I think mental is the wrong word for it. That’s rather anthrocentric. It would be more accurate to say that the universe is information itself.
The entirety of the universe is only accessible as the solution to a massive (or maybe not, we may discover, although that’s not likely given the state of physics at the moment) set of governing equations.
The origin of these equations is mathematics itself, i.e. a completely platonic and immaterial thing. The fact that they exist means that a single solution may spool out of them: set an initial condition, and carry forward until t=infinity. The universe is exactly the product of this. But it’s not because anything actually computes anything - it’s just a natural consequence of the existence of such equations that there is some set of solutions to them.
This also means: an infinite number of IVPs for the governing equations of “our universe,” and an infinite number of such governing equations for all the other universes.
The spring mass damper model that I can see in my textbook exists in mathematical fact, and is a universe thusly.
Why is that? Well, it arises from the purity of mathematics itself, which is actually God.
It was my understanding that the observer effect (the act of observing a system can affect that system) is not due to the system "knowing" that a conscious mind is observing it, but rather that the instruments used to observe the system alter the system. But then this essay says
> the wave function is collapsed simply by your human mind seeing nothing. The Universe is entirely mental.
So what is this "mental nature of the Universe"? If the things we see at the macro scale are not made of underlying particles and waves, what are they made of?
The idea is that by clever positioning of detectors, it is possible to make a quantum observation before the detection physically occurs. That challenges the notion that wave-function collapse is a result of instruments interfering with the system.
This doesn't imply that the system "knows" anything about the conscious mind observing it. Very few physicists actually believe that consciousness affects physical mechanisms in this way. A more plausible interpretation may be that the wave-function collapse represents a belief-update process on the part of the observing agent.
There is a class of interpretations of quantum theory which take a so-called epistemic perspective of the wave-function. In the epistemic perspective, the wave function represents an agent's knowledge, belief or information regarding a system.
This has a lot of appeal partly because wave function collapse looks very similar to the way that probabilities are updated in bayesian statistics when new information comes to light. For example, if I measure the polarisation of a photon in the vertical component and get a "yes" results (V1=y), then I have complete confidence that future measurements of the vertical will again get a "yes" result (V2=y), whereas future measurements of the horizontal component will be 50-50 between a "yes" result (H2=y) and a "no" result (H2=n).
P(V2=y | V1=y) = 1
P(V2=n | V1=y) = 0
P(H2=y | V1=y) = 0.5
P(H2=n | V1=y) = 0.5
You can sum this up as "the wave function is a way for me to keep track of probabilities, rather than an objective fact about the system".
Of course this idea has its own set of challenges. For many people the question becomes "what does the wave function represent knowledge of"? Also, a few years ago there was a thought-experiment known as the PBR theorem, which rules out some epistemic interpretations: https://en.wikipedia.org/wiki/PBR_theorem
A "strong" version of quantum bayesianism is QBism, which asserts that quantum theory is no more than an effective user manual for organising subjective beliefs about the outcomes of future interactions with the world. Chris Fuchs and Ruediger Schack are two prominent theorists advocating QBism.
Particles and waves are mental. What was the dream you had last night made up of? Maybe you dreamt of running scientific experiments and finding atoms, would that get you any nearer to the metaphysical truth of what that particular dream is made up of?
Consider you never stopped dreaming when you woke up, the dream just shifted into a more concrete and physical state. But there is no physical you sleeping in some higher reality.
"Once, Zhuang Zhou dreamed he was a butterfly, a butterfly flitting and fluttering about, happy with himself and doing as he pleased. He didn't know that he was Zhuang Zhou.
Suddenly he woke up and there he was, solid and unmistakable Zhuang Zhou. But he didn't know if he was Zhuang Zhou who had dreamt he was a butterfly, or a butterfly dreaming that he was Zhuang Zhou. Between Zhuang Zhou and the butterfly there must be some distinction! This is called the Transformation of Things"
Quantum mechanics and the "observer effect" seem to be coming to similar conclusions, dragging postmodern materialists to consider the "mind" as fundamental to physics.
My understanding is rudimentary, but it doesn't alter the system. But it fixes what state the system should have to produce the given observation, retroactively. Which is counterintuitive in lot of ways. It can be thought as if the observation caused the determination of past state. Do I make sense or I am just talking absolute non-sense.
> As Sir Arthur Eddington explained: “It is difficult for the matter-of-fact physicist to accept the view that the substratum of everything is of mental character.”
Framing it in this way ("substratum") is perhaps flawed because it assumes a layering up of sorts with an initial unfurling form null. After all, what generates the mental-like substrate? What's at the bottom of the stack? While layers may be an emergent appearance, I'm less convinced that it is the fundamental nature.
What if it is more circular, not layered? Feedback loops with co-dependent unfurling, emergence, and renewal.
The entirety of the universe is only accessible as the solution to a massive (or maybe not, we may discover, although that’s not likely given the state of physics at the moment) set of governing equations.
The origin of these equations is mathematics itself, i.e. a completely platonic and immaterial thing. The fact that they exist means that a single solution may spool out of them: set an initial condition, and carry forward until t=infinity. The universe is exactly the product of this. But it’s not because anything actually computes anything - it’s just a natural consequence of the existence of such equations that there is some set of solutions to them.
This also means: an infinite number of IVPs for the governing equations of “our universe,” and an infinite number of such governing equations for all the other universes.
The spring mass damper model that I can see in my textbook exists in mathematical fact, and is a universe thusly.
Why is that? Well, it arises from the purity of mathematics itself, which is actually God.
That’s my theory at least.