Results 1 to 15 of 15

20210315, 08:18 PM (ISO 8601)
 Join Date
 Feb 2016
Why is it possible to build analogs of quantum effects using conventional mechanics?
There's a couple of experiments I've read about where people model quantum phenomena using materials that follow classical mechanics. The [url=https://en.wikipedia.org/wiki/Sonic_black_hole]sonic black hole[/i] is one, or specifically the claim that it gives off a sonic analog of hawking radiation.
The thing that always bugged me about these experiments is that they're modeling things that are supposedly nondeterministic using deterministic systems. Doesn't that imply that the normal versions of these things can be explained without invoking nondeterminism?Omegaupdate Forum
WoTC Forums Archive + Indexing Projext
PostImage, a free and sensible alternative to Photobucket
Temple+ Modding Project for Atari's Temple of Elemental Evil
Morrus' RPG Forum (EN World v2)
If we shadows have offended, think but this, and all is mended. That you have but slumbered here, while these visions did appear, and this weak and idle theme, no more yielding but a dream. Midsummer Night's Dream, Act 5, Scene 1

20210315, 08:34 PM (ISO 8601)
 Join Date
 Dec 2010
Re: Why is it possible to build analogs of quantum effects using conventional mechani
Stochastic and deterministic systems have a lot in common. A deterministic system that is partially observed or which has chaotic dynamics is effectively stochastic. Also, randomness only enters QM when you're explaining the outcome of measurements  the wave equation itself is deterministic.

20210315, 09:44 PM (ISO 8601)
 Join Date
 Aug 2020
Re: Why is it possible to build analogs of quantum effects using conventional mechani
@NichG is right, a deterministic system can seem as effectively stochastic, think for example a dice. When you throw a dice in fact it's deterministic, If you know all the angles and force, the elasticity etc. you could predict the value of any give throw, but at the same time you can model the throw as stochastic. In fact any very complex deterministic model can be better understood by using probabilities then exact modeling, which is foundation of Chaos theory.
As for QM in fact you are right, there are deterministic interpretation of quantum mechanics, for example Pilot wave theory. Additionally multiverse theory assume that every outcome happens, just you can observe one instance of that, which also for me makes it quite deterministic.Last edited by asda fasda; 20210316 at 01:36 AM.
"By Google's own reckoning, 60% of the ads that are charged for are never seen by any human being – literally the majority of the industry's product is a figment of feverish machine imaginations." Pluralistic
The bots are selling ads to bots which mostly bots are viewing, We really are living in XXI century.

20210316, 01:24 AM (ISO 8601)
 Join Date
 Aug 2019
Re: Why is it possible to build analogs of quantum effects using conventional mechani
I dont understand why people cling to determinism. Isnt it like killed three times over on the quantum scale?

20210316, 03:52 AM (ISO 8601)
 Join Date
 Dec 2010
Re: Why is it possible to build analogs of quantum effects using conventional mechani
In general, for any stochastic system if you write the update equations in terms of distributions, those update equations themselves become deterministic. For example, going from a stochastic ODE such as the Langevin equation to the equivalent FokkerPlanck formulation. This is generally accompanied by going from a finite number of degrees of freedom (position, velocity, etc variables) to an infinite number of degrees of freedom (parameters of joint distributions over all positions, velocities, etc).
In some sense, classical stochastic systems are even more nondeterministic than quantum ones in that for classical systems there is an actual set of values at any point in time and the distributions are just a description of inferred probabilities, whereas in quantum mechanical systems the probability amplitudes are the actual fundamental degrees of freedom of the theory and there is not really such a thing as 'the particle's actual position' or 'the particle's actual velocity' that those amplitudes are just approximating. Also, the QM equation of motion is a timereversible wave equation in which entropy does not increase, whereas the classical FokkerPlanck equations that are equivalent are descriptions with an arrow of time and monotonically increasing entropy.

20210316, 04:59 AM (ISO 8601)
 Join Date
 Aug 2019
Re: Why is it possible to build analogs of quantum effects using conventional mechani

20210316, 07:05 AM (ISO 8601)
 Join Date
 Jul 2008
 Location
 Sweden
 Gender
Re: Why is it possible to build analogs of quantum effects using conventional mechani
Black text is for sarcasm, also sincerity. You'll just have to read between the lines and infer from context like an animal

20210316, 08:24 AM (ISO 8601)
 Join Date
 Aug 2019
Re: Why is it possible to build analogs of quantum effects using conventional mechani
Its what the measurements spit out. The opposite claim, that there are underlying mechanics we just cant measure is at least more unscientific because it postulates something exists which cant be measured.
As you said, whether its 'real' randomness or not is atm a philosophical debate.
That you cannot predict the outcome of your measurements inuniverse as a single determined state is the current scientific knowledge. So your actual predictions will be probability distributions and thus not deterministic.

20210316, 09:23 AM (ISO 8601)
 Join Date
 Aug 2020
Re: Why is it possible to build analogs of quantum effects using conventional mechani
Yes, but this thread is pretty much philosophical : ) like what it means to be random ? is our fate determined ? is there Laplace demon who knows how everything starts and ends ? or is every second just some random noise in quantum field ? Settling on "it's easiest to calculate outcome with probability distribution so it's stochasting" is quite boring answer I would say : )
"By Google's own reckoning, 60% of the ads that are charged for are never seen by any human being – literally the majority of the industry's product is a figment of feverish machine imaginations." Pluralistic
The bots are selling ads to bots which mostly bots are viewing, We really are living in XXI century.

20210316, 09:54 AM (ISO 8601)
 Join Date
 Jul 2008
 Location
 Sweden
 Gender
Re: Why is it possible to build analogs of quantum effects using conventional mechani
In the many worlds interpretation it would be fully deterministic. In the pilot light interpretation it would be fully deterministic. If you pick the Copenhagen interpretation then the universe follows a neighdeterministic timeline that breaks down at the subatomic level. You can prefer one interpretation over the other but [the dude] like, that's just your opinion man [/the dude]. I have equal standing in saying that the many worlds interpretation is correct, the measurements only look like they spit out unpredictable outcomes, they spit out all the outcomes in different worlds.. Then the underlying mechanics are truly deterministic, and all probabilities are real.
Last edited by Mastikator; 20210316 at 09:57 AM.
Black text is for sarcasm, also sincerity. You'll just have to read between the lines and infer from context like an animal

20210316, 11:36 AM (ISO 8601)
 Join Date
 Feb 2016
Re: Why is it possible to build analogs of quantum effects using conventional mechani
The fact that we can build equivalent systems without randomness implies that randomness is not a necessary part
The existence of quarks is accepted even though it's also accepted that we can never seperate them out and observe them directly like we do with electrons and suchOmegaupdate Forum
WoTC Forums Archive + Indexing Projext
PostImage, a free and sensible alternative to Photobucket
Temple+ Modding Project for Atari's Temple of Elemental Evil
Morrus' RPG Forum (EN World v2)
If we shadows have offended, think but this, and all is mended. That you have but slumbered here, while these visions did appear, and this weak and idle theme, no more yielding but a dream. Midsummer Night's Dream, Act 5, Scene 1

20210316, 12:37 PM (ISO 8601)
 Join Date
 Apr 2009
 Location
 Germany
Re: Why is it possible to build analogs of quantum effects using conventional mechani
Also, black holes are not quantum phenomenons. Gravity is famously the one phenomenon that we can't explain with quantum mechanics. Getting that figured out may be the biggest open question in physics.
We are not standing on the shoulders of giants, but on very tall tower of other dwarves.
Beneath the Leaves of Kaendor  Writing Sword & Sorcery
Spriggan's Den Heroic Fantasy Roleplaying

20210316, 04:47 PM (ISO 8601)
 Join Date
 Jan 2007
Re: Why is it possible to build analogs of quantum effects using conventional mechani
There are quite a few possible candidates for quantum gravity. One of the main problems is that so far we cannot test them with experiments the same way the advanced elementary particle theories are not verifiable with currently available technology. Besides, the main problem IIRC with quantum gravity is less about not being able to explain gravity and more about technical problems with building a viable mathematical machinery that will grasp the key ideas.
That being said, there are already some interesting cosmological results using those possible quantum gravity theories. One of the most renown was the last publication by Hawking, where it was proven that black holes actually do not destroy information  they just scramble it beyond recognition. I did not follow the newer advances, so there might be much more right now.In a war it doesn't matter who's right, only who's left.

20210316, 08:58 PM (ISO 8601)
 Join Date
 Jul 2010
Re: Why is it possible to build analogs of quantum effects using conventional mechani

20210317, 01:51 AM (ISO 8601)
 Join Date
 Jan 2007
Re: Why is it possible to build analogs of quantum effects using conventional mechani
Hawking radiation is a result of considering quantum electrodynamics in a classic curved spacetime. Quantum gravity is about quantizing the spacetime itself. The same difference as between including classic electromagnetic fields in quantum mechanics and quantizing the electromagnetic field itself.
In a war it doesn't matter who's right, only who's left.