The issue is that basically claims non-locality. If our problem is an inability to locate particles, then our local space is defined by something else, by things which cannot be pinpointed in our immediate vicinity.

It also effectively claims a hidden variable: if only we knew this hidden state we can never know about, then we could recognise how an electron was pre-determined to hit the screen. — TheWillowOfDarkness

No, because he's basically rejecting point particles in favor of a quantum fields. The fields have wave-like properties. When they interact with something like a detector, then the exact quantum state of that detector determines the exact measurement. A particle is just a certain kind of excitation of the quantum field.

As such, there is no need for any hidden variables or non-locality.

But then how do you account for all the things that General Relativity does? Gravitational lensing of stars and Galaxies, Mercury's orbit, neutron stars and black holes, gravity waves, time dilation, the Big Bang and inflation, red shifting of distant galaxies, etc?

And there's the fact that acceleration gives you the same force as gravity, which is what led Einstein to GR.

Gravity? You mean space-time curvature I hope, and no, space-time is real. — tom

Gravitons, I would presume. And space has quantum foam, where virtual particles pop in and out of existence, creating energy that supplies most of the mass for particles.

Your other questions are meaningless. Shut up and calculate instead. If you don't like being told what to do, tough! Probabilities are normative. — tom

Yeah, but part of science is asking why phenomena appears the way it does. What's going on behind the scenes? Imagine if Newton and Einstein had stopped at an equation for gravity and told everyone to shut up about the reality behind the equation.

The related concern is why should Schrodinger's equation work at all? Just saying that it fits experimental data is no answer at all. I was watching a video last night where Brian Green brought in four people to discuss the various interpretations of QM. One of them summed up the measurement problem as asking the question: what sort of world do we live in to get the sort of results that the double slit experiment gives us?

More interestingly, a universal computer inside a black hole could simulate the black hole. — tom

So a universal computer could compute the result of itself being sucked into a black hole and having contact with the interior (singularity or whatever lies there).

Although, this seems unfair. I'm guessing the idea of simulating precludes the thing doing the simulating, otherwise we have regress and self-referential issues. I might as well ask if the computer can simulate itself itself being introduced to a really strong magnet, or whatever would disrupt a QC.

Perhaps a more fair question would be could a QC compute a black hole used as a computer? I ask, because there are some articles out there about the possibility of black hole computers:

https://aeon.co/essays/is-the-black-hole-at-our-galaxy-s-centre-a-quantum-computer

Surprisingly, according to the laws of physics, simulating the entire visible universe is indeed possible using a universal computer, from within the universe. — tom

Back to this. Let's say all of physics is computable with a few hundred qubits, including black holes and Microsoft Office for all sentient beings insid the visible universe. Do we know what the algorithm for consciousnes is, such that our simulated Office users experience the Joys of making yet another thrilling Powerpoint presentation?

It depends on the size of the black hole. If the black hole is smaller than the visible universe, then yes. More interestingly, a universal computer inside a black hole could simulate the black hole. — tom

What does the algorithm for computing a black hole look like? Do we know that a quantum computer can operate as a turing machine, and do we know that black holes are computable?

Let's say the answer to the first is yes, do we know that a simulation running on qubits is more efficient than a classical computer? I know that quantum computers can perform some algorithms much faster, but I'm pretty sure there are plenty of programs that would not benefit. Like say, running Microsoft Office on a quantum computer.

So let's say you have hundreds of qubits available. Does that mean you could run Office 365 as a service for every human being on the planet?

The visible universe is thought to contain about 10123 bits of information. A rudimentary quantum computer containing only a few hundred qubits vastly outstrips that! — tom

Do you think that a few hundred qubits could completely simulate a black hole? And by that, I mean the object itself, not just the effect on things outside the event horizon.

How would the computer compute the future of the universe without being the entire universe? And if the entire universe isn't computing ahead such that we know the future, then you can't have a computer inside the universe doing so.

At any rate, if someone assigns no meaning to that sentence, then "This sentence is meaningless" is simply true. — Terrapin Station

If the sentence is meaningless, then it can't be true.

It's not true. The sentence isn't truth-apt.

It really is a straightforward proof by contradiction. If it being either true or false leads to a contradiction then it must be neither true nor false. — Michael

That seems like cheating. Now you can just remove any paradoxical statement by saying it's neither true or false. Let's try this as a result:

"This statement is neither true or false."

Does that lack a truth value? I say no, it has a truth value if what you stated is true. And then you're right back at the liar paradox.

Surely, if it were that easy, the liar paradox wouldn't have remained a puzzle to philosophers for 2300 years!

Any of them. — Michael

The third one is the "strengthened" liar paradox. Consider:

"This sentence does not express a true proposition."

If it's true, then you're back at the same contradiction.

The Liar sentence is not of the form 'L and not-L', and attempts to derive a sentence of that form from the Liar sentence make untenable assumptions. — andrewk

Which form of the liar statement?

I am lying.

This sentence is false.

This sentence is not true.

The next sentence is true.
The previous sentence is false.

With math and logic it's a matter of using the axioms and the rules of inference to determine what follows from what.

There's nothing like either of that for liar-like statements. — Michael

I don't know how you can say that. The contradiction in the liar statement stems from following the rules of logic. If not, then why is it considered an issue?

I've never really understood the problem of the liar paradox, even after reading a little about it. Think of checking for truth like running a program, and a program can loop infinitely without output. Same with self-referential paradoxes. — The Great Whatever

From finally getting curious enough to read up a bit on it, seems the motivation is to be able to define a theory of truth free of contradiction. Wittgenstein was of a different opinion. He thought it better to ignore the liar paradox instead of trying to figure out a way to resolve it, which in his view, might have worse consequences. I found that interesting.

Star Trek version:

KIRK: "Everything Harry tells you is a lie. Remember that! Everything Harry tells you is a lie!"

HARRY: "Now listen to this carefully, Norman: I AM LYING!"

NORMAN: "You say you are lying, but if everything you say is a lie then you are telling the truth, but you cannot tell the truth because everything you say is a lie, but... you lie, you tell the truth, but you cannot for you l... Illogical! Illogical! Please explain! You are Human! Only Humans can explain their behavior! Please explain!"

However you are still using binary logic in your clever example — TheMadFool

Here's an even better one that dates back to ancient times:

A crocodile takes a child but promise the parent he will return the child if the parent guesses what the crocodile will do. The parent responds that the crocodile will not give the child back.

What does the crocodile do in response? How would the crocodile get around this using an alternate form of logic?

This one is grounded, btw (other than the fact that crocodiles don't talk, but you can substitute a human kidnapper.)

There must be some evaluable fact about the world for the statement(s) to be "grounded", and so have a truth-value, but there isn't such a thing for the above. — Michael

Math and logic aren't grounded by the world. Also, there's fictional truths, such as Harry Potter performs magic.

If we refrain from any or both the paradox disappears. — TheMadFool

Well, here's a clever way to remove the self reference and still end up with the liar's paradox:

Socrates: "What Plato is saying is false"
Plato: "What Socrates is saying is true"

Post the representation, with details of the formal language being used, and we can discuss it. — andrewk

You requested that of MindForge, but since he hasn't gotten back to you yet, what do you think of the argument that SEP presents?

L = "This sentence is false" or "I am lying"
Q = "1 + 1 = 3" or any other false sentence

1. L and not-L from the Liar Paradox
2. L from 1
3. L or Q from 2 using the Law of Addition
4. not-L from 1
5. Q from 3 and 4

Consider "this sentence is true". That doesn't say anything, as TS says, there's no substance. It's like saying 'this sentence is a sentence", "this chair is a chair", etc.. — Metaphysician Undercover

SEP's counter to this is the sentence, "This sentence is not in Italian", which is not meaningless, but is in the same form as the liar sentence. And in ordinary language, people sometimes do say things like, "Now this car is a car!"

Also, there is this very big counter to the claim that the liar sentence is without meaning:

"This sentence is meaningless."

Which would be true if the liar sentence is meaningless, but then we get ourselves into another regress.

"this chair is not a chair", or "this table is not a table" — Metaphysician Undercover

But we do say things like that on occasion. For example, "This party is not a party", meaning it's a party in name only. I'm pretty sure I have said something akin to "this chair is not a chair" when being forced to sit on something uncomfortable that served as a chair. I've also said, "I'm not myself today", which would seem to be a violation of the law of identity, but clearly it's not meant to be taken in literal terms.

A bunch of natural language words does not a contradiction make, no matter how much it may feel as though they do. — andrewk

We use the word contradiction in natural language. That politician is stating contradictory things, or you're contradicting yourself, etc. This is the first time I've heard that contradiction is only a term applicable to formal logic. The dictionary and everyday use of the word would lead one to believe otherwise. I can make a contradictory statement in natural language quite easily. The unicorn is both pink and invisible.

If the only problem is that the sentence feels unintuitive, and the things one feels like one ought to be able to deduce from it feel as though they would contradict one another, then that's not a problem of psychology, not of symbolic logic. — andrewk

I don't understand what feelings have to do with this. The liar's paradox presents a logical contradiction. I can't always be lying if I'm telling the truth, so that's clearly false, but if it's false, then I'm telling the truth, but then if it's true, I'm lying so ....

How can it prima facie not be a contradiction?

Perhaps we make a basic "existential" choice whether or not take radical skepticism seriously. It's like Samuel Johnson kicking the rock. — R-13

Idealism isn't skepticism. It's a response to skepticism, in that an alternative metaphysics is being proposed such that one can't doubt that one is kicking a rock or waving hands in front of their face, because they are ideas in the mind.

Contrast this with materialism, where an experience of thing can be mistaken. I could be a BIV thinking I'm kicking a material rock, or material rocks might be just a how we humans perceive clumpy hard things, or what have you. The reality could be entirely different, once you propose that reality is different from experience. Metaphysical realism brings with it the specter of skepticism.

Berkeley was defeated by G. E. Moore. Many people hate idealism. — mosesquine

If waving one's hands was enough to defeat Berkeley's arguments, then surely kicking a rock would have been as well?

Both totally mischaracterize idealism.

Yes, it's like your brain and your body have different ideas.

I suppose so.

What is an essence? — Banno

The properties that make a thing a certain something. What is the essence of an electron?

Mass, charge, spin, and whatever else distinguishes electrons from other particles.

What makes a cat different from a dog?

Biological species are less exact, but the genetic and phenotypic properties of a feline that are unique. The big difference between an electron and an animal species is that the first might not be made of simpler parts, while the second is made of many simplers. But that still results in unique properties such that we can classify animals.

don't think that's much of a challenge though, unless one simply doesn't understand what similarities are, and one wants to pretend to not be able to understand any explanations/"in other words" descriptions (such as "(family) resemblances") etc. of what similarities are. — Terrapin Station

So what are similarities? Every single electron in the universe is similar because it has the same mass and amount of charge. Mass is similar because it attracts by the same relationship, for all bodies of mass, across the entire cosmos. How does one account for such universalities in science?

An electron is an electron because it has certain properties that all electrons "share", or however you want to put that.

Apo and Streetlight in a similar thread to this months ago said that everything starts off the same, and then because of symmetry breaking and what not early on, things differentiate.

If so, then the question of universals is the wrong question. It's not why things are similar, it's why they're different that needs explaining.

Is that convincing? How would a proponent of universals respond?

Just as a fun side-bar, who do you think is the "true" hero of LotR? My brothers and I figured it out in our late teens, and many years later it was verified to me when I read a letter Tolkien wrote to his son shortly after WWII in which he explicitly mentions who he meant the true hero to be. You can find it in his collected letters edited by Humphrey Carpenter. Any guesses? — Real Gone Cat

Gollum, because he saved Middle Earth by biting off Frodo's finger with the ring on it at the last moment.

So, instead of a deserted blob, it's a bunch of particulars.

But what is the relationship between particulars such that some particulars are more similar than others. We conceptualize because the world can be conceptualized, because of similarity.

The challenge for nominalism is accounting for similarity without falling back into universals.

What in hell does it mean for the human condition to be a logical entity?

An empirical question that would shed light is whether the brain uses the same resources to imagine, hallucinate, and dream that it does for perception. For visual experiences, is there a visual ability that gets used by all of them? If so, that lends credence to the brain creating a virtual world of sorts, and not direct perception.

that the human mind is beyond the description of any formal system due to Godel's Incompleteness Theorem. — Question

I don't think that's the fundamental issue. I think it's that an objective description is abstracted away from first person experience. So the question is whether a third person description can account for first person.

Now some think if you can the mechanisms resulting in consciousness, then there's nothing more to explain. Basically, consciousness becomes brute, or beyond explanation, since explanation is third person. Or identical to those mechanisms.

So then the question becomes whether a simulation of those mechanisms results in consciousness, or whether consciousness is identical to certain biological processes. And furthermore, can we know whether other kinds of simulations would lead to non-human consciousnes? Is that a question that can be answered? Which is also related to asking questions about animal consciousness.

If we lack an explanation, then I'm not sure we can answer those sorts of questions.

Yes, but God, by definition, is always thinking about everything. — John

Why would God need to think? It occurred to me a while back that God has no need for intelligence, because there are no problems God needs to solve. Intelligence is for animals, who are limited by their bodies and environments. They have challenges to overcome to survive.

God has none.

If consciousness is decidable then solving the problem of other minds simply means discovering the correct algorithm of consciousness. — m-theory

How would one go about showing that consciousness is decidable? I take it that if it is, consciousness can be computed, which means a Turing machine can be conscious.

Although, it makes me wonder. Would an abstract algorithm be conscious, or just the instantiation of it?

Why is this one real as opposed to the others I'm not experiencing where I instead went to sleep instead of replying to your post, now? — Question

Because in this one you're replying to the post. In another one, you're sleeping. What you're asking is why you're experiencing posting and not going to sleep. That's because you're not that "version" of you. That other you experienced it.

t doesn't matter if it's 5 or 5 million feet away. What is the connection between brain activity and some other physical thing such that the former is a thought about the latter? — Michael

Obviously, thought would need to be physical in a way that's connected to the physical thing. Computation is one such attempt to do so. How can a computer compute an action based on some event not inside the computer, or some event that doesn't exist now?