Why is Quantum thoery so confusing that no body actually understand it ?

In summary, Richard Feynman says that nobody understands quantum mechanics and that it is confusing because there is no frame of reference for us to understand it. He also says that quantum mechanics is like a spider web in a dream, and that it will be easier to understand in the future.
  • #1
Rico L
37
0
It says that:

I think I can safely say that nobody understands quantum mechanics...Do not keep saysing to yourself, if you can possibly avoid it. But how can it be like that? Because you will go "down the drain" into a blind alley from which nobody has yet escaped. Nobody knows how it can be like that.
by Richard Feynman


what does he mean by "down to the drain" and "blind alley"? . .

why is quantum world so confusing?

can anyone just come up with an example would be great



cheers..
 
Physics news on Phys.org
  • #2
I mean I have read a few articles about them and I think its mainly to do with possibilities.. I haven't gone deep enough to find it confusing... so can anyone sort of explain for bit .. an example would be great


thanks
 
  • #3
entanglement, unitary evolution (continuous, deterministic) and state reduction (discontinuous, probabilistic).

quantum jumping, I'll state that I had only read the textbooks and listened to lectures for the last 15yrs not as a student but as a hobby, weird I know. Now that I have a bit more spare time I'm taking the time to learn more of the math. I'll say that it to me seems to further divide probabilistic vs state vector.
just by measuring the momentum of the particle it jumps into an eigenstate of the momentum operator and if I've got this right it's now a wave form and spread over all of space. but if you try and measure this new state it jumps again, I think this is the collapse of the wave function or state reduction to probabilistic. So based on that the measuring is part of the system and each measurement effects it state so that you'll always have a missing piece.
That's how i see it for now, still learning and I'll say that don't expect it to get easier or make more sense. I enjoy going down the 'rabbit hole' though.
 
  • #4
There is a fundamental limitation with any attempt to self reference your own design. This is something computer programmers discovered when trying to build the ultimate debugger. We are trying to understand the elementary particles that make up the same tools we are using to measure them.
 
  • #5
i see..

cheers ppl
 
  • #6
I think there is a more fundamental reason here. It's not that we can't understand it because it is confusing. It's not confusing -- it's unimaginable. When we say we understand something this usually means we have explained the new thing in terms we have experienced. It's like going to a foreign culture: there is no decent frame of reference. But then you talk to people and learn what things are like. You gain experience.

But quantum mechanics is different because we cannot gain this direct experience. So we try and grasp it through analogies. But every analogy is to something macroscopic: is it a particle (read: billiard ball) or a wave (read: water wave). Well, it's a bit of both -- which makes no sense for billiard balls and water waves. Nonetheless that's the way the microscopic works.
 
  • #7
The problem isn't with QM, which is just a set of rules that tells us how to calculate probabilities of possibilities. The problem is with the idea that "QM describes the world out there". It's very tempting to believe that this statement is true, or even obvious, but it's probably not even logically consistent.
 
  • #8
dulrich said:
I think there is a more fundamental reason here. It's not that we can't understand it because it is confusing. It's not confusing

thats confusing.. :) lol

i see your point
 
  • #9
There is also the reality that without an understanding of linear algebra, understanding QM is going to be approximate, and confusing.
 
  • #10
I think its more like a spider web in a dream*.



edit:
*nightmare
 
Last edited:
  • #11
I don't like that Feynman's quote. It's too ambiguous and open to interpretation. QM is a well defined mathematical framework that is based on postulates the same way special relativity is, and it makes reliable predictions up to a certain limit.

What we don't understand is the theory of everything, if there ever is such an idea.
 
  • #12


waht said:
I don't like that Feynman's quote. It's too ambiguous and open to interpretation. QM is a well defined mathematical framework that is based on postulates the same way special relativity is, and it makes reliable predictions up to a certain limit.

What we don't understand is the theory of everything, if there ever is such an idea.

I have a feeling it will be easier to understand than quantum
 
  • #13
Rico L said:
thats confusing.. :) lol

i see your point


It is classical physics that was confusing for me. Although, I could do it with my eyes shut I could not really understand why. It was the same old thing, we do experiments plot and get the equations no explanation as such( like f=GMm/r^2). Thank god for QM/QFT things make much more sense.
 
  • #14
Fredrik said:
The problem isn't with QM, which is just a set of rules that tells us how to calculate probabilities of possibilities. The problem is with the idea that "QM describes the world out there". It's very tempting to believe that this statement is true, or even obvious, but it's probably not even logically consistent.


Any formalism that makes stunningly correct predictions about the world out there must be describing the world out there. Proposing otherwise is probably not even logically consistent.
 
  • #15
GeorgCantor said:
Any formalism that makes stunningly correct predictions about the world out there must be describing the world out there. Proposing otherwise is probably not even logically consistent.

That is absurd.
 
  • #16
IcedEcliptic said:
That is absurd.


No. What is very obviously absurd is that an ape-like creature that historically has just descended from the trees, actually thinks that reality MUST conform to his/her prejudice and intuition. I don't think that nature, the world, reality, or call it whatever, cares about how you want the world to be. In a wider context, everything is absurd - how reality works is absurd, existence is absurd, life is absurd, self-awareness is absurd, but it's a brute fact. Face it or suggest a reason why it must NOT be absurd.

It must all be stemming from the fact that we thought for so long that we understood reality and existence. We do not, and this is exactly 100.00% certain. We have no proper understanding of what is going on, how it is going on and why it is going on. We are still dumb animals born in a fairly absurd reality. Face this fact, or join the religious who think they have the important answers figured out.
 
  • #17
So the choice is to remain monkey or be a man? Hurm...

I think the thing QM is that it's concepts are fairly simple on the surface but have a level of complexity at the bottom that you would need a super computer and 10 years at MIT to understand. So while everyone thinks they understand QM at the basics the reality is only a select few really get what its saying about the world. It's sort of like poker or chess :) Everyone thinks they know how to play yet only a select few end up at the championships year after year. Sorry if this comment gets the thread locked :( :(
 
  • #18
GeorgCantor said:
Any formalism that makes stunningly correct predictions about the world out there must be describing the world out there. Proposing otherwise is probably not even logically consistent.
GeorgCantor said:
No. What is very obviously absurd is that an ape-like creature that historically has just descended from the trees, actually thinks that reality MUST conform to his/her prejudice and intuition.
You don't even seem to realize that the claim you made is only based on your own prejudice and intuition. The truth of the proposition that QM describes the physical system under consideration even at times between state preparation and measurement does not follow logically from the truth of the proposition that QM describes the system immediately after each measurement.

It's quite bizarre that you take what I said as evidence that I think reality must conform to my prejudice and intuition. The only unsual thing I've done is to let go of the prejudice that every theory that makes accurate predictions about probabilities of possible results of experiments must be a description of reality at all times.

I'm not saying that QM isn't a description of a physical system. I'm saying that maybe it is, and maybe it isn't. The information we get from experiments just isn't enough to rule one of these options out. I'm also not saying that the idea that "QM describes a physical system at all times" is logically inconsistent. As far as I know, it isn't. But it does seem to imply the existence of many worlds. So as far as I can tell, the idea that QM describes reality and the idea that reality consists of only our universe, can't both be true.

GeorgCantor said:
It must all be stemming from the fact that we thought for so long that we understood reality and existence. We do not, and this is exactly 100.00% certain. We have no proper understanding of what is going on, how it is going on and why it is going on. We are still dumb animals born in a fairly absurd reality. Face this fact, or join the religious who think they have the important answers figured out.
There are times and places where comments like these are appropriate, but this is definitely not one of them.
 
  • #19
Quantum mechanics as a tool is understood by those who use it, professional physicists. What knowbody knows is why nature is this way. Most specifically, from Feynman, nobody knows why or how quantum interference takes place in nature. But that it does, and that it quantum theory is incredibly accurate is not in dispute.

As to the absurdity or not of asserting that QM describes thecreal world, it's a matter of fidelity. The 4 elements, air, earth, fire, water describe the world to a certain fidelity. The fidelity of QM is a lot higher but it is not the last word in understanding the physical world. In fact it's just the opening sentence. Humans have not addresed the how or why of it yet.
 
  • #20
Fredrik said:
You don't even seem to realize that the claim you made is only based on your own prejudice and intuition. The truth of the proposition that QM describes the physical system under consideration even at times between state preparation and measurement does not follow logically from the truth of the proposition that QM describes the system immediately after each measurement.


I understand your unwillingness to say specifically that QM describes the system between measurements, but if everytime we do a measurement/observation we get an accurate result that exactly conforms to the calculations, what could it be that the said formalism is describing except reality itself? How could it even be otherwise? We have to be logical and logic dictates that if said theory makes correct predictions(so far QM is the most successful theory there is in physics), then it must describe reality. Be specific, how could it be otherwise? How could the world be different than QM describes, if QM's predictions are always accurate to a striking degree of precision?



I'm not saying that QM isn't a description of a physical system. I'm saying that maybe it is, and maybe it isn't. The information we get from experiments just isn't enough to rule one of these options out.


Right. But what is the other option and how would that be? We have a theory that makes correct predictions but you are saying it might not be a description of reality? How so? Are you proposing abandoning causality at certain level? If so, we'd be essentially abandoning science as we know it. I am not saying reality isn't that way, but if there is no fundamental cause as to why things happen the way they do at the macro scale, that'd be the end of the quest for answers to the deep philosophical questions. And abandoning causality opens the door to a myriad of "God did it" interpretations.



I'm not saying that QM isn't a description of a physical system. I'm saying that maybe it is, and maybe it isn't. The information we get from experiments just isn't enough to rule one of these options out. I'm also not saying that the idea that "QM describes a physical system at all times" is logically inconsistent. As far as I know, it isn't. But it does seem to imply the existence of many worlds. So as far as I can tell, the idea that QM describes reality and the idea that reality consists of only our universe, can't both be true.


Correct but MWI could be said to be "flowing" out of the QM formalism and experiments. As such, it is also a correct description of the world out there, as per qm formalism. Even between measurements and interactions.
 
Last edited:
  • #21
GeorgCantor said:
I understand your unwillingness to say specifically that QM describes the system between measurements, but if everytime we do a measurement/observation we get an accurate result that exactly conforms to the calculations, what could it be that the said formalism is describing except reality itself?
A fictional universe with the property that a description of some aspect of it resembles a description of the real universe.

GeorgCantor said:
We have to be logical and logic dictates that if said theory makes correct predictions(so far QM is the most successful theory there is in physics), then it must describe reality.
That conclusion does not follow from that premise.

GeorgCantor said:
Be specific, how could it be otherwise? How could the world be different than QM describes, if QM's predictions are always accurate to a striking degree of precision?
I think this reveals what your mistake is. You're making an "argument from incredulity". You don't see how what I'm suggesting is possible, so it must be impossible. That's not a logical argument, it's a logical fallacy.

For the record, I don't see how it's possible either. To really see it, we would have to find a more fundamental theory from which QM can be derived.
 
  • #22
GeorgCantor said:
No. What is very obviously absurd is that an ape-like creature that historically has just descended from the trees, actually thinks that reality MUST conform to his/her prejudice and intuition. I don't think that nature, the world, reality, or call it whatever, cares about how you want the world to be. In a wider context, everything is absurd - how reality works is absurd, existence is absurd, life is absurd, self-awareness is absurd, but it's a brute fact. Face it or suggest a reason why it must NOT be absurd.

It must all be stemming from the fact that we thought for so long that we understood reality and existence. We do not, and this is exactly 100.00% certain. We have no proper understanding of what is going on, how it is going on and why it is going on. We are still dumb animals born in a fairly absurd reality. Face this fact, or join the religious who think they have the important answers figured out.

Fredrik beat me to this, but I will say that you keep the "dumb animal" part, and that may be true. Perhaps the universe is comprehensible to a dumb animal, you are not dealing in logic, just virulent personal bias. The real Cantor would be appalled.
 
  • #23
IcedEcliptic said:
Fredrik beat me to this, but I will say that you keep the "dumb animal" part, and that may be true. Perhaps the universe is comprehensible to a dumb animal, you are not dealing in logic, just virulent personal bias. The real Cantor would be appalled.


No. He has not beat you to it. You clearly did not understand what he said and what he had meant to say with his previous posts, considering his last post. If you have nothing better than an ad hominem, i am not intersted in contunuing this discussion with you.
 
  • #24
Fredrik said:
A fictional universe with the property that a description of some aspect of it resembles a description of the real universe.


If the fictional universe becomes real according to the rules and predictions of qm, then the fictional universe is our universe and it is described by QM. I.e. QM describes the world "out there".



GeorgCantor said:
We have to be logical and logic dictates that if said theory makes correct predictions(so far QM is the most successful theory there is in physics), then it must describe reality.


That conclusion does not follow from that premise.



It doesn't? Why?


Fredrik said:
I think this reveals what your mistake is. You're making an "argument from incredulity". You don't see how what I'm suggesting is possible, so it must be impossible. That's not a logical argument, it's a logical fallacy.

For the record, I don't see how it's possible either. To really see it, we would have to find a more fundamental theory from which QM can be derived.


OK, one could be faithful that QM doesn't describe reality for fear or anxiety. But the fact that it has made the most successful and tested predictions in science means something very disturbing - that it is very likely the right description of reality. I still fail to see how one would justify a world different than the one 'projected' by qm, yet conforming to the experiments like DCE, the c60 molecules in the twin slit, observed superpositions, etc.
 
  • #25
GeorgCantor said:
No. He has not beat you to it. You clearly did not understand what he said and what he had meant to say with his previous posts, considering his last post. If you have nothing better than an ad hominem, i am not intersted in contunuing this discussion with you.

What discussion? You're relying on nonscientific reasoning to reach conclusions. There is nothing to discuss except the flaws in your reasoning. Your personal prejudices and views, intuition as Frederik has said, is what you rely on here. That's just not useful in this context.
 
  • #26
IcedEcliptic said:
What discussion? You're relying on nonscientific reasoning to reach conclusions. There is nothing to discuss except the flaws in your reasoning. Your personal prejudices and views, intuition as Frederik has said, is what you rely on here. That's just not useful in this context.


What prejudice? Please site the post that exposes my prejudices, as i claim I have no answers to philosophical questions. You never even made a statement so far, apart for the cryptic incoherent "That's absurd" reply to my post:

Any formalism that makes stunningly correct predictions about the world out there must be describing the world out there. Proposing otherwise is probably not even logically consistent.


And yes, it is a discussion even if you don't understand what is being discussed. The argument that QM doesn't describe reality isn't a new one, though i have not seen it being discussed here.

Further, what "nonscientific reasoning to reach conclusions" am i using? I claim that you don't understand at least 90% of what is being discussed here, so what's the point of your participation? Do you even understand that science is silent as to what happens to quantum systems between measurements? What science exactly do you have in mind? That of your fantasy or that of your personal philosophy?


Your personal prejudices and views, intuition as Frederik has said, is what you rely on here.


Fredrik DOESN'T KNOW how reality could be, if QM isn't a true description of it. But he is hopeful that it will be understood(one day). Do you understand as much?
 
Last edited:
  • #27
GeorgCantor said:
What prejudice? Please site the post that exposes my prejudices, as i claim I have no answers to philosophical questions. You never even made a statement so far, apart for the cryptic incoherent "That's absurd" reply to my post:




And yes, it is a discussion even if you don't understand what is being discussed. The argument that QM doesn't describe reality isn't a new one, though i have not seen it being discussed here.

Further, what "nonscientific reasoning to reach conclusions" am i using? I claim that you don't understand at least 90% of what is being discussed here, so what's the point of your participation? Do you even understand that science is silent as to what happens to quantum systems between measurements? What science exactly do you have in mind? That of your fantasy or that of your personal philosophy?





Fredrik DOESN'T KNOW how reality could be, if QM isn't a true description of it. But he is hopeful that it will be understood(one day). Do you understand as much?

Here is what I understand: The formalism of QM is a tool for making meaningful predictions, and not a complete theory. While it may describe some elements of reality, it is incomplete. This is hardly a stretch. I have seen it argued many times that QM is a series of mathematical tools, and not an ontology, if you have not, you have not been reading other people's posts.

For your prejudice, I would point to the monkeys in trees bit. I have no notion as to whether reality, if there is such a thing, can be understood. Perhaps human beings are perfectly capable of doing so, unlikely as that seems. Your prejudice is that reality must be of a nature and complexity that evolved apes cannot describe or understand that. It is not a bad assumption, but it is still just that, an assumption.

You also keep going on about how "dumb" we are as a species, so I'll ask you: compared to what? Arguing for the "What fools these mortals be." angle is rhetorical and biased, and you belabor it beyond all reason, as Frederik has already pointed out, thus "beating me to it" as I said earlier.

Frederik isn't certain as to the nature of reality, except that he personally believes in some limits (MWI for instance), but you are certain of its incomprehensibility. Why!? Where have you found evidence in our short history (which you keep referrring to) which proves your point? The fact that people once thought that the world was flat, did not stop the eventual understanding that it is spheroid. That understanding does not stop us from appreciating the possibility of a holographic principle, or some other deeper description either.

Arguing that past ignorance predicts a future of ignorance may be a likely thing, but it is not the biblical certainty that you present it as. For the "90%" comment, I assume that is a joke about statistical certainty, and not a baseless statement you have no hope of confirming.

GeorgCantor said:
Any formalism that makes stunningly correct predictions about the world out there must be describing the world out there. Proposing otherwise is probably not even logically consistent.

That is ABSURD, and not logical. QM makes stunningly correct predictions which have not been sufficiently tested to lead to the conclusion that it is a description of nature. In fact, that notion is on conflict with your argument of perpetual stupidity of people. Further, GR is a formalism that makes stunningly correct predictions which eventually break down and clash with QM, and visa versa. Which "stunningly correct" set of predictions is correct? This would seem to indicate that we are dealing in partial descriptions to accommodate our, how would you enjoy it, "monkey brains". There may be no need for non standard QM interpretations, but the fact is that they arose because of a conflict with the nature we predict and the nature we routinely observe.

It is not logically absurd, although I do not believe it, to conclude that all probabilities are expressed, and no collapse occurs. Your refutation is a bit of an ad hominem attack against, well, Hominids. My guess is that you are quite religious, and not well versed with the day to day workings of QM as applied by engineers and physicists doing work. It is only a guess, I may be wrong, and by your "reasoning" I only have about 10% to work with! :rofl:
 
  • #28
GeorgCantor said:
Any formalism that makes stunningly correct predictions about the world out there must be describing the world out there. Proposing otherwise is probably not even logically consistent.
But classical physics made stunningly correct predictions for 200 years. It turned out that the equations were excellent approximations in limited circumstances while the theoretical underpinnings were simply wrong.
 
  • #29
Jimmy Snyder said:
But classical physics made stunningly correct predictions for 200 years. It turned out that the equations were excellent approximations in limited circumstances while the theoretical underpinnings were simply wrong.


Yet, classical physics was a partial description of reality. Quantum physics, according to most physicists, is a better description of reality(in the sense of 'truer' description of reality). Although it may be incomplete, it's hardly possible to call it a wrong description of reality or that it's NOT a description of reality(I still fail to see how an experimentally verified theory could be a wrong description of reality). Of course it is a better and fuller, though incomplete, description of reality. Is somebody arguing that point?
 
Last edited:
  • #30
I can if you want me too?
 
  • #31
magpies said:
I can if you want me too?


Yes, experiments that confirm thousands of times the formalism of QM are wrong and your ape-like intuition is right. Keep it coming.
 
  • #32
Well the main problem I see with QM and any other theory is that none of them actually explain what "stuff" is made out of. You can say it's made out of electrons or particles or wood ect... But it will always leave you wondering what is that made out of... It may be an unanswerable question really. Because how do we define substance without using substance it's self? So this is really what QM or any other theory is trying to answer the question of the chicken and the egg clearly. I suppose the answer to what stuff is may exist however I highly doubt we will ever find it.

I would be willing to bet that it is in our nature to not find this answer and for it to be found will take a different type of being. I would guess that most humans would think that our children either in the form of actual children or some type of AI would be able to find it. However I'm thinking it will take a completely different type of mind to solve these problems and that mind either already exists or will at some point or will never. Most likely it does not exist and by what means it will come into existence I can not really think of. I suppose when this being does come into existence the world will never be the same.
 
  • #33
GeorgCantor said:
Yet, classical physics was a partial description of reality.
What does classical physics get even partially right? As I understand it, the equations are slightly wrong in all circumstances and wildly wrong in some. But more to the point, the theoretical basis is incorrect.
 
  • #34
GeorgCantor said:
If the fictional universe becomes real according to the rules and predictions of qm, then the fictional universe is our universe and it is described by QM. I.e. QM describes the world "out there".
Indirectly yes, but I don't think it's appropriate to say that "the theory describes reality" if this is the case. That phrase should be reserved for situations when the theory describes only the relevant aspects of our universe, and not for situations when it describes a much larger system that may or may not exist.

GeorgCantor said:
It doesn't? Why?
You're the one who says that it does, so the burden of proof is on you.

GeorgCantor said:
OK, one could be faithful that QM doesn't describe reality for fear or anxiety.
No fear or anxiety is needed to admit that the possibility exists. A healthy respect for logic is sufficient.
 
Last edited:
  • #35
Jimmy Snyder said:
What does classical physics get even partially right?
Orbits of planets, that if you drop an apple it falls to the ground, that a current through a wire will produce a magnetic field, that a gas cools when it expands, time dilation, the expansion of the universe, ... We could probably fill a book just with the examples.
 
Last edited:

Similar threads

  • Quantum Physics
Replies
7
Views
985
Replies
20
Views
3K
Replies
7
Views
1K
Replies
4
Views
6K
  • Quantum Interpretations and Foundations
Replies
13
Views
3K
  • Quantum Physics
Replies
3
Views
1K
Replies
46
Views
2K
Replies
10
Views
2K
  • Quantum Physics
Replies
15
Views
2K
  • Quantum Interpretations and Foundations
Replies
16
Views
545
Back
Top