View Full Version : Diffraction
Flupdoodle
Aug12-10, 03:57 PM
How could you describe qualitatively how diffraction of a wave through a aperture in terms of the uncertainty principle?
Cat
lets take a single slit and shine light through it . If i make this slit smaller and force the light to go through it , i know to much about the position of the photons they must be though that opening (delta x) so now i must get an uncertainty in the momentum of the photons , so (dx)(dp)=(h-bar) , When i make the slit to small the light starts to spread out and diffract .
The smaller i make the slit the more uncertainty i will have in the photons momentum .
I don't know if this is what you were looking for .
Flupdoodle
Aug16-10, 03:49 PM
Thank you, much appreciated.
sophiecentaur
Aug16-10, 04:37 PM
lets take a single slit and shine light through it . If i make this slit smaller and force the light to go through it , i know to much about the position of the photons they must be though that opening (delta x) so now i must get an uncertainty in the momentum of the photons , so (dx)(dp)=(h-bar) , When i make the slit to small the light starts to spread out and diffract .
The smaller i make the slit the more uncertainty i will have in the photons momentum .
I don't know if this is what you were looking for .
Does that treatment yield a sin(x)/x distribution? Wave theory does- and it agrees with measurement very well.
These might not answer your question but you might want to look at them.
http://univirtual.info/elementaryphysics/pc/cutnell3158c29/cutnell3158c29_7.htm
http://www.physicsforums.com/showthread.php?t=227296
sophiecentaur
Aug17-10, 04:11 AM
Oh I see, now. Interesting. The calculations do, in fact, seem to use a wave approach to get actual values but relate it to uncertainty. Fair enough - it's always useful to tie things together.
vBulletin® v3.8.7, Copyright ©2000-2012, vBulletin Solutions, Inc.