B Did Thomas Young Misinterpret His Double Slit Experiment Results?

[elou]

You said that 27 posts into the thread. Before that you were bemoaning not being able to understand how Young could do his experiment:

I've told you how to do that. The key difference between Young's set up and yours is the diverging nature of Young's natural illumination versus a collimated laser beam (hence the use of my glasses to make my beam diverge). Young was working in the near field (which is how he gets "shadow with fringes in it" rather than a $\mathrm{sinc}^2$ intensity profile), while almost certainly anything you are doing is in the far field.

As to his explanation, what's he saying that's more complex than "we get diffraction, and when I modify the slit I get different diffraction"?

"I do not understand how Young did his experiment" and " I do not understand Young's explanations" are one and the same thing. He says that the interference pattern disappears, and I wonder: from where? From the wall, from the small screens close to the slip, the ones further away?
And it is much more that "a different diffraction". For him, the disappearance of the interference pattern did not have the same meaning as it did since the 20th century. It was simply a confirmation of the wave nature of light. But his explanation of the disappearance of the interference pattern does not make sense, whatever the nature of light is. Not if it turns out that the disappearance can be gradual instead of sudden. And not if it turns out that only the fringes blocked are involved, and not automatically both sides.

 

[Ibix]

He says that the interference pattern disappears, and I wonder: from where?

From the screen, where he was observing it.

For him, the disappearance of the interference pattern did not have the same meaning as it did since the 20th century. It was simply a confirmation of the wave nature of light.

What do you think the meaning of it is in the 21st century if not a confirmation of the wave nature of light?

But his explanation of the disappearance of the interference pattern does not make sense, whatever the nature of light is.

He adjusts the things that are causing the diffraction and the pattern changes. How are you going to explain that without waves? Bear in mind that you can see interference fringes, which are a strong hint that you've got waves anyway.

If you really want to understand it you need the Fresnel-Kirchoff integral, probably via Huygens' Principle first. I'd recommend buying Born and Wolf's Principles of Optics rather than randomly attempting to replicate two century old experiments.

 

[elou]

Thank you for your advice. This thread can be closed.

 

[Vanadium 50]

You said that 27 posts into the thread.

The ground is certainly shifting. It started out with the claim Young (and the thousands, possibly millions of people after him) measured it wrong. Now it's that his explanation is wrong.

This ground was covered in his previously closed thread. While I suppose we can go around and around again, I very much doubt much will have changed in the intervening two weeks.

 

[berkeman]

If you really want to understand it you need the Fresnel-Kirchoff integral, probably via Huygens' Principle first. I'd recommend buying Born and Wolf's Principles of Optics rather than randomly attempting to replicate two century old experiments.

Thank you for your advice. This thread can be closed.

This ground was covered in his previously closed thread. While I suppose we can go around and around again, I very much doubt much will have changed in the intervening two weeks.

Presumably @elou will take the advice from both threads and read some textbooks before posting any more questions like this.

This thread is now closed. Thanks to all who have been trying to help the OP understand this material better.