Feynman Lec, problem with diffraction

In summary, the conversation discusses a concept that Feynman does not explain in his book. The concept involves the approximation of two paths, one for finite distance and one for infinity, in terms of h. The limit of h going to infinity results in a linearly proportional difference between the two paths, and this is considered the advantage of the "sources" method. The solution to the paradox is that at infinity, the difference between the two paths is always proportional to h, making the approximation more accurate. It is suggested to read the passages in the book for a better understanding.
  • #1
rpf_rr
15
0

Homework Statement


It is a thing feynman doesn't explain, it is meant to be obvious, but for me and some friends is not. If you have the first book, chapter 30-6, "Diffraction by opaque screen", he is talking about the approssimation of the two path: for finite distance is h^2/s, and is quadratic proportional to h, while if you go to infinity, that is the point, is linearly proportional to h. I really don't understand what does it means, the approssimation is more good if you go to infinity, is always quadratic, for any finite distance, the limit is proportional to h^2. It is an important sentence, for him this is the advantage of the "sources" method

Homework Equations


You have to read all the passages of the book, if you don't have it i can send that page to you.

The Attempt at a Solution


Another note, say that the difference of paths is linearly proportional to h is like saying that the path is equivalent (times a coefficient) to the path going straight on and then go 90 deg to the right, that for me is not the fastest
 
Physics news on Phys.org
  • #2
way, so it is not the most efficient. I think that the solution of this paradox is that we are talking about the limit of h going to infinity, so if we go to infinity, the difference between the two paths is always proportional to h, and the approssimation is more good.
 

FAQ: Feynman Lec, problem with diffraction

1. What is the Feynman Lectures?

The Feynman Lectures are a series of physics lectures given by the Nobel Prize-winning physicist Richard Feynman. They were originally delivered at Caltech in the early 1960s and have since been published in a three-volume set.

2. What is diffraction?

Diffraction is a phenomenon that occurs when a wave, such as light or sound, encounters an obstacle or aperture and bends or spreads out. This can create interference patterns, which can be observed in various everyday situations, such as when light passes through a small opening or when sound waves are diffracted by a door.

3. What is the problem with diffraction?

The main problem with diffraction is that it can make it difficult to accurately measure or observe the properties of a wave. This is because diffraction can cause the wave to spread out or bend in unexpected ways, making it challenging to isolate and study specific aspects of the wave.

4. How does Feynman address the problem of diffraction?

In his lectures, Feynman discusses the concept of diffraction in depth and provides a mathematical explanation for its behavior. He also offers practical examples and demonstrations to help students better understand and visualize the phenomenon.

5. What is the significance of Feynman's work on diffraction?

Feynman's work on diffraction has contributed to our understanding of wave behavior and has been applied in various fields, including optics, acoustics, and signal processing. His lectures on the subject continue to be a valuable resource for students and researchers studying diffraction and related topics.

Similar threads

Replies
2
Views
2K
Replies
5
Views
2K
Replies
8
Views
25K
Replies
12
Views
1K
Replies
2
Views
10K
Replies
4
Views
4K
Replies
1
Views
3K
Replies
4
Views
7K
Back
Top