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Why Quantum Mechanics?

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Re: Why Quantum Mechanics?

#91

Post by MichaelRazum »

Schroedingers2c wrote: post #90
MichaelRazum wrote: post #80

Im just taking the easy course of QM by Suesskind. He had an example like you have two coins and give them randomy to your kids. The they move far away. Then one kid discovers what it got, it knows what the other has. So what I dont get is why QM you could argue that there is some hidden shared state. Guess this is a typical question. But anyway I‘m somehow not convinced that it is really random.

You can think of scenarios in which any classical state (i.e. the shared state is completely specified by the local states of the two kids) does the task with some success probability that is upper bounded, say by 75%. And you can even include some unspecified hidden variable in your classical state and could even allow the two kids to share some classical randomness (think: each of them has a button that returns the…

But as I understand if you break the non locality assumption for the state, then you could make it kind of work. So lets just say by introducing a global variable for the shared state you could explain it (hidden dimension or whatever). Ok maybe it breaks a classical assumptions. I have no doubt that QM works, just wondering if it is really the final resolution we can get.

Re: Why Quantum Mechanics?

#92

Post by _Nat_ »

> 4. To keep the discussion focused, in this post I’d like to exclude answers along the lines of “but what if QM is merely an approximation to something else?,” [...] imagine that, as fantastical as it sounds, QM were not only exactly true, [...]

Seems like an absurd, conceptually-crippling stipulation, analogous to asking why [the fine-structure-constant is exactly 1/137](https://en.wikipedia.org/wiki/Fine-structure_constant#Numero... ).

I mean, while one might reasonably wonder why alpha~=1/137, wondering why alpha=1/137 exactly doesn't seem like a simplification but rather a different question that'd invite a different sort of reasoning.

Re: Why Quantum Mechanics?

#93

Post by octoberfranklin »

_Nat_ wrote: post #92

> 4. To keep the discussion focused, in this post I’d like to exclude answers along the lines of “but what if QM is merely an approximation to something else?,” [...] imagine that, as fantastical as it sounds, QM were not only exactly true, [...] Seems like an absurd, conceptually-crippling stipulation, analogous to asking why [the fine-structure-constant is exactly 1/137]( https://en.wikipedia.org/wiki/Fine-structur…

Dude, what are you talking about, the fine structure constant is exactly 1/137. The TimeCube [1] told me so.

[1] https://en.wikipedia.org/wiki/Time_Cube

Re: Why Quantum Mechanics?

#94

Post by EMM_386 »

trixie_ wrote: post #27
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…

That's why physicists are so opposed to super determinism because like you say it would make life 'utterly meaningless' (I dont agree, a bit dramatic). Super determinism is the unpopular answer that solves many problems in quantum mechanics and relativity. It also makes a lot of sense if you think of the universe as pre-rendered, just like you would a CGI movie. Determine where all the particles land upfront througho…

> Life can still be fun even it is pre-rendered. Like a movie you don't know what's going to happen next anyways.

What if my life isn't "fun"?

A lot of people live out lives of complete suffering. Childhood cancer? Poverty? Disease? Genetic mental health issues? Inbreeding? Childhood trauma? That list goes on and on.

That isn't a movie I signed up for.

Does determinism think this is supposed to be a lesson of some sort?

Re: Why Quantum Mechanics?

#95

Post by EMM_386 »

MattPalmer1086 wrote: post #41
trixie_ wrote: post #27

Earlier quoted context omitted.

That's why physicists are so opposed to super determinism because like you say it would make life 'utterly meaningless' (I dont agree, a bit dramatic). Super determinism is the unpopular answer that solves many problems in quantum mechanics and relativity. It also makes a lot of sense if you think of the universe as pre-rendered, just like you would a CGI movie. Determine where all the particles land upfront througho…

Physicists don't largely choose physical theories on whether they make life meaningful or not. I think you're thinking of religious people.

> Physicists don't largely choose physical theories on whether they make life meaningful or not. I think you're thinking of religious people.

I disagree, I think quite the opposite.

Physicists often seem to adhere to a "religion" of sorts, that being atheism. Anything to get rid of the "God problem".

It's not all so cut and dry.

> “I believe in Spinoza's God, who reveals himself in the lawful harmony of the world, not in a God who concerns himself with the fate and the doings of mankind.” - Albert Einstein

I'm not religious.

Re: Why Quantum Mechanics?

#96

Post by jiggawatts »

dskloet wrote: post #82
MichaelRazum wrote: post #80

Im just taking the easy course of QM by Suesskind. He had an example like you have two coins and give them randomy to your kids. The they move far away. Then one kid discovers what it got, it knows what the other has. So what I dont get is why QM you could argue that there is some hidden shared state. Guess this is a typical question. But anyway I‘m somehow not convinced that it is really random.

You'll be convinced once you understand the EPR paradox and Bell's inequality. So look those up if you want to be convinced.

I did, and they make perfect sense if you look at them through the lens of MWI, which however seems weirdly unpopular in QM circles. I was taught the Copenhagen interpretation, which is just... madness.

Re: Why Quantum Mechanics?

#97

Post by octoberfranklin »

lordnacho wrote: post #47
chaxor wrote: post #17

Earlier quoted context omitted.

Right hand rule only works in 3d and 7d

That is rather fascinating, where can I read about this?

In the early chapters of the Feynman Lectures on Physics (volume II) there is a really good explanation of why cross product and curl make absolutely no sense in more than three dimensions. The fact that they can be defined unambiguously is a complete accident which occurs only in three dimensions.

Not sure if this is what GP was talking about. But the explanation there is excellent. It's in the chapter where curl is introduced for the first time. After you read it, you'll get annoyed whenever you see curls or cross products.

Also: https://en.wikipedia.org/wiki/Seven-dimensional_cross_produc...

Re: Why Quantum Mechanics?

#98

Post by jiggawatts »

guerrilla wrote: post #5

I've always liked these kinds of questions. Myself, I always wondered why specifically three dimensions. (Please don't start telling me about string theory.)

String theory is just intellectual wankery at this point.

However, a more interesting and much simpler variation has just 5 dimensions, and was seriously studied by Einstein: https://en.wikipedia.org/wiki/Kaluza%E2%80%93Klein_theory

Re: Why Quantum Mechanics?

#99

Post by jiggawatts »

dboreham wrote: post #2

Q1: because that wouldn't be consistent with simulation. Q2: because that's how the simulator works. Joking aside, I wonder if there's some principle that: physics will always look like you'd expect it to look if it's a simulation. Perhaps that's what Yang-Mills Gauge Theory is about?

I'm the type of person that likes to visualise the space of all possible theories of everything like a surface. A table, let's say. I like to imagine placing similar theories together, like stacking papers. Likely candidates closer to the middle of the table, fringe theories physically further away, under a pile of other junk.

I've never been able to mentally put the "we're in a simulation" paper away. It's always been persistently plausible, and refuses to budge.

A friend of mine keeps insisting that a lot of the complexity we see in physics stems from floating point arithmetic rounding error.

Re: Why Quantum Mechanics?

#100

Post by raindeer2 »

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?

The human machine is not programmed in the traditional sense, it's learned to a large extent. Guilt is a signal that some behavior should be changed/relearned/reprogrammed.

The open question is why and how humans can "feel" guilt. How can a machine have a subjective experience at all? What is a subjective experience? This is the so-called "hard problem".

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