Determinism is an irrelevant theory because of Gödel’s incompleteness and the Halting problem.
Predictions are always made from inside the universe, thus affect their own results. Therefore, perfect predictions are irredeemably impossible.
Now, can the universe be fully predicted from the outside ? Who cares ! What is outside the universe, by definition, cannot affect it, so the question is irrelevant, again by definition.
The only case where that could hypothetically matter is if there is a one-way gate to exit the universe (if you can come back, then it’s just a weird part of the universe, not truly outside, so the first arguments still stand).
And even then, proving the universe deterministic would at best be just one hint that maybe the “outside universe” is itself deterministic, not even a full proof.
Also, observing the universe without affecting it is a pretty weird concept, with what we know about quantum measurements affecting their own results. Not impossible by definition, but it would look quite different from what we do right now.
According to our current model, we would probably observe un-collapsed quantum field waves, which is a concept inaccessible from within the universe, and could very well just be an artifact of the model instead of ground truth.
But again, this is all irrelevant until someone builds the universe an exit door. That door being one-way only by definition also means there would be no way to know what’s on the other side and if it’s worth crossing (or if it instantly kills you) before you do.
So, if we do build such a door, there would be no way to experimentally confirm it is indeed an exit from the universe, and not just a wormhole with a very far exit, or a long lived pocket dimension, or an absolute annihilator that doesn’t lead anywhere.
According to our current model, we would probably observe un-collapsed quantum field waves, which is a concept inaccessible from within the universe, and could very well just be an artifact of the model instead of ground truth.
It so strange to me that this is the popular way people think about quantum mechanics. Without reformulating quantum mechanics in any way or changing any of its postulates, the theory already allows you to recover the intermediate values of all the observables in any system through retrospection, and it evolves locally and deterministically.
The “spreading out as a wave” isn’t a physical thing, but an epistemic one. The uncertainty principle makes it such that you can’t accurately predict the outcome of certain interactions, and the probability distribution depends upon the phase, which is the relative orientation between your measurement basis and the property you’re trying to measure. The wave-like statistical behavior arises from the phase, and the wave function is just a statistical tool to keep track of the phase.
The “collapse” is not a physical process but a measurement update. Measurements aren’t fundamental to quantum mechanics. It is just that when you interact with something, you couple it to the environment, and this coupling leads to the effects of the phase spreading out to many particles in the environment. The spreading out of the influence of the phase dilutes its effects and renders it negligible to the statistics, and so the particle then briefly behaves more classically. That is why measurement causes the interference pattern to disappear in the double-slit experiment, not because of some physical “collapsing waves.”
People just ignore the fact that you can use weak values to reconstruct the values of the observables through any quantum experiment retrospectively, which is already a feature baked into the theory and not something you need to add, and then instead choose to believe that things are somehow spreading out as waves when you’re not looking at them, which leads to a whole host of paradoxes: the Einstein-Podolsky-Rosen paradox, the Wigner’s friend paradox, the Frauchiger-Renner paradox, etc.
Literally every paradox disappears if we stop pretending that systems are literally waves and that the wave-like behavior is just the result of the relationship between the phase and the statistical distribution of the system, and that the waves are ultimately a weakly emergent phenomena. We only see particle waves made up of particles. No one has ever seen a wave made up of nothing. Waves of light are made up of photons of light, and the wave-like behavior of the light is a weakly emergent property of the wave-like statistical distributions you get due to the relationship between the statistical uncertainty and the phase. It in no way implies everything is literally made up waves that are themselves made of nothing.
Now, can the universe be fully predicted from the outside ? Who cares ! What is outside the universe, by definition, cannot affect it, so the question is irrelevant, again by definition.
Determinism is an irrelevant theory because of Gödel’s incompleteness and the Halting problem.
Predictions are always made from inside the universe, thus affect their own results. Therefore, perfect predictions are irredeemably impossible.
Now, can the universe be fully predicted from the outside ? Who cares ! What is outside the universe, by definition, cannot affect it, so the question is irrelevant, again by definition.
The only case where that could hypothetically matter is if there is a one-way gate to exit the universe (if you can come back, then it’s just a weird part of the universe, not truly outside, so the first arguments still stand).
And even then, proving the universe deterministic would at best be just one hint that maybe the “outside universe” is itself deterministic, not even a full proof.
Also, observing the universe without affecting it is a pretty weird concept, with what we know about quantum measurements affecting their own results. Not impossible by definition, but it would look quite different from what we do right now.
According to our current model, we would probably observe un-collapsed quantum field waves, which is a concept inaccessible from within the universe, and could very well just be an artifact of the model instead of ground truth.
But again, this is all irrelevant until someone builds the universe an exit door. That door being one-way only by definition also means there would be no way to know what’s on the other side and if it’s worth crossing (or if it instantly kills you) before you do.
So, if we do build such a door, there would be no way to experimentally confirm it is indeed an exit from the universe, and not just a wormhole with a very far exit, or a long lived pocket dimension, or an absolute annihilator that doesn’t lead anywhere.
It so strange to me that this is the popular way people think about quantum mechanics. Without reformulating quantum mechanics in any way or changing any of its postulates, the theory already allows you to recover the intermediate values of all the observables in any system through retrospection, and it evolves locally and deterministically.
The “spreading out as a wave” isn’t a physical thing, but an epistemic one. The uncertainty principle makes it such that you can’t accurately predict the outcome of certain interactions, and the probability distribution depends upon the phase, which is the relative orientation between your measurement basis and the property you’re trying to measure. The wave-like statistical behavior arises from the phase, and the wave function is just a statistical tool to keep track of the phase.
The “collapse” is not a physical process but a measurement update. Measurements aren’t fundamental to quantum mechanics. It is just that when you interact with something, you couple it to the environment, and this coupling leads to the effects of the phase spreading out to many particles in the environment. The spreading out of the influence of the phase dilutes its effects and renders it negligible to the statistics, and so the particle then briefly behaves more classically. That is why measurement causes the interference pattern to disappear in the double-slit experiment, not because of some physical “collapsing waves.”
People just ignore the fact that you can use weak values to reconstruct the values of the observables through any quantum experiment retrospectively, which is already a feature baked into the theory and not something you need to add, and then instead choose to believe that things are somehow spreading out as waves when you’re not looking at them, which leads to a whole host of paradoxes: the Einstein-Podolsky-Rosen paradox, the Wigner’s friend paradox, the Frauchiger-Renner paradox, etc.
Literally every paradox disappears if we stop pretending that systems are literally waves and that the wave-like behavior is just the result of the relationship between the phase and the statistical distribution of the system, and that the waves are ultimately a weakly emergent phenomena. We only see particle waves made up of particles. No one has ever seen a wave made up of nothing. Waves of light are made up of photons of light, and the wave-like behavior of the light is a weakly emergent property of the wave-like statistical distributions you get due to the relationship between the statistical uncertainty and the phase. It in no way implies everything is literally made up waves that are themselves made of nothing.
What if our universe is a simulation?