[hamdani yusuf (OP)]

I just got an even stronger evidence that diffracted light is produced by the edges of the obstacle, instead of the space between those edges. The experiment involves linear polarization.

I've finally uploaded the video.

[hamdani yusuf (OP)]

Just in case you get confused by the polarization markings of the polarizer films, I recommend you to watch this informative video.

Linear polarization is easier to understand using microwave frequency since the physical shape of the polarizer can be observed using naked eye.

I’ve been teaching microwave polarisation wrong! - A Level Physics

So it turns out the way I've been teaching microwave polarisation is wrong!! Well, it's not so much wrong, it's the fact that the 'picket fence' analogy for polarisation isn't what it first seems. Where the picket fence only allows vertically polarised light through, a corresponding polarising filter only allows horizontally polarised light through! Watch this video for more explanation.

[hamdani yusuf (OP)]

I've finished editing a new video on horizontally tilted diffraction. The first part is just fixing my old clips, while the last part contains new material. I'll share it here when I finished uploading it to my Youtube channel.
Many sources say that diffraction-interference pattern in a single slit experiment require the slit to be narrow, and comparable to the wavelength of the light wave. The word comparable in this context is not well defined.
Some of them also mention that the edges of the slit must be sharp.
My experiments will show that they are not necessarily true.

[hamdani yusuf (OP)]

I've also finished editing a short video showing the occurrence of half interference pattern.
The laser beam seemingly only interact with a single edge of the obstructing object.

[hamdani yusuf (OP)]

I've finished editing a new video on horizontally tilted diffraction. The first part is just fixing my old clips, while the last part contains new material. I'll share it here when I finished uploading it to my Youtube channel.
Many sources say that diffraction-interference pattern in a single slit experiment require the slit to be narrow, and comparable to the wavelength of the light wave. The word comparable in this context is not well defined.
Some of them also mention that the edges of the slit must be sharp.
My experiments will show that they are not necessarily true.

Here you are.

[hamdani yusuf (OP)]

I've also finished editing a short video showing the occurrence of half interference pattern.
The laser beam seemingly only interact with a single edge of the obstructing object.

It's a bit surprising.

[Bored chemist]

It's a bit surprising.

To whom?

[hamdani yusuf (OP)]

It's a bit surprising.

To whom?

To me.
My previous experiments of single edge diffraction using various materials didn't show any interference pattern. They include glass, acrylic, plastics, wood, paper, graphite, rubber, aluminum, carbon steel, stainless steel, copper, and some others.

[hamdani yusuf (OP)]

Here's another video about the real experiment by another Youtuber, not just some animations which don't represent physical reality.

The Real Double Slit Experiment.
This video was edited 30-12-2022. I removed everything but the experimental parts of the original video. The reason for this is that I was no longer behind the way I explained the experiments, especially the quantum aspects. What I will do i upload the original video for reference as unlisted and place the reference to it here.

In the video I show you how you can use a microscope to visualize theEM- wave propagation after light has passed the slits.

[Bored chemist]

My previous experiments of single edge diffraction using various materials didn't show any interference pattern. They include glass, acrylic, plastics, wood, paper, graphite, rubber, aluminum, carbon steel, stainless steel, copper, and some others.

Was the rest of the experimental setup identical?

[hamdani yusuf (OP)]

My previous experiments of single edge diffraction using various materials didn't show any interference pattern. They include glass, acrylic, plastics, wood, paper, graphite, rubber, aluminum, carbon steel, stainless steel, copper, and some others.

Was the rest of the experimental setup identical?

Some of them were, but some were not. The shapes of their edges were arbitrary, depending on the objects that I could randomly find. But they can be classified into two general category : those with sharp edge and those with blunt edge, just like my experiments with the galvanized bent plate.

[Bored chemist]

My previous experiments of single edge diffraction using various materials didn't show any interference pattern. They include glass, acrylic, plastics, wood, paper, graphite, rubber, aluminum, carbon steel, stainless steel, copper, and some others.

Was the rest of the experimental setup identical?

Some of them were, but some were not. The shapes of their edges were arbitrary, depending on the objects that I could randomly find. But they can be classified into two general category : those with sharp edge and those with blunt edge, just like my experiments with the galvanized bent plate.

So, you did different things, and got different results.
You think this is surprising.

Do you understand why we don't think this is surprising?

[hamdani yusuf (OP)]

Do you understand why we don't think this is surprising?

Perhaps because you haven't done those various experiments yourself.
Perhaps you don't have adequate knowledge about diffraction of light which allows you to make a testable prediction.

[hamdani yusuf (OP)]

So, you did different things, and got different results.
You think this is surprising.

It seems that you misunderstood my simple sentence.

Some of them were,

It means that my previous experiments with the same setups as this one (the only difference is the material of the obstacle), shown no interference pattern in the shadow region of the obstacle.

[hamdani yusuf (OP)]

I've finished editing another short video investigating diffraction of light. It started with the setup from horizontally tilted diffraction, where two knifves forming a single slit aperture are separated away from each other. One knife is further away from the light source.
In the new video, the far knife is flipped, so it obstructs the light beam from the same side as the near knife.
The next experiment replaces the knives with the folded galvanized plate used in previous video. You'll see what happens.

[Bored chemist]

It means that my previous experiments with the same setups as this one (the only difference is the material of the obstacle), shown no interference pattern in the shadow region of the obstacle.

How carefully did you look?
How big and how bright would you expect the pattern to be?

[hamdani yusuf (OP)]

It means that my previous experiments with the same setups as this one (the only difference is the material of the obstacle), shown no interference pattern in the shadow region of the obstacle.

How carefully did you look?
How big and how bright would you expect the pattern to be?

To make sure, I've rechecked the result for some materials in single edge diffraction experiment. It turned out that some of them also show some interference pattern on the shadow region, although the contrast is not that clear, which made me unsure if it's just an artefact from the laser pointer. Furthermore, the size of the pattern is so small that it's only visible if the distance of the screen is long enough. Although the pattern can be seen by naked eye, my camera can't capture it clearly.
 
Nevertheless, the interference pattern on the shadow region produced by galvanized steel plate is much obvious, as shown in my experiment of diffraction interference effect by obstacles on the same side.

[Bored chemist]

At 1: 27 you say it's not clear if you have a pattern.
I think you need a better experimental setup.
Do you have a spatial filter?

[hamdani yusuf (OP)]

At 1: 27 you say it's not clear if you have a pattern.
I think you need a better experimental setup.
Do you have a spatial filter?

You can see in the video, there are some spots slightly darker than the average. But they don't seem to appear at regular interval.
No, I don't have any.