- #1
okgo
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So I understand that thin hair or wire can make a diffraction pattern, but why would the diffraction pattern be horizontal when the hair is vertical?
Why does thin hair create a horizontal diffraction pattern?
- Thread starter okgo
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Homework Help Overview
The discussion revolves around the diffraction pattern created by thin hair or wire, specifically addressing why the observed pattern appears horizontal when the hair is oriented vertically. Participants explore the principles of diffraction and wave propagation in relation to the geometry of the hair.
Discussion Character
- Exploratory, Conceptual clarification, Assumption checking
Approaches and Questions Raised
- Participants discuss the nature of wavelets as described by Huygens' principle and their propagation around the hair. Questions arise regarding the orientation of the diffraction pattern compared to the orientation of the hair itself, particularly in relation to single-slit diffraction patterns.
Discussion Status
The discussion is active, with participants seeking clarification on the relationship between the physical setup and the resulting diffraction pattern. Some guidance has been offered regarding the interpretation of images and the behavior of light in diffraction, but confusion remains about specific visual representations and the implications of the diffraction pattern's orientation.
Contextual Notes
There are references to images that may not clearly convey the relationship between the vertical hair and the horizontal diffraction pattern, leading to misunderstandings. The discussion also touches on the conditions under which diffraction occurs, particularly in relation to the size of the object compared to the wavelength of light.
- #2
ehild
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The pattern consists of vertical dark and bright lines arranged horizontally. Do you know how and why the diffraction pattern is formed?
ehild
ehild
- #3
okgo
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I believe so. The wavelets due to huygen's principle can still propagate at the edges of the hair. Do the wavelets propagate horizontally around the vertical hair? It just confuses because single slit oriented vertically produce vertical patterns. But hair doesn't and I am told it acts similar to a single slit.
- #4
ehild
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Yes, the wavelets starts to propagate at every possible directions at the edges of the hair. The picture shows the hair and wavelets from above.
If you use a laser light, its image is dot-like on the screen, and all diffracted images are dot-like so the pattern is a horizontal arrangement of dots. If the light source is a vertical filament or a slit illuminated with an extended source, the pattern consist of vertical lines.
ehild
If you use a laser light, its image is dot-like on the screen, and all diffracted images are dot-like so the pattern is a horizontal arrangement of dots. If the light source is a vertical filament or a slit illuminated with an extended source, the pattern consist of vertical lines.
ehild
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- #5
okgo
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I'm still a bit confused as to why the dot like patterns are horizontal. What is the black dot? Is that suppose to indicate a circular single slit?
In the following picture, I'm confused as to how the picture on the left translate to the one on the right. As the diffraction pattern on the left is vertical?
http://www.screencast.com/users/trinhn812/folders/Jing/media/f8f8251b-5a86-4deb-bde2-335702fbd1dd
In the following picture, I'm confused as to how the picture on the left translate to the one on the right. As the diffraction pattern on the left is vertical?
http://www.screencast.com/users/trinhn812/folders/Jing/media/f8f8251b-5a86-4deb-bde2-335702fbd1dd
- #6
ehild
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The black dot is the cross-section of hair, as seen from vertically above.
The left hand picture in your atatchment is misleading. It shows the vertical hair from the side, but the diffraction pattern is horizontal on the screen, as it is shown in the right-hand picture.
Note that light is diffracted from those places of the surface of an object where the radius of curvature is in the range or less than the wavelength.
ehild
The left hand picture in your atatchment is misleading. It shows the vertical hair from the side, but the diffraction pattern is horizontal on the screen, as it is shown in the right-hand picture.
Note that light is diffracted from those places of the surface of an object where the radius of curvature is in the range or less than the wavelength.
ehild
- #7
ehild
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The black dot is the cross-section of hair, as seen from vertically above.
The left hand picture in your atatchment is misleading. It shows the vertical hair from the side, but the diffraction pattern is horizontal on the screen, as it is shown in the right-hand picture.
Note that light is diffracted from those places of the surface of an object where the radius of curvature is in the range or less than the wavelength.
ehild
The left hand picture in your atatchment is misleading. It shows the vertical hair from the side, but the diffraction pattern is horizontal on the screen, as it is shown in the right-hand picture.
Note that light is diffracted from those places of the surface of an object where the radius of curvature is in the range or less than the wavelength.
ehild
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