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Why Quantum Mechanics?

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Re: Why Quantum Mechanics?

#61

Post by srcreigh »

adrianN wrote: post #33
srcreigh wrote: post #19

Earlier quoted context omitted.

Physics is based on what can be measured objectively. In other words the probability could be an approximate description of a real (and perhaps knowable) yet un-objectively-measurable process. The idea "everything that is natural can only be everything we can objectively measure" should be problematic right? Of course whatever out there that is unmeasurable is rife with confusion, messiness, lies etc but that shouldn…

You seem to suggest some kind of hidden variable theory for free will: https://en.wikipedia.org/wiki/Hidden-variable_theory . As far as I know they're not particularly popular among physicists, although we haven't (completely) ruled out such an explanation.

Newton and Einstein both seem to be on the side of hidden variables, so I'm not sure if it's unpopular among the elites.

I have a lot of trouble imagining any experiment which could completely rule out every other influencing factor. There are silly thought experiments such as what if the world has been objective for the last x00 years - prior to that and after, the laws we've observed during the period would bend; things will become inconsistent.

It's silly and I don't even believe it, but it does show that science is incapable of completely ruling out everything.

The truth could be endemic mystery. Endemic insanely and terrifyingly simple endless levels of understanding. In a way science is nothing unless that's the reality.

Re: Why Quantum Mechanics?

#62

Post by _0w8t »

trixie_ wrote: post #11

Randomly found a link to this video on super determinism from his blog and found it super interesting. 100% agree, what is 'free will' anyways? A concept with no scientific definition. Why is it even used to explain anything in quantum mechanics? https://www.youtube.com/watch?v=ytyjgIyegDI

The notion that quantum mechanics is associated with inherent chance in the universe thus explaining free will is itself problematic.

There is no chance in the equations of quantum mechanics as the equations are fully deterministic. The probabilities appear only when we try to explain interaction of classical systems with quantum ones. Traditional explanation is that those probabilities are inherent to the world. But this rise the question how this can be as there is no in reality classical systems, everything is quantum with deterministic equations. So more natural interpretation is that at classical level the system looses access to some information about global properties of the system and probabilities are just a natural consequence of this.

Re: Why Quantum Mechanics?

#63

Post by feoren »

c01n wrote: post #57

I will give it a shot :) Q: Because consciousness is all there is. Q2: Because you need consciousness to observe the universe as classical. Q3: Way over my head.

You seem to be asserting the anthropic principal, but in doing so you're assuming that quantum mechanics is required for consciousness. But that's not really an answer to this post -- he explicitly calls that out as a possible answer, but why is QM required for consciousness?

Re: Why Quantum Mechanics?

#64

Post by meroes »

seiferteric wrote: post #15
trixie_ wrote: post #11

Randomly found a link to this video on super determinism from his blog and found it super interesting. 100% agree, what is 'free will' anyways? A concept with no scientific definition. Why is it even used to explain anything in quantum mechanics? https://www.youtube.com/watch?v=ytyjgIyegDI

I think the question of free will is even simpler. It doesn't come down to determinism vs indeterminism because either way it's not "you" making a decision. At the lowest level (neuron or whatever) when a decision is "made" it is either deterministic (determinism) or probabilistic (indeterminism) based on physics but either way, where is the "you" in the process? Only way free will makes sense is if something superna…

This goes against the idea of strong emergence (mainly the bottom up causation part). I’m not arguing for or against it, but the SEP has an entry about it https://plato.stanford.edu/entries/properties-emergent/

“This often takes the form of rejecting physical realization, affirming fundamental higher-level causal powers, or both.”

I find it fascinating to wonder about causal powers in multiple directions. Does it even make sense? Does it conflict with physicalism? What is the physical anymore? Chomsky says there is no physical for the past few hundred years. It’s worth reading about at least.

Re: Why Quantum Mechanics?

#65

Post by feanaro »

seiferteric wrote: post #25
guerrilla wrote: post #20

Earlier quoted context omitted.

> At the lowest level (neuron or whatever) when a decision is "made" it is either deterministic (determinism) or probabilistic (indeterminism) based on physics but either way, where is the "you" in the process? It's a matter of scale. At the highest level, of the individual, if you present them with two options, they will chose one of the options. At that level, the question is a trivial: yes, obviously they have "th…

It's not satisfying that it would be considered free will if the outcome is based on the result of a probabilistic random number generator but perhaps that's what they mean... As for moral responsibility, essential no, it cannot exist again unless supernatural is involved for the same reasons outlined above, there is no "you" making a decision, just a process. As for whether you should feel guilty... well again I am…

The fact that your process knows about and is able to comprehend and reason about its own workings gives it the opportunity to change itself based on this knowledge.

To hear about it and to then decide "this absolves me of any guilt, because I couldn't have done it any differently" is also a choice your process made. Counterfactually, it could've made the opposite choice (though it didn't do so).

Now, me pointing this out presents yet another choice and opportunity for change. And these opportunities keep happening for the rest of your life.

In essence, even though you cannot change your actions in a very deep sense, concluding "I can't change myself because it's already determined" is always a premature conclusion, whenever it is made.

Re: Why Quantum Mechanics?

#66

Post by go_elmo »

feoren wrote: post #63
c01n wrote: post #57

I will give it a shot :) Q: Because consciousness is all there is. Q2: Because you need consciousness to observe the universe as classical. Q3: Way over my head.

You seem to be asserting the anthropic principal, but in doing so you're assuming that quantum mechanics is required for consciousness. But that's not really an answer to this post -- he explicitly calls that out as a possible answer, but why is QM required for consciousness?

Because since we dont understand consciousness, we cannot assume qm to be irrelevant for it, being the basis of the universe, which were just a part of?

Re: Why Quantum Mechanics?

#68

Post by guerrilla »

inter_netuser wrote: post #58
raindeer2 wrote: post #36

Earlier quoted context omitted.

"moral responsibility, essential no, it cannot exist again unless supernatural is involved for the same reasons outlined above, there is no "you" making a decision, just a process." This view is based on a misunderstanding of what moral responsibility is. Moral responsibility is essentially credit assignment [1]. It exists as a concept not because it matters whether or not you actually could have done differently bef…

if the "machine" is programmed to make a certain "choice", and "obeys" that programming, why is it guilty?

Because it's the source of the problem to be correct. That's it. Which part of this car is faulty? Same thing.

Re: Why Quantum Mechanics?

#69

Post by ketozhang »

6gvONxR4sf7o wrote: post #40
sam-2727 wrote: post #18

Earlier quoted context omitted.

> Can you do QM with just the real valued probability distribution? You can't. The key fact is that other observables, such as momentum, depend on the complex part of the wave function.

But those have real valued probability distributions too, right? Does modeling the evolution of the joint distribution of all the observables not count?

Yes you're right, every superposition of quantum systems have a real valued probability distribution for some observable variable.

QM has very specific rules when it comes to how two random variables are dependent. That specific rule comes up when you have quantum interference and this is best described by the conjugate square of two complex functions A^2 + B^2 + A*B + B*A. This is just a special case of the union probability: P(A) + P(B) - P(AB).

Re: Why Quantum Mechanics?

#70

Post by hansbo »

breuleux wrote: post #34
EMM_386 wrote: post #24

Earlier quoted context omitted.

I strongly feel that the mystery of consciousness is somehow deeply tied into why we have things like QM and not classical physics. If it was just classical physics, then you get yourself into the thinking that you can rewind time and all the "billiard balls" knock into each other the same way, which is why you order a soup and not a sandwich every single time on that day. That eliminate free will. There is something…

> If it was just classical physics, then you get yourself into the thinking that you can rewind time and all the "billiard balls" knock into each other the same way, which is why you order a soup and not a sandwich every single time on that day. I don't understand this line of reasoning. If I ordered a soup for lunch, and then time is rewound and I order a sandwich instead, it would appear that my choice is in fact r…

I view this the same way. Determinism vs randomness says nothing about free will.

I think the problem with arguments regarding free will is that it's very hard to define (like consciousness for that matter). I am my brain. My brain controls what I do. Therefore, I control what I do. Only if we lift up our consciousness or free will as something higher than our brain does this become a problem.

The fact that my free will is deterministic, that is, a consequence of how the brain is structured and how the environment looks, does not change the fact that I, that is, my brain, controls what my body does. If anything, randomness makes this worse - then it is not my brain controlling my body, but some random result of a wave function collapse.

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