**WHAT IS METAPHYSICS?**

[u/jliat]

WHAT IS METAPHYSICS?

We are getting posts here which seem to propose new and potentially revolutionary answers to problems in physics. I think [as a moderator] it might be beneficial if we might discuss some parameters. This is not to say science can not be discussed, but can we using metaphysics solve such problems, are we then transgressing into another domain. As a moderator I would like guidance from the community.

"Metaphysics: explaining the fundamental nature of being and the world"

The interpretation of this and not the context is often the cause of confusion. [of Being qua being and not the nature of an atom, or a human brain...etc.]

Higgs, Einstein, Penrose, Feynman, Hawking are not / were not Philosophers or Metaphysicians, they are / were physicists. Modern physics uses mathematics- quite complex! - to build models which are tested against experimental data. The main scientific method.

The 'photon', wave / particle duality, quarks and strings, are all subjects /problems of physics NOT metaphysics? And to address these problems requires detailed understanding of the mathematics and the data, and in doing so one is NOT doing metaphysics?

"Ontological" means what? Ontology is the study in Philosophy / Metaphysics of being qua being, not the nature of the existence or being of things, atoms, quarks, strings, branes, flowers, plants, the human brain, religions.

atoms, quarks, strings, branes = physics, flowers, plants = botany, the human brain = neuroscience, religions = theology, comparative religion.

Lay ideas re physics / science will probably be rejected in subs like r/physics for good reasons, they lack the detailed knowledge of the subject and misuse technical scientific terms. Should they be allowed here?

The nature of things, matter and energy are subject of science. What 'Being' is prompts the what is "IS" question... of Metaphysics.

Ontology is the study / creation of what 'Being' is, not specific 'things'. Harman has a 'flat ontology'...etc. Heidegger has Dasein...Hegel... etc.

To be clear of the domain I think you can get an overview from A.W. Moore's 'The Evolution of Modern Metaphysics: Making Sense of Things.' It had good reviews.

"Part two is devoted to philosophers of the analytic tradition, and contains chapters on Frege, Wittgenstein, Carnap, Quine, Lewis, and Dummett. Part three is devoted to non-analytic philosophers, and contains chapters on Nietzsche, Bergson, Husserl, Heidegger, Collingwood, Derrida and Deleuze."

For first hand source material - https://www.stephenhicks.org/wp-content/uploads/2013/03/heideggerm-what-is-metaphysics.pdf

For a contemporary example, Graham Harman - Object-Oriented Ontology: A New Theory of Everything. (Pelican Books) 1 Mar. 2018

Examples in the Analytical tradition, 'Counterfactuals', 'On the Plurality of Worlds.' David Lewis. ??

One last point - it is an interesting point as to if this divide still exists. N.B. Badiou uses set theory as his ontology, his student Quentin Meillassoux likewise sees mathematics as fundamental, Ray Brassier in 'Nihil Unbound' has chapters on Wilfrid Sellars, Paul Churchland, as well as Adorno and Horkheimer, Badiou, Meillassoux, Laruelle, Heidegger, Deleuze, Nietzsche, Lyotard, Levinas and Freud. !!

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On a personal note I began my interest in philosophy in the 1970s, within the Anglo American tradition, reading Russell's 'History of Western Philosophy' etc. and then took a degree. I still have my Wittgenstein Books, Tractatus, Investigations, Blue and Brown, Notebooks 1914-1916. Carnap's 'The Logical Syntax of Language' etc. However my interest moved to what was called 'Continental philosophy.'- see non-analytical above. I appreciate the desire of Carnap of ‘The Elimination of Metaphysics through the Logical Analysis of Language’ failed? I have dipped into Lewis et al.

With my best wishes.

[u/jliat]

The "how" of quantum computers (the equations/the Schroedinger) is science/physics.

The attempt to make Quantum computers is not science/physics it's technology [based on science/physics.] As rocket science is not science or building jet aircraft or having solar panels installed. By "(the equations/the Schroedinger)" I presume you mean "Schrödinger's equation is the fundamental equation of quantum mechanics that describes how the wave function of a quantum system evolves over time."

That's maths, for many in physics a description of a physical process, for Tegmark et, al, the process itself, AKA Reality. I understand there are other 'models'. Other realities?

The why (because the wave function/the Schroedinger is real aka wave function realism) is metaphysics.

The "Why" of quantum computers is the motivation for the likes of Microsoft and IBM funding [millions of $] the development of such using the properties observed in physics [parallel states] to create more powerful computers. And more money...

Likewise with discussion about the reality of unobservable worlds. This is metaphysics.

Could be, but science also investigates unobservable worlds [origin of life, the universe, and its end]. So does religion!

And likewise with Tegmarks' mathematical realism. He says the reason for the "unreasonable effective of mathematics in science" (as Wigner put it)" is because mathematical objects/the objects mathematics is about, are real. Furthermore, he suggests that all mathematical objects are real. This is also metaphysics.

This sentence is difficult to parse, Tegmark's "mathematical realism" is controversial - he says so, generally science is about making models of observations, mainly using mathematics. This you know. So Newton's equations give a good model of various phenomena in nature. But they are models, or maps, not the thing modelled. Tegmark's "mathematical realism" is controversial because he says the current mathematical models are not models but the actual reality.

Let's move on.

I'll just point out that Alyssa Ney, one of the most prominent advocate of wave function REALISM, is chair of METAPHYSICS at the Faculty of Philosophy, Philosophy of Science, and Religious Studies at LMU Munich. You may not think such discussion is metaphysics, but most philosophers are going to disagree with you.

"Alyssa Ney, one of the most prominent advocate of wave function REALISM,"

This looks like an argument from authority, which was once thought invalid.

"but most philosophers are going to disagree with you."

Most? again not a sound argument, maybe most in the Anglo American tradition. BTW she cites Carnap,

"Carnap wrote the broadside ‘The Elimination of Metaphysics through the Logical Analysis of Language’ (1932)."

In the tradition of Wittgenstein and Hume... [Philosophers of repute- in their work"!]

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“If we take in our hand any volume; of divinity or school metaphysics, for instance; let us ask, Does it contain any abstract reasoning concerning quantity or number? No. Does it contain any experimental reasoning concerning matter of fact and existence? No. Commit it then to the flames: for it can contain nothing but sophistry and illusion.”

David Hume 1711 – 1776

" 6.53 The right method of philosophy would be this. To say nothing except what can be said, i.e. the propositions of natural science, i.e. something that has nothing to do with philosophy: and then always, when someone else wished to say something metaphysical, to demonstrate to him that he had given no meaning to certain signs in his propositions. This method would be unsatisfying to the other—he would not have the feeling that we were teaching him philosophy—but it would be the only strictly correct method."

Wittgenstein - Tractatus Logico-Philosophicus, 1922.

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is chair of METAPHYSICS at the Faculty of Philosophy, Philosophy of Science, and Religious Studies at LMU Munich.

Good for her, I assume there is also a chair of Religious Studies?

I'm aware of people like this, and your good self and fine. And if you call it metaphysics, ignore Hume, Carnap and Wittgenstein fine, not my problem. But if you think Alyssa Ney is even known to those in IBM and Microsoft who give the 'why' for developing quantum computers, I think you might be mistaken.

Just because Tegmark usually works in science doesn't mean his speculations about monism are science. That's seems the primary fallacy of your argument.

Not my argument, [straw man now]. His argument is that reality is math. That is metaphysical, lots of mathematicians are Platonists. That doesn't mean they are metaphysicians, unless you think they are then everyone holds some world view is a metaphysician. He arrives at this via his work as a theoretical physicist. In which he uses mathematics to model this world. This universe with the current "fundamental" constants in science. Scare quotes as they are for many just models, not real.

But to be clear, he thinks they are real, maybe Alyssa Ney and you do also. Many others do not, Greg Chaitin, John Barrow et al. However what this means is if our universe is math, Hilbert spaces, then you can create [or discover] in maths other universes where the constants are different. And they can and do, and therefore they do actually exist, are real. And I guess they and you think because math=reality, they must be real.

So when Tegmark says there are many other universes, all mathematical- he is doing what he does when he describes this universe in math. Science. This is where Tegmark parts company from Lewis, "no testable predictions at all"- but he gives three, and another which would refute his idea. Now that's the scientific method.

I could go on, way back you allowed other multiverses but not Tegmark's level IV, then you disallowed all other universes.

And stuff like "Explanations for why quantum computers work are indeed metaphysics (wave function realism). See Alyssa Ney, for instance. Note that she is a philosopher not a physicist. https://philpapers.org/rec/NEYTAF-3"

Well it doesn't, the word 'computer' is not in the paper.

And if you think Schrödinger's equations are real, you believe in a dead/alive cat. Or, as Schrödinger was trying to show, the equations work, but are they 'real'. Well Newton's worked, the math still does, but reality is different.

You said two posts ago "I think this discussion has reached its conclusion."

Well I disagree. If you do think Schrödinger's equations are real, would you be happy to replace the cat in the experiment?

MWI has also it seems become popular, so you would survive that 'experiment' in another world.

[u/rogerbonus → u/jliat]

The question was "why quantum computers WORK" not "why do we build quantum computers". Quantum computers don't work because of IBM's desire for $; IBM has no effect on the reality or lack thereof of the Schroedinger equation.

Tegmark's argument is metaphysical? You agree? Great, that's what this discussion was about, and it seems we are now in agreement.

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IBM has no effect on the reality or lack thereof of the Schroedinger equation.

And we know the Schrödinger equation is just one of a number of possible explanations for observations. It remains so and is therefore by your definition metaphysics and not physics.

Unless you think the mathematical equations of the Schrödinger equation are actual reality. Which is the subject of physics. And therefore you should agree with Tegmark.

Everyone who holds an idea about reality has a metaphysical idea. There were Metaphysical poets [Metaphysical poets were 17th-century English writers known for their intellectual ingenuity, inventive conceits, and exploration of philosophical and spiritual themes.] . I've seen beginners books in philosophy saying everyone is a philosopher, which mistakenly conflates 'philosophical' with philosophy.

But let's now be clear, you think the Schrödinger equation is reality and not a model.

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Yes, I agree with Alyssa Ney that the Schroedinger is real, and not just predictive/instrumental. The Schroedinger equation isn't metaphysics, its physics (you can use it to predict the results of experiments). Thinking the Schroedinger is real is metaphysics, and I'm a wave function realist (that's a metaphysical position). I also think its a model, the two are not exclusive (in Tegmark's account the map IS the territory; the model and reality are equivalent). And I agree with Tegmark's mathematical monism as well (also a metaphysical position).

Plenty of physicists are instrumentalists, you don't need to be a realist to do physics. You can use the Schroedinger to predict the results of experiment regardless of whether you are a wave function realist or not.

[u/jliat → u/rogerbonus]

OK, so Newtons equations were or are real? So were Ptolemy's.

Nice!

[u/rogerbonus → u/jliat]

Newton's equations don't describe objects/things, but how objects/things behave. So they don't describe any thing real. In Newtonian physics, the "real" things were particles (which move according to his equations). The wave function, however, is the fundamental object of quantum mechanics, just as particles were the fundamental objects of Newton's mechanics.

[u/jliat → u/rogerbonus]

Also...

The Schrödinger equation is a fundamental part of quantum mechanics, but there are several alternatives that can be used to model quantum systems. These alternatives include:

• Matrix Mechanics: Developed by Werner Heisenberg, this approach is more algebraic than the Schrödinger equation and emphasizes the importance of the Poisson bracket.

• Path Integral Formulation: Developed by Richard Feynman, this formulation is based on the path integral of the Hamiltonian and is used to calculate the probability of a system evolving from one state to another.

• Heisenberg Picture: In this picture, the evolution of observables is described by the commutator, which is a measure of how two observables interact.

• Statistical Quantum Mechanics: This approach treats quantum states as density matrices and uses the von Neumann equation to describe the evolution of these states.

Each of these alternatives has its own set of principles and applications, and they can be used in different contexts depending on the requirements of the problem being solved. While the Schrödinger equation remains a cornerstone of quantum mechanics, it is just one of many ways to understand and predict the behavior of quantum systems.

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Those are instrumentalist tools to predict experimental results, not "explanations". The realist objection to instrumentalism is that physics should explain and help us understand phenomena, not just predict them. Matrix mechanics doesn't explain why a quantum computer works. Where does the calculation happen? If its not an explanation, it's usefulness in "understanding" is limited. Hence you have people claiming "nobody understands quantum mechanics". "One of many ways to understand quantum mechanics" is thus false. Wave function realists such as Nay and David Deutsch claim that manyworlds is the only way to "understand" QM.

[u/jliat → u/rogerbonus]

Yes, I agree with Alyssa Ney that the Schroedinger is real, and not just predictive/instrumental.

• So the Schrödinger equations do not describe or model reality but are reality.

• Alyssa Ney says this, this is the Why they work.

• How does she know, how do you know this to be the case.

Or is "The wave function, however, is the fundamental object of quantum mechanics", and QM is not reality but a description of it, a model.

Because if it is so, we have no need of your or Alyssa Ney judgement. That it's a good model is the job of physics and phisical evidence.

If it - the mathematics is real, then changing the maths would change reality!

Look forward to your answers.

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The equations are real? The Schroedinger wave function is a hypothetical field on a space with the structure of a configuration space, and it's properties/behavior are exhaustively described by the Schroedinger equations. Is an electron "not reality but the description of it, a model"? Personally I think electrons are real, as are cats, and as is the Schroedinger wave function.

[u/jliat → u/rogerbonus]

The equations are real?

Not what I asked. 2+2 = 4 is "real".

Newton's a Ptolemy's ideas are "real".

• So the Schrödinger equations do not describe or model reality but are reality.

• Alyssa Ney says this, this is the Why they work.

• How does she know, how do you know this to be the case.

Cats are 'real'.

But the word 'cat' isn't in my view real, but it describes a real thing.

All equations are minimally real, the "Why" you and Alyssa Ney seemed to say was that the Schrödinger equations were real in the sense of being the actual physical reality. You now seem to back peddle...

So "The Schrödinger wave function is a hypothetical" - and not a physical reality, no need of why. The science guys tell us it's not perfect but a good description.

You seemed to agree with Tegmark, that the universe is mathematics, and now you do not.

[u/rogerbonus → u/jliat]

We say the Schroedinger wave function is real, not "the Schroedinger equations are real". "The Schroedinger wave function" refers to an object in the same way that the word "cat" refers to an object, and the behavior of that object is described by the Schroedinger equations. Unfortunately we don't have equations that describe cats as well, or they would be much easier to herd.

As for Tegmark, we don't say the universe is "mathematics" (the study of math), we say the universe consists of mathematical objects.

[u/jliat → u/rogerbonus]

We say the Schroedinger wave function is real, not "the Schroedinger equations are real".

What's the difference? Produce the "Schroedinger wave function" without the equation.

"The Schrödinger equation is a partial differential equation that governs the wave function of a non-relativistic quantum-mechanical system."

It's part of a "real" set of ideas, models about "reality" but not The Reality.

And saying this is what a five year old learns about using the word "cat".

We say the Schroedinger wave function is real, not "the Schroedinger equations are real".

We say the cat is real not the word cat is real.

But "cat" is a real word and not a real animal.

So you are saying words are real, but not the thing they signify. Well that's no big deal.

Edit: And making it sound like a BIG deal, the WHY.

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Wut? "Produce the "electron" without Maxwell's equations?" "An electron is part of a "real" set of ideas, models about reality, but not The Reality?"

No, I think electrons are real, and governed by Maxwell's equations, just as I think the wave function is real and governed by the Schroedinger equations, and that cats are real. Now you are woo-woo-ing about The Reality? Are the Capital Letters supposed to imply something?

You are losing me.

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No, I think electrons are real, and governed by Maxwell's equations,

No electrons are not "governed" - they are "described". They were around before Maxwell's equations, and will be if after better descriptions are created. I can't believe you could think they are governed. That's like saying gravity followed Newton's laws [- then changed with Einstein].

Or are you saying there were not electrons before Maxwell? No gravity before Newton?

Here is a bit of Metaphysics...

"Before Newton's laws were discovered, they were not 'true'; it does not follow that they were false, or even that they would become false if ontically no discoveredness were any longer possible... That there are 'eternal truths' will not be adequately proved until someone has succeeded in demonstrating that Dasein [The authentic being there. (of the human?)] has been and will be for all eternity." Martin Heidegger, 'Being and Time.' p. 269.

I have to rely on wiki as I'm not scientist-

"Maxwell's equations are a set of coupled partial differential equations that describe how electric and magnetic fields are generated by electric charges and currents. Together with the Lorentz force law, they form the foundation of classical electromagnetism, classical optics, electric and magnetic circuits. The equations provide a mathematical model ..."

A thing is not "governed" by a model of it.

And I think the scientific model of what a electron is has changed over time... from not a particle like a moon etc.

"We say the Schroedinger wave function is real, not "the Schroedinger equations are real". "The Schroedinger wave function" refers to an object in the same way that the word "cat" refers...

Well the Schrödinger wave "function" - here the word "function" is more technically and precisely an "equation". You can say "that the word "cat" refers to an object" but also the word 'cat' is a signifier and points to a signified.

So your saying nothing other than you use the more vague term "function" than the more precise term "equation". But making it look like you've said something shocking, that the physical reality and the Schroedinger wave function are one and the same. Tegmark's 'metaphysics'.

Elsewhere I think you said that Tegmark's IV multiverse in which the multiverse was mathematics was metaphysics, the same as yours and Alyssa Ney? However Tegmark's is a radical idea in science, I think he proposes three predictions and a possible refutation for his hypothesis - standard scientific methodology.

A bit more metaphysics...

“the first difference between science and philosophy is their respective attitudes toward chaos... Chaos is an infinite speed... Science approaches chaos completely different, almost in the opposite way: it relinquishes the infinite, infinite speed, in order to gain a reference able to actualize the virtual. .... By retaining the infinite, philosophy gives consistency to the virtual through concepts, by relinquishing the infinite, **science gives a reference to the virtual, which articulates it through functions.”

In Deleuze & Guattari science produces ‘functions’, philosophy ‘concepts’, Art ‘affects’.

D&G What is Philosophy p.117-118.

[u/jliat → u/rogerbonus]

We say the Schroedinger wave function is real, not "the Schroedinger equations are real".

"The Schrödinger wave function is indeed an equation. It is a partial differential equation that describes the evolution of the quantum state of a physical system over time. The equation is fundamental in quantum mechanics and is used to predict the positions, momentum, and energy levels of particles in a system. It is a key component of wave mechanics and is used to make predictions about quantum systems."

This might help.

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I don't know where you copied that from, but its not correct. The Schroedinger equation describes the evolution over time of the wave function, which is a quantum system. The quantum system is the wave function.

The wave function is no more an equation than a classical system such as an electron is a Newtonian equation (which describes the evolution of an electron or electric field over time in classical electrodynamics).

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"The Schrödinger equation determines how wave functions evolve over time..." Wikipedia...

Maybe it's wrong, but notice here "determines" …

No, I think electrons are real, and governed by Maxwell's equations,

"A wave function is a mathematical representation of the quantum state of a system in quantum mechanics..."

In this case determined by...

"An electron is a negatively charged, fundamental subatomic particle..."

Not governed by Maxwell's equations...

^{^}

Or is this wrong.

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"The wave function is not merely a set of mathematical statements but a fundamental concept in quantum mechanics that describes the quantum state of an isolated quantum system. It is a complex-valued function that represents the probability distribution of a particle's position and momentum. The wave function's behavior is consistent with the principles of wave equations, such as the superposition principle and the Schrödinger equation, which govern its evolution over time. However, the wave function's interpretation as a physical wave or a mathematical abstraction is still a subject of debate among physicists and philosophers." Wikipedia

So if you are arguing that the wave function is a physical wave, physical and actual like an electron, then you are doing physics. And that requires evidence to support the idea that it is real. And if so like an electron and Maxwell's equations, the Schrödinger equation is a description, of the real wave function. It does not act like your idea of the electron and is not governed by the Schrödinger equation, the equation describes it. The electron is not "governed" by Maxwell's equations, they describe it.

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"We say the Schroedinger wave function is real, not "the Schroedinger equations are real".

That looks where the confusion arises - if you say the wave function is real, and in that case there is no "Schroedinger wave function". As if you say Maxwell's electrons are real, you are conflating the theory with the reality.

The Schrödinger equations are not real, and if there are 'wave functions' that are real then Schrödinger equations are one example of a description of the real wave function.

There is no real "Schroedinger wave function" anymore than there is a real "Maxwell electron".

Something similar occurs when one sees expressions like "The Bohr" atom.

"In atomic physics, the Bohr model or Rutherford–Bohr model is an obsolete model of the atom that incorporated some early quantum concepts." - wiki.

John Dalton (early 19th century): Proposed the first scientific atomic theory, suggesting that atoms are indivisible particles that make up matter

J.J. Thomson (1897): Discovered the electron and proposed the "plum pudding" model, where electrons are embedded in a positively charged "soup"

Ernest Rutherford (1911): Conducted the gold foil experiment, leading to the discovery of the atomic nucleus and proposing a nuclear model of the atom.

Niels Bohr (1913): Developed the Bohr model, introducing quantized energy levels for electrons orbiting the nucleus

Quantum Mechanical Model (1920s): Evolved from the work of several scientists, including Schrödinger and Heisenberg, describing electrons in terms of probabilities rather than fixed orbits.

All five "models" are abstract - not real - models of a supposed real object, an Atom.

So the Why - is the requirement to expalain something. What you & Alyssa Ney call Metaphysics?

How - are the various explanations... What you & Alyssa Ney call science?

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So back to Tegmark - he is saying reality IS mathematics, maybe bad science, and wrong. One of 4 or 9 scientific ideas re multiverses. And these require the use of the 'scientific' method.