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Quote from: hamdani yusuf on 14/12/2022 02:56:58You seem to have forgotten what you've said previously.It only seems that way to you.All the things I said are consistent with each other.Do you understand that an aperture and an edge mean the same thing?The only reason you have a beam of finite width is that something got in the way of light outside the beam.
You seem to have forgotten what you've said previously.
Quote from: Bored chemist on 14/12/2022 08:31:25Quote from: hamdani yusuf on 14/12/2022 02:56:58You seem to have forgotten what you've said previously.It only seems that way to you.All the things I said are consistent with each other.Do you understand that an aperture and an edge mean the same thing?The only reason you have a beam of finite width is that something got in the way of light outside the beam.Do you now accept that you were talking nonsense when you said Quote from: hamdani yusuf on 14/12/2022 02:56:58You seem to have forgotten what you've said previously.
In optics, an aperture is a hole or an opening through which light travels. More specifically, the aperture and focal length of an optical system determine the cone angle of a bundle of rays that come to a focus in the image plane.https://en.wikipedia.org/wiki/Aperture
Quote from: Bored chemist on 08/12/2022 12:57:2026 seconds into the first video you say that diffraction by a single edge can not be explained.In fact, it can be explained (and modeled).https://physics.stackexchange.com/questions/232254/how-to-calculate-a-straight-edge-diffraction-patternHere's a diagram shown in the link above.This pattern can only appear with diverging light beam before hitting a diffractive edge. My experiment in video #11 Non-parallel light sourceshows this phenomenon.Single edge diffraction of a narrow parallel light beam like an ordinary laser pointer doesn't produce interference pattern.
26 seconds into the first video you say that diffraction by a single edge can not be explained.In fact, it can be explained (and modeled).https://physics.stackexchange.com/questions/232254/how-to-calculate-a-straight-edge-diffraction-pattern
The rest of the video can be watched here//www.youtube.com/watch?v=rVmE_O-f6Q4video #2 Edge shapes effect//www.youtube.com/watch?v=VOZtpoqajusvideo #3 Diffraction by transparent objects
It seems like edge is not the same as aperture
#282 shows a very interesting graph, suggesting that, 1 m from the edge, 140% of the incident intensity appears 12 meters into the shadow area and 100% is still present at 50m.
Quote from: hamdani yusuf on 14/12/2022 13:57:58It seems like edge is not the same as apertureDo you understand that you can't have one without the other?
Quote from: hamdani yusuf on 08/12/2022 08:36:38From my experience, diffraction requires partial opacity/transparency. Perfectly opaque objects, as well as perfectly transparent objects don't produce observable diffraction.I haven't found a published source mentioning the necessity of partial opacity/transparency of the obstacle to produce diffraction of light. Please let me know if I miss something.
From my experience, diffraction requires partial opacity/transparency. Perfectly opaque objects, as well as perfectly transparent objects don't produce observable diffraction.
Perfectly opaque objects, as well as perfectly transparent objects don't produce observable diffraction.
#282 shows a very interesting graph, suggesting that, 1 m from the edge, 140% of the incident intensity appears 12 meters into the shadow area and 100% is still present at 50m. Beyond Nikola Tesla's wildest dreams! The fringe spacing of between 5m and 12 m seems remarkable considering the incident light wavelength is 0.0000005 m. I wonder what phenomenon is occurring here?
Quote from: hamdani yusuf on 15/12/2022 08:14:22Perfectly opaque objects, as well as perfectly transparent objects don't produce observable diffraction.Most people consider a ball bearing to be perfectly opaque to visible light.https://en.wikipedia.org/wiki/Arago_spot
Quote from: Bored chemist on 15/12/2022 08:33:54Quote from: hamdani yusuf on 15/12/2022 08:14:22Perfectly opaque objects, as well as perfectly transparent objects don't produce observable diffraction.Most people consider a ball bearing to be perfectly opaque to visible light.https://en.wikipedia.org/wiki/Arago_spotIt's not perfectly opaque in visible light, especially at the edge.
The diffraction pattern now makes perfect sense - we are looking at interference between the primary beam and the diffracted light in the illuminated area. However the horizontal scale in the calculated graph you presented earlier is wrong by several orders of magnitude! The dangerous stuff actually occurs in the dark area, where a diffracted medium wave radio signal is detectable and appears to be coming from somewhere other than the transmitter. This can result in flying into a cliff or a mountain, thinking that the edge of the obstruction is actually the nondirectional homing beacon some miles away.
You won't find the Poisson's spot if you use a laser pointer with a light beam narrower than the ball.
You are saying that light goes through hardened steel.Do you have evidence of that?
Most people consider a ball bearing to be perfectly opaque to visible light.
The depth of a ball is nearly zero at its edge.
So far this is all classical optics, from last century's textbooks. Is this discussion going anywhere in the direction of new theories?
Considering how many misconceptions we can find online,