The double slit experiment and Superposition

[Dalo]

Just now, Strange said:

ncidentally, "theoretical assumption" doesn't really makes sense. Assumptions are based on little or no evidence, theories are based on large amounts of evidence. You may have meant, "a theoretical conclusion that hasn't been observed." Except that isn't the case. It was a theoretical prediction that has been shown to be correct.

Show it to me.

[Strange]

5 minutes ago, Dalo said:

Show it to me.

LMGTFY

https://scholar.google.co.uk/scholar?q=single+photon+double+slit+experiment

https://link.springer.com/article/10.1007%2Fs00016-011-0079-0

http://aapt.scitation.org/doi/10.1119/1.10184

http://aapt.scitation.org/doi/10.1119/1.1987321

https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.87.160401

http://aapt.scitation.org/doi/10.1119/1.1531580

https://link.springer.com/article/10.1007%2FBF00734319

 

[Dalo]

34 minutes ago, Strange said:

LMGTFY

https://scholar.google.co.uk/scholar?q=single+photon+double+slit+experiment

https://link.springer.com/article/10.1007%2Fs00016-011-0079-0

http://aapt.scitation.org/doi/10.1119/1.10184

http://aapt.scitation.org/doi/10.1119/1.1987321

https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.87.160401

http://aapt.scitation.org/doi/10.1119/1.1531580

https://link.springer.com/article/10.1007%2FBF00734319

 

link 1 is  a google listing. Which article am I supposed to read?

link 2 concerns interferometers. See above.

link 3 shows interference patterns. They are not the issue.

This is as far as I got.

Could you please choose one link which you think proves me wrong?

edit: link 4 is behind a pay wall

same for link 5

same for link 6

same for link 7 that also concerns interferometers.

 

Edited December 13, 2017 by Dalo

[Strange]

16 minutes ago, Dalo said:

link 1 is  a google listing. Which article am I supposed to read?

How about: all of them, until you find one that satisfies your bizarre criteria.

[Dalo]

6 minutes ago, Strange said:

How about: all of them, until you find one that satisfies your bizarre criteria.

Why bizarre? They are really simple:

- it must concern double slit experiments; You can start a thread on interferometers and I will gladly contribute by explaining why I think they cannot be considered as the equivalent of a double slit experiment. You won't agree with me and we will have to come back to this thread.

- the disappearance of the interference pattern must be shown "live" and not as a theoretical assumption or conclusion.

[Dalo]

17 hours ago, Mordred said:

Ok lets describe my view point, I don't follow the metaphysics debates. I focus on what is going on under the math. Under what the models truly state under the math. I rarely see any metaphysics paper truly address what the math shows.

Here is a key detail QM  and QFT operators  are not the same. In QFT the fields are the operators. Changes a lot of the arguments or should.

 

 

Maybe you will like this quote, written by a Bohmian author:

"our most basic physical theory 
contains no account of the constitution and structure of matter,  
corresponding to the interacting particles and fields of classical physics. It is a means to 
compute the statistical results of macroobservations carried out on systems 
that are unspecified and, indeed, unspecifiable. The word 'electron' does not 
actually mean anything at all - it is simply shorthand for a mathematical 
function. Quantum mechanics is the subject where we never know what we 
are talking about. " Peter R. Holland, The Quantum Theory of Motion : An Account of the de Broglie-Bohm Causal Interpretation of Quantum Mechanics, 1993.

[Mordred]

Like I stated I only deal with observed evidence, and the mathematics and physics. Metaphysics bores me. Far too often it is used as a wall that prevents even understanding the topic being discussed.

Good example is the mathematical definition of Observer itself under Pilot wave theory. Do you know the mathematical definition?

Have you bothered to even study the mathematics of De-Broglie Pilot wave which is Bohmian to even understand the theory itself?

If you did you wouldn't be presenting the arguments you have thus far posted.

Edited December 14, 2017 by Mordred

[Dalo]

13 minutes ago, Mordred said:

Like I stated I only deal with observed evidence, and the mathematics and physics. Metaphysics bores me. Far too often it is used as a wall that prevents even understanding the topic being discussed.

Good example is the mathematical definition of Observer itself under Pilot wave theory. Do you know the mathematical definition?

Have you bothered to even study the mathematics of De-Broglie Pilot wave which is Bohmian to even understand the theory itself?

No. I leave that to mathematicians, which I am not. I consider myself a philosopher (didn't finish my Phd  through circumstances not relevant to the subject, and now I am too old to care.).

13 minutes ago, Mordred said:

Like I stated I only deal with observed evidence

did you ever observe a particle passing through two slits at the same time?

Edited December 14, 2017 by Dalo

[Mordred]

Yes via Toshiba quantum single dot emitters and detectors. I did this experiment with those devices.

[Dalo]

1 minute ago, Mordred said:

Yes via Toshiba quantum single dot emitters and detectors. I did this experiment with those devices.

I have no reason to doubt you. This is after all your domain. I would be very curious about the setup of the experiment though. Maybe you could post a link or a reference?

[Mordred]

The experiment has been done by others as well. These experiments were far more accurately done than my own. (that and it included a student body, where I assist at on occassions as my work time allows)

However here is an example setup.

https://www.google.ca/url?sa=t&source=web&rct=j&url=https://arxiv.org/pdf/1507.02962&ved=0ahUKEwirtOK-sojYAhVM2WMKHXLdB5kQFggiMAE&usg=AOvVaw0YryFuM4IZJkBZ3maQC8Wv

this link directly uses the Toshiba devices

https://www.google.ca/url?sa=t&source=web&rct=j&url=https://arxiv.org/pdf/1201.3475&ved=0ahUKEwirtOK-sojYAhVM2WMKHXLdB5kQFggdMAA&usg=AOvVaw0g9rlEJ0bJ4hs-jlUQfSyg

Trying to get the datasheets specifically on the detector and emitters but Toshiba changed its website.

Edited December 14, 2017 by Mordred

[Dalo]

16 minutes ago, Mordred said:

The experiment has been done by others as well. These experiments were far more accurately done than my own. (that and it included a student body, where I assist at on occassions as my work time allows)

However here is an example setup.

https://www.google.ca/url?sa=t&source=web&rct=j&url=https://arxiv.org/pdf/1507.02962&ved=0ahUKEwirtOK-sojYAhVM2WMKHXLdB5kQFggiMAE&usg=AOvVaw0YryFuM4IZJkBZ3maQC8Wv

this link directly uses the Toshiba devices

https://www.google.ca/url?sa=t&source=web&rct=j&url=https://arxiv.org/pdf/1201.3475&ved=0ahUKEwirtOK-sojYAhVM2WMKHXLdB5kQFggdMAA&usg=AOvVaw0g9rlEJ0bJ4hs-jlUQfSyg

Trying to get the datasheets specifically on the detector and emitters but Toshiba changed its website.

Thank you. I will study them very carefully.

[Mordred]

Yeah all the datasheets are behind paywalls or AAAS membership. You used to be able to get the Spec pdfs on its earlier devices. Anyways there are numerous papers using these devices particularly for quantum encryption applications.

As I mentioned before older articles and metaphysics arguments don't really apply in modern understanding. The metaphysics arguments on Bohm is one such example.

Lol if you study the math itself the pilot is a wave. Its descriptive of a particle is the Debroglie wavelength. Most of the formulas used by Pilot wave are also used in QFT. You really have to examine the mathematics to even find any differences in the treatment. Though comparing Pilotwave to QM it is a different case altogether.

A rough general description 

1) start with particle entanglement diodes with a RC circuit to regulate the rate of production.

2) use Logic gates to seperate the entangled pairs

3) pass each single photon through slits

4) count the hits at specific locations on the quantum detection silicon wafers (quantum detectors

We weren't interested in preserving the entangled states themselves hence the seperation methodology. (student project low budget lol)

Here is a listing of applications for the single quantum dot detectors.

http://www.singlequantum.com/publications/

 

Here is a Toshiba room temperature test of the QKD detector.

https://www.google.ca/url?sa=t&source=web&rct=j&url=https://arxiv.org/pdf/1412.1586&ved=0ahUKEwiRyJb1wIjYAhVP5WMKHfm6Bx0QFggmMAA&usg=AOvVaw0xLkyJWINRaMj2LfM-Ou3E

Here is some details involving the quantum entanglement emitter and some of its applications.

https://www.google.ca/url?sa=t&source=web&rct=j&url=https://arxiv.org/pdf/1702.08823&ved=0ahUKEwjuyoz-wYjYAhVB82MKHeajCCwQFggoMAA&usg=AOvVaw0n8x6XWO31roN5bCPz7nu7

lol the last link is a bit of an eye opener on some of the properties of light.

The last link also describes the Einstein Podolski Rosen Bohm experiment. see figure 11. Prior to that 

"This is an optical variant of Bohm’s version of the EPR:

Edited December 14, 2017 by Mordred

[Dalo]

48 minutes ago, Mordred said:

1) start with particle entanglement diodes with a RC circuit to regulate the rate of production.

2) use Logic gates to seperate the entangled pairs

3) pass each single photon through slits

4) count the hits at specific locations on the quantum detection silicon wafers (quantum detectors

We weren't interested in preserving the entangled states themselves hence the seperation methodology.

First reaction to the first article.
The article is obviously way above my pay grade, and I would certainly not presume reviewing it.
To be honest, I do not see how it relates to the subject of this thread. It concerns definitely not a double slit experiment, and, even if I disregard the use of a Mach-Zehnder interferometer (see my previous posts), there are, if I understood correctly, two sources of light involved, instead of one.
It certainly shows the degree of expertise of all involved in the experiment, but, once again, I fail to see the relevance to this thread

Edited December 14, 2017 by Dalo

[Mordred]

Of course they relate. These devices repeat the older experiments. Your arguments have been based on older and out of date understandings.

Time to get modern, time to actually understand what Bohmian theory is really about under the math because it actually involved a spin zero field. Thats the third component.

Let me get you a proper paper on Bohmian pilot wave.

Edited December 14, 2017 by Mordred

[Dalo]

4 minutes ago, Mordred said:

Of course they relate. These devices repeat the older experiments. Your arguments have been based on older and out of date understandings.

Time to get modern, time to actually understand what Bohmian theory is really about under the math because it actually involved a spin zero field. Thats the third component.

Let me get you a proper paper on Bohmian pilot wave.

I can understand the wrong impression my references may have conveyed. But I am not beholden to the Bohmian theory, even though I find the fact that there is an alternative to the Copenhagen interpretation very reassuring.

My claim does not depend on the validity of the Bohmian approach, even though it is incompatible with Bohr's convictions.

[Mordred]

Based on which arguments, those of older Niave understandings ? This is the problem with trying to understand physics topics via metaphysics. I mentioned before most of the arguments aren't examining the actual mathematics. hence they are more often flawed simply on that basis in my opinion.

 Lets look at both, here is a decent paper though more my pay grade.

https://workspace.imperial.ac.uk/theoreticalphysics/Public/MSc/Dissertations/2009/Ellen Kite Dissertation.pdf

Now it has an interesting statement with regards to the Copenhagen interpretation.

"the Copenhagen Interpretation of quantum mechanics (Bohm calls it the “usual interpretation”) centres on Heisenberg‟s uncertainty principle and the assumption that the physical state of a system can be most completely specified by a wavefunction. Only probability densities can be calculated and the probability description is inherent in matter." 

see section 3.4 which will refer you back to section 2 but the quoted section is from 3.4.

well so does QFT.  Under QFT an uncharged field is spin zero.

 So what does that do to your reassurance now?

 
 

Edited December 14, 2017 by Mordred

[Dalo]

1 minute ago, Mordred said:

So what does that do to your reassurance now?

It leaves me slightly indifferent. The debate between Copenhagen and Bohm is interesting, but certainly not life changing.

[Mordred]

Yes but isn't it reassuring to see certain Bowmian lessons already being applied under QFT ? though with more rigor under treatment

 

[Dalo]

18 minutes ago, Mordred said:

Yes but isn't it reassuring to see certain Bowmian lessons already being applied under QFT ? though with more rigor under treatment

 

I am not sure what you are expecting from me. I have no opinion on QFT. I do not feel the need to attack it, nor to defend it.

What I do not understand is how all you have been saying relates to the following:

- in a double slit experiment, when one slit is open nobody doubts that all particles go through that slit, even if single particle interference may create interference patterns.

- when two slits are open, there is a clear interference pattern, and the question is how that happens. The theory is constructive and destructive interference. Okay.

- when the experimenter tries to find out through which slit the "particle" has gone through, it is said that the interference pattern disappears.

- I say, that is not true, that it has never be shown in a real experiment. All we have are theoretical justifications.

If you think that you can prove my claim wrong, empirically prove my claim wrong, and not just by appealing to theoretical considerations however respectable they may be, then I welcome your contribution and will change my mind accordingly.

Edited December 14, 2017 by Dalo

[Mordred]

  I am asking you to truly understand what is involved and supplying this material to assist you in such an enterprise. Remember one of the rules on any wave-function.  Probabilistic or not, measuring causes interference due to needing to interact via other waveforms (wave functions). A probabilistic wave-function is not a physical wave-function ( there is a distinct difference, example correlation functions). With the Heisenberg we involve both, but not only of the particle locality region but also any field coordinates.

  The problem with Copenhagen an QM is more specifically the position operator itself. In QFT this is downgraded to a propagator and the field is upgraded to Operator.  Significant difference I mentioned this numerous times, most metaphysics papers rarely examine the math fully.

I'll have to remember this line from 5.2 with regards to QM its nicely put in a very succinct manner.

"One of the main arguments of the Copenhagen Interpretation of quantum mechanics is that it is meaningless to ask about the position of a particle when it is not being detected. This means that if the trajectory of the particle is not being continually tracked, no information other than the start and end points of the trajectory can be known."

section 5.2

 Definitely applies to QFT methodology

the QFT Hamilton primarily concerns itself with the end points via Principle of least action.

 Anyways its a good reference to help understand properly the physics and not the metaphysics arguments.

.

 

Edited December 14, 2017 by Mordred

[Dalo]

Just now, Mordred said:

  I am asking you to truly understand what is involved and supplying this material to assist you in such an enterprise. Remember one of the rules on any wave-function.  Probabilistic or not, measuring causes interference due to needing to interact via other waveforms (wave functions). A probabilistic wave-function is not a physical wave-function ( there is a Add to distinct difference, example correlation functions). With the Heisenberg we involve both, but not only of the particle locality region but also any field coordinates.

  The problem with Copenhagen an QM is more specifically the position operator itself. In QFT this is downgraded to a propagator and the field is upgraded to Operator.  Significant difference I mentioned this numerous times, most metaphysics papers rarely examine the math fully.

I'll have to remember this line from 5.2 with regards to QM its nicely put in a very succinct manner.

"One of the main arguments of the Copenhagen Interpretation of quantum mechanics is that it is meaningless to ask about the position of a particle when it is not being detected. This means that if the trajectory of the particle is not being continually tracked, no information other than the start and end points of the trajectory can be known."

section 5.2

 Definitely applies to QFT methodology

 Anyways its a good reference to help understand properly the physics and not the metaphysics arguments.

.

 

Those are theoretical arguments, now show me how they apply to the problem at hand. If you argue that observation in itself destroys the interference pattern, it would only mean that the theory is unprovable and must therefore be considered as a metaphysical position.

[Mordred]

19 minutes ago, Dalo said:

 

If you think that you can prove my claim wrong, empirically prove my claim wrong, and not just by appealing to theoretical considerations however respectable they may be, then I welcome your contribution and will change my mind accordingly.

How can you make claims without even understanding the theories your quoting in your defenses?

1 minute ago, Dalo said:

Those are theoretical arguments, now show me how they apply to the problem at hand.

Isn't your argument itself theoretical?

 

[Dalo]

17 minutes ago, Mordred said:

How can you make claims without even understanding the theories your quoting in your defenses?

Isn't your argument itself theoretical?

 

My claim is empirical as can be. It can be easily infirmed, all you need to do is show one single experiment in which observation destroys the interference patterns. Empirically, not theoretically.

 

By the way, I am not quoting any theory to my defense. I am using examples from different books to show cases of double slit experiments. My claim does not need Bohm, Bohr or Einstein to make it empirical.

Edited December 14, 2017 by Dalo

[Mordred]

That's been done as empirically as possible. Your refusal to accept all the references provided isn't my problem.