High School Poor man's double slit etc. setup

[Nugatory]

So where to buy the Stern-Gerlach setup

These aren't things that you can buy off the shelf. Each experimenter will have their own requirements so there's no possibility of building a standardized product and putting it in a catalog or up on Amazon. The building blocks (micrometers, polarizes, lenses, power supplies, oscilloscopes, electrical wire, timers, photodetectors, coincidence counters and other electronic bits, ...) are easily purchased, but it's up to the experimenter to figure out how to assemble these into an apparatus that they can use for whatever experiment they're conducting.

 

[Nugatory]

I want to test if I or my friends can see both the superposition of up and down..

Superpositions are pretty much by definition not something that can be seen. The best you can do is to come up with experiments like the polarizer one that I suggested, in which the results can only be easily explained by assuming the existence of a superimposed state.

 

[Vanadium 50]

Also, a single Stern-Gerlach experiment doesn't tell you anything about superposition.

I think you need to think more carefully - and this probably involves books - exactly what it is you want to show.

 

[Blue Scallop]

Also, a single Stern-Gerlach experiment doesn't tell you anything about superposition.

I think you need to think more carefully - and this probably involves books - exactly what it is you want to show.

In the double slit. There seems to be two kinds of superposition to wathc out for.. the superposition of going through left or right slit and the branches (the different spots in the detector) or the eigenvalues. Just want a device to prove there is no way to see the electron going via left and right at the same time. And there is no way to see all eigenvalues (screen positions) at all branches at the same time. Unitarity forbids them I know. But won't it be possible Unitarity can be distributed among Quantum sytem, Spacetime and Observer? Got this insight from Ken G when he suggested entanglement may be the norm and ordinary unentangled particles just a special case. Whatever even if he was wrong, just want to see it for myself Unitarity is 100% true all the time without any exception. If there is no a single double slit device anywhere in Hong Kong or Singapore.. I guess there is one in Japan, where?

Is there no Entanglement Museum anywhere in the world where you can see all these devices plus the Clauser, Aspect Bell devices? I'm just curious just like how kids want to see prism gets rainbows. Aren't you the public curious to see such actual devices?

 

[jtbell]

Its large divergence of laser beam when it is partially blocked by a barrier versus small divergence of freely propagating laser beam. I don't see that this can be explained by Huygens principle

"Far enough" away from a circular aperture (the technical term here is "Fraunhofer approximation"), the angular width θ of the central maximum of the diffraction pattern is proportional to λ/d where λ is the wavelength and d is the diameter of the aperture. This is well-established classical wave optics, see e.g. here:

http://hyperphysics.phy-astr.gsu.edu/hbase/phyopt/cirapp2.html#c2

The aperture that produces a laser beam is much wider than a pinhole, therefore light emerging from a laser aperture spreads much less than light emerging from a pinhole.

[added]

You get the same λ/d dependence in single-slit diffraction, which is easier to derive because one deals only with the transverse dimension across the slit, not along it. (With a circular aperture one has to deal with two dimensions, usually in polar coordinates, and introduce Bessel functions. ). A Google search for "single slit diffraction intensity derivation" brings up numerous mathematical derivations, of which this one is probably typical (I did this sort of thing in an intermediate optics course that I taught for many years):

https://courses.physics.ucsd.edu/2011/Winter/physics4d/files/Intensity in 1-slit pattern.pdf

Here's a graphical version involving phasors ("phase vectors") which one sometimes sees in first-year physics courses:

http://hyperphysics.phy-astr.gsu.edu/hbase/phyopt/sinint.html

 

[rrogers]

Concerning the original question: Have you tried youtube? For instance

 

[Blue Scallop]

A lab tried to build its own Mach-Zehnder Interferometer experiment.. but the length of upper path and lower path has to be kept at the nano-meter level or both detector A and detector B would be triggered. A right setup should only have one detector trigger.. and they can't do it..


According to http://www.users.csbsju.edu/~frioux/two-slit/MZ-WhichWay.pdf "The detection of the photon exclusively at Dx is the equivalent of the appearance of the interference fringes in the double-slit experiment."

It is said 9 out of 10 use interfometer for which way path experiment. I'm looking for description of actual experiments (the 1 out of 10) where they use double slits.. single photon source.. and single photon detector.. why is single photon detector so difficult? and what is the complete setup for this test? So even if you hide a tiny camera in one of the slits.. the photon or electron knows? how about any that won't cause decoherence or is the explanation of the following correct?

https://www.st-andrews.ac.uk/~kd1/PH5015/Rempe.pdf

"The principle of complementarity refers to the ability of quantum-mechanical entities to behave as particles or waves under different experimental conditions. For example, in the famous double-slit experiment, a single electron can apparently pass through both apertures simultaneously, forming an interference pattern. But if a`which-way' detector is employed to determine the particle's path,the interference pattern is destroyed.This is usually explained in terms of Heisenberg's uncertainty principle, in which the acquisition of spatial information increases the uncertainty in the particle's momentum, thus destroying the interference."

Is this explanation correct? If not, what is the correct explanation? Thank you.