Talk:Quantum collapse

At what percent of scientific disagreement is a view not a fringe belief? The wiki seems to generally agree 3% of clmiate scientists doesn't make AGW-denial a legitimate scientific view. Other more popular beliefs like Many Worlds clearly aren't fringe. What percentage is the dividing line at? Does it matter if the scientists are provably wrong? In any case, I've not changed the stance of the article that Consciousness Causes Collapse is in general unscientific, as the support amongst the experts is still rather low. 68.231.187.183 (talk) 18:02, 16 January 2015 (UTC)

In this case it's not just that support is "rather low," so much that it's provably false. Measurement doesn't require a conscious observer in order to happen. - Grant (talk) 18:13, 16 January 2015 (UTC)

Almost all scientists use 95% confidence interval as being mostly good enough, and science like that has gotten humans on the moon and robots on comets, so I'd say that something is fringe if it has less than 5% support within the relevant scientific community. Fuzzy "Cat" Potato, Jr. (talk/stalk) 19:41, 16 January 2015 (UTC)

Sorry, what? That's not really how things work when it comes to actual published papers. Hypotheses and theories stand or fall on their merits alone, not on their popularity. There is no dividing line for where a hypothesis becomes "fringe" beyond one basic tenet: does it fit the evidence and observations we have, or does it not? - Grant (talk) 19:44, 16 January 2015 (UTC)

I think you misunderstand "fringe" versus "wrong". Something can be fringe and still be right -- Galileo or Newton or Plate tectonics or General relativity for example. Right merely means that it fits observations. Fringe merely means that few people accept it as true. Fuzzy "Cat" Potato, Jr. (talk/stalk) 20:55, 16 January 2015 (UTC)

Not in the context that the BoN is using and in its most common usage here in RW. "Fringe" also has different (and usually negative) connotations in science, as a quick look-over of the "Fringe science" article on Wikipedia will show. - Grant (talk) 21:02, 16 January 2015 (UTC)

I think you may be misinterpreting the many-worlds interpretation?

Admittedly I'm very not sure, thus comment spam.

But it seems to me that the section's author understood the MWI's shtick as mainly a semantical difference from Copenhagen one. Because, indeed, replacing the concept of ad-hoc wavefunction reduction with a functionally equivalent concept of ad-hoc world-splitting is not very sensible, especially since the latter also makes unprovable predictions about some parallel realities. But the main selling point here is actually that "world-splitting" process can be easily represented by quantum entanglement, which is a pretty established concept by now. Thus, as I understand it, we still have a single universe, but one that actually exists in a superposition of every possible reality. They can be regarded as separate 'worlds' only because there're no means of interaction 'between' them.

So, MWI is a bit cuter, at least to me, because (a) it uses existing mechanism to explain the collapse phenomenon, and (b) the universe ends up deterministic, even though there's no practical way to utilise it. Without noting this it indeed seems redundant, cranky even. But I haven't ever got around to verify & clarify my understanding of this whole business, so it's just my semi-uneducated opinion which I won't bet on. So I'm just gonna dump it here and maybe someone'll bother to get to the bottom of this? --95.220.200.193 (talk) 12:11, 29 January 2015 (UTC)

I'm not sure the article really interprets it as a semantic difference, so to speak. I'm also not sure where the article suggests that it's cranky; rather, the article seems to point out that the MWI is used a fair bit in sci-fi and can be used to justify some cranky things.

Interpretations of quantum mechanics are not provable or testable in general, which of course is why they're referred to as interpretations. Whether MWI is cuter is more or less a matter of opinion. While you're right that things become local and deterministic, certain things also don't make much sense under MWI (e.g. we can't assume the Born rule any longer, and efforts to derive it have met with mixed success). Suffice it to say that while I'm not a fan of the Copenhagen interpretation, I'm also not a huge fan of the MWI. :P

Anyways, if you could explain a bit more as to where you see the problem and what you would like added/changed to fix it, we can talk about that. I'm just not 100% sure what you think the misinterpretation is. - Grant (talk) 16:02, 29 January 2015 (UTC)

Yeah, MWI does indeed have some issues if you try to dig deeper. They all do, I guess, since (as I get it) they're more or less just conceptual approximations of lovecraftian microcosm and are bound to diverge after some threshold. Still, CI sparked weak measurements, and MWI has, say, some nice solutions for the grandfather paradox. I used to favor MWI with zeal, but it's probably no better than restrict oneself to a single programming language. They're all just tools!

But what troubled me is that the plus sides of the interpretation are left unexplained. It actually reminded me of a schooldays argument wherein I tried to convert some guy to one true many-world faith: I've pointed how observation is ill-defined and how much better is to replace it with much clearer multiverse split. Dude logically retorted that we then have to define the split conditions in much the same way; unfortunately, I've completely forgot why it isn't the case and was left stupefied. Because, indeed, without noting that entanglement happens all the time and does not depend on observation it is entirely unclear why to bother with this at all!

And I didn't really mean that the article itself implied MWI being cranky, it's just the conclusion I would make. Especially if:

"By replacing the concept of a collapse to a single state with a split in the universe, it only replaces one mystery with another."

Indeed, while we're at it, why not to explain it with divine interference instead? That's even more understandable, and we have our proof of God right here! Or of anything else I fancy. Like aliens from another dimension.

Basically, I'd read this here MWI description as of some vague pseudoscience that serves no useful purpose except for asserting the existence of parallel worlds. Of course, YMMV, but it certainly doesn't mention why would anyone use it? I think this is somewhat deluding. --95.220.200.193 (talk) 18:47, 29 January 2015 (UTC)

Avoiding the problem of quantum collapse is the reason it would be used. Even the deterministic and local nature of the MWI stem from the removal of quantum collapse. MWI really does simply replace one set of problems (the non-deterministic and non-local nature of quantum collapse) with another (among other things, the need to derive the Born rule), so I'm not sure why that sentence stands out. As for the grandfather paradox, I don't believe speculative musings like that should be present in a scientific article. Given that time travel as a possibility is purely speculative as is (and the MWI wouldn't change that), why mention the grandfather paradox at all? MWI can't solve problems that don't exist. - Grant (talk) 19:14, 29 January 2015 (UTC)