirable loop?
Some forms of Buddhism teach something very similar to QI, except that Nirvana is the end of all suf
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Your willpower and intent allow you to chart your own course through reality. Hell is a very small and abstract concept, a creation of this world.
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People do not exist without intent or will power. You can choose what to experience.
-FL
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Sure most of the other Yous who decided not to do such a stupid thing live merrily on in their Many Worlds, but the Yous who decided to Quantum Suicide might find out the hard way that "the wrong turn ends here".
Why should MWI mean that ALL chosen paths will avoid 100% Darkness? To me that's like saying the two slit experiment doesn't have destructive interference.
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Probably the most interesting practical question is what percentage of futures include all our lost family members and f
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Talk about nitpicking critiques, dude. ("Dude", because I've never met a chick with such a need to strain gnats.)
"Should have died" => colloquialism for "surviving a situation in which I had a high chance of dying." Does that make you feel superior, now?
As to the charge that I was espousing philosophy... you are incredibly dense. I said, explicitly, that I was referring to "personal experience" regarding what I subjectively "observed." I made no philosophical or
Shoot (Score:2)
Anyone who knows if they'll be selling this one in other universes?
Old (Score:5, Informative)
It would be nice if scientists, when talking to non-scientists, drafted lively images like this one. IMHO, it would go a long way in bridging the gap between them and "normal" people, who don't think in terms of numbers and mathematical concepts.
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English is a very good language for describing a lot of things; but math is also a language, and sometimes (in the sciences, often) it's a much better one for describing certain things. You can often write the mathematical terms out rather than using symbols, of course, but honestly, when you're dealing with inherently mathematical subjects such as physics, that's as close as you can come without losing a lot of informatio
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Shiva, which together with Vishnu and Brahma form the (main) Hinduist Trinity, the Trimurti, wears around his neck an infinitely long necklace with an infinite number of beads. Each bead is a full universe, ours being just one among them, and Earth with us just an infinitesimal aspect of that single bead.
It would be nice if scientists, when talking to non-scientists, drafted lively images like this one.
So, you are saying that science should invent religion in order to explain the world?
What an original idea!
Late to the party, but... (Score:2)
All of them?
Take me to the parallel universe... (Score:2)
Noein (Score:2)
Wow, an entire thread on the multiverse hypothesis, and no one's mentioned Noein [anidb.info] yet? By far one of the best anime programs of the past couple of years, Noein depicts a conflict between alternative universes that comes to involve a group of middle-school kids in Japan. The producers actually try to explain some of the science involved, including a cute scene with Schrodinger's cat. One of the most experimental animes I've ever watched, and I've watched quite a few. The style of animation is rather unusu
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Isn't being a physicist enough of a punishment in itself?
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Re:50 year of an untestable hypothesis (Score:4, Insightful)
Sorry, your computer now refuses to work because it no longer obeys quantum mechanics. The electrons are just stuck at the N-P junctions and nothing happens because they're all in a fully defined position with no way of jumping across it at the energy levels they have. Bump the energy up, and they behave classically and just burn their way through without any of the nice semiconductor properties that make computation with them possible.
On the upside, now you'll have a lot more time to tar and feather the quacks who made your nonfunctional computer!
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Big red button x 6000000000 (Score:2)
But lets assume for argument sake that nobody does. People will quickly learn that nobody will push their button, and nobody will seriously care that others have them. We will be in much the same place we are right now.
That's the problem with the current (and former) arms race. We weren't willing to "push the button" (meaning nuke Russia), and Russia wasn't either. Both countries were reduced to non-nuclear m
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I think the point was that there will be -some- universe where nobody pushes the button---we can ignore the dead non-utopians who did.
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Even so, the middle of my post stands. We all would simply come to accept that nobody will push the button. Life would otherwise continue almost completely uninterrupted. It would not end war, or crime, or poverty, etc.
And if we were each to hit the button when we saw something un-Utopian, then it would only truly drive the possibility to zero. (I'm postulating that some things are deterministi
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There's really no way to drive the probability to zero. In the worst case, the nukes just fail to kill everyone and they survive in a ruined world. In the best case, they just fail to work at all. I suppose it's a matter of degree; the closer society approached to utopia, the mo
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Could be you'd be alive in the Many Worlds where you/others didn't do/start something stupid, but you = dead when you/others did - no way out even in the infinite MWI possibilities from there.
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Nope. You sound very sane.
I rather like Buddhism, but I have found that there is no need to label one's belief as 'Buddhist', or anything else for that matter. The operating system of the universe does not care what you call it or who has labeled it in the past. There are elements of Buddhist thinking which don't ring true for me, so who needs 'em? Others make a lot of sense. --And there are ideas from other practices which also make a lot of sense. And since they