So if 'many worlds' doesn't invoke 'many worlds', why is it called by that name? ('Invoke' meaning 'to cite or appeal to (someone or something) as an authority for an action or in support of an argument.) — Wayfarer

It was called "The Relative State Formulation" by its originator. "Many Worlds" was a catchy name coined by DeWitt. Those working in foundations, seem to prefer "Everett Interpretation", though recently its started to be called Unitary Quantum Mechanics or even simply Quantum Mechanics

As I said, Many Worlds doesn't invoke anything - it is simply quantum mechanics taken as a universal theory.

The quote you provide rightly states that many worlds are an implication of Unitary Quantum Mechanics. It then wrongly states that they are a hypothesis, though that seems more like sloppy use of language.

I had the idea that it was Kepler who discovered the elliptical movement of the planets. — Wayfarer

Kepler invoked ellipses, Newton did not.

Many Worlds does not invoke anything, let alone many worlds.

Your question is like - "What problem does 'elliptical planetary orbits' solve? Why does Newton invoke ellipses?"

Newton never invokes ellipses, they are a consequence of his theory.

MW is notable for its lack of invocations - it does not invoke the Born Rule - it derives it, and it does not invoke wavefunction collapse, or state-vector reduction.

Yet another thing that MW does not invoke is Classical Mechanics, which is required under the Copenhagen Interpretation. Neither does it invoke consciousness to get around "Wigner's Friend" type experiments.

The many worlds interpretation, if taken at all literally (rather than being taken as an instrumental interpretation strictly of the mathematics involved), strikes me as completely ridiculous. — Terrapin Station

The old argument from personal incredulity!

Don't take MW seriously, just take the Schrödinger Equation seriously!

I find the idea of decoherence too at odds with the MWI to take the MWI seriously. — Question

?????!

Decoherence was discovered and developed under Everettian* quantum mechanics!

*While H. D. Zeh - the discoverer of decoherence - was an Everettian, he developed a flavour of Many Worlds known as "Many Minds".

There needs to be empirical evidence backing it up at some point, or else it will always remain an interpretation. If no empirical evidence can ever be given, then it's not scientific, but it's rather metaphysics, akin to saying we're living inside a simulation. — Marchesk

All quantum interference experiments are evidence of Many Worlds.

A particularly fun experiment is the Elitzur-Vaidman bomb tester. All interaction free measurements are evidence of Many Worlds.

The famous Before-Before experiment is evidence of Many Worlds, as are all experiments on entanglement.

The quantum computer was invented to test Many Worlds.

Quantum Cosmology can't be done outside Many Worlds.

Many who work on quantum foundations will disagree with you that MW is an interpretation, as it has fewer axioms than standard QM.

A quasi deterministic universe always seems more appealing; but, why can't we have determinism within a many worlds interpretation. — Question

??????!

I don't know how you failed to notice, but Many Worlds is deterministic. In fact, it is the entire point of it!

Many Worlds, is not just deterministic, it is unitary and local. All dynamics is unitary; the Schrödinger Equation is obeyed by all things at all times.

It was in fact Schrödinger who first discovered the other Worlds, but he was reticent to talk about them, because he knew other people would think he was crazy. It was left to Everett to summon the courage to develop the idea, motivated as he was by the desire to unify QM and general relativity. Everett paid the ultimate scientific price for his discovery.

There has been some progress since Everett. The Born Rule is now dropped as an axiom of QM, Decoherence has been discovered, and the quantum computer has been discovered, all as a result of Everett's idea.

If we go a bit further back in time to 1935, the Bohr-Einstein debate was essentially about the nature of science. Einstein was a realist - he thought scientific theories were about what exists in reality; Bohr was an anti-realist. Out of this debate came Einstein's discovery of Entanglement.

I'm going to chalk-up Entanglement to Everett's side of the argument, because it still is an argument between realists and anti-realists.

If Einstein's theories were written in incomprehensible code, then the books and papers would be forgotten.

DNA contains information that, when instantiate in a suitable environment, causes itself to be replicated.

The weird thing about this, is that information theory is fundamentally counterfactual. If you do not accept that the code could have been otherwise, then information does not exist.

So, what do you think, determinism or information?

I don't know what you mean. The information (though more precisely knowledge) encoded in DNA can be transferred through multiple media and preserved. There has to be something objectively independent of DNA for that to be possible.

That "thing" is the subject of information theory.

I agree that brains do not cause conscious experience. Rather, brains, in particular states, ARE conscious experience. It's not a causal relationship. It's a relationship of identity. — Terrapin Station

Well, it can't be an identity. The information content of DNA is not the DNA. The program that won at Go is not the hardware, the symphony is not the notes on paper.

The limits of science aren't due to the limits of the process itself, but due to the limits of our own senses and ability to reason in a consistent way — Harry Hindu

So, you claim that the method of science does not impose any limits, but rather it is human frailty that does.

Why not employ tools to help us, such as paper, pencils, universities, computers?

Have you figured out how an abstract chess program communicates with the physical world? How about the information contained in DNA, how does that communicate?

So do you suggest you have a better non-fallacious basis that works better? — FLUX23

Yes we do. For details see "The Logic of Scientific Discovery" by Karl Popper.

Let us just assume that Beethoven chose his final version based on whatever criterion he choose. Was he wrong?

So, is Beethoven fooling himself that when he thinks the final version is better than previous versions of his symphonies?

So, you disagree that scientific discovery and artistic creation involve the same process?

This is a particularly interesting talk, given at the Irish Museum of Modern Art. Give it a few minutes and complain when you encounter something objectionable!

What I'm not figuring out is why you'd think that only bees and humans being attracted to flowers would imply anything about whether beauty is objective. — Terrapin Station

Try this:

I'm not sure if I believe in beauty being an innate concept. From an evolutionary standpoint I don't see much value to beauty. — MonfortS26

If you deny that beauty is an objective property, and deny that humans are able to develop a theory of that property, then how do you explain why only bees and humans are attracted to flowers?

So, the abstraction - i.e. the real tiger in reality, is not the same thing as your conception of the abstraction.

Seems obvious, why is that important?

But you said...

abstractions are not something separate from, or additional to, the matter. They are ways of looking at matter. — Andrew M

Now you claim tigers are real?

What's going on?

So, tigers are real, but our concept of them is not part of the physics underlying the operation of tigers?

Is that supposed to mean anything?

So we have abstractions of matter. But the abstractions are not something separate from, or additional to, the matter. They are ways of looking at matter. However it still requires a cognitive process to actually look at and conceptualize matter in that way. — Andrew M

Is what you are claiming that, the autonomous and complex entities, that appear in most of our explanations and indeed in our best theories, are not in fact real?

I'm asking for precision here. If you're referring to future laws of physics, then you should say so. If you are referring to them, how can you know what will be in them? — mcdoodle

Future laws of physics must respect current knowledge and experimental evidence.

Are you aware of Noether's theorem? If you are, how can you doubt that conservation principles will always be respected by the laws of physics?

I'll ask the question again. Do you think that the unification of the Standard Model with General Relativity will render the statement "Everything obeys the laws of physics" false?

Can you imagine the situation where a law of physics is falsified, and the scientist declares that certain particles at a certain time just happened to be NOT obey the laws of physics? Best of luck publishing that paper!

Well, panpyschic material is not more nor less undiscovered than your 'unification of quantum mechanics and general relativity'. They're both speculations. — mcdoodle

That is nothing more than an expression of ignorance. Yeh sure, the Standard Model and fairy-theory are intellectually equivalent.

This is the particular area I'm reading about at the moment in fact - those sciences where a mixture of mental and physical terms are accepted in scientific discourse, like the study of placebo effects — mcdoodle

Placebo effects!!?

Instead of the chess program, pick literally anything.

The chess program obeys the laws of physics as does everything else.

These two statements seem to contradict one another, or to be, at the very least, inconsistent with one another. If states of the world cannot be explained in purely physical terms then what warrant do you have for saying they obey the laws of physics? — John

Explain what a chess program does in terms of the Standard Model. Then show how what it does contradicts any law of physics. Then get back to me.

But mind is neither reducible to matter nor something immaterial in addition to the matter. — Andrew M

Bravo!

You should be saying that you had a subjective experience of seeing Alice--that's what seeing Alice is, after all, but of course you're also saying that you trust your subjective experience to be an accurate perception of something objective--Alice crossing the street. Alice crossing the street isn't identical to having the experience of seeing Alice cross the street of course. — Terrapin Station

By your definition, a mindless facial-recognition-equipped robot would have the "experience" of "seeing" Alice.

This is of course nonsense. The sequence of events can be explained, and even predicted, with a simple theory of how a computer works with certain software running. To impute any subjectivity to the robot is just superstitious irrationality.

'Everything obeys the laws of physics', for instance, won't do: is that the current laws, liable to be overturned in future, or the future imagined perfect ones? — mcdoodle

Over the last 200 years, the understanding of the laws of physics has reached a point where we know certain principles that all future laws will respect: unitarity, conservation laws, computational universality, Lorentz invariance ...

When quantum mechanics and general relativity are unified, do you really think that will render the statement "everything obeys the laws of physics" false?

But if it's the future ones, mightn't they actually include what's currently called 'mental' within their purview? — mcdoodle

It's past laws that did that. All sorts of inexplicable phenomena were "explained" by positing some strange essence or force - phlogiston, vital forces, etc. Of course, as these were investigated, they were found to be fictions, yet flammable substances still burn and life goes on.

Consciousness is very much a mystery, but pretending to solve it by declaring that matter possesses some unyet discovered physics that only manifests itself in the human brain, seems strikingly unscientific.

If it is a reasonable starting point, what's the phrase 'the mental' doing? What are beliefs? What is phenomenological experience? What meaning do first person accounts have? Is all our mental stuff just epiphenomenal? — mcdoodle

These things are software feature.

and I managed to describe it without using that awkward beginning with qu-.... — mcdoodle

The idea that animals have qualia, is an improvement on the idea that everything does. It is still unscientific and wrong.

I'm still trying to understand what it could possibly mean to be a "non-reductive materialist". — John

It's quite simple - theories at the appropriate level of emergence cannot be reduced. e.g. the theory of evolution cannot be reduced to quantum field theory.

if the mind is not reducible to material, then "states of the world" surely are not either. — John

It means that the "states of the world" cannot be explained in purely physical terms. In the end, any complete astrophysical theory will have to take account of intelligent life in proximity to stars, and what they choose to do.

Everything obeys the laws of physics.

You're much more inclined to condescension than debate. — Wayfarer

Says th expert in "sleight-of-hand pop metaphysics".

I don't think that any such theory has been established. — Wayfarer

The theory is called The Theory of Evolution.

But is mind reducible to matter? — Wayfarer

Um,, well, since life is not reducible to matter, which has been pointed out to you several times, how could anything at a higher level of abstraction such as a mind. So, the answer is NO!

As a matter of note, no theory at the appropriate level of abstraction is reducible.

If time is every process in the universe, then how is a single number sufficient to tell us the current state of time? — hypericin

Here's a slightly different take on things: time does not only *not* flow (which I think you may have realised), but it is *not* an observable under quantum mechanics either. Rather, time exists in quantum mechanics as a non-physical parameter upon which observables and states depend. As such it is a relic of classical physics, and presumably will disappear under quantum gravity.

Progress along these lines was made in the 60s and more in the 80s. The remarkably beautiful solution that was discovered is that the universe as a whole is at rest. i.e. the quantum state of the universe is in an eigenstate of its Hamiltonian, which frees the wavefunction and observables from any time-dependence.

Because the universe is in an eigenstate of its Hamiltonian, it is not in the eigenstate of the position of hands on clocks, or any other observable that humans might use to tell the time. Rather, the universe is in a superposition of such eigenstates, whose eigenvalues are different hand positions! Thus time is a correlation phenomenon.

Amazingly, there has been recent experimental support for this solution to the nature of time:

https://medium.com/the-physics-arxiv-blog/quantum-experiment-shows-how-time-emerges-from-entanglement-d5d3dc850933

As one who was accused before of presenting a 'charicature of physicalism', I have to take issue with this statement. First, I think it is a reference to David Deutsch's so called 'constructor theorem', which is not actually a predictive scientific theory at all, but sleight-of-hand pop metaphysics based on questionable interpretations of quantum physics. — Wayfarer

Be honest, you haven't read a single Constructor Theory paper. And no, it's a reference to the theory of evolution, maybe you've heard of it?

Secondly, the conundrums that have been thrown up by physics about the nature of matter have given rise to all manner of metaphysical speculation, such as those proposed by David Deutsch and also by Max Tegmark, comprising the idea of infinitely many parallel universes. And these extravagent speculations are based on nothing more than the difficulties of explaining what is seen in experiments involving sub-atomic particles (so called). There's nothing in any of that which comes close to addressing the physical issues involved in the origination of Life OS (otherwise known as DNA). — Wayfarer

The good old bait-and-switch.

We don't know the historical events that gave rise to the abstractions with which the theory of life operates. But once we have digital information, error correction, replication under variation and selection, we have life, according to the theory of evolution. (Though admittedly, digital information and error correction are "pop-metaphysical sleights of hand" introduced by Constructor Theory)

So how it can now be declared that 'the mysteries of life' have been 'solved', when the purported 'simplest components in the Universe' turn out to require the inference of infinite parallel dimensions? As if this has all been solved, as if we know what there is to know. Remember well Lord Kelvin's famous prediction, that 'the details have all been worked out, now it's just a matter of decimal places'. — Wayfarer

Are you offering your conceptual difficulties with quantum mechanics as an argument against evolution in particular, or theories at the appropriate level of emergence in general?

What we think and feel may not always be noticeable in everyday observable behavior but, per materialism, there is always some material instantiation (e.g., in brain activity, particles shifting around, or some such). — Andrew M

Everything always obeys the laws of physics - even tigers must do that. But what is remarkable about these laws is that they permit abstractions that are real and causal. The Schrödinger equation is completely uninformative if you wish to explain why a person was eaten by the tiger, yet it is universal and applies to the tiger and the tiger's meal.

Life used to be a deep mystery, and no doubt there were those who maintained that it could not be explained physically. But then a theory at the correct level of emergence was discovered, which not only explains life, bit explains it rather simply as a phenomenon of replicators subject to variation and selection.Life must obey the laws of physics just like everything else, but these laws appear nowhere in its explanation.

The claim that consciousness or qualia cannot be addressed from the physicalist perspective, is the claim that no theory of them, at the appropriate level of emergence, is possible. i.e. The problem of qualia is insoluble and not amenable to reason.

So I'm arguing that self, in this sense, is something that must be excluded by materialism, or at any rate, it has to be accounted for in terms of the activities of brains, molecules, and physical forces, and so on - if there is a real subject, it defeats materialism. That attitude is what materialism or physicalism is, after all. And it appears possible to exclude the subject, because it really is nowhere 'out there'; it never is an object of experience, in the way others are, or animals are, or planets, stars, mountains, etc; it is not 'objectively existent'. — Wayfarer

If you are arguing that the self must be excluded from physicalism because physicalism can only account for things in terms of physics, then why don't you start with an easier target. Under your caricature of physicalism, it certainly cannot account for life. Physical forces are nowhere mentioned in the theory of evolution, but rather replicators subject to variation and selection.

And what sensory experience leads you to posit the square root of -1, pray tell! — Barry Etheridge

That is a good example, but then you could have picked just about any concept in science or mathematics.

The quale, qualia being a term conventionally limited to mental contexts, is produced by the phenomena of electromagnetic radation being reflected off of an object in conjunction with the light waves traveling through the air between you and the object in conjunction with your eye being stimulated by those light waves in conjunction with your optic nerve sending that signal to your brain etc. In other words, it's the product of a "system" that includes all of those things (plus we could go back to the light source and so on). — Terrapin Station

So why doesn't the robot possess qualia then? It has all of those features. Why don't non-human animals possess them?

And by the way, it is possible to create qualia in the human mind by direct nerve stimulation, or by use of the imagination.

It doesn't have a brain. Mentality, which is what experience is a part of, seems to be something peculiar about the particular materials, in the particular structures, undergoing the particular processes, that comprise brains functioning in mental ways. — Terrapin Station

Are you pretending to have invented new physics that only occurs in brains? Seems very Deepak Chopra to me. Claiming that there is "something peculiar about the particular materials" doesn't strike me as as particularly scientific.

But we know that because the human brain is computationally universal, it can be put in 1-to-1 correspondence with any other computationally universal device, so qualia cannot be a "peculiar" property of "particular materials". No new physics required!

I think this is quite misleading, there is a confusion about what we are denoting with the word "blue".
There are two possibilities:

"blue" is denoting the radiation with wavelenght 450-495 nm: in this case saying "experience blue" doesn't make sense because the experience comes from the interaction between the radiation and the human sensory apparatus: one could experience the radiation in different ways if he is a different animal
"blue" is denoting the quale produced by the radiation, in this case the robot wouldn't "experience blue" but there is no point in considering the knowledge about the light radiation that produces that quale on the human sensory apparatus — Babbeus

If you had been paying attention, you would have noticed that sensory apparatus of the scientist and of the robot can detect blue light, but neither is capable of transmitting that signal to their respective CPUs.

You claim that the quale of blue is "produced by the radiation", but it cannot be. It cannot even be produced by the electrical or nerve signal. You further claim that the robot cannot "experience blue", why not? It is certainly detect blue, is affected by blue, and can make decisions based on this.

Furthermore you claim that "there is no point in considering the knowledge about the light radiation". Really?

I don't think we know any such thing, especially not via "computational universality." For one, that would surely rest on a mistaken ontology of mathematics. — Terrapin Station

Computational universality is a principle of physics. It has nothing to do with mathematics, or its ontology. All known laws of physics, and all future laws will respect this principle.

We know that a universal computer can be put in 1-to-1 correspondence with the human brain (or any other finite physical system).

Both the scientist's and robot's blue has qualities that are unique to the blue phenomenon at their respective terminuses. The robot's blue isn't a quale, because we reserve that word for a conscious experience of blue, which we don't believe the robot has. There's no reason to believe at this point that conscious experience isn't a peculiarity of the exact matter, structures and processes of functining brains. — Terrapin Station

But where is the "terminus"? Both robot and scientist are being affected by blue light - i.e. some atoms are being affected.

We know, via computational universality, that consciousness *cannot* be a peculiarity of an exact state of matter.

Also, depending on how you define consciousness, there exist conscious entities that don't possess qualia - e.g. all non-human animals.

The fact remains that qualia are unpredictable and indescribable - very odd indeed!

The curious case of the robot and the scientist.

Consider a faulty scientist and a faulty robot. The scientist is an expert in light, but was born with a rare condition affecting her optic nerve, that makes it unable to transmit blue light signals. The robot has a loose wire, so it too is unable to transmit blue light signals from its camera. The scientist is fixed by a doctor, and the robot is fixed by an engineer.

So, what has changed? Both the robot and the scientist can now recognise blue and are able to use that recognition to perform certain tasks. Both the robot and scientist experience blue.

But, only the scientist now *knows* what it is like to experience blue, the robot does not. There are also a couple of curious aspects of this experience that she notices - she, despite her extensive knowledge, could not predict what the experience was going to be like, and she can't describe it either.

Only the scientist possesses the quale of blue.

It seems a bit easy just to deny qualia exist, rather than recognise there is a potentially deep philosophical problem to solve.