Heisenberg incertitude principe ? contradicting ?

[JPC]

hey

does the Heisenberg incertitude principe really show that there are random numbers in nature ? Because to me doesn't sound very logic that the future is not predefined. I mean that it would mean that if my magic we could "Roll back time , and press the play button", things won't happen the same, different events would occur. And, if there are random numbers, what determines these random numbers ? It would sound way more logic that a precise object/reaction/event leads to a precise object/reaction/event.

And, what tells us that behind what we see as intercitudes, there is actually a billion lines long equation ?

And, Heisenberg says that things do not have a precise location, properties , ect until they are measured ?
But what does it mean to be measured ? why would everything be imprecise just because one being from one specie on Earth hasnt measured it ? why would a rubber have an imprecise length until one type of complexly assembled object (human) put a ruler besides it.

 

[meopemuk]

hey

does the Heisenberg incertitude principe really show that there are random numbers in nature ? Because to me doesn't sound very logic that the future is not predefined. I mean that it would mean that if my magic we could "Roll back time , and press the play button", things won't happen the same, different events would occur.

Yes, this is exactly the major point of quantum mechanics. Events in nature occur as if there was a random noise that wouldn't allow them to be repeatable. Nobody knows what is the reason of this indeterminism.

And, Heisenberg says that things do not have a precise location, properties , ect until they are measured ?
But what does it mean to be measured ? why would everything be imprecise just because one being from one specie on Earth hasnt measured it ? why would a rubber have an imprecise length until one type of complexly assembled object (human) put a ruler besides it.

This is another important lesson of quantum mechanics: we should't even ask what are system's properties before they are measured. All we can know about physical system comes from measurements, and the goal of theory is to predict results of these measurements. That's what quantum mechanics does brilliantly. Questions about "what happens in reality?" (i.e., while we are not measuring) don't belong to science, because whatever answer is given it cannot be verified by experiment.

Eugene.

 

[AppleBite]

And, Heisenberg says that things do not have a precise location, properties , ect until they are measured ?
But what does it mean to be measured ?

Well, the thing with measurement is that the observer will always affect the observed. A simplistic illustration is imagine being in a dark room. To observe the things around you, you lit your flashlight. The light from your flashlight however, has energy and this energy is transferred to the objects which you are observing. Obviously, by adding energy to what is observed, the observed is affecting the observed! That is why nothing can be determined precisely before being measured. It's just like Schrödinger's cat. From the reference frame of the observer, the cat is both dead and alive until the observer affects the observed by opening the box.

This is why the position and speed of an electron may never be determined simultaneously. Imagine, if you want to observe the electron's position, you have to add energy to it in order to observe, and this will affect the speed. If measuring the speed however, position will be affected as the electron is being observed.

Quantum theory does seem contradictory yes, but it's all about "stepping outside the box" and being willing to accept new ideas.

 

[fleem]

QM predicts the classical result of very low energy experiments. It does not explain what actually happened, and we just don't know. We can only guess. Look up the difference between "Copenhagen interpretation" and "hidden variables".

In a nutshell, part of the Copenhagen interpretation is "shut up and calculate", which can be interpreted as we may never know what "really happens", or maybe "all that happens is what we see classically and nothing more".

The "hidden variables" interpretation assumes, just as you say, reality really is deterministic and there are things going on that we just don't know about. I'm a hidden variable-ist. I believe Mach's principle is manifested as continual interactions between all particles in the universe, and these are the hidden variables. (How silly to claim a particle can exist without interacting with the other particles of the universe!)

However, one of the big reasons the jury is still out on this is because of superposition. Apparently energy need not be conserved until the results of an experiment is observed, and the definition of "observation" is debatable. So that's why the heated debate rages on what really happens.

 

[Hurkyl]

Because to me doesn't sound very logic that the future is not predefined. I mean that it would mean that if my magic we could "Roll back time , and press the play button", things won't happen the same, different events would occur. And, if there are random numbers, what determines these random numbers ? It would sound way more logic that a precise object/reaction/event leads to a precise object/reaction/event.

Nothing you said here is logical; you haven't made any deductive or inductive arguments that derive a conclusion from stated hypotheses.

The determinism / indeterminism question has been around for a long time; I think it goes back at least as far as the ancient Greeks. And, incidentally, pre-quantum mechanics doesn't imply determinism nor does quantum mechanics imply indeterminism.

e.g. all of classical mechanics is perfectly consistent with the hypothesis that physical quantities are random variables. And the class of 'unitary evolution' interpretations of QM state that the 'wavefunction of the universe' evolves in a strictly deterministic fashion.

And, what tells us that behind what we see as intercitudes

By the way, it's the Heisenberg uncertainty principle.

why would everything be imprecise just because one being from one specie on Earth hasnt measured it ? why would a rubber have an imprecise length until one type of complexly assembled object (human) put a ruler besides it.

The point is that the classical description of the universe is not exactly correct. Quantum mechanics is not merely classical objects with random behavior; quantum mechanics is a whole new theory. And the easiest way to prevent yourself from understanding quantum mechanics is to insist upon describing things in classical terms.

 

[JPC]

It's just like Schrödinger's cat. From the reference frame of the observer, the cat is both dead and alive until the observer affects the observed by opening the box.

Yes, but I mean there should be a either Dead or Alive property for the cat ? Its not because we cannot determine if he's dead or alive that he's not either dead or alive ? Why couldn't things be without being measured ?

Why couldn't there be hidden variables as fleem says ? Like equations that we don't know yet to calculate , but that to get the variables we need to use systems that modify these variables, so meaning we can only get aproximations.

 

[JPC]

oh sorry, for the cat experience, i didnt see "From the reference frame of the observer,"

 

[Hurkyl]

Yes, but I mean there should be a either Dead or Alive property for the cat ? Its not because we cannot determine if he's dead or alive that he's not either dead or alive ? Why couldn't things be without being measured ?

Why couldn't there be hidden variables as fleem says ? Like equations that we don't know yet to calculate , but that to get the variables we need to use systems that modify these variables, so meaning we can only get aproximations.

Because, as per the experimental confirmations of Bell's theorem, we have to give up some 'desirable' feature of the universe. If you want to keep hidden variables, then you have to give up some other 'desirable' property of the universe. (And you have to deal with the fact that it's quantum mechanics that has all of the empirical support, not the hidden variable theories)

 

[JPC]

yes but where would these random numbers come from ?

 

[AppleBite]

Well what do you mean "come from"?

Quantum theory describes that it's a matter of probability. Like rolling a die, you can't really say that the outcome "comes from" anywhere. The outcome is a matter of probability, like the energy levels around a nuclues where there is a high probability that an electron can be found. Basically, it's a matter of probability.

 

[Gokul43201]

hey

does the Heisenberg incertitude principe really show that there are random numbers in nature ? Because to me doesn't sound very logic that the future is not predefined.

Where is the logical flaw?

I mean that it would mean that if my magic we could "Roll back time , and press the play button", things won't happen the same, different events would occur.

This is mostly correct, though it is not really what the Heisenberg Uncertainty Principle deals directly with.

And, if there are random numbers, what determines these random numbers ?

'Random' or 'stochastic' is the exact opposite in meaning to 'deterministic'. In other words, if something occurs randomly, then by definition, there is nothing that determines when it occurs. Your question is akin to asking: "if there are uncountable numbers, how are these numbers counted?"

It would sound way more logic that a precise object/reaction/event leads to a precise object/reaction/event.

It seems you do not understand the meaning of the word 'logic'. A thing is either a logical result of the chosen axioms under the rules that make up the logic, or it is not. Besides, logical correctness is not a function of how an assertion "sounds" - so unless you provide an argument for your assertion, your statement is empty.

And, what tells us that behind what we see as intercitudes, there is actually a billion lines long equation ?

A very tiny fraction of scientists actually do believe there is something like this involved - look up theories of "hidden variables" but also look into "Bell's Theorem".

And, Heisenberg says that things do not have a precise location, properties , ect until they are measured ?

Actually, this is not from Heisenberg. This is part of what is called the Copenhagen Interpretation of Quantum Mechanics, but the basic idea is right.

But what does it mean to be measured ?

This is not easily answered and there are many threads here devoted to the measurement problem in QM.

why would everything be imprecise just because one being from one specie on Earth hasnt measured it ?

Because it is that one being of that one species that is pondering the precision.

why would a rubber have an imprecise length until one type of complexly assembled object (human) put a ruler besides it.

This has nothing to do with the species doing the measurement. If giraffes were describing the length of the object, they too would have to use a distribution until one of them made a measurement.

 

[fleem]

hey

does the Heisenberg incertitude principe really show that there are random numbers in nature ? Because to me doesn't sound very logic that the future is not predefined.

Where is the logical flaw?

"Randomness" is "following no rules". "Logic" is "rules".

We can certainly use the concept of randomness in logical thought, but obviously we cannot use something that is random in logical thought--for when we do the thought becomes illogical (it follows no rules).

For example, consider the sequence -12, 902, .037, 41, -4.5e17

I can make the logical statement, "That sequence appears to be random". However, if the sequence really is random, then i cannot use the numbers, themselves as a part of a logical statement.

I believe JPC is saying that the random values, themselves, are illogical (they follow no rules).

Therefore if you believe there is true randomness in reality, then you believe there is an illogical component of reality. That is, you believe there is a subset of reality that follows no rules.

 

[JPC]

"Randomness" is "following no rules". "Logic" is "rules".

We can certainly use the concept of randomness in logical thought, but obviously we cannot use something that is random in logical thought--for when we do the thought becomes illogical (it follows no rules).

For example, consider the sequence -12, 902, .037, 41, -4.5e17

I can make the logical statement, "That sequence appears to be random". However, if the sequence really is random, then i cannot use the numbers, themselves as a part of a logical statement.

I believe JPC is saying that the random values, themselves, are illogical (they follow no rules).

Therefore if you believe there is true randomness in reality, then you believe there is an illogical component of reality. That is, you believe there is a subset of reality that follows no rules.

Yes,

and with the dice, calculator, ect for example they don't really give really random numbers, there actually a logic for the random number they give (with the dice depends how you throw it, how it its the surface, the characteristics of the surface, ect ; and for the calculator there is a algorithm behind it)

And, some ingeneers have spent years trying to find algorithm to produce numbers as random as possible, and Heisenberg says random numbers actually exist in a pure form in nature

But , now , how can nature produce random numbers in a pure form ? is infinite a random number ? Where does the next random number come from ? is it affected by the preceding ? Simply, how can nature produce a pure random number ? How can there be not a single rule behind it ? (apart from the probability) ? I mean the random numbers must come from somewhere , something must generate them ?

 

[fleem]

Right. "Logic" says that it is impossible for there to be an algorithm that produces (truly) random data, yet we claim the universe is capable of doing just that. That is illogical--we can't have it both ways.

 

[JPC]

but, since a lot of scientist believe the universe can create random numbers , what arguments do they give to explain it ?

 

[russ_watters]

Right. "Logic" says that it is impossible for there to be an algorithm that produces (truly) random data, yet we claim the universe is capable of doing just that. That is illogical--we can't have it both ways.

It is not claimed that an "algorithm" produces random results. Yes, that would be illogical.

"Randomness" is "following no rules". "Logic" is "rules".

That is also incorrect. And it is also a little misleading to call the predictions of QM "random". They are probability based.

 

[JPC]

But if there are probabilities, wouldn't that mean that there some kind of control on what numbers turn out ? Meaning that there is a part of determinism inside this Indeterminism ?

And even if they are probability based, it still has a part of random numbers of a different type (instead of having the same probability for each random number, different probabilities for each random number) ?? And here i could ask the same questions , what generates these probability based random numbers ?

 

[Hurkyl]

"Randomness" is "following no rules". "Logic" is "rules".

Those scare quotes are essential, because that 'explanation' has little or nothing to do with the technical meaning of the word "randomness" and of "logic".

 

[fleem]

Those scare quotes are essential, because that 'explanation' has little or nothing to do with the technical meaning of the word "randomness" and of "logic".

To prove this, you must now give an example of a random sequence that follows certain rules, and an example of logic that is not based on rules.

 

[fleem]

But if there are probabilities, wouldn't that mean that there some kind of control on what numbers turn out ? Meaning that there is a part of determinism inside this Indeterminism ?

And even if they are probability based, it still has a part of random numbers of a different type (instead of having the same probability for each random number, different probabilities for each random number) ?? And here i could ask the same questions , what generates these probability based random numbers ?

You're right. The modern definition of "randomness" is "that which cannot be compressed". If a set of data has any correlation at all with an orderly set (for example, a Gaussian distribution correlates with a Gaussian curve), then that data set can be compressed and is therefore not "random". Some might call such a set "bounded random data" or "partly random". I don't mind it being called that too much as long as it is not called simply "random".

BTW, for other readers, let me point out that the term "random" is sometimes used in mathematics to indicate a variable whose randomness is not yet known or was presumed random. For example, the term is sometimes used to refer to two variables being examined for correlation--and if a correlation is proven, it is wrong to refer to the variables as "random". That is not the definition we are using in this context.

 

[fleem]

Forgot to mention in the previous post: The degree of randomness, then, is a function of the compressibility.

 

[Hurkyl]

To prove this, you must now give an example of a random sequence that follows certain rules, and an example of logic that is not based on rules.

Or... I could prove what I actually said.

Logic consists of a language (whose elements are called "statements") and a very specific set of rules for operating on the language. It is wrong to call any arbitrary set of rules a "logic".

Random variables obey a very specific set of mathematical axioms. If a physical theory contains random variables and asserts that measurements sample from these random variables, that is meant in the sense of the frequentist interpretation: the physical theory is asserting that, in the limit as the number of measurements goes to infinity, the observed distribution of measurements matches the probability distribution of the random variable.

 

[Hurkyl]

You're right. The modern definition of "randomness" is "that which cannot be compressed".

No.

The theory of random variables is entirely separate from the theory of computability; compressibility plays no part.


In computer science, there is a term called "Kolmogorov randomness" which is as you state. The point of Kolmogorov randomness is to capture the notion of "unpredictability", in the sense that any (Turing computable) algorithm that produces a very large incompressible string must itself be very large. This is something entirely different than the randomness appearing in physical theories.

 

[fleem]

It is wrong to call any arbitrary set of rules a "logic".

I didn't say that.

Random variables obey a very specific set of mathematical axioms.

As i said in my immediately preceding post, I am not talking about "random variables", but talking about "randomness", and that they are not the same thing.

 

[Hurkyl]

As i said in my immediately preceding post, I am not talking about "random variables", but talking about "randomness", and that they are not the same thing.

The stop. You are off-topic, and worse, you are probably confusing the opening poster who I expect doesn't realize that the way you are using randomness is essentially unrelated to the randomness seen in physical theories.

 

[fleem]

Hurkyl,

The original poster is simply realizing and questioning that old problem of hidden variables vs. Copenhagen ("shut up and calculate"). This is the same old problem that physicists have argued about for many decades (since Einstein said God does not play dice), and I think the original poster made it clear that that is what he was talking about. And that is what I have addressed, rightly or wrongly. You, however, have spent your entire time misquoting me by clearly saying I said "logic is any arbitrary set of rules" when I said nothing of the kind, and then pretending I claimed "random variables" and "randomness" mean the same thing, when I said nothing of the kind. Then when I point out your spin, you tell me to stop posting because I am simply confusing the original poster. I must say I am not impressed.

Now on to that old argument...

One of the other posters said that those embracing hidden variables are currently an extremely small minority. That is simply not true--its just that there is no reason to argue about it when neither side can prove their agenda, so the hidden variable-ists understandably "shut up and calculate" because that's all they can do. This doesn't mean they embrace that aspect of Copenhagen, it just means they see no reason to argue the matter. QM doesn't explain what happens in very low energy experiments--it explains our classical measurements of it (because we have classical brains), and that is all.

When the hidden variable-ists and Copenhagen-ists do argue about it, they don't spend their time arguing about the definition of "randomness", because, in this context, enough about its definition is agreed upon between both groups, because both groups agree that QM is a good theory. Note that QM does not defend either claim--it simply predicts classical results of very low energy experiments, and nothing more.

In fact, the differences in the commonly used definitions of "randomness" among different sciences is not that great, especially in the context and purpose of this thread. Those differences are variations in the units used to measure the degree of randomness in a data set, and in whether we should judge the randomness of a data set according to whether we know how it is coded or not (or if it is coded), but neither of these details applies here because the issue of hidden variables vs. Copenhagen does not require a precise measurement of the degree of randomness in a data set (the argument is more general than that), and because we agree that the random component in QM events probably does not have a coding of any great complexity! So in summary, the purpose of this thread was to explain how it is possible for us to say on one hand that it is impossible for a process to produce truly random data (because it requires a process that follows no rules), yet claim the universe does just that.

 

[meopemuk]

it is impossible for a process to produce truly random data (because it requires a process that follows no rules)

I find rather intriguing the idea that quantum processes are truly random and don't follow any rules. In particular, this means that it is pointless to look for their explanations. For centuries the major quest of physics was to find the ultimate cause of all events. It might be that through quantum mechanics nature tries to tell us that we already reached the final answer. Instead of finding the ultimate cause (which is, anyway, impossible, because one can always ask: "what is the reason for this cause?") we found that at the very fundamental level nature is random and unexplainable. So, any further inquiries become useless.

I am not claiming that this is the true meaning of quantum mechanics. I just find this thought interesting, though, most likely, it is wrong.

Eugene.

 

[fleem]

I find rather intriguing the idea that quantum processes are truly random and don't follow any rules. In particular, this means that it is pointless to look for their explanations. For centuries the major quest of physics was to find the ultimate cause of all events. It might be that through quantum mechanics nature tries to tell us that we already reached the final answer. Instead of finding the ultimate cause (which is, anyway, impossible, because one can always ask: "what is the reason for this cause") we found that at the very fundamental level nature is random and unexplainable. So, any further inquiries become useless.

I am not claiming that this is the true meaning of quantum mechanics. I just find this thought interesting, though, most likely, it is wrong.

Eugene.

Yes, definitely! Is it that reality is simply that set of rules that are consistent, and thus evolved from axioms through a sort of cosmic evolutionary natural selection (and we see in QM events a glimmer of that foundation of reality which is the set of ALL rules, consistent or not). Or are there hidden variables. I've wandered to both sides of that fence. Mach's principle--that it is silly to claim an object exists that does not interact, even for a short time, with the other objects in the universe--makes me wonder if those continual "Mach" interactions are the hidden variables. then there's the question of "how much order is there". Is there infinite order? Neither time nor space would be a limit to order, for they are only facets of it.

 

[AppleBite]

Yes,

But , now , how can nature produce random numbers in a pure form ? is infinite a random number ? Where does the next random number come from ?

Well, you can't really say that infinite is a "number" as it is by definition infinite. However, it can seem like a difficult thing to accept, but why can there not be a random number generated from some equation. If an equation was generating the number, it would by definition NOT be random.

 

[JPC]

So in conclusion is there really inderteminism ? Or does it just appear as inderteminism to us because we cannot yet find any logic behind it ?

- If the theory of hidden variables is true, it would mean no ?
- If nature can produce true probability based random numbers it would mean yes ?

 

[fleem]

So in conclusion is there really inderteminism ? Or does it just appear as inderteminism to us because we cannot yet find any logic behind it ?

- If the theory of hidden variables is true, it would mean no ?
- If nature can produce true probability based random numbers it would mean yes ?

Correct. We don't know what really happens. It might even be that what really happens is something our classical brains can never understand, although I hope that isn't the case! QM says nothing about what really happens, it just let's us predict the statistical (and classical) results of experiments.