How Many Worlds?

No idea why whoever downvoted you did so, but here’s why I think I felt your comment was not useful to me, or much less useful of what it could have been if you happen to know what you’re talking about (I don’t so I can’t tell):

Your statement states a fact without any explanation, examples or pointers to such. If you had said something like “When you mix regions of stability and chaos, things never settle down into discrete zones... it’s all smeared out all over the place.” — then the effect of reading it would pretty much have been the same unless I already knew about the subject enough not to need your comment.

Imagine someone not having any education in astronomy saying something like “I thought the sun and stars turn around the Earth”, and you commenting “Actually, the Earth spins around itself, and it turns around the sun, while the other stars pretty much go every which way.” Unless the first person knew you were a good astronomer, they don’t really learn anything. And even if they did believe you knew you to be an expert on what you were talking about, they might learn it as a rote fact, but won’t really understand much.

The part where you say "it is absurd to suppose" when it isn't made clear in plain English what it is that is absurd. However I mostly included the statement about derogatory comments in reference to your other comments.

Perhaps a better term than "technical jargon" would be "convoluted grammar." I pointed out specific examples of phrasing I found unpleasant to read in my original reply.

Also someone else may have pointed this out but the general policy on lesswrong is not to vote on agree/disagree but on this comment was worth reading/was not worth reading. Saying you are not interested in upvotes is essentially saying you are not interested in contributing to the community. If you don't want to explain yourself in a friendly and accessible way then you have no obligation to, but I think you will be the one who misses out.

You obviously aren't familiar with the concept

Are you being obtuse to justify your down-vote or something? This is ridiculous.

I'm not sure how you'd pose this question seriously.

Then you obviously aren't familiar with MWI.

For your information, I am familiar with both concepts, I pose all my questions seriously and I don't need to justify my downvotes. I also consider your debating style condescending and generally hostile. This prevents me from continuing in this debate.

I have no clear idea what a probability of event happening in the Omniverse means.

You obviously aren't familiar with the concept (for which I cannot be held accountable). In any event, I'll explain it briefly: the omniverse is that state of affairs in which all possibilities are realized. Hence, that any event should obtain therein is an absolute certainty.

The word 'omniverse' does not represent a recognized concept in mainstream physics. You give a definition for it and implicitly imply in your root comment that MWI implies the existence of an omniverse,

Consider that on the scale of the Omniverse [...],

but provide no justification for this.

What is "long run"? Does it mean "in other universes" (that would make sense, but the choice of words "long run" to denote that seems bizarre) or does it mean "sometimes later in this universe" (that would be the natural interpretation of "long run", but then the statement says "p(the event happens) = 0 and the event can happen", which is a contradiction).

This is the standard understanding of what objective probability teaches: given any universe you please, a given probability of an event is supposed to hold for a particular situation in the case that one were to observe all cases (for all time). Thus, the "long run" considers a particular situation for all time. If you flip a coin, you will not observe an outcome of 50% heads and 50% tails, but were you to flip this coin for eternity, the net result is just such an outcome.

You are either using different definitions of "long run" or making contradictory statements across your comments. Here you state that this specific outcome will obtain in the long run, but in your root comment you argued that any alternative outcome can obtain in the long run:

[E]ven if the probability for an event in our universe were 0 that would in no way serve as an impediment to its occurring in the long run.

And of all that, how does anything imply, or even relate to, the "uncountably many" answer you gave at the beginning?

I'm not sure how you'd pose this question seriously. For one, the MWI and nature of QM decoherence shows a state of information as unrelated instances of a general state of things (in a coherent superposition). That there are uncountably many universes (as inhabited by any observer you please) in which the cat is alive, and so too for the cat being dead. The "cat" could even be an infinite variety of other objects, for all we damn well know.

You use the phrase "uncountably many" without providing justification. I can substitute this phrase with "countably infinitely many" and the structure and strength of your arguments would not be changed. Provide justification for why the cardinality of the natural numbers is not enough. (This was Prase's point in eir reply to your root comment, which you did not address.)

I even don't understand what do you mean by "taking the universe as a QM event".

Then you obviously aren't familiar with MWI. Even Penrose and Hawking agree that QM applied to the universe implies MWI.

This response is not constructive. Provide references. Also, you changed context from

taking the universe as a QM event

to

QM applied to the universe,

without clarifying what you meant by the first phrase, which I cannot parse in a way that makes sense.

From the single sentence the OP consists of, could you quote the section where it very clearly asks for non-standard instances of the (which?) question?

Are you being obtuse to justify your down-vote or something? This is ridiculous. Now I have to justify my answer to the OP to you? Absurd. But I'll play along, quoting OP:

...what about non-50/50 scenarios...

I think that the universe is a "non-50/50 scenario", but I guess you can make the case it isn't.

First, your tone unnecessarily escalates the hostility in this comment thread. Second, a binary quantum event in which the final quantum states have unequal probabilities is standard. It is the opposite, where the probabilities are equal, which requires specific preparations, because we would need to make sure that the square of the modulus of the probability amplitude of both states are equal.

The sensitivity is merely a measure of my newness to LW.

Don't sweat it. I don't think much of this nonsense "karma" thing. It's a total joke but makes sense only for those who regard the "wisdom" of the mass as somehow reflective of a post's quality. A post should be judged according to its merits, not the "points" accorded to it by (anonymous) persons who can't provide a justification for their vote.

Except things like quantum computers. It's almost like those worlds do exist and that we can even use their transistors to parallel process stuff.

Well that is definitely a fun thing to say. It doesn't seem to be consistent with what is currently thought about quantum computers and Many Worlds, though.

Upon returning and rereading... no. Branches in MWI aren't said to have 'split off' until they are mutually decoherent. That renders them unsuitable for quantum computing.

Irrespective of my below comment where i get more empathetic wiht the motivation for MWI, I do want to point out some of the reasons why I think MWI may be a "bridge too far" to solve any problems.

The universe as we know it has proven to be gigantically "conservative" in the sense of having a bunch of conservation laws that it simply never violates. Conservation of mass-energy being among the deepest and most powerful. In this universe, at this epoch, stuff is neither created nor destroyed: it is converted from one kind of stuff into another with strict conservation. Even particle pairs that arise from random vacuum fluctuations all soon "realize" if they are violating conservation of energy and disappear before you can say within the uncertainty principle that they were ever there.

So now we come along, have a subtle issue with wavefunction collapse and what really causes it and what does it all mean, and the solution is: the universe may be strictly conservative, but the multiverse is growing in total mass and energy about as fast as any growth fuction that you can conceive, and THAT is what makes the direction of time so strong?

Yes, of course this COULD wind up being right and being the simplest. I await proposed experimental verifications, without them I can NEVER pick a non-conservative multiverse.

But thanks for making it clearer what some of the things that are gained are.

Yes I see the motivation there. MWI may seem like an OK alternative to wave functions actually changing in the presence of consciousnesses, but not in their absence.

I guess I've never really believed the consciousness was an important part of it. Take for example setting up a two-slit experiment with a slow stream of electrons launched at it and a recording electron detector array beyond the slits. One would have a time series of locations the electrons hit the array which would probabilistically over time build a two-slit diffraction pattern, but in which each electron particle was identified with where on the array it ended up. Suppose you set this up in a room. In one version you send an observer in 3 days later to look at what happened, and you see all those evidences of each electron wavefunction collapse into a position eigenstate on the array detector. In the other version you don't send someone in to the room until 10 years later, at that point the observer sees the historical record of all those wave function collapses. Finally there is a version where you never send someone in to the room.

It has always been my opinion that whatever collapses happened actually happened at the time recorded for each electron wave function hitting the screen. The version of the Copenhagen interpretation used here seems to go with the idea that the entire room including the detector array and the equipment used to record its results exist in a quantum superposition of all the wavefunctions UNTIL the observer finally goes in to the room, at which point they collapse in to a state with all the data stored showing one allowed version of the historical record of electron collapses.

Very intriguing. There is literally no way in this experiment to distinguish between "the wave functions collapsed as the electron hit the detector, that I came along later to see the record of it isn't what caused the collapse" and "all possible histories of that room were swirling around in a quantum superposition until I finally came along and my peaking in the door caused it to collapse on to one possible outcome."

I've never fully understood Bell's theorem and EPR, but I suppose I am stating a version of the same question. How do I design an experiment that distinguishes between that room being in a quantum superposition until I finally get there, and that room being a dry tomb of the records of wave functions that collapsed long ago? Bells theorem, if I am right and it applies here, says you can distinguish and that the room does exist in a quantum superposition until you get there, that there are certain subtle statistics of correlations that are true but not possible in a room which is merely the tomb of old dead wave functions.

I realize as I participate in this discussion that for me, the collapse has been a result of the wave function and the observing EQUIPMENT, not a function of my consciousness. It is possible that Bells theorem test results mean I am just wrong about this, but maybe not and bear with me.

I did work for years on the quantum treatment of one example of "measuring equipment," a linear amplifier for radio waves. The quantum uncertainty in radio waves is manfested as "photon counting noise." You think you have a pure sine wave, but it has some randomnesses due to quantum uncertainty, and a variety of bookkeeping methods for characterizing that uncertainty show it is equivalent to one-photon's worth of noise power in the system even at absolute zero of temperature when all removable noise has been removed. THe linear amplifier, we see, amplifies those fluctuations so at the output of the amplifer those quantum fluctuations are now large, comprised of the energy of a million photons each (for an amplifier with gain one-million) and therefore, essentially, treatable as a classical phenomenon. My interpretation is: the linear amplifier collapsed the original input wavefunction, and turned its quantum noise into solidly instantiated classical noise.

But I have a feeling if I understood EPR and Bells theorem that I would see it is not the amplification that collapses it. Hmmm.