Many thanks to Rushan Ziatdinov for sharing a link at: https://en.m.wikipedia.org/wiki/Shadow_blister_effect

However, the result and the way of considering the shadow phenomena is similar to the Photoshop drawing I showed on YouTube which doesn't match the reality. https://youtu.be/iT5uoTXeOUo

gölgeler arası deformasyon olması optik eksende gölgeler oluşurken kimyasal değişime uğramış olmasıdır. Üçgen prizmada farklı renklerin oluşması örnek verilebilir.

Şükrü Aktaş Dear Şükrü Aktaş, I tried to translate your message by Google Translate. I hope it worked well. So, I didn't get the Chemical issues. The shadows are produced with two hard opaque materials. There is nothing to do with the chemical things.

Dear Farhad Vedad ,

thanks for the video link about the Shadow blister effect...

But with respect to your video(s), there is no 'moving in ' of parts of the shadow rim for the case of the rectangular shadow. On the contrary, there might be a tiny 'stretching out' of the shadow rim there...

Please see the attached figures; here I masked/covered the left side in order to prevent optical illusion effects, which show up in the upper part of the attachments...

Best regards

G.M.

Gerhard Martens Dear Gerhard, thanks for your reply. That is not they. You make it obscured. I have already done this experiment with RGB lasers and of course, the combination will be the shadow similar to the video.

Please see the attachments.

Gerhard Martens The green is 532 nm, and the red is 635 nm.

Please double-check how the center point is shifted aside along with other deformations of the fringes.

Gerhard Martens I am going to make a video with 3 lasers. meanwhile, please see the combination of RG:

Dear Farhad Vedad ,

sorry, but such laser experiments have nothing to do with the shadow blister effect.

In the shadow experiments, which are handling with bright white light from extended sources, one only deals with penumbras; diffraction effects cannot be seen due to the very low amount of diffracted light on a huge background.

In your diffraction related videos it is mentioned by yourself, that you have to (i) darken the lab for avoiding any backgroud signal and (ii) that you have to acquire the data over a lot of time...

Best regards

G.M.

Gerhard Martens Honesty, I don't recommend Photoshop or similar programs to analyze these things. You need a powerful program such as Alias or IcemSurf.

Please see the attached file:

Gerhard Martens 1- the setup of those lasers is exactly the same as the shadow experiment. 2- Actually this is exactly what I mean that diffraction occurs with any kind of light including a simple pinhole that can be used as a magnifire. Of course, it doesn't have a focal point but the trajectories are opening so we see the image larger. the other similar diffraction phenomena is the Glory and so on.

If you double-check then you will find all in the same structure.

Please take time and have a look at my other works that may bring more definition of what I am trying to explain,

Experimental Investigation of Diffraction Caused by Transparent Barriers:

https://www.ej-physics.org/index.php/ejphysics/article/view/19/13

A Geometrical Analysis of Diffraction Based on Fractal Inhomogeneous Space:

https://www.ej-physics.org/index.php/ejphysics/article/view/36/30

Thanks Farhad Vedad for feedback;

you have done a lot of nice things here. Many thanks for the detailed literature.

I agree, that both types of experiments (diffraction with laser beams and penumbra superposition of extentded white light sources) show similar effects with respect to beam or shadow deflections.

But the physics behind is quite different:

one is based on Huygens description of wave propagation and bending of light trajectory at edges via diffraction;

the other is geometrical optics dealing with superposition of penumbras.

The latter case for sure will include diffraction contributions, but one cannot see them due to high background signal, divergent beams in connection with extended light source and lack of monochromaticity.

Best regards

G.M.

Gerhard Martens Dear Gerhard, Thank you so much for spending time on this subject.

Actually, my main concern is what exactly appeared in your expression as well. How many different points of view and interpretations are needed to explain a single phenomenon? (here it is light)

Neither the Huygens principle nor the superposition is able to explain the central dark band caused by transparent barriers in the far field, and even worse, when that central dark band may vary to the bright one due to the contrast between the refractive index of the barriers and the medium. Also, Rayleigh–Sommerfeld diffraction theory is not able to explain this state.

Please take the time to watch these two videos. There you see how the central band changes from zero to the maximum intensity and vice versa corresponding to the temperature of the medium and also the dimensions of the apertures:

https://youtu.be/M7cMS-YNBEM?si=rfFHXm0ggKoS8WFT

This video is similar but a bit longer and follows "Experimental Investigation of Diffraction Caused by Transparent Barriers"

https://youtu.be/d0qX4es9X_c?si=zL03swEZ7fw9teMo

In my opinion, after more than a century, we need to change our minds and try to solve all optical issues in a single way.

For the shadow, I will prepare another video using 3 lasers, but it may take me a few weeks.

Kind regards,

Farhad

Şükrü Aktaş To find out more information on the updated video, please take time and visit: https://youtu.be/ULfcla1Gl3A?si=QFNykjWpbwu2xVSt

Gerhard Martens Şükrü Aktaş

Dear Researchers, I am pleased to share my latest work on optics and diffraction, focusing on the deformation of shadows when they intersect. This article has recently been published in the European Journal of Applied Physics. I hope you find it intriguing. http://www.ej-physics.org/index.php/ejphysics/article/view/304

Best regards, Farhad