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Oil droplets guided by pilot waves do not give rise to double-slit interference

quantamagazine.org

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Re: Oil droplets guided by pilot waves do not give rise to double-slit interference

#51

Post by perl4ever »

reitanqild wrote: post #47
perl4ever wrote: post #44

Earlier quoted context omitted.

Suppose they are twins and therefore there is no older and younger. Does that change the probability from 2/3 in the first case?

I guess this is one of a few place to answer mu. One of the twins is still considered to be born first and therefore older :-)

I wrote a program and successfully got the right answers experimentally for each case, so I'm not doubting the answers, but I don't buy the explanation.

While you may argue that one twin is always born first, this is an idealized mathematical problem, so it can't depend on particular details of physical reality in that way. There is nothing logically preventing them from being the same age, so it can't be pivotal to solving the problem.

And in fact, I experimentally got the right result without any reference to ages.

Re: Oil droplets guided by pilot waves do not give rise to double-slit interference

#52

Post by simion314 »

she11c0de wrote: post #48
simion314 wrote: post #40

Earlier quoted context omitted.

But didn't we (HN users) asked a lot for publishing of negative results?

HN users asked for results of experiments that "tried but failed to contradict the null-hypothesis", not "tested something not related to null hypothesis and claimed that it contradicts it". That's what I think the OP meant, don't know much about QM either.

But still, someone had thought this question and experiment, if they published how it was done and the results others that have same question can look at it, decide to redo it but in a different way or not waste the time doing it again. And we have an answer for a question, I assume if the result was different then the reaction from OP would be different,

Re: Oil droplets guided by pilot waves do not give rise to double-slit interference

#53

Post by m12k »

I'm a bit sad that they couldn't reproduce the double slit interference pattern. I'm still holding out hope that we'll eventually develop a model of reality where the apparent indeterminism of quantum mechanics can be explained by currently unobservable interactions in higher dimensional space (such as the space described here: https://www.quantamagazine.org/physicists-discover-geometry-... )

Re: Oil droplets guided by pilot waves do not give rise to double-slit interference

#54

Post by szemet »

perl4ever wrote: post #44
pg_bot wrote: post #22

Earlier quoted context omitted.

Here's the math, I will break it down based on Boy/Girl and seen. For the first case here are the different combinations for two children based on sex (let's say left denotes older and right denotes younger to distinguish the difference between girl and a boy and boy and a girl.) B B B G G B G G These outcomes are each equally likely, but since we know that one has to be a boy we can eliminate the (G G) case leaving…

Suppose they are twins and therefore there is no older and younger. Does that change the probability from 2/3 in the first case?

If you assume that the siblings can be differentiated (thus ordered), it makes no difference. You can for example order them taking their names alphabetically, or by weight, or by location at a given time, etc...

If differentiation is not possible, then they are the exact same person [1], so the parents have one child and it must be boy then ;)

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

Re: Oil droplets guided by pilot waves do not give rise to double-slit interference

#55

Post by msslx »

m12k wrote: post #53

I'm a bit sad that they couldn't reproduce the double slit interference pattern. I'm still holding out hope that we'll eventually develop a model of reality where the apparent indeterminism of quantum mechanics can be explained by currently unobservable interactions in higher dimensional space (such as the space described here: https://www.quantamagazine.org/physicists-discover-geometry-... )

At least locally, there are no hidden variables (e.g., in higher dimensional space). You might have a look at Bell's work on hidden-variable theory: https://en.wikipedia.org/wiki/Hidden-variable_theory#Bell%27...

Re: Oil droplets guided by pilot waves do not give rise to double-slit interference

#56

Post by whatshisface »

m12k wrote: post #53

I'm a bit sad that they couldn't reproduce the double slit interference pattern. I'm still holding out hope that we'll eventually develop a model of reality where the apparent indeterminism of quantum mechanics can be explained by currently unobservable interactions in higher dimensional space (such as the space described here: https://www.quantamagazine.org/physicists-discover-geometry-... )

What you're describing has been desired by many (including Einstein). However, John Bell more or less proved it impossible[0] in a landmark, sweepingly general result. He would have won a Nobel for it if he had lived long enough.

On the other hand, if you are willing to accept superluminal messages and also unobservable mechanics, there is always the pilot wave interpretation[1]. The fluid analogy is disappointing to see go but pilot wave theory lives on.

[1]https://en.wikipedia.org/wiki/Pilot_wave_theory [0]https://en.wikipedia.org/wiki/Bell%27s_theorem

Edit: fixed order of references.

Re: Oil droplets guided by pilot waves do not give rise to double-slit interference

#57

Post by ibigb »

pg_bot wrote: post #9

I was thinking about the double-slit problem the other day, and was trying to make connections to any other phenomenon that exists in the natural world and I think I came up with one. In conditional probability theory, there exists something called the boy or girl paradox. The paradox shows that the likelihood of an event can be drastically affected by how you know even seemingly innocuous information. I think that o…

Information changes the question asked. You don't state the questions. Did you mean: neighbor has 2 children, we don't know the sex, what is the probability one or more is a girl? Next question is: neighbor has 1 child of unknown sex, odds of it being a girl?

Are these not different questions?

Re: Oil droplets guided by pilot waves do not give rise to double-slit interference

#58

Post by twtw »

Bohm's pilot wave theory is interesting to me not because it is so intuitive or tasteful or something, but because it works without sacrificing realism, and thus demonstrates that the Cophenhagen interpretation (neither local nor real) claims strictly more about the nature of the universe than is required by the evidence we have. Nonlocality is established by experiment, non-realism is not. In my experience, this tends to be underappreciated (or I'm misunderstanding - please teach me if so).

I personally favor epistemological interpretations, in which the wave function models our knowledge, and the universe operates via an as-yet-unknown dynamics. Wave function collapse on measurement isn't weird anymore if the wave function represents your knowledge of the system. Thinking about it this way makes "shut up and calculate" work nicely in my head.

Re: Oil droplets guided by pilot waves do not give rise to double-slit interference

#59

Post by whatshisface »

stupidcar wrote: post #50
mehwoot wrote: post #5

Why does this matter? Does anybody seriously question whether the basic math can work? So somebody found a nice parallel between pilot wave theory and another physical phenomenon, but then the parallel wasn't as strong as thought. This experiment is the equivalent of arguing that light isn't a particle because your tennis ball doesn't bounce off the wall the way you thought it would. When I saw the droplet experiment…

It matters because the theory in this case wasn’t that both light and tennis balls behave like a particle. It was that light behaves like a tennis ball. As such, demonstrating that tennis balls succeed or fail to display certain light-like behavior is certainly an important result. So, the most controversial aspect of pilot wave theory is the idea that a classical system can reproduce some phenomena considered only t…

One excercise that is fun to do: reduce the Schrodinger equation by splitting the real and complex parts, the figure out how to build a damped spring system that can support the wave. My interpretation of quantum mechanics is that everything is springs and dashpots in the end.

Re: Oil droplets guided by pilot waves do not give rise to double-slit interference

#60

Post by twtw »

whatshisface wrote: post #56
m12k wrote: post #53

I'm a bit sad that they couldn't reproduce the double slit interference pattern. I'm still holding out hope that we'll eventually develop a model of reality where the apparent indeterminism of quantum mechanics can be explained by currently unobservable interactions in higher dimensional space (such as the space described here: https://www.quantamagazine.org/physicists-discover-geometry-... )

What you're describing has been desired by many (including Einstein). However, John Bell more or less proved it impossible[0] in a landmark, sweepingly general result. He would have won a Nobel for it if he had lived long enough. On the other hand, if you are willing to accept superluminal messages and also unobservable mechanics, there is always the pilot wave interpretation[1]. The fluid analogy is disappointing to…

FYI your references are swapped.
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